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29 Sep 2022 at 02:22
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Bibliography on: Symbiosis


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RJR: Recommended Bibliography 29 Sep 2022 at 02:22 Created: 


Symbiosis refers to an interaction between two or more different organisms living in close physical association, typically to the advantage of both. Symbiotic relationships were once thought to be exceptional situations. Recent studies, however, have shown that every multicellular eukaryote exists in a tight symbiotic relationship with billions of microbes. The associated microbial ecosystems are referred to as microbiome and the combination of a multicellular organism and its microbiota has been described as a holobiont. It seems "we are all lichens now."

Created with PubMed® Query: symbiosis NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2022-09-28

Finley JR, F Naaz (2022)

Strategic use of internal and external memory in everyday life: episodic, semantic, procedural, and prospective purposes.

Memory (Hove, England) [Epub ahead of print].

Humans have access to both internal memory (information stored in the brain) and external memory (information stored in the environment). To what extent do we use each in everyday life? In two experiments, participants rated both internal and external memory for frequency of use, dependability, ease of use (Experiment 1), and likelihood of use (Experiment 2) across four purposes: episodic, semantic, procedural, and prospective. Experiment 1 showed that internal memory was favoured for episodic and procedural purposes, while external memory was favoured for semantic purposes. Experiment 2 further clarified that internal memory was favoured for episodic and common procedural purposes, while external memory was favoured for uncommon semantic, uncommon procedural, and far-term prospective purposes. This strategic division of labour plays to the strengths of both forms of memory. Participants also generally rated external memory as more dependable and easier to use. Results support the memory symbiosis framework.

RevDate: 2022-09-28

Kitchen SA, Jiang D, Harii S, et al (2022)

Coral larvae suppress the heat stress response during the onset of symbiosis thereby decreasing their odds of survival.

Molecular ecology [Epub ahead of print].

The endosymbiosis between most corals and their photosynthetic dinoflagellate partners begins early in the host life history, when corals are larvae or juvenile polyps. The capacity of coral larvae to buffer climate-induced stress while in the process of symbiont acquisition could come with physiological trade-offs that alter behavior, development, settlement and survivorship. Here we examined the joint effects of thermal stress and symbiosis onset on colonization dynamics, survival, metamorphosis and host gene expression of Acropora digitifera larvae. We found that thermal stress decreased symbiont colonization of hosts by 50% and symbiont density by 98.5% over two weeks. Temperature and colonization also influenced larval survival and metamorphosis in an additive manner, where colonized larvae fared worse or prematurely metamorphosed more often than non-colonized larvae under thermal stress. Transcriptomic responses to colonization and thermal stress treatments were largely independent, while the interaction of these treatments revealed contrasting expression profiles of genes that function in the stress response, immunity, inflammation and cell cycle regulation. The combined treatment either canceled or lowered the magnitude of expression of heat-stress responsive genes in the presence of symbionts, revealing a physiological cost to acquiring symbionts at the larval stage with elevated temperatures. In addition, host immune suppression, a hallmark of symbiosis onset under ambient temperature, turned to immune activation under heat stress. Thus, by integrating the physical environment and biotic pressures that mediate pre-settlement event in corals, our results suggest that colonization may hinder larval survival and recruitment under projected climate scenarios.

RevDate: 2022-09-28

Dudzic JP, Curtis CI, Gowen BE, et al (2022)

A highly divergent Wolbachia with a tiny genome in an insect-parasitic tylenchid nematode.

Proceedings. Biological sciences, 289(1983):20221518.

Wolbachia symbionts are the most successful host-associated microbes on the planet, infecting arthropods and nematodes. Their role in nematodes is particularly enigmatic, with filarial nematode species either 100% infected and dependent on symbionts for reproduction and development, or not at all infected. We have discovered a highly divergent strain of Wolbachia in an insect-parasitic tylenchid nematode, Howardula sp., in a nematode clade that has not previously been known to harbour Wolbachia. While this nematode is 100% infected with Wolbachia, we did not detect it in related species. We sequenced the Howardula symbiont (wHow) genome and found that it is highly reduced, comprising only 550 kilobase pairs of DNA, approximately 35% smaller than the smallest Wolbachia nematode symbiont genomes. The wHow genome is a subset of all other Wolbachia genomes and has not acquired any new genetic information. While it has lost many genes, including genes involved in cell wall synthesis and cell division, it has retained the entire haem biosynthesis pathway, suggesting that haem supplementation is critical. wHow provides key insights into our understanding of what are the lower limits of Wolbachia cells, as well as the role of Wolbachia symbionts in the biology and convergent evolution of diverse parasitic nematodes.

RevDate: 2022-09-27

Vigneron A, M Kaltenpoth (2022)

Symbiosis: Creating a tractable intracellular insect-microbe association.

Current biology : CB, 32(18):R943-R946.

Endosymbioses are widespread among insects and have far-reaching implications for their hosts' ecology and evolution. However, the molecular underpinnings of symbiosis remain largely obscure. In a new study, Su et al. successfully established a transmissible synthetic symbiosis, opening up exciting new opportunities to explore the initial dynamics of endosymbiotic interactions.

RevDate: 2022-09-27

Pal G, Saxena S, Kumar K, et al (2022)

Endophytic Burkholderia: Multifunctional roles in plant growth promotion and stress tolerance.

Microbiological research, 265:127201 pii:S0944-5013(22)00241-5 [Epub ahead of print].

The genus Burkholderia has proven potential in improving plant performance. In recent decades, a huge diversity of Burkholderia spp. have been reported with diverse capabilities of plant symbiosis which could be harnessed to enhance plant growth and development. Colonization of endophytic Burkholderia spp. have been extensively studied through techniques like advanced microscopy, fluorescent labelling, PCR based assays, etc., and found to be systemically distributed in plants. Thus, use of these biostimulant microbes holds the promise of improving quality and quantity of crops. The endophytic Burkholderia spp. have been found to support plant functions along with boosting nutrient availability, especially under stress. Endophytic Burkholderia spp. improve plant survival against deadly pathogens via mechanisms like competition, induced systemic resistance, and antibiosis. At the same time, they are reported to extend plant tolerance towards multiple abiotic stresses especially drought, salinity, and cold. Several attempts have been made to decipher the potential of Burkholderia spp. by genome mining, and these bacteria have been found to harbour genes for plant symbiosis and for providing multiple benefits to host plants. Characteristics specific for host recognition and nutrient acquisition were confirmed in endophytic Burkholderia by genomics and proteomics-based studies. This could pave the way for harnessing Burkholderia spp. for biotechnological applications like biotransformation, phytoremediation, insecticidal activity, antimicrobials, etc. All these make Burkholderia spp. a promising microbial agent in improving plant performance under multiple adversities. Thus, the present review highlights critical roles of endophytic Burkholderia spp., their colonization, alleviation of biotic and abiotic stresses, biotechnological applications and genomic insights.

RevDate: 2022-09-28

Dearing MD, Kaltenpoth M, J Gershenzon (2022)

Demonstrating the role of symbionts in mediating detoxification in herbivores.

Symbiosis (Philadelphia, Pa.), 87(1):59-66.

Plant toxins constitute an effective defense against herbivorous animals. However, many herbivores have evolved adaptations to cope with dietary toxins through detoxification, excretion, sequestration, target site insensitivity and/or via behavioral avoidance. While these adaptations are often directly encoded in herbivore genomes, evidence is accumulating that microbial symbionts can reduce the dose of plant toxins by metabolizing or sequestering them prior to absorption by the herbivore. Here, we describe a few well-studied examples to assess such symbiont-mediated detoxification and showcase different approaches that have been used for their analyses. These include: (i) a host phenotypic route in which the symbiotic association is manipulated to reveal host fitness costs upon toxin exposure in the presence/absence of detoxifying symbionts, including function restoration after symbiont re-infection, (ii) a molecular microbiological approach that focuses on the identification and characterization of microbial genes involved in plant toxin metabolism, and (iii) an analytical chemical route that aims to characterize the conversion of the toxin to less harmful metabolites in vivo and link conversion to the activities of a detoxifying symbiont. The advantages and challenges of each approach are discussed, and it is argued that a multi-pronged strategy combining phenotypic, molecular, and chemical evidence is needed to unambiguously demonstrate microbial contributions to plant toxin reduction and the importance of these processes for host fitness. Given the interdisciplinary nature of the topic, we aim to provide a guideline to researchers interested in symbiont-mediated detoxification and hope to encourage future studies that contribute to a more comprehensive and mechanistic understanding of detoxification in herbivores and their symbionts.

RevDate: 2022-09-28

Pise R, Patil K, Laad M, et al (2022)

Dataset of vector mosquito images.

Data in brief, 45:108573.

Mosquitoes pose substantial threat to public health resulting in million number of deaths wordlwide every year. They act as the vectors responsible for diseases such as Dengue, Yellow fever,Chikungunya, Zika etc. The harmful mosquito species are contained in the genera Aedes, Anopheles and Culex. Automated species identification of vectors is essential to implement targeted vector control strategies. The objective of the proposed paper is to construct a novel dataset of images of dangerous mosquito species. We have prepared a dataset of images of adult mosquitoes belonging to three species: Aedes Aegypti, Anopheles stephensi and Culex quinquefasciatus stored in two folders. The first folder comprises of total 2640 augmented images of mosquitoes belonging to the three species. The second folder contains original images of the the three species. The dataset is valuable for training machine and deep learning models for automatic species classification.

RevDate: 2022-09-28
CmpDate: 2022-09-28

Ferrarini MG, Dell'Aglio E, Vallier A, et al (2022)

Efficient compartmentalization in insect bacteriomes protects symbiotic bacteria from host immune system.

Microbiome, 10(1):156.

BACKGROUND: Many insects house symbiotic intracellular bacteria (endosymbionts) that provide them with essential nutrients, thus promoting the usage of nutrient-poor habitats. Endosymbiont seclusion within host specialized cells, called bacteriocytes, often organized in a dedicated organ, the bacteriome, is crucial in protecting them from host immune defenses while avoiding chronic host immune activation. Previous evidence obtained in the cereal weevil Sitophilus oryzae has shown that bacteriome immunity is activated against invading pathogens, suggesting endosymbionts might be targeted and impacted by immune effectors during an immune challenge. To pinpoint any molecular determinants associated with such challenges, we conducted a dual transcriptomic analysis of S. oryzae's bacteriome subjected to immunogenic peptidoglycan fragments.

RESULTS: We show that upon immune challenge, the bacteriome actively participates in the innate immune response via induction of antimicrobial peptides (AMPs). Surprisingly, endosymbionts do not undergo any transcriptomic changes, indicating that this potential threat goes unnoticed. Immunohistochemistry showed that TCT-induced AMPs are located outside the bacteriome, excluding direct contact with the endosymbionts.

CONCLUSIONS: This work demonstrates that endosymbiont protection during an immune challenge is mainly achieved by efficient confinement within bacteriomes, which provides physical separation between host systemic response and endosymbionts. Video Abstract.

RevDate: 2022-09-28
CmpDate: 2022-09-28

Kirsch R, Okamura Y, Haeger W, et al (2022)

Metabolic novelty originating from horizontal gene transfer is essential for leaf beetle survival.

Proceedings of the National Academy of Sciences of the United States of America, 119(40):e2205857119.

Horizontal gene transfer (HGT) provides an evolutionary shortcut for recipient organisms to gain novel functions. Although reports of HGT in higher eukaryotes are rapidly accumulating, in most cases the evolutionary trajectory, metabolic integration, and ecological relevance of acquired genes remain unclear. Plant cell wall degradation by HGT-derived enzymes is widespread in herbivorous insect lineages. Pectin is an abundant polysaccharide in the walls of growing parts of plants. We investigated the significance of horizontally acquired pectin-digesting polygalacturonases (PGs) of the leaf beetle Phaedon cochleariae. Using a CRISPR/Cas9-guided gene knockout approach, we generated a triple knockout and a quadruple PG-null mutant in order to investigate the enzymatic, biological, and ecological effects. We found that pectin-digestion 1) is exclusively linked to the horizontally acquired PGs from fungi, 2) became fixed in the host genome by gene duplication leading to functional redundancy, 3) compensates for nutrient-poor diet by making the nutritious cell contents more accessible, and 4) facilitates the beetles development and survival. Our analysis highlights the selective advantage PGs provide to herbivorous insects and demonstrate the impact of HGT on the evolutionary success of leaf-feeding beetles, major contributors to species diversity.

RevDate: 2022-09-26

Riley AB, Grillo MA, Epstein B, et al (2022)

Discordant population structure among rhizobium divided genomes and their legume hosts.

Molecular ecology [Epub ahead of print].

Symbiosis often occurs between partners with distinct life history characteristics and dispersal mechanisms. Many bacterial symbionts have genomes comprised of multiple replicons with distinct rates of evolution and horizontal transmission. Such differences might drive differences in population structure between hosts and symbionts and among the elements of the divided genomes of bacterial symbionts. These differences might, in turn, shape the evolution of symbiotic interactions and bacterial evolution. Here we use whole genome resequencing of a hierarchically-structured sample of 191 strains of Sinorhizobium meliloti collected from 21 locations in southern Europe to characterize population structures of this bacterial symbiont, which forms root nodule symbiosis with host plant Medicago truncatula. Sinorhizobium meliloti genomes showed high local (within-site) variation and little isolation by distance. This was particularly true for the two symbiosis elements pSymA and pSymB, which have population structures that are similar to each other, but distinct from both the bacterial chromosome and the host plant. Given limited recombination on the chromosome, compared to the symbiosis elements, distinct population structures may result from differences in effective gene flow. Alternatively, positive or purifying selection, with little recombination, may explain distinct geographical patterns at the chromosome. Discordant population structure between hosts and symbionts indicates that geographically and genetically distinct host populations in different parts of the range might interact with genetically similar symbionts, potentially minimizing local specialization.

RevDate: 2022-09-28
CmpDate: 2022-09-28

Kaur H, Ali SA, F Yan (2022)

Interactions between the gut microbiota-derived functional factors and intestinal epithelial cells - implication in the microbiota-host mutualism.

Frontiers in immunology, 13:1006081.

Mutual interactions between the gut microbiota and the host play essential roles in maintaining human health and providing a nutrient-rich environment for the gut microbial community. Intestinal epithelial cells (IECs) provide the frontline responses to the gut microbiota for maintaining intestinal homeostasis. Emerging evidence points to commensal bacterium-derived components as functional factors for the action of commensal bacteria, including protecting intestinal integrity and mitigating susceptibility of intestinal inflammation. Furthermore, IECs have been found to communicate with the gut commensal bacteria to shape the composition and function of the microbial community. This review will discuss the current understanding of the beneficial effects of functional factors secreted by commensal bacteria on IECs, with focus on soluble proteins, metabolites, and surface layer components, and highlight the impact of IECs on the commensal microbial profile. This knowledge provides a proof-of-concept model for understanding of mechanisms underlying the microbiota-host mutualism.

RevDate: 2022-09-28

Kumar P, Kushwaha AK, Kar AK, et al (2022)

Managing buyer experience in a buyer-supplier relationship in MSMEs and SMEs.

Annals of operations research [Epub ahead of print].

Monitoring buyer experience provides competitive advantages for suppliers as buyers explore the market before reaching a salesperson. Still, not many B2B suppliers monitor their buyers' expectations throughout their procurement journey, especially in MSMEs and SMEs. In addition, the inductive research on evaluating buyer experience in buyer-supplier relationships is minimal, leaving an unexplored research area. This study explores antecedents of buyer experience during the buyer-supplier relationship in MSMEs and SMEs. Further, we investigate the nature of the influence of extracted precursors on the buyer experience. Firstly, we obtain the possible antecedents from the literature on buyer-supplier experience and supplier selection criteria. We also establish hypotheses based on transaction cost theory, resource-based view (RBV), and information processing view. Secondly, we employ an investigation based on the social media analytics-based approach to uncover the antecedents of buyer experience and their nature of influence on MSMEs and SME suppliers. We found that buyer experience is influenced by sustainable orientation, management capabilities (such as crisis management and process innovation), and suppliers' technology capabilities (digital readiness, big data analytical capability).

RevDate: 2022-09-28
CmpDate: 2022-09-28

Quaglio AEV, Grillo TG, De Oliveira ECS, et al (2022)

Gut microbiota, inflammatory bowel disease and colorectal cancer.

World journal of gastroenterology, 28(30):4053-4060.

The gut microbiota is a complex community of microorganisms that inhabit the digestive tracts of humans, living in symbiosis with the host. Dysbiosis, characterized by an imbalance between the beneficial and opportunistic gut microbiota, is associated with several gastrointestinal disorders, such as irritable bowel syndrome (IBS); inflammatory bowel disease (IBD), represented by ulcerative colitis and Crohn's disease; and colorectal cancer (CRC). Dysbiosis can disrupt the mucosal barrier, resulting in perpetuation of inflammation and carcinogenesis. The increase in some specific groups of harmful bacteria, such as Escherichia coli (E. coli) and enterotoxigenic Bacteroides fragilis (ETBF), has been associated with chronic tissue inflammation and the release of pro-inflammatory and carcinogenic mediators, increasing the chance of developing CRC, following the inflammation-dysplasia-cancer sequence in IBD patients. Therefore, the aim of the present review was to analyze the correlation between changes in the gut microbiota and the development and maintenance of IBD, CRC, and IBD-associated CRC. Patients with IBD and CRC have shown reduced bacterial diversity and abundance compared to healthy individuals, with enrichment of Firmicute sand Bacteroidetes. Specific bacteria are also associated with the onset and progression of CRC, such as Fusobacterium nucleatum, E. coli, Enterococcus faecalis, Streptococcus gallolyticus, and ETBF. Future research can evaluate the advantages of modulating the gut microbiota as preventive measures in CRC high-risk patients, directly affecting the prognosis of the disease and the quality of life of patients.

RevDate: 2022-09-26

Wuerz M, Lawson CA, Ueland M, et al (2022)

Symbiosis induces unique volatile profiles in the model cnidarian Aiptasia.

The Journal of experimental biology pii:276847 [Epub ahead of print].

The establishment and maintenance of the symbiosis between a cnidarian host and its dinoflagellate symbionts is central to the success of coral reefs. To explore the metabolite production underlying this symbiosis, we focused on a group of low weight secondary metabolites, biogenic volatile organic compounds (BVOCs). BVOCs are released from an organism or environment, and can be collected in the gas phase, allowing non-invasive analysis of an organism's metabolism (i.e. 'volatilomics'). We characterised volatile profiles of the sea anemone Exaiptasia diaphana ('Aiptasia'), a model system for cnidarian-dinoflagellate symbiosis, using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry. We compared volatile profiles between: 1) symbiotic anemones containing their native symbiont, Breviolum minutum; 2) aposymbiotic anemones; and 3) cultured isolates of B. minutum. Overall, 152 BVOCs were detected, and classified into 14 groups based on their chemical structure, the most numerous groups being alkanes and aromatic compounds. A total of 53 BVOCs were differentially abundant between aposymbiotic anemones and B. minutum cultures; 13 between aposymbiotic and symbiotic anemones; and 60 between symbiotic anemones and cultures of B. minutum. More BVOCs were differentially abundant between cultured and symbiotic dinoflagellates than between aposymbiotic and symbiotic anemones, suggesting that symbiosis may modify symbiont physiology more than host physiology. This is the first volatilome analysis of the Aiptasia model system and provides a foundation from which to explore how BVOC production is perturbed under environmental stress, and ultimately the role they play in this important symbiosis.

RevDate: 2022-09-26

Avanthi A, S Venkata Mohan (2022)

Emerging innovations for sustainable production of bioethanol and other mercantile products from circular economy perspective.

Bioresource technology pii:S0960-8524(22)01346-3 [Epub ahead of print].

Biogenic municipal solid waste (BMSW) and food waste (FW) with high energy density are ready to tap renewable resources for industrial scale ethanol refinery foreseen for establishing bio-based society. Circular economy has occupied limelight in the domain of renewable energy and sustainable chemicals production. The present review highlights the importance of BMSW/FW as newer feed reserves that can cater as parent molecules for an array of high-visibility industrial products along with bioethanol upon implementing a judicious closed-cascade mass-flow mechanism enabling ultimate feed and waste stream valorisation. Though these organics are attractive resources their true potential for energy production has not been quantified yet owing to their heterogeneous composition and associated technical challenges thus pushing waste refinery and industrial symbiosis concepts to backseat. To accelerate this industrial vision, the novel bioprocessing strategies for enhanced and low-cost production of bioethanol from BMSW/FW along with other commercially imperative product portfolio have been discussed.

RevDate: 2022-09-28
CmpDate: 2022-09-28

Davis CV, Shaw JO, D'haenens S, et al (2022)

Photosymbiont associations persisted in planktic foraminifera during early Eocene hyperthermals at Shatsky Rise (Pacific Ocean).

PloS one, 17(9):e0267636 pii:PONE-D-21-33519.

Understanding the sensitivity of species-level responses to long-term warming will become increasingly important as we look towards a warmer future. Here, we examine photosymbiont associations in planktic foraminifera at Shatsky Rise (ODP Site 1209, Pacific Ocean) across periods of global warming of differing magnitude and duration. We compare published data from the Paleocene-Eocene Thermal Maximum (PETM; ~55.9 Ma) with data from the less intense Eocene Thermal Maximum 2 (ETM2; ~54.0 Ma), and H2 events (~53.9 Ma). We use a positive relationship between test size and carbon isotope value (size-δ13C) in foraminifera shells as a proxy for photosymbiosis in Morozovella subbotinae and Acarinina soldadoensis, and find no change in photosymbiont associations during the less intense warming events, in contrast with PETM records indicating a shift in symbiosis in A. soldadoensis (but not M. subbotinae). Declines in abundance and differing preservation potential of the asymbiotic species Subbotina roesnaesensis along with sediment mixing likely account for diminished differences in δ13C between symbiotic and asymbiotic species from the PETM and ETM2. We therefore conclude that photosymbiont associations were maintained in both A. soldadoensis and M. subbotinae across ETM2 and H2. Our findings support one or both of the hypotheses that 1) changing symbiotic associations in response to warming during the PETM allowed A. soldadoensis and perhaps other acarininids to thrive through subsequent hyperthermals or 2) some critical environmental threshold value was not reached in these less intense hyperthermals.

RevDate: 2022-09-26

Saha UB, SD Saroj (2022)

Lactic acid bacteria: prominent player in the fight against human pathogens.

Expert review of anti-infective therapy [Epub ahead of print].

INTRODUCTION: The human microbiome is a unique repository of diverse bacteria. Over 1000 microbial species reside in the human gut, which predominantly influences the host's internal environment and plays a significant role in host health. Lactic acid bacteria have long been employed for multiple purposes, ranging from food to medicines. Lactobacilli, which are often used in commercial food fermentation, have improved to the point that they might be helpful in medical applications.

AREAS COVERED: This review summarises various clinical and experimental evidence on efficacy of lactobacilli in treating a wide range of infections. Both laboratory based and clinical studies have been discussed.

EXPERT OPINION: Lactobacilli are widely accepted as safe biological treatments and host immune modulators (GRAS- Generally regarded as safe) by the US Food and Drug Administration and Qualified Presumption of Safety. Understanding the molecular mechanisms of lactobacilli in the treatment and pathogenicity of bacterial infections can help with the prediction and development of innovative therapeutics aimed at pathogens which have gained resistance to antimicrobials. To formulate effective lactobacilli based therapy significant research on the effectiveness of different lactobacilli strains and its association with demographic distribution is required. Also, the side effects of such therapy needs to be evaluated.

RevDate: 2022-09-27
CmpDate: 2022-09-26

Yang S, Anikst V, PC Adamson (2022)

Endofungal Mycetohabitans rhizoxinica Bacteremia Associated with Rhizopus microsporus Respiratory Tract Infection.

Emerging infectious diseases, 28(10):2091-2095.

We report Mycetohabitans rhizoxinica bacteremia in a 65-year-old woman in California, USA, who was undergoing chimeric antigen receptor T-cell therapy for multiple myeloma. Acute brain infarction and pneumonia developed; Rhizopus microsporus mold was isolated from tracheal suction. Whole-genome sequencing confirmed bacteria in blood as genetically identical to endofungal bacteria inside the mold.

RevDate: 2022-09-24

Bagliani G, Leonelli FM, R De Ponti (2022)

Atrial Flutter and Precision Electrocardiology: An Indissoluble Symbiosis.

Cardiac electrophysiology clinics, 14(3):xiii-xiv.

RevDate: 2022-09-24

Shang JY, Zhang P, Jia YW, et al (2022)

Coordinated regulation of symbiotic adaptation by NodD proteins and NolA in the type I peanut bradyrhizobial strain Bradyrhizobium zhanjiangense CCBAU51778.

Microbiological research, 265:127188 pii:S0944-5013(22)00228-2 [Epub ahead of print].

Type I peanut bradyrhizobial strains can establish efficient symbiosis in contrast to symbiotic incompatibility induced by type II strains with mung bean. The notable distinction in the two kinds of key symbiosis-related regulators nolA and nodD close to the nodABCSUIJ operon region between these two types of peanut bradyrhizobia was found. Therefore, we determined whether NolA and NodD proteins regulate the symbiotic adaptations of type I strains to different hosts. We found that NodD1-NolA synergistically regulated the symbiosis between the type I strain Bradyrhizobium zhanjiangense CCBAU51778 and mung bean, and NodD1-NodD2 jointly regulated nodulation ability. In contrast, NodD1-NolA coordinately regulated nodulation ability in the CCBAU51778-peanut symbiosis. Meanwhile, NodD1 and NolA collectively contributes to competitive nodule colonization of CCBAU51778 on both hosts. The Fucosylated Nod factors and intact type 3 secretion system (T3SS), rather than extra nodD2 and full-length nolA, were critical for effective symbiosis with mung bean. Unexpectedly, T3SS-related genes were activated by NodD2 but not NodD1. Compared to NodD1 and NodD2, NolA predominantly inhibits exopolysaccharide production by promoting exoR expression. Importantly, this is the first report that NolA regulates rhizobial T3SS-related genes. The coordinated regulation and integration of different gene networks to fine-tune the expression of symbiosis-related genes and other accessory genes by NodD1-NolA might be required for CCBAU51778 to efficiently nodulate peanut. This study shed new light on our understanding of the regulatory roles of NolA and NodD proteins in symbiotic adaptation, highlighting the sophisticated gene networks dominated by NodD1-NolA.

RevDate: 2022-09-24

Cook J, M Prinz (2022)

Regulation of microglial physiology by the microbiota.

Gut microbes, 14(1):2125739.

The mammalian gut contains a large, complex community of microorganisms collectively termed the microbiota. It is increasingly appreciated that gut microbes are closely integrated into mammalian physiology, participating in metabolic symbiosis, promoting immune function and signaling to a wide variety of distant cells, including the brain, via circulating metabolites. Recent advances indicate that microglia, the brain's resident immune cells, are influenced by microbial metabolites at all stages of life, under both physiological and pathological conditions. The pathways by which microbiota regulate microglial function are therefore of interest for investigating links between neurological disorders and gut microbiome changes. In this review, we discuss the effects and mechanisms of microbiota-microglia signaling in steady state, as well as evidence for the involvement of this signaling axis in CNS pathologies.

RevDate: 2022-09-23

Valim HF, Dal Grande F, Otte J, et al (2022)

Identification and expression of functionally conserved circadian clock genes in lichen-forming fungi.

Scientific reports, 12(1):15884.

Lichen-forming fungi establish stable symbioses with green algae or cyanobacteria. Many species have broad distributions, both in geographic and ecological space, making them ideal subjects to study organism-environment interactions. However, little is known about the specific mechanisms that contribute to environmental adaptation in lichen-forming fungi. The circadian clock provides a well-described mechanism that contributes to regional adaptation across a variety of species, including fungi. Here, we identify the putative circadian clock components in phylogenetically divergent lichen-forming fungi. The core circadian genes (frq, wc-1, wc-2, frh) are present across the Fungi, including 31 lichen-forming species, and their evolutionary trajectories mirror overall fungal evolution. Comparative analyses of the clock genes indicate conserved domain architecture among lichen- and non-lichen-forming taxa. We used RT-qPCR to examine the core circadian loop of two unrelated lichen-forming fungi, Umbilicaria pustulata (Lecanoromycetes) and Dermatocarpon miniatum (Eurotiomycetes), to determine that the putative frq gene is activated in a light-dependent manner similar to the model fungus Neurospora crassa. Together, these results demonstrate that lichen-forming fungi retain functional light-responsive mechanisms, including a functioning circadian clock. Our findings provide a stepping stone into investigating the circadian clock in the lichen symbiosis, e.g. its role in adaptation, and in synchronizing the symbiotic interaction.

RevDate: 2022-09-23

Salazar OR, N Arun P, Cui G, et al (2022)

The coral Acropora loripes genome reveals an alternative pathway for cysteine biosynthesis in animals.

Science advances, 8(38):eabq0304.

The metabolic capabilities of animals have been derived from well-studied model organisms and are generally considered to be well understood. In animals, cysteine is an important amino acid thought to be exclusively synthesized through the transsulfuration pathway. Corals of the genus Acropora have lost cystathionine β-synthase, a key enzyme of the transsulfuration pathway, and it was proposed that Acropora relies on the symbiosis with dinoflagellates of the family Symbiodiniaceae for the acquisition of cysteine. Here, we identify the existence of an alternative pathway for cysteine biosynthesis in animals through the analysis of the genome of the coral Acropora loripes. We demonstrate that these coral proteins are functional and synthesize cysteine in vivo, exhibiting previously unrecognized metabolic capabilities of animals. This pathway is also present in most animals but absent in mammals, arthropods, and nematodes, precisely the groups where most of the animal model organisms belong to, highlighting the risks of generalizing findings from model organisms.

RevDate: 2022-09-23

Kulkarni PY, Bhawalkar JS, AA Jadhav (2022)

Anemia control program in india needs to be more comprehensive.

Indian journal of public health, 66(3):358-361.

Iron-deficiency anemia has continued to remain high in India. It is possibly due to relying on only iron-folic acid (IFA) supplementation through Anemia Control Program (ACP) that is National Iron Plus Initiative (NIPI). Based on the WHO's recommendations, we studied different interventions that can help to increase the effectiveness of NIPI such as Vitamin C supplementation with IFA, low-dose iron (LDI) with intensified health education (IHE), LDI with Vitamin C, and iron-rich food items to increase hemoglobin (Hb%) among adolescent girls through public-private partnership named Rashtriya Kishor Swasthya Karyakram. Increments in Hb after 12 weeks of interventions were compared with that of control groups one with NIPI and the other without any intervention. Highest increment in Hb% was observed in IFA under NIPI plus Vitamin C group, followed by LDI plus IHE group which was comparable to Hb increment in only the NIPI group. It emphasizes the need of making existing NIPI more stringent and comprehensive by integrating effective measures based on up-to-date scientific knowledge.

RevDate: 2022-09-23

Jing M, Shi Z, Zhang M, et al (2022)

Nitrogen and Phosphorus of Plants Associated with Arbuscular and Ectomycorrhizas Are Differentially Influenced by Drought.

Plants (Basel, Switzerland), 11(18): pii:plants11182429.

Leaf nitrogen (N) and phosphorus (P) are the most important functional traits in plants which affect biogeochemical cycles. As the most widely observed plant-fungus mutualistic symbiosis, mycorrhiza plays a vital role in regulating plant growth. There are different types of mycorrhiza with various ecological functions in nature. Drought, as a frequent environmental stress, has been paid more and more attention due to its influence on plant growth. Numerous studies have confirmed that drought affects the concentration of N and P in plants, but few studies involve different mycorrhizal types of plants. In this study, the differences of N and P between arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) plants under different drought patterns, drought duration and cultivation conditions were explored based on a dataset by a meta-analysis. Drought stress (DS) showed negative effects on AM plant N (-7.15%) and AM plant P (-13.87%), and a positive effect on AM plant N:P ratio (+8.01%). Drought significantly increased N and the N:P ratio of ECM plants by 1.58% and 3.58%, respectively, and decreased P of ECM plants by -2.00%. Short-term drought (<30 d) reduces more N and P than long-term drought (<30 d) in AM plant species. The duration of drought did not change the N concentration of ECM plant N, while short-term drought reduced ECM plant P. The effects of N and P on DS also varied with different planting conditions and functional groups between AM and ECM plants. Therefore, mycorrhizal effects and stoichiometry of N and P play a key role in plant response to drought. So mycorrhizal effects should be considered when studying plant responses to drought stress.

RevDate: 2022-09-23

Belimov AA, Shaposhnikov AI, Azarova TS, et al (2022)

Rhizobacteria Mitigate the Negative Effect of Aluminum on Pea Growth by Immobilizing the Toxicant and Modulating Root Exudation.

Plants (Basel, Switzerland), 11(18): pii:plants11182416.

High soil acidity is one of the main unfavorable soil factors that inhibit the growth and mineral nutrition of plants. This is largely due to the toxicity of aluminum (Al), the mobility of which increases significantly in acidic soils. Symbiotic microorganisms have a wide range of beneficial properties for plants, protecting them against abiotic stress factors. This report describes the mechanisms of positive effects of plant growth-promoting rhizobacteria Pseudomonas fluorescens SPB2137 on four pea (Pisum sativum L.) genotypes grown in hydroponics and treated with 80 µM AlCl3. In batch culture, the bacteria produced auxins, possessed 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, alkalized the medium and immobilized Al, forming biofilm-like structures and insoluble phosphates. Inoculation with Ps. fluorescens SPB2137 increased root and/or shoot biomass of Al-treated plants. The bacteria alkalized the nutrient solution and transferred Al from the solution to the residue, which contained phosphorus that was exuded by roots. As a result, the Al concentration in roots decreased, while the amount of precipitated Al correlated negatively with its concentration in the solution, positively with the solution pH and negatively with Al concentration in roots and shoots. Treatment with Al induced root exudation of organic acids, amino acids and sugars. The bacteria modulated root exudation via utilization and/or stimulation processes. The effects of Al and bacteria on plants varied depending on pea genotype, but all the effects had a positive direction and the variability was mostly quantitative. Thus, Ps. fluorescens SPB2137 improved the Al tolerance of pea due to immobilization and exclusion of toxicants from the root zone.

RevDate: 2022-09-23

Yurkov AP, Puzanskiy RK, Kryukov AA, et al (2022)

The Role of Medicago lupulina Interaction with Rhizophagus irregularis in the Determination of Root Metabolome at Early Stages of AM Symbiosis.

Plants (Basel, Switzerland), 11(18): pii:plants11182338.

The nature of plant-fungi interaction at early stages of arbuscular mycorrhiza (AM) development is still a puzzling problem. To investigate the processes behind this interaction, we used the Medicago lupulina MlS-1 line that forms high-efficient AM symbiosis with Rhizophagus irregularis. AM fungus actively colonizes the root system of the host plant and contributes to the formation of effective AM as characterized by a high mycorrhizal growth response (MGR) in the host plant. The present study is aimed at distinguishing the alterations in the M. lupulina root metabolic profile as an indicative marker of effective symbiosis. We examined the root metabolome at the 14th and 24th day after sowing and inoculation (DAS) with low substrate phosphorus levels. A GS-MS analysis detected 316 metabolites. Results indicated that profiles of M. lupulina root metabolites differed from those in leaves previously detected. The roots contained fewer sugars and organic acids. Hence, compounds supporting the growth of mycorrhizal fungus (especially amino acids, specific lipids, and carbohydrates) accumulated, and their presence coincided with intensive development of AM structures. Mycorrhization determined the root metabolite profile to a greater extent than host plant development. The obtained data highlight the importance of active plant-fungi metabolic interaction at early stages of host plant development for the determination of symbiotic efficiency.

RevDate: 2022-09-23

Kono K, Murakami Y, Ebara A, et al (2022)

Fluctuations in Intestinal Microbiota Following Ingestion of Natto Powder Containing Bacillus subtilis var. natto SONOMONO Spores: Considerations Using a Large-Scale Intestinal Microflora Database.

Nutrients, 14(18): pii:nu14183839.

Improving the intestinal microbiota using probiotics, prebiotics, and synbiotics has attracted attention as a method of disease prevention and treatment. This is the first study to discuss the effects of food intake on the intestinal microbiota using a large Japanese intestinal microbiota database. Here, as a case study, we determined changes in the intestinal microbiota caused by ingestion of a processed natto food containing B. subtilisvar. natto SONOMONO spores, SONOMONO NATTO POWDER CAPSULESTM, by analyzing 16S rRNA sequence data generated using next-generation sequencing techniques. The results showed that the relative abundance of Bifidobacterium and Blautia as well as the relative abundance of Bifidobacterium were increased in males and females in the ingesting group, respectively. Additionally, the effects of SONOMONO NATTO POWDER CAPSULESTM intake on Bifidobacterium and Blautia abundance depended on the relative abundance of Bifidobacterium at baseline. Finally, analysis of a large Japanese intestinal microbiota database suggested that the bacterial genera that fluctuated with the ingestion of SONOMONO NATTO POWDER CAPSULESTM may be associated with lifestyle-related diseases such as diabetes.

RevDate: 2022-09-23

Sanakkayala DC, Varadarajan V, Kumar N, et al (2022)

Explainable AI for Bearing Fault Prognosis Using Deep Learning Techniques.

Micromachines, 13(9): pii:mi13091471.

Predicting bearing failures is a vital component of machine health monitoring since bearings are essential parts of rotary machines, particularly large motor machines. In addition, determining the degree of bearing degeneration will aid firms in scheduling maintenance. Maintenance engineers may be gradually supplanted by an automated detection technique in identifying motor issues as improvements in the extraction of useful information from vibration signals are made. State-of-the-art deep learning approaches, in particular, have made a considerable contribution to automatic defect identification. Under variable shaft speed, this research presents a novel approach for identifying bearing defects and their amount of degradation. In the proposed approach, vibration signals are represented by spectrograms, and deep learning methods are applied via pre-processing with the short-time Fourier transform (STFT). A convolutional neural network (CNN), VGG16, is then used to extract features and classify health status. After this, RUL prediction is carried out with the use of regression. Explainable AI using LIME was used to identify the part of the image used by the CNN algorithm to give the output. Our proposed method was able to achieve very high accuracy and robustness for bearing faults, according to numerous experiments.

RevDate: 2022-09-23

Jo Y, Choi H, Chu H, et al (2022)

Unveiling Mycoviromes Using Fungal Transcriptomes.

International journal of molecular sciences, 23(18): pii:ijms231810926.

Viruses infecting fungi are referred to as mycoviruses. Here, we carried out in silico mycovirome studies using public fungal transcriptomes mostly derived from mRNA libraries. We identified 468 virus-associated contigs assigned to 5 orders, 21 families, 26 genera, and 88 species. We assembled 120 viral genomes with diverse RNA and DNA genomes. The phylogenetic tree and genome organization unveiled the possible host origin of mycovirus species and diversity of their genome structures. Most identified mycoviruses originated from fungi; however, some mycoviruses had strong phylogenetic relationships with those from insects and plants. The viral abundance and mutation frequency of mycoviruses were very low; however, the compositions and populations of mycoviruses were very complex. Although coinfection of diverse mycoviruses in the fungi was common in our study, most mycoviromes had a dominant virus species. The compositions and populations of mycoviruses were more complex than we expected. Viromes of Monilinia species revealed that there were strong deviations in the composition of viruses and viral abundance among samples. Viromes of Gigaspora species showed that the chemical strigolactone might promote virus replication and mutations, while symbiosis with endobacteria might suppress virus replication and mutations. This study revealed the diversity and host distribution of mycoviruses.

RevDate: 2022-09-23

Trifonova NA, Kamyshinsky R, Coba de la Peña T, et al (2022)

Sodium Accumulation in Infected Cells and Ion Transporters Mistargeting in Nodules of Medicago truncatula: Two Ugly Items That Hinder Coping with Salt Stress Effects.

International journal of molecular sciences, 23(18): pii:ijms231810618.

The maintenance of intracellular nitrogen-fixing bacteria causes changes in proteins' location and in gene expression that may be detrimental to the host cell fitness. We hypothesized that the nodule's high vulnerability toward salt stress might be due to alterations in mechanisms involved in the exclusion of Na+ from the host cytoplasm. Confocal and electron microscopy immunolocalization analyses of Na+/K+ exchangers in the root nodule showed the plasma membrane (MtNHX7) and endosome/tonoplast (MtNHX6) signal in non-infected cells; however, in mature infected cells the proteins were depleted from their target membranes and expelled to vacuoles. This mistargeting suggests partial loss of the exchanger's functionality in these cells. In the mature part of the nodule 7 of the 20 genes encoding ion transporters, channels, and Na+/K+ exchangers were either not expressed or substantially downregulated. In nodules from plants subjected to salt treatments, low temperature-scanning electron microscopy and X-ray microanalysis revealed the accumulation of 5-6 times more Na+ per infected cell versus non-infected one. Hence, the infected cells' inability to withstand the salt may be the integral result of preexisting defects in the localization of proteins involved in Na+ exclusion and the reduced expression of key genes of ion homeostasis, resulting in premature senescence and termination of symbiosis.

RevDate: 2022-09-23

Ji L, Yang X, F Qi (2022)

Distinct Responses to Pathogenic and Symbionic Microorganisms: The Role of Plant Immunity.

International journal of molecular sciences, 23(18): pii:ijms231810427.

Plants must balance both beneficial (symbiotic) and pathogenic challenges from microorganisms, the former benefitting the plant and agriculture and the latter causing disease and economic harm. Plant innate immunity describes a highly conserved set of defense mechanisms that play pivotal roles in sensing immunogenic signals associated with both symbiotic and pathogenic microbes and subsequent downstream activation of signaling effector networks that protect the plant. An intriguing question is how the innate immune system distinguishes "friends" from "foes". Here, we summarize recent advances in our understanding of the role and spectrum of innate immunity in recognizing and responding to different microbes. In addition, we also review some of the strategies used by microbes to manipulate plant signaling pathways and thus evade immunity, with emphasis on the use of effector proteins and micro-RNAs (miRNAs). Furthermore, we discuss potential questions that need addressing to advance the field of plant-microbe interactions.

RevDate: 2022-09-23

Javed J, Rauf M, Arif M, et al (2022)

Endophytic Fungal Consortia Enhance Basal Drought-Tolerance in Moringa oleifera by Upregulating the Antioxidant Enzyme (APX) through Heat Shock Factors.

Antioxidants (Basel, Switzerland), 11(9): pii:antiox11091669.

Global climate change has imposed harsh environmental conditions such as drought. Naturally, the most compatible fungal consortia operate synergistically to enhance plant growth and ecophysiological responses against abiotic strains. Yet, little is known about the interactions between phytohormone-producing endophytic fungal symbionts and plant growth under drought stress. The existing research was rationalized to recognize the role of newly isolated drought-resistant, antioxidant-rich endophytic fungal consortia hosting a xerophytic plant, Carthamus oxycantha L., inoculated to Moringa oleifera L. grown under drought stress of 8% PEG (polyethylene glycol-8000). Under drought stress, the combined inoculation of endophytic strain Microdochium majus (WA), Meyerozyma guilliermondi (TG), and Aspergillus aculeatus (TL3) exhibited a significant improvement in growth attributes such as shoot fresh weight (1.71-fold), shoot length (0.86-fold), root length (0.65-fold), dry weight (2.18-fold), total chlorophyll (0.46-fold), and carotenoids (0.87-fold) in comparison to control (8% PEG). Primary and secondary metabolites were also increased in M. oleifera inoculated with endophytic consortia, under drought stress, such as proteins (1.3-fold), sugars (0.58-fold), lipids (0.41-fold), phenols (0.36-fold), flavonoids (0.52-fold), proline (0.6-fold), indole acetic acid (IAA) (4.5-fold), gibberellic acid (GA) (0.7-fold), salicylic acid (SA) (0.8-fold), ascorbic acid (ASA) (1.85-fold), while abscisic acid (ABA) level was decreased (-0.61-fold) in comparison to the control (8% PEG). Under drought stress, combined inoculation (WA, TG, TL3) also promoted the antioxidant activities of enzymes such as ascorbate peroxidase (APX) (3.5-fold), catalase (CAT) activity (1.7-fold), and increased the total antioxidant capacity (TAC) (0.78-fold) with reduced reactive oxygen species (ROS) such as H2O2 production (-0.4-fold), compared to control (8% PEG), and stomatal aperture was larger (3.5-fold) with a lesser decrease (-0.02-fold) in water potential. Moreover, combined inoculation (WA, TG, TL3) up regulated the expression of MolHSF3, MolHSF19, and MolAPX genes in M. oleifera under drought stress, compared to the control (8% PEG), is suggestive of an important regulatory role for drought stress tolerance governed by fungal endophytes. The current research supports the exploitation of the compatible endophytic fungi for establishing the tripartite mutualistic symbiosis in M. oleifera to alleviate the adverse effects of drought stress through strong antioxidant activities.

RevDate: 2022-09-23

Gao M, Armin G, K Inomura (2022)

Low-Ammonium Environment Increases the Nutrient Exchange between Diatom-Diazotroph Association Cells and Facilitates Photosynthesis and N2 Fixation-a Mechanistic Modeling Analysis.

Cells, 11(18): pii:cells11182911.

Diatom-diazotroph associations (DDAs) are one of the most important symbiotic dinitrogen (N2) fixing groups in the oligotrophic ocean. Despite their capability to fix N2, ammonium (NH4+) remains a key nitrogen (N) source for DDAs, and the effect of NH4+ on their metabolism remains elusive. Here, we developed a coarse-grained, cellular model of the DDA with NH4+ uptake and quantified how the level of extracellular NH4+ influences metabolism and nutrient exchange within the symbiosis. The model shows that, under a fixed growth rate, an increased NH4+ concentration may lower the required level of N2 fixation and photosynthesis, and decrease carbon (C) and N exchange. A low-NH4+ environment leads to more C and N in nutrient exchange and more fixed N2 to support a higher growth rate. With higher growth rates, nutrient exchange and metabolism increased. Our study shows a strong effect of NH4+ on metabolic processes within DDAs, and thus highlights the importance of in situ measurement of NH4+ concentrations.

RevDate: 2022-09-23

Pérez-Mendoza D, Romero-Jiménez L, Rodríguez-Carvajal MÁ, et al (2022)

The Role of Two Linear β-Glucans Activated by c-di-GMP in Rhizobium etli CFN42.

Biology, 11(9): pii:biology11091364.

Bacterial exopolysaccharides (EPS) have been implicated in a variety of functions that assist in bacterial survival, colonization, and host-microbe interactions. Among them, bacterial linear β-glucans are polysaccharides formed by D-glucose units linked by β-glycosidic bonds, which include curdlan, cellulose, and the new described Mixed Linkage β-Glucan (MLG). Bis-(3',5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a universal bacterial second messenger that usually promote EPS production. Here, we report Rhizobium etli as the first bacterium capable of producing cellulose and MLG. Significant amounts of these two β-glucans are not produced under free-living laboratory conditions, but their production is triggered upon elevation of intracellular c-di-GMP levels, both contributing to Congo red (CR+) and Calcofluor (CF+) phenotypes. Cellulose turned out to be more relevant for free-living phenotypes promoting flocculation and biofilm formation under high c-di-GMP conditions. None of these two EPS are essential for attachment to roots of Phaseolus vulgaris, neither for nodulation nor for symbiotic nitrogen fixation. However, both β-glucans separately contribute to the fitness of interaction between R. etli and its host. Overproduction of these β-glucans, particularly cellulose, appears detrimental for symbiosis. This indicates that their activation by c-di-GMP must be strictly regulated in time and space and should be controlled by different, yet unknown, regulatory pathways.

RevDate: 2022-09-23

Chitayat Levi L, Rippin I, Ben Tulila M, et al (2022)

Modulating Gene Expression within a Microbiome Based on Computational Models.

Biology, 11(9): pii:biology11091301.

Recent research in the field of bioinformatics and molecular biology has revealed the immense complexity and uniqueness of microbiomes, while also showcasing the impact of the symbiosis between a microbiome and its host or environment. A core property influencing this process is horizontal gene transfer between members of the bacterial community used to maintain genetic variation. The essential effect of this mechanism is the exposure of genetic information to a wide array of members of the community, creating an additional "layer" of information in the microbiome named the "plasmidome". From an engineering perspective, introduction of genetic information to an environment must be facilitated into chosen species which will be able to carry out the desired effect instead of competing and inhibiting it. Moreover, this process of information transfer imposes concerns for the biosafety of genetic engineering of microbiomes as exposure of genetic information into unwanted hosts can have unprecedented ecological impacts. Current technologies are usually experimentally developed for a specific host/environment, and only deal with the transformation process itself at best, ignoring the impact of horizontal gene transfer and gene-microbiome interactions that occur over larger periods of time in uncontrolled environments. The goal of this research was to design new microbiome-specific versions of engineered genetic information, providing an additional layer of compatibility to existing engineering techniques. The engineering framework is entirely computational and is agnostic to the selected microbiome or gene by reducing the problem into the following set up: microbiome species can be defined as wanted or unwanted hosts of the modification. Then, every element related to gene expression (e.g., promoters, coding regions, etc.) and regulation is individually examined and engineered by novel algorithms to provide the defined expression preferences. Additionally, the synergistic effect of the combination of engineered gene blocks facilitates robustness to random mutations that might occur over time. This method has been validated using both computational and experimental tools, stemming from the research done in the iGEM 2021 competition, by the TAU group.

RevDate: 2022-09-22

Keller-Costa T, Kozma L, Silva SG, et al (2022)

Metagenomics-resolved genomics provides novel insights into chitin turnover, metabolic specialization, and niche partitioning in the octocoral microbiome.

Microbiome, 10(1):151.

BACKGROUND: The role of bacterial symbionts that populate octocorals (Cnidaria, Octocorallia) is still poorly understood. To shed light on their metabolic capacities, we examined 66 high-quality metagenome-assembled genomes (MAGs) spanning 30 prokaryotic species, retrieved from microbial metagenomes of three octocoral species and seawater.

RESULTS: Symbionts of healthy octocorals were affiliated with the taxa Endozoicomonadaceae, Candidatus Thioglobaceae, Metamycoplasmataceae, unclassified Pseudomonadales, Rhodobacteraceae, unclassified Alphaproteobacteria and Ca. Rhabdochlamydiaceae. Phylogenomics inference revealed that the Endozoicomonadaceae symbionts uncovered here represent two species of a novel genus unique to temperate octocorals, here denoted Ca. Gorgonimonas eunicellae and Ca. Gorgonimonas leptogorgiae. Their genomes revealed metabolic capacities to thrive under suboxic conditions and high gene copy numbers of serine-threonine protein kinases, type 3-secretion system, type-4 pili, and ankyrin-repeat proteins, suggesting excellent capabilities to colonize, aggregate, and persist inside their host. Contrarily, MAGs obtained from seawater frequently lacked symbiosis-related genes. All Endozoicomonadaceae symbionts harbored endo-chitinase and chitin-binging protein-encoding genes, indicating that they can hydrolyze the most abundant polysaccharide in the oceans. Other symbionts, including Metamycoplasmataceae and Ca. Thioglobaceae, may assimilate the smaller chitin oligosaccharides resulting from chitin breakdown and engage in chitin deacetylation, respectively, suggesting possibilities for substrate cross-feeding and a role for the coral microbiome in overall chitin turnover. We also observed sharp differences in secondary metabolite production potential between symbiotic lineages. Specific Proteobacteria taxa may specialize in chemical defense and guard other symbionts, including Endozoicomonadaceae, which lack such capacity.

CONCLUSION: This is the first study to recover MAGs from dominant symbionts of octocorals, including those of so-far unculturable Endozoicomonadaceae, Ca. Thioglobaceae and Metamycoplasmataceae symbionts. We identify a thus-far unanticipated, global role for Endozoicomonadaceae symbionts of corals in the processing of chitin, the most abundant natural polysaccharide in the oceans and major component of the natural zoo- and phytoplankton feed of octocorals. We conclude that niche partitioning, metabolic specialization, and adaptation to low oxygen conditions among prokaryotic symbionts likely contribute to the plasticity and adaptability of the octocoral holobiont in changing marine environments. These findings bear implications not only for our understanding of symbiotic relationships in the marine realm but also for the functioning of benthic ecosystems at large. Video Abstract.

RevDate: 2022-09-23

Gao Y, Gao S, Bai Y, et al (2022)

Parametarhizium hingganense, a Novel Ectomycorrhizal Fungal Species, Promotes the Growth of Mung Beans and Enhances Resistance to Disease Induced by Rhizoctonia solani.

Journal of fungi (Basel, Switzerland), 8(9): pii:jof8090934.

The mutualistic interactions between mycorrhizae and plants first occurred along with the terrestrialization of plants. The majority of vascular plants are in symbiosis with mycorrhizal fungi. Due to their importance to the economy and ecology, arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi emerge as the most popular ones. However, the mechanism underlying the beneficial function of ECM fungi is not as clear as AM fungi. Here, the interaction between Parametarhizium hingganense, a novel fungal species isolated from forest litter, and mung bean (Vigna radiata) was studied. P. hingganense demonstrated P solubilization ability in vitro. Treatment of P. hingganense on the seeds resulted in promoted growth with enhanced P content. The hyphae of green fluorescence protein (GFP)-tagged P. hingganense were found to surround the roots and develop between cells, suggesting the establishment of an ectomycorrhizal symbiosis. Upon symbiosis with P. hingganense, the levels of jasmonic acid (JA) and gibberellin (GA1) and total phenolic and flavonoid content elevated. Meanwhile, damping off caused by Rhizoctonia solani in mycorrhizal plants was alleviated. Taken together, the above findings suggested that symbiosis with P. hingganense conferred growth promotion and priming of defense responses to host plants which should be associated with facilitated P uptake and increased JA and GA1 levels.

RevDate: 2022-09-23

Thube SH, Pandian RTP, Josephrajkumar A, et al (2022)

Xylosandrus crassiusculus (Motschulsky) on Cocoa Pods (Theobroma cacao L.): Matter of Bugs and Fungi.

Insects, 13(9): pii:insects13090809.

Exudation of mucilage from pinhead-sized boreholes in cocoa pods was recorded in Karnataka, India, during 2021. Further investigations showed the association of scolytine beetles with infested pods. The identity of the pest, Xylosandrus crassiusculus, was confirmed through morphological characterization and sequencing of the mitochondrial COI gene. We studied the predisposing factors for its infestation, visible and concealed damaging symptoms, and fungal symbionts. In addition to its well-known symbiotic fungus, Ambrosiella roeperi, a new association of yeast, Ambrosiozyma monospora, was discovered. We also traced the possible role of the mirid bug, Helopeltis theivora, in host selection by X. crassiusculus. Overall results indicated that a 'mirid bug-ambrosia beetle-pathogen complex' is responsible for the severe damage to cocoa pods in South India.

RevDate: 2022-09-22

Zaura E (2022)

A Commentary on the Potential Use of Oral Microbiome in Prediction, Diagnosis or Prognostics of a Distant Pathology.

Dentistry journal, 10(9): pii:dj10090156.

In health, the oral microbiome is in balance with its host. If this balance is lost, this symbiosis is replaced by dysbiotic microbial communities, which are thought to affect the rest of the body either directly or via metabolites or pro-inflammatory molecules. The association of oral microbiome with general health has led to attempts to use oral microbial biomarkers for the prediction, diagnosis or prognosis of distant pathologies such as colorectal carcinoma or pancreatic cancer. These attempts however have no chance to succeed if the complexity of the oral ecosystem and the interplay of environmental, behavioral and biological factors is not taken into account. Standardized, well-documented oral sample collection procedures together with detailed clinical oral examination and behavioral data are the prerequisites for the successful evaluation of the oral microbiome as a potential biomarker for distant pathologies.

RevDate: 2022-09-23
CmpDate: 2022-09-23

Wang T, Cheng KK, Cai ZH, et al (2022)

[Research advances in communication interactions among the symbionts of "bacteria-zooxanthellae-coral"].

Ying yong sheng tai xue bao = The journal of applied ecology, 33(9):2572-2584.

"Bacteria-zooxanthellae-coral" is a pair of typical triangular relationships in the marine ecosystem. There are complex flows of material, information, and energy in this system. The balance and stability of the symbionts is an important guarantee for maintaining the health of coral reef ecosystems. Many studies have been conducted on the interaction of coral symbionts in the past 20 years, which help clarify the material metabolism and nutrient exchange between "bacteria-zooxanthellae-coral" and their interaction with the environment. Due to the complexity of this symbiotic system, the mechanisms of some phenomena are still not well understood, especially for the communication among the symbionts. The interaction mediated by signal molecules is the internal driving force for the homeostatic maintenance and efficient operation of coral symbionts. In this review, we tried to summarize the latest research progress by focusing on the chemical signaling molecules in coral symbiotic system, including the communications between the bacteria and bacteria, bacteria and corals, bacteria and zooxanthellae, and zooxanthellae and corals. The main signals molecules include quorum sensing (QS) molecules, dimethylsulfoniopropionate (DMSP), glycans signals, lipid signals, and the noncoding RNAs. We focused on the functional mode and ecological significance of signal molecules in symbionts, and selectively exemplified microbial cooperation and competition mediated by QS signals, the interaction between bacteria and corals under the regulation of DMSP, and the response process of corals and zooxanthellae to noncoding RNAs under environmental stresses. We proposed the future research focus and possible directions, including the expansion of research dimensions, the application of new technologies and new methods, and the construction of ecological models. This work would help improve the understanding of interactions between "bacteria-zooxanthellae-coral". The exploration about the ways based on communication language would provide new ideas for the restoration and protection of coral reef ecosystems.

RevDate: 2022-09-22
CmpDate: 2022-09-22

Nogueira BR, de Oliveira AA, da Silva JP, et al (2022)

Collection and Long-Term Maintenance of Leaf-Cutting Ants (Atta) in Laboratory Conditions.

Journal of visualized experiments : JoVE.

Ants are one of the most biodiverse groups of animals on the planet and inhabit different environments. The maintenance of ant colonies in controlled environments enables an enriched comprehension of their biology that can contribute to applied research. This practice is usually employed in population control studies of species that cause economic loss, such as Atta ants. To cultivate their mutualistic fungus, these leaf-cutting ants collect leaves and for this are considered agricultural pests widely distributed throughout the American continent. They are highly socially organized and inhabit elaborated underground nests composed of a variety of chambers. Their maintenance in a controlled environment depends on a daily routine of several procedures and frequent care that are described here. It starts with the collection of queens during the reproductive season (i.e., nuptial flight), which are then individually transferred to plastic containers. Due to the high mortality rate of queens, a second collection can be carried out about 6 months after the nuptial flight, when incipient nests with developed fungus wad are excavated, hand-picked, and placed in plastic containers. In the laboratory, leaves are daily provided to established colonies, and ant-produced waste is weekly removed along with remaining dry plant material. As the fungus garden keeps growing, colonies are transferred to different types of containers according to the experimental purpose. Leaf-cutting ant colonies are placed in interconnected containers, representing the organizational system with functional chambers built by those insects in nature. This setup is ideal to monitor factors such as waste amount, fungus garden health, and the behavior of workers and queen. Facilitated data collection and more detailed observations are considered the greatest advantage of keeping ant colonies in controlled conditions.

RevDate: 2022-09-22
CmpDate: 2022-09-22

Dhiman S, Ulrich JF, Wienecke P, et al (2022)

Stereoselective Total Synthesis of (-)-Thallusin for Bioactivity Profiling.

Angewandte Chemie (International ed. in English), 61(39):e202206746.

Chemical mediators are key compounds for controlling symbiotic interactions in the environment. Here, we disclose a fully stereoselective total synthesis of the algae differentiation factor (-)-thallusin that utilizes sophisticated 6-endo-cyclization chemistry and effective late-stage sp2 -sp2 -couplings using non-toxic reagents. An EC50 of 4.8 pM was determined by quantitative phenotype profiling in the green seaweed Ulva mutabilis (Chlorophyte), underscoring this potent mediator's enormous, pan-species bioactivity produced by symbiotic bacteria. SAR investigations indicate that (-)-thallusin triggers at least two different pathways in Ulva that may be separated by chemical editing of the mediator compound structure.

RevDate: 2022-09-23
CmpDate: 2022-09-23

Lai Y, Hayashi N, TK Lu (2022)

Engineering the human gut commensal Bacteroides thetaiotaomicron with synthetic biology.

Current opinion in chemical biology, 70:102178.

The role of the microbiome in health and disease is attracting the attention of researchers seeking to engineer microorganisms for diagnostic and therapeutic applications. Recent progress in synthetic biology may enable the dissection of host-microbiota interactions. Sophisticated genetic circuits that can sense, compute, memorize, and respond to signals have been developed for the stable commensal bacterium Bacteroides thetaiotaomicron, dominant in the human gut. In this review, we highlight recent advances in expanding the genetic toolkit for B. thetaiotaomicron and foresee several applications of this species for microbiome engineering. We provide our perspective on the challenges and future opportunities for the engineering of human gut-associated bacteria as living therapeutic agents.

RevDate: 2022-09-22
CmpDate: 2022-09-22

Song S, TK Wood (2022)

Manipulating indole symbiont signalling.

Environmental microbiology reports, 14(5):691-696.

RevDate: 2022-09-22
CmpDate: 2022-09-22

Li G, Zheng X, Zhu Y, et al (2022)

Bacillus symbiont drives alterations in intestinal microbiota and circulating metabolites of lepidopteran host.

Environmental microbiology, 24(9):4049-4064.

The symbiotic association between bacterial symbionts and insect hosts is a complicated process that is not completely understood. Herein, we used a silkworm model to study the association between symbiotic Bacillus and lepidopteran insect by investigating the changes in intestinal microbiota and hemolymph circulating metabolites of silkworm after symbiotic Bacillus subtilis treatment. Results showed that B. subtilis can generate a variety of primary and secondary metabolites, such as B vitamins and antimicrobial compounds, to provide micronutrients and enhance the pathogen resistance of their insect host. Shifts in the relative abundance of Enterococcus, Brevibacterium, Buttiauxella, Pseudomonas, Brevundimonas and Limnobacter had significant correlations with the concentrations of differential metabolites (e.g. phospholipids and certain amino acids) in insect hemolymph. The antimicrobial compounds secreted by B. subtilis were the primary driving force for the reconstruction of intestinal microbiota. Meanwhile, the altered levels of circulating metabolites in multiple metabolic pathways were potential adaptive mechanism of insect hosts in response to the shifts of intestinal microbiota. Our findings provided concrete evidence that bacterial intestinal symbiont can alter the physiological state of insects and highlighted the importance of the compositional alterations of intestinal microbiota as a source of variation in circulating metabolites of insect hosts.

RevDate: 2022-09-21

Torres-Sánchez M, AV Longo (2022)

Linking pathogen-microbiome-host interactions to explain amphibian population dynamics.

Molecular ecology [Epub ahead of print].

Symbiotic interactions can determine the evolutionary trajectories of host species, influencing genetic variation through selection and changes in demography. In the context of strong selective pressures such as those imposed by infectious diseases, symbionts providing defenses could contribute to increase host fitness upon pathogen emergence. Here, we generated genome-wide data of an amphibian species to find evidence of evolutionary pressures driven by two skin symbionts: a batrachochytrid fungal pathogen and an antifungal bacterium. Using demographic modeling, we found evidence of decreased effective population size likely due to pathogen infections. Additionally, we investigated host genetic associations with infection status, antifungal bacterium abundance, and overall microbiome diversity using structural equation models. We uncovered relatively lower nucleotide diversity in infected frogs and potential heterozygote advantage to recruit the candidate beneficial symbiont and fight infections. Our models indicate that environmental conditions have indirect effects in symbiont abundance through both host body traits and microbiome diversity. Likewise, we uncovered a potential offsetting effect among host heterozygosity-fitness correlations, plausibly pointing to different ecological and evolutionary processes among the three species due to dynamic interactions. Our findings revealed that evolutionary pressures not only arise from the pathogen but also from the candidate beneficial symbiont, and both interactions shape the genetics of the host. Our results advance the knowledge about multipartite symbiotic relationships providing a framework to model ecological and evolutionary dynamics in wild populations. Finally, our study approach can be applied to inform conservation actions such as bioaugmentation strategies for other imperiled amphibians affected by infectious diseases.

RevDate: 2022-09-21

Weiss BL, Rio RVM, S Aksoy (2022)

Microbe Profile: Wigglesworthia glossinidia: the tsetse fly's significant other.

Microbiology (Reading, England), 168(9):.

Wigglesworthia glossinidia is an obligate, maternally transmitted endosymbiont of tsetse flies. The ancient association between these two organisms accounts for many of their unique physiological adaptations. Similar to other obligate mutualists, Wigglesworthia's genome is dramatically reduced in size, yet it has retained the capacity to produce many B-vitamins that are found at inadequate quantities in the fly's vertebrate blood-specific diet. These Wigglesworthia-derived B-vitamins play essential nutritional roles to maintain tsetse's physiological homeostasis as well as that of other members of the fly's microbiota. In addition to its nutritional role, Wigglesworthia contributes towards the development of tsetse's immune system during the larval period. Tsetse produce amidases that degrade symbiotic peptidoglycans and prevent activation of antimicrobial responses that can damage Wigglesworthia. These amidases in turn exhibit antiparasitic activity and decrease tsetse's ability to be colonized with parasitic trypanosomes, which reduce host fitness. Thus, the Wigglesworthia symbiosis represents a fine-tuned association in which both partners actively contribute towards achieving optimal fitness outcomes.

RevDate: 2022-09-21

Kumar A, Lin H, Li Q, et al (2022)

Anthocyanin pigmentation as a quantitative visual marker for arbuscular mycorrhizal fungal colonization of Medicago truncatula roots.

The New phytologist [Epub ahead of print].

Visualization of root colonization by arbuscular mycorrhizal fungi (AMF) is the most elementary experiment in the field of mycorrhizal symbiosis. The most widely used approach for evaluating AMF colonization levels is staining with trypan blue or ink which is scored using the time-consuming grid-intersection method. Here we demonstrate the use of an anthocyanin-based visual-marker system for visualizing AMF colonization of Medicago truncatula roots. Expression of MtLAP1, a transcription factor which regulates the production of anthocyanins, from the AMF-induced Kunitz Protease Inhibitor 106 promoter, allowed the visualization of arbuscules in live plant tissues without microscopy or staining. This marker system allowed the straightforward evaluation of the qualitative ram1, vpy and dmi3 AMF- phenotypes using Agrobacterium rhizogenes hairy-root transformation. For the strigolactone biosynthesis mutant carotenoid cleavage dioxygenase 8a and a novel mutant scooby, which show quantitative AMF symbiotic phenotypes, the amount of anthocyanins in the roots estimated by spectrophotometry correlated very well with colonization levels estimated by staining and scoring using the grid intersection method. The LAP1-based marker system therefore provides a highly efficient approach for mutant screening and monitoring of AMF colonization in live tissues by the naked eye, or for quantitative assessment using a simple and quick photometric assay.

RevDate: 2022-09-20

Du Toit A (2022)

Cross-domain symbiosis.

Nature reviews. Microbiology [Epub ahead of print].

RevDate: 2022-09-20

Lau JA, Hammond MD, Schmidt JE, et al (2022)

Contemporary evolution rivals the effects of rhizobium presence on community and ecosystem properties in experimental mesocosms.

Oecologia [Epub ahead of print].

Because genotypes within a species commonly differ in traits that influence other species, whole communities, or even ecosystem functions, evolutionary change within one key species may affect the community and ecosystem processes. Here we use experimental mesocosms to test how the evolution of reduced cooperation in rhizobium mutualists in response to 20 years of nitrogen fertilization compares to the effects of rhizobium presence on soil nitrogen availability and plant community composition and diversity. The evolution of reduced rhizobium cooperation caused reductions in soil nitrogen, biological nitrogen fixation, and leaf nitrogen concentrations that were as strong as, or even stronger than, experimental rhizobium inoculation (presence/absence) treatments. Effects of both rhizobium evolution and rhizobium inoculation on legume dominance, plant community composition, and plant species diversity were often smaller in magnitude, but suggest that rhizobium evolution can alter the relative abundance of plant functional groups. Our findings indicate that the consequences of rapid microbial evolution for ecosystems and communities can rival the effects resulting from the presence or abundance of keystone mutualists.

RevDate: 2022-09-20

Martinez S, Grover R, Baker DM, et al (2022)

Symbiodiniaceae Are the First Site of Heterotrophic Nitrogen Assimilation in Reef-Building Corals.

mBio [Epub ahead of print].

Coral reefs depend on the highly optimized mutualistic relationship between corals and Symbiodiniaceae dinoflagellates. Both partners exchange nutrients obtained through heterotrophy of the host and autotrophy of the symbionts. While heterotrophy helps corals withstand the harmful effects of seawater warming, the exchange of heterotrophic nutrients between the two partners is poorly understood. Here, we used compound-specific δ15N and δ13C of amino acids (δ15NAA and δ13CAA) and a 15N pulse-chase experiment with Artemia salina nauplii in two coral-dinoflagellate associations to trace the assimilation and allocation of heterotrophic nutrients within the partners. We observed that changes in the trophic position (TPGlx-Phe), δ15NAA, and δ13CAA with heterotrophy were holobiont-dependent. Furthermore, while TPGlx-Phe and δ15N of all AAs significantly increased with heterotrophy in the symbionts and host of Stylophora pistillata, only the δ15NAA of the symbionts changed in Turbinaria reniformis. Together with the pulse-chase experiment, the results suggested a direct transfer of heterotrophically acquired AAs to the symbionts of S. pistillata and a transfer of ammonium to the symbionts of T. reniformis. Overall, we demonstrated that heterotrophy underpinned the nutrition of Symbiodinaceae and possibly influenced their stress tolerance under changing environmental conditions. IMPORTANCE Coral reefs rely upon the highly optimized nutritional symbiosis between corals and Symbiodiniaceae dinoflagellates. Heterotrophic feeding on plankton is key to the resistance of corals to environmental stress. Yet, a detailed understanding of heterotrophic nutrient assimilation and utilization within the symbiosis is lacking. Here, we used the advanced tools of compound-specific isotope analysis of amino acids and 15N-labeling of plankton to show that heterotrophy underpinned the nutrition of Symbiodinaceae. Symbionts received either heterotrophically acquired amino acids or recycled ammonium due to their association with the coral host. This study brought new insight into the nutrient exchanges in coral-Symbiodiniaceae associations and allowed a better understanding of the mechanisms involved in coral resistance to environmental stress.

RevDate: 2022-09-20

Uppal S, Metz JL, Xavier RKM, et al (2022)

Uncovering Lasonolide A Biosynthesis Using Genome-Resolved Metagenomics.

mBio [Epub ahead of print].

Invertebrates, particularly sponges, have been a dominant source of new marine natural products. For example, lasonolide A (LSA) is a potential anticancer molecule isolated from the marine sponge Forcepia sp., with nanomolar growth inhibitory activity and a unique cytotoxicity profile against the National Cancer Institute 60-cell-line screen. Here, we identified the putative biosynthetic pathway for LSA. Genomic binning of the Forcepia sponge metagenome revealed a Gram-negative bacterium belonging to the phylum Verrucomicrobia as the candidate producer of LSA. Phylogenetic analysis showed that this bacterium, here named "Candidatus Thermopylae lasonolidus," only has 88.78% 16S rRNA identity with the closest relative, Pedosphaera parvula Ellin514, indicating that it represents a new genus. The lasonolide A (las) biosynthetic gene cluster (BGC) was identified as a trans-acyltransferase (AT) polyketide synthase (PKS) pathway. Compared with its host genome, the las BGC exhibits a significantly different GC content and pentanucleotide frequency, suggesting a potential horizontal acquisition of the gene cluster. Furthermore, three copies of the putative las pathway were identified in the candidate producer genome. Differences between the three las repeats were observed, including the presence of three insertions, two single-nucleotide polymorphisms, and the absence of a stand-alone acyl carrier protein in one of the repeats. Even though the verrucomicrobial producer shows signs of genome reduction, its genome size is still fairly large (about 5 Mbp), and, compared to its closest free-living relative, it contains most of the primary metabolic pathways, suggesting that it is in the early stages of reduction. IMPORTANCE While sponges are valuable sources of bioactive natural products, a majority of these compounds are produced in small quantities by uncultured symbionts, hampering the study and clinical development of these unique compounds. Lasonolide A (LSA), isolated from marine sponge Forcepia sp., is a cytotoxic molecule active at nanomolar concentrations, which causes premature chromosome condensation, blebbing, cell contraction, and loss of cell adhesion, indicating a novel mechanism of action and making it a potential anticancer drug lead. However, its limited supply hampers progression to clinical trials. We investigated the microbiome of Forcepia sp. using culture-independent DNA sequencing, identified genes likely responsible for LSA synthesis in an uncultured bacterium, and assembled the symbiont's genome. These insights provide future opportunities for heterologous expression and cultivation efforts that may minimize LSA's supply problem.

RevDate: 2022-09-19

Martinez J, Ant TH, Murdochy SM, et al (2022)

Genome sequencing and comparative analysis of Wolbachia strain wAlbA reveals Wolbachia-associated plasmids are common.

PLoS genetics, 18(9):e1010406 pii:PGENETICS-D-22-00790 [Epub ahead of print].

Wolbachia are widespread maternally-transmitted bacteria of arthropods that often spread by manipulating their host's reproduction through cytoplasmic incompatibility (CI). Their invasive potential is currently being harnessed in field trials aiming to control mosquito-borne diseases. Wolbachia genomes commonly harbour prophage regions encoding the cif genes which confer their ability to induce CI. Recently, a plasmid-like element was discovered in wPip, a Wolbachia strain infecting Culex mosquitoes; however, it is unclear how common such extra-chromosomal elements are in Wolbachia. Here we sequenced the complete genome of wAlbA, a strain of the symbiont found in Aedes albopictus, after eliminating the co-infecting and higher density wAlbB strain that previously made sequencing of wAlbA challenging. We show that wAlbA is associated with two new plasmids and identified additional Wolbachia plasmids and related chromosomal islands in over 20% of publicly available Wolbachia genome datasets. These plasmids encode a variety of accessory genes, including several phage-like DNA packaging genes as well as genes potentially contributing to host-symbiont interactions. In particular, we recovered divergent homologues of the cif genes in both Wolbachia- and Rickettsia-associated plasmids. Our results indicate that plasmids are common in Wolbachia and raise fundamental questions around their role in symbiosis. In addition, our comparative analysis provides useful information for the future development of genetic tools to manipulate and study Wolbachia symbionts.

RevDate: 2022-09-20

Aher R, Punde A, Shinde P, et al (2022)

Synthesis, Structural and Optical Properties of ZrBi2Se6 Nanoflowers: A Next-Generation Semiconductor Alloy Material for Optoelectronic Applications.

ACS omega, 7(36):31877-31887.

ZrBi2Se6 nanoflower-like morphology was successfully prepared using a solvothermal method, followed by a quenching process for photoelectrochemical water splitting applications. The formation of ZrBi2Se6 was confirmed by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The estimated value of work function and band gap were found to be 5.5 and 2.26 eV measured using diffuse reflection spectroscopy and ultraviolet photoelectron spectroscopy, suggesting the potential candidate for water splitting. The highest current density of 9.7 μA/cm2 has been observed for the ZrBi2Se6 photoanode for the applied potential of 0.5 V vs SCE. The flat-band potential value was -0.46 V, and the 1.85 nm width of the depletion region is estimated from the Mott-Schottky (MS) analysis. It also reveals that the charge carrier density for the ZrBi2Se6 nanoflowers is 4.8 × 1015 cm-3. The negative slope of the MS plot indicates that ZrBi2Se6 is a p-type semiconductor. It was observed that ZrBi2Se6 nanoflowers had a high charge transfer resistance of ∼730 kΩ and equivalent capacitance of ∼40 nF calculated using electrochemical impedance spectroscopy (EIS) measurements. Using chronoamperometry, the estimated rise time and decay time were 50 ms and 0.25 s, respectively, which reveals the fast photocurrent response and excellent PEC performance of the ZrBi2Se6 photoanode. Furthermore, an attempt has been made to explain the PEC activity of ZrBi2Se6 nanoflowers using an energy band diagram. Thus, the initial results on ZrBi2Se6 nanoflowers appear promising for the PEC activity toward water splitting.

RevDate: 2022-09-20

Lucido A, Basallo O, Sorribas A, et al (2022)

A mathematical model for strigolactone biosynthesis in plants.

Frontiers in plant science, 13:979162.

Strigolactones mediate plant development, trigger symbiosis with arbuscular mycorrhizal fungi, are abundant in 80% of the plant kingdom and help plants gain resistance to environmental stressors. They also induce germination of parasitic plant seeds that are endemic to various continents, such as Orobanche in Europe or Asia and Striga in Africa. The genes involved in the early stages of strigolactones biosynthesis are known in several plants. The regulatory structure and the latter parts of the pathway, where flux branching occurs to produce alternative strigolactones, are less well-understood. Here we present a computational study that collects the available experimental evidence and proposes alternative biosynthetic pathways that are consistent with that evidence. Then, we test the alternative pathways through in silico simulation experiments and compare those experiments to experimental information. Our results predict the differences in dynamic behavior between alternative pathway designs. Independent of design, the analysis suggests that feedback regulation is unlikely to exist in strigolactone biosynthesis. In addition, our experiments suggest that engineering the pathway to modulate the production of strigolactones could be most easily achieved by increasing the flux of β-carotenes going into the biosynthetic pathway. Finally, we find that changing the ratio of alternative strigolactones produced by the pathway can be done by changing the activity of the enzymes after the flux branching points.

RevDate: 2022-09-20

de Souza MR, Caruso C, Ruiz-Jones L, et al (2022)

Community composition of coral-associated Symbiodiniaceae differs across fine-scale environmental gradients in Kāne'ohe Bay.

Royal Society open science, 9(9):212042.

The survival of most reef-building corals is dependent upon a symbiosis between the coral and the community of Symbiodiniaceae. Montipora capitata, one of the main reef-building coral species in Hawai'i, is known to host a diversity of symbionts, but it remains unclear how they change spatially and whether environmental factors drive those changes. Here, we surveyed the Symbiodiniaceae community in 600 M. capitata colonies from 30 sites across Kāne'ohe Bay and tested for host specificity and environmental gradients driving spatial patterns of algal symbiont distribution. We found that the Symbiodiniaceae community differed markedly across sites, with M. capitata in the most open-ocean (northern) site hosting few or none of the genus Durusdinium, whereas individuals at other sites had a mix of Durusdinium and Cladocopium. Our study shows that the algal symbiont community composition responds to fine-scale differences in environmental gradients; depth and temperature variability were the most significant predictor of Symbiodiniaceae community, although environmental factors measured in the study explained only about 20% of observed variation. Identifying and mapping Symbiodiniaceae community distribution at multiple scales is an important step in advancing our understanding of algal symbiont diversity, distribution and evolution and the potential responses of corals to future environmental change.

RevDate: 2022-09-20

Power NR, Rugman-Jones PF, Stouthamer R, et al (2022)

High temperature mortality of Wolbachia impacts the sex ratio of the parasitoid Ooencyrtus mirus (Hymenoptera: Encyrtidae).

PeerJ, 10:e13912.

Background: Wolbachia bacteria are estimated to occur in more than half of all insect species. In Hymenoptera, Wolbachia often manipulates its host's reproduction to its own advantage. Wolbachia is likely the reason that males are rare in the uniparental Ooencyrtus mirus Triapitsyn & Power (Hymenoptera: Encyrtidae). The likelihood of producing male offspring can be increased by giving mothers a continuous supply of Bagrada hilaris (Burmeister) (Heteroptera: Pentatomidae) host eggs to parasitize for 2-3 weeks, by feeding the parents antibiotics, or by rearing parent wasps at high temperatures; all variables that have been shown to correlate with depleting Wolbachia titers in other organisms. The purpose of the current study was to determine whether thelytoky in O. mirus is due to Wolbachia, and if so, at what time in development the sex change occurs. We also wished to determine if Wolbachia removal results in the production of intersexes, as in some other hymenopterans. Finally, mating behavior was observed to see if and where it breaks down as a result of the species becoming thelytokous.

Methods: Females were collected from parental lines of O. mirus reared at 26, 30, 31, 32, 33, 34, and 36 °C. The offspring of these females were reared at 26 °C, and their sex-ratio was determined. In a subsequent experiment, the parental generation was switched between 26 °C and 36 °C during development to narrow down the critical period at which changes occurred that subsequently affected the sex-ratio of their offspring.

Results: The sex ratio was male biased in the offspring of O. mirus parents reared at 34 °C and 36 °C (high temperatures), even if the offspring themselves were reared at 26 °C. The constant temperature at which the percentage of males started to increase after two generations was 31 °C (10% males), rising to 39% males at 33 °C, and 100% males at 34 °C and 36 °C. Lasting more than 2 days, the critical period for the change toward a male biased sex ratio was during the second half of the parent's development. Molecular diagnostic assays confirmed that O. mirus females contain Wolbachia and males do not. Examination of preserved males and male-female pairs under a dissecting microscope showed no signs of intersex characters. Observation of the mating behavior of live O. mirus showed that males initiate courtship by drumming their antennae on a female's antennae, but after a few seconds, the females typically turn and walk away. However, a few instances of possible copulation were noted.

Conclusions: As hypothesized, the results indicated that thelytoky in O. mirus is likely mediated by Wolbachia bacteria. To maximize the population growth rate without generating males, the best temperature for mass rearing this species is 30 °C.

RevDate: 2022-09-20
CmpDate: 2022-09-20

Gabrielle PH (2022)

Lipid metabolism and retinal diseases.

Acta ophthalmologica, 100 Suppl 269:3-43.

PURPOSE: The retina has enormous lipids demands and must meet those needs. Retinal lipid homeostasis appears to be based on the symbiosis between neurons, Müller glial cells (MGC), and retinal pigment epithelium (RPE) cells, which can be impacted in several retinal diseases. The current research challenge is to better understand lipid-related mechanisms involved in retinal diseases, such as age-related macular degeneration (AMD) and glaucoma.

RESULTS: In a first axis, in vitro and focus on Müller glial cell, we aimed to characterize whether the 24S-hydroxycholesterol (24S-OHC), an overexpressed end-product of cholesterol elimination pathway in neural tissue and likely produced by suffering retinal ganglion cells in glaucoma, may modulate MGC membrane organization, such as lipid rafts, to trigger cellular signalling pathways related to retinal gliosis. We have found that lipid composition appears to be a key factor of membrane architecture, especially for lipid raft microdomain formation, in MGC. However, 24S-OHC did not appear to trigger retinal gliosis via the modulation of lipid or protein composition within lipid rafts microdomains. This study provided a better understanding of the complex mechanisms involved in the pathophysiology of glaucoma. On a second clinical ax, we focused on the lipid-related mechanisms involved in the dysfunction of aging RPE and the appearance of drusenoid deposits in AMD. Using the Montrachet population-based study, we intend to report the frequency of reticular pseudodrusen (RPD) and its ocular and systemic risk factors, particularly related to lipid metabolisms, such as plasma lipoprotein levels, carotenoids levels, and lipid-lowering drug intake. Our study showed that RPD was less common in subjects taking lipid-lowering drugs. Lipid-lowering drugs, such as statins, may reduce the risk of RPD through their effect on the production and function of lipoproteins. This observation highlights the potential role of retinal lipid trafficking via lipoproteins between photoreceptors and retinal pigment epithelium cells in RPD formation. Those findings have been complemented with preliminary results on the analysis of plasma fatty acid (FA) profile, a surrogate marker of short-term dietary lipid intake, according to the type of predominant drusenoid deposit, soft drusen or RPD, in age-related maculopathy.

CONCLUSION: Further research on lipid metabolism in retinal diseases is warranted to better understand the pathophysiology of retinal diseases and develop new promising diagnostic, prognostic, and therapeutic tools for our patients.

RevDate: 2022-09-21
CmpDate: 2022-09-20

Hedblom GA, Dev K, Bowden SD, et al (2022)

Comparative genome analysis of commensal segmented filamentous bacteria (SFB) from turkey and murine hosts reveals distinct metabolic features.

BMC genomics, 23(1):659.

BACKGROUND: Segmented filamentous bacteria (SFB) are intestinal commensal microorganisms that have been demonstrated to induce the innate and adaptive immune responses in mouse and rat hosts. SFB are Gram-positive, spore-forming bacteria that fail to grow optimally under in vitro conditions due to unique metabolic requirements. Recently, SFB have been implicated in improved health and growth outcomes in commercial turkey flocks. To assess the nature and variations in SFB of turkeys and how they may differ from mammalian-associated SFB, the genome of turkey-associated SFB was compared with six representative genomes from murine hosts using an in silico approach.

RESULTS: The SFB-turkey genome is 1.6 Mb with a G + C content of 26.14% and contains 1,604 coding sequences (CDS). Comparative genome analyses revealed that all the seven SFB strain possesses a common set of metabolic deficiencies and auxotrophies. Specifically, the inability of all the SFB strains to synthesize most of the amino acids, nucleotides and cofactors, emphasizing the importance of metabolite acquisition from the host intestinal environment. Among the seven SFB genomes, the SFB-turkey genome is the largest and contains the highest number of 1,604 predicted CDS. The SFB-turkey genome possesses cellular metabolism genes that are absent in the rodent SFB strains, including catabolic pathways for sucrose, stachyose, raffinose and other complex glycans. Other unique genes associated with SFB-turkey genome is loci for the biosynthesis of biotin, and degradation enzymes to recycle primary bile acids, both of which may play an important role to help turkey associated SFB survive and secure mutualism with its avian host.

CONCLUSIONS: Comparative genomic analysis of seven SFB genomes revealed that each strain have a core set of metabolic capabilities and deficiencies that make these bacteria challenging to culture under ex vivo conditions. When compared to the murine-associated strains, turkey-associated SFB serves as a phylogenetic outgroup and a unique member among all the sequenced strains of SFB. This turkey-associated SFB strain is the first reported non-mammalian SFB genome, and highlights the impact of host specificity and the evolution of metabolic capabilities.

RevDate: 2022-09-17

Chiu CH, Roszak P, Orvošová M, et al (2022)

Arbuscular mycorrhizal fungi induce lateral root development in angiosperms via a conserved set of MAMP receptors.

Current biology : CB pii:S0960-9822(22)01391-4 [Epub ahead of print].

Root systems regulate their branching patterns in response to environmental stimuli. Lateral root development in both monocotyledons and dicotyledons is enhanced in response to inoculation with arbuscular mycorrhizal (AM) fungi, which has been interpreted as a developmental response to specific, symbiosis-activating chitinaceous signals. Here, we report that generic instead of symbiosis-specific, chitin-derived molecules trigger lateral root formation. We demonstrate that this developmental response requires the well-known microbe-associated molecular pattern (MAMP) receptor, ChitinElicitorReceptorKinase 1 (CERK1), in rice, Medicago truncatula, and Lotus japonicus, as well as the non-host of AM fungi, Arabidopsis thaliana, lending further support for a broadly conserved signal transduction mechanism across angiosperms. Using rice mutants impaired in strigolactone biosynthesis and signaling, we show that strigolactone signaling is necessary to regulate this developmental response. Rice CERK1 operates together with either Chitin Elicitor Binding Protein (CEBiP) or Nod Factor Receptor 5 (NFR5) in immunity and symbiosis signaling, respectively; for the lateral root response, however, all three LysM receptors are required. Our work, therefore, reveals an overlooked but a conserved role of LysM receptors integrating MAMP perception with developmental responses in plants, an ability that might influence the interaction between roots and the rhizosphere biota.

RevDate: 2022-09-20

Ferrer B, Suresh H, Santamaria A, et al (2022)

Corrigendum to "The antioxidant role of STAT3 in methylmercury-induced toxicity in mouse hypothalamic neuronal GT1-7 cell line" [Free Radic. Biol. Med. 171 (2021) 245-259].

RevDate: 2022-09-19

Wang J, Tian Q, Cui L, et al (2022)

Effect of extracellular proteins on Cd(II) adsorption in fungus and algae symbiotic system.

Journal of environmental management, 323:116173 pii:S0301-4797(22)01746-7 [Epub ahead of print].

Fungus-algae symbiotic systems (FASS) are typically used to assist in the immobilization of algae and strengthen the adsorption of heavy metals. However, the adsorption behavior of the symbiotic system and the molecular regulation mechanism of extracellular proteins in the adsorption of heavy metals have not been reported in detail. In this study, a stable FCSS (fungus-cyanobacterium symbiotic system) was used to study Cd(II) adsorption behavior. The fixation efficiency of fungus to cyanobacterium reached more than 95% at pH7.0, 30 °C, 150 rpm, and a medium ratio of 100%. The biomass, chlorophyll content, and total fatty acid content of the symbiotic system were much higher than those of cyanobacterium and fungus alone. The photosynthetic fluorescence parameters showed that the presence of fungus enhanced the light tolerance of cyanobacterium. The original light energy conversion efficiency and potential activity of PSII were enhanced, indicating that symbiosis could promote the photosynthetic process of cyanobacterium. The Cd(II) adsorption efficiency can achieve 90%. The system maintained excellent adsorption after six adsorption cycles. Differential proteins were mainly enriched in areas such as metabolism, ABC transport system, and pressure response. Cd(II) stress promotes an increase in efflux proteins. Moreover, cadmium can be fixed as much as possible by secreting extracellular proteins, and the toxicity of cadmium to cells can be alleviated by regulating the metabolism of glutathione, reducing oxidative phosphorylation level, and reducing oxidative stress, thus improving the resistance to Cd(II). Meanwhile, the expression of enzymes involved in glycolysis and the pentose phosphate pathway was upregulated, while the expression of those in the TCA cycle was downregulated. The expression of substances related to PSI and PSII in the photosynthetic system and rubisco, a key enzyme in the Calvin cycle, was significantly upregulated, indicating that the glucose metabolism and photosynthetic pathways of the symbiotic system were involved in resistance to Cd toxicity. This revealed the response mechanism of the fungus-algal symbiotic system in the process of Cd adsorption, and also provided reference value for industrial application in water treatment.

RevDate: 2022-09-20
CmpDate: 2022-09-20

Zapalski MK, Vinn O, Toom U, et al (2022)

Bryozoan-cnidarian mutualism triggered a new strategy for greater resource exploitation as early as the Late Silurian.

Scientific reports, 12(1):15556.

Bryozoans were common benthic invertebrates in the Silurian seas. The large biodiversity among Silurian benthic organisms prompted diversified interactions, and as a result bryozoans hosted many other organisms as symbionts. Here we analyse the cystoporate bryozoan Fistulipora przhidolensis and unidentified trepostomes intergrown with auloporid tabulate corals and putative hydrozoans. The material comes from the uppermost Přídolí Series (Late Silurian) of the Sõrve Peninsula, Saaremaa, Estonia. Our analysis shows that the interaction was beneficial for both organisms-cnidarians benefited from feeding currents created by the host bryozoan, while the latter benefited from the protection from predators by cnidae, it can thus be classified as mutualism. Such associations are common in modern seas. The analysed organisms are typically encrusting when the symbiosis is absent, when intergrown they display erect, branching morphologies, raised over the substratum, thus exploiting a higher suspension-feeding tier. While similar associations were known from the Devonian, we demonstrate that this novel ecological strategy for greater resource exploitation started as early as the latest Silurian.

RevDate: 2022-09-21
CmpDate: 2022-09-20

Local Burden of Disease Household Air Pollution Collaborators (2022)

Mapping development and health effects of cooking with solid fuels in low-income and middle-income countries, 2000-18: a geospatial modelling study.

The Lancet. Global health, 10(10):e1395-e1411.

BACKGROUND: More than 3 billion people do not have access to clean energy and primarily use solid fuels to cook. Use of solid fuels generates household air pollution, which was associated with more than 2 million deaths in 2019. Although local patterns in cooking vary systematically, subnational trends in use of solid fuels have yet to be comprehensively analysed. We estimated the prevalence of solid-fuel use with high spatial resolution to explore subnational inequalities, assess local progress, and assess the effects on health in low-income and middle-income countries (LMICs) without universal access to clean fuels.

METHODS: We did a geospatial modelling study to map the prevalence of solid-fuel use for cooking at a 5 km × 5 km resolution in 98 LMICs based on 2·1 million household observations of the primary cooking fuel used from 663 population-based household surveys over the years 2000 to 2018. We use observed temporal patterns to forecast household air pollution in 2030 and to assess the probability of attaining the Sustainable Development Goal (SDG) target indicator for clean cooking. We aligned our estimates of household air pollution to geospatial estimates of ambient air pollution to establish the risk transition occurring in LMICs. Finally, we quantified the effect of residual primary solid-fuel use for cooking on child health by doing a counterfactual risk assessment to estimate the proportion of deaths from lower respiratory tract infections in children younger than 5 years that could be associated with household air pollution.

FINDINGS: Although primary reliance on solid-fuel use for cooking has declined globally, it remains widespread. 593 million people live in districts where the prevalence of solid-fuel use for cooking exceeds 95%. 66% of people in LMICs live in districts that are not on track to meet the SDG target for universal access to clean energy by 2030. Household air pollution continues to be a major contributor to particulate exposure in LMICs, and rising ambient air pollution is undermining potential gains from reductions in the prevalence of solid-fuel use for cooking in many countries. We estimated that, in 2018, 205 000 (95% uncertainty interval 147 000-257 000) children younger than 5 years died from lower respiratory tract infections that could be attributed to household air pollution.

INTERPRETATION: Efforts to accelerate the adoption of clean cooking fuels need to be substantially increased and recalibrated to account for subnational inequalities, because there are substantial opportunities to improve air quality and avert child mortality associated with household air pollution.

FUNDING: Bill & Melinda Gates Foundation.

RevDate: 2022-09-19

Han X, Wang J, Zhang Y, et al (2022)

Changes in the m6A RNA methylome accompany the promotion of soybean root growth by rhizobia under cadmium stress.

Journal of hazardous materials, 441:129843 pii:S0304-3894(22)01636-3 [Epub ahead of print].

Cadmium (Cd) is the most widely distributed heavy metal pollutant in soil and has significant negative effects on crop yields and human health. Rhizobia can enhance soybean growth in the presence of heavy metals, and the legume-rhizobia symbiosis has been used to promote heavy-metal phytoremediation, but much remains to be learned about the molecular networks that underlie these effects. Here, we demonstrated that soybean root growth was strongly suppressed after seven days of Cd exposure but that the presence of rhizobia largely eliminated this effect, even prior to nodule development. Moreover, rhizobia did not appear to promote root growth by limiting plant Cd uptake: seedlings with and without rhizobia had similar root Cd concentrations. Previous studies have demonstrated a role for m6A RNA methylation in the response of rice and barley to Cd stress. We therefore performed transcriptome-wide m6A methylation profiling to investigate changes in the soybean RNA methylome in response to Cd with and without rhizobia. Here, we provide some of the first data on transcriptome-wide m6a RNA methylation patterns in soybean; m6A modifications were concentrated at the 3' UTR of transcripts and showed a positive relationship with transcript abundance. Transcriptome-wide m6A RNA methylation peaks increased in the presence of Cd, and the integration of m6A methylome and transcriptome results enabled us to identify 154 genes whose transcripts were both differentially methylated and differentially expressed in response to Cd stress. Annotation results suggested that these genes were associated with Ca2+ homeostasis, ROS pathways, polyamine metabolism, MAPK signaling, hormones, and biotic stress responses. There were 176 differentially methylated and expressed transcripts under Cd stress in the presence of rhizobia. In contrast to the Cd-only gene set, they were also enriched in genes related to auxin, jasmonic acid, and brassinosteroids, as well as abiotic stress tolerance. They contained fewer genes related to Ca2+ homeostasis and also included candidates with known functions in the legume-rhizobia symbiosis. These findings offer new insights into how rhizobia promote soybean root growth under Cd stress; they provide candidate genes for research on plant heavy metal responses and for the use of legumes in phytoremediation.

RevDate: 2022-09-20

Rinsky M, Weizman E, Ben-Asher HW, et al (2022)

Temporal gene expression patterns in the coral Euphyllia paradivisa reveal the complexity of biological clocks in the cnidarian-algal symbiosis.

Science advances, 8(37):eabo6467.

Studying chronobiology in reef-building corals is challenging due to the tightly coupled symbiosis with their photosynthetic algae, Symbiodiniaceae. Although symbiosis requires metabolic synchronization and coordination of cellular processes in the holobiont, the cross-talk between the host and symbiont's clocks is still puzzling. Here, we use the mesophotic coral Euphyllia paradivisa to examine temporal gene expression patterns in symbiotic and aposymbiotic morphs exposed to natural light/dark cycles and constant darkness. Our comparative transcriptomic analyses revealed circadian and circatidal cycles of gene expression with a predominant diel pattern in both coral morphs. We found a substantial number of transcripts consistently rhythmic under both light conditions, including genes likely involved in the cnidarians' circadian clock, thus indicating that an endogenous clock, which can oscillate independently from the Symbiodiniaceae clock, exists in E. paradivisa. The analysis further manifests the remarkable impacts of symbiosis on transcriptional rhythms and implies that the algae's presence influences the host's biorhythm.

RevDate: 2022-09-17

Janke RS, Moog S, Weiss B, et al (2022)

Morphological adaptation for ectosymbiont maintenance and transmission during metamorphosis in Lagria beetles.

Frontiers in physiology, 13:979200.

The diversity and success of holometabolous insects is partly driven by metamorphosis, which allows for the exploitation of different niches and decouples growth and tissue differentiation from reproduction. Despite its benefits, metamorphosis comes with the cost of temporal vulnerability during pupation and challenges associated with tissue reorganizations. These rearrangements can also affect the presence, abundance, and localization of beneficial microbes in the host. However, how symbionts are maintained or translocated during metamorphosis and which adaptations are necessary from each partner during this process remains unknown for the vast majority of symbiotic systems. Here, we show that Lagria beetles circumvent the constraints of metamorphosis by maintaining defensive symbionts on the surface in specialized cuticular structures. The symbionts are present in both sexes throughout larval development and during the pupal phase, in line with a protective role during the beetle's immature stages. By comparing symbiont titer and morphology of the cuticular structures between sexes using qPCR, fluorescence in situ hybridization, and micro-computed tomography, we found that the organs likely play an important role as a symbiont reservoir for transmission to female adults, since symbiont titers and structures are reduced in male pupae. Using symbiont-sized fluorescent beads, we demonstrate transfer from the region of the dorsal symbiont-housing organs to the opening of the reproductive tract of adult females, suggesting that symbiont relocation on the outer surface is possible, even without specialized symbiont adaptations or motility. Our results illustrate a strategy for holometabolous insects to cope with the challenge of symbiont maintenance during metamorphosis via an external route, circumventing problems associated with internal tissue reorganization. Thereby, Lagria beetles keep a tight relationship with their beneficial partners during growth and metamorphosis.

RevDate: 2022-09-17

Virdi JK, P Pethe (2022)

Soft substrate maintains stemness and pluripotent stem cell-like phenotype of human embryonic stem cells under defined culture conditions.

Cytotechnology, 74(4):479-489.

Human embryonic stem cells (hESCs) are derived from the inner cell mass (ICM) of the pre-implantation blastocyst. Prior to embryo implantation, the ICM cells are surrounded by trophoblasts which have mechanical stiffness ranging from Pascal (Pa) to kilopascal (kPa). However, under in vitro conditions these cells are cultured on stiff tissue culture treated plastic plates (TCP) which have stiffness of approximately 1 gigapascal (GPa). This obvious dichotomy motivated us to investigate the fate of hESCs cultured on softer substrate, and to probe if the hESCs undergo differentiation or they retain pluripotency on soft substrates. We investigated the expression of pluripotency markers, and lineage-specific markers; we particularly looked at the expression of transcriptional coactivator YAP (Yes-associated protein), an important mediator of extracellular matrix (ECM) mechanical cues and a known downstream transducer of Hippo pathway. Downregulation of YAP has been correlated to the loss of multipotency of human mesenchymal stem cells (hMSCs) and pluripotency in mouse ESCs (mESCs); but we report that hESCs maintain their stemness on soft substrate of varying stiffness. Our findings revealed that on soft substrate hESCs express pluripotency markers and does not undergo substrate-mediated differentiation. Interestingly we show that hESCs maintained basal level of YAP expression for cell survival and proliferation, but YAP expression does not correlate directly with pluripotency in hESCs. To summarize, our results show that hESCs retain their stemness on soft substrate despite downregulation of YAP.

Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-022-00537-z.

RevDate: 2022-09-15

Rayamajhee B, Willcox MDP, Henriquez FL, et al (2022)

Acanthamoeba, an environmental phagocyte enhancing survival and transmission of human pathogens.

Trends in parasitology pii:S1471-4922(22)00184-2 [Epub ahead of print].

The opportunistic protist Acanthamoeba, which interacts with other microbes such as bacteria, fungi, and viruses, shows significant similarity in cellular and functional aspects to human macrophages. Intracellular survival of microbes in this microbivorous amoebal host may be a crucial step for initiation of infection in higher eukaryotic cells. Therefore, Acanthamoeba-microbe adaptations are considered an evolutionary model of macrophage-pathogen interactions. This paper reviews Acanthamoeba as an emerging human pathogen and different ecological interactions between Acanthamoeba and microbes that may serve as environmental training grounds and a genetic melting pot for the evolution, persistence, and transmission of potential human pathogens.

RevDate: 2022-09-19
CmpDate: 2022-09-19

Singh S, LN Segal (2022)

A lung pathobiont story: Thinking outside the Koch's postulate box.

Cell host & microbe, 30(9):1196-1198.

Li et al., demonstrate how Neisseria spp., thought to be a commensal, can play a pathogenic role in bronchiectasis. Here, we discuss how our thinking has evolved from the classical Koch's postulates to a complex network of microbial-host interactions and their role in disease pathogenesis.

RevDate: 2022-09-15

Diallo I, Ho J, Lambert M, et al (2022)

A tRNA-derived fragment present in E. coli OMVs regulates host cell gene expression and proliferation.

PLoS pathogens, 18(9):e1010827 pii:PPATHOGENS-D-22-00647 [Epub ahead of print].

RNA-sequencing has led to a spectacular increase in the repertoire of bacterial sRNAs and improved our understanding of their biological functions. Bacterial sRNAs have also been found in outer membrane vesicles (OMVs), raising questions about their potential involvement in bacteria-host relationship, but few studies have documented this issue. Recent RNA-Sequencing analyses of bacterial RNA unveiled the existence of abundant very small RNAs (vsRNAs) shorter than 16 nt. These especially include tRNA fragments (tRFs) that are selectively loaded in OMVs and are predicted to target host mRNAs. Here, in Escherichia coli (E. coli), we report the existence of an abundant vsRNA, Ile-tRF-5X, which is selectively modulated by environmental stress, while remaining unaffected by inhibition of transcription or translation. Ile-tRF-5X is released through OMVs and can be transferred to human HCT116 cells, where it promoted MAP3K4 expression. Our findings provide a novel perspective and paradigm on the existing symbiosis between bacteria and human cells.

RevDate: 2022-09-15

Yamazaki A, Battenberg K, Shimoda Y, et al (2022)

NDR1/HIN1-Like Protein 13 Interacts with Symbiotic Receptor Kinases and Regulates Nodulation in Lotus japonicus.

Molecular plant-microbe interactions : MPMI [Epub ahead of print].

Lysin-motif receptor-like kinases (LysM-RLKs) are involved in the recognition of microbe-associated molecular patterns to initiate pattern-triggered immunity (PTI). LysM-RLKs are also required for recognition of microbe-derived symbiotic signal molecules upon establishing mutualistic interactions between plants and microsymbionts. A LysM-RLK CHITIN ELICITOR RECEPTOR KINASE1 (CERK1) plays central roles both in chitin-mediated PTI and in arbuscular mycorrhizal symbiosis, suggesting the overlap between immunity and symbiosis, at least in the signal perception and the activation of downstream signal cascades. In this study, we screened for the interacting proteins of Nod factor Receptor1 (NFR1), a CERK1 homolog in the model legume Lotus japonicus, and obtained a protein orthologous to NONRACE-SPECIFIC DISEASE RESISTANCE1/HARPIN-INDUCED1-LIKE13 (NHL13), a protein involved in the activation of innate immunity in Arabidopsis thaliana, which we named LjNHL13a. LjNHL13a interacted with NFR1 and with the symbiosis receptor kinase SymRK. LjNHL13a also displayed positive effects in nodulation. Our results suggest that NHL13 plays a role both in plant immunity and symbiosis, possibly where they overlap. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

RevDate: 2022-09-15

Wu X, Wang Y, Ni Q, et al (2022)

GmYSL7 controls iron uptake, allocation and cellular response of nodule in soybean.

Journal of integrative plant biology [Epub ahead of print].

Iron (Fe) is essential for DNA synthesis, photosynthesis and respiration of plants. The demand for Fe substantially increases during legumes-rhizobia symbiotic nitrogen fixation because of the synthesis of leghemoglobin in host and Fe-containing proteins in bacteroids. However, the mechanism by which plant controls iron transport to nodule remains largely unknown. Here we demonstrate that GmYSL7 serves as a key regulator controlling Fe uptake from root to nodule and distribution in soybean nodule. GmYSL7 is Fe responsive and GmYSL7 transports iron across the membrane and into the infected cells of nodule. Alterations of GmYSL7 substantially affect iron distribution between root and nodule, resulting in defective growth of nodule and reduced nitrogenase activity. GmYSL7 knockout increases the expression of GmbHLH300, a transcription factor required for Fe response of nodule. Overexpression of GmbHLH300 decreases nodule number, nitrogenase activity and Fe content in nodule. Remarkably, GmbHLH300 directly binds to the promoters of ENOD93 and GmLbs, which regulate nodule number and nitrogenase activity, and represses their transcription. Our data reveal a new role of GmYSL7 in controlling Fe transport from host root to nodule and Fe distribution in nodule cells, and uncover a molecular mechanism by which Fe affects nodule number and nitrogenase activity. This article is protected by copyright. All rights reserved.

RevDate: 2022-09-18
CmpDate: 2022-09-16

Ren X, Cao S, Akami M, et al (2022)

Gut symbiotic bacteria are involved in nitrogen recycling in the tephritid fruit fly Bactrocera dorsalis.

BMC biology, 20(1):201.

BACKGROUND: Nitrogen is considered the most limiting nutrient element for herbivorous insects. To alleviate nitrogen limitation, insects have evolved various symbiotically mediated strategies that enable them to colonize nitrogen-poor habitats or exploit nitrogen-poor diets. In frugivorous tephritid larvae developing in fruit pulp under nitrogen stress, it remains largely unknown how nitrogen is obtained and larval development is completed.

RESULTS: In this study, we used metagenomics and metatranscriptomics sequencing technologies as well as in vitro verification tests to uncover the mechanism underlying the nitrogen exploitation in the larvae of Bactrocera dorsalis. Our results showed that nitrogenous waste recycling (NWR) could be successfully driven by symbiotic bacteria, including Enterobacterales, Lactobacillales, Orbales, Pseudomonadales, Flavobacteriales, and Bacteroidales. In this process, urea hydrolysis in the larval gut was mainly mediated by Morganella morganii and Klebsiella oxytoca. In addition, core bacteria mediated essential amino acid (arginine excluded) biosynthesis by ammonium assimilation and transamination.

CONCLUSIONS: Symbiotic bacteria contribute to nitrogen transformation in the larvae of B. dorsalis in fruit pulp. Our findings suggest that the pattern of NWR is more likely to be applied by B. dorsalis, and M. morganii, K. oxytoca, and other urease-positive strains play vital roles in hydrolysing nitrogenous waste and providing metabolizable nitrogen for B. dorsalis.

RevDate: 2022-09-16
CmpDate: 2022-09-16

Spring J, Khan AA, Lara S, et al (2022)

Gut commensal bacteria enhance pathogenesis of a tumorigenic murine retrovirus.

Cell reports, 40(11):111341.

The influence of the microbiota on viral transmission and replication is well appreciated. However, its impact on retroviral pathogenesis outside of transmission/replication control remains unknown. Using murine leukemia virus (MuLV), we found that some commensal bacteria promoted the development of leukemia induced by this retrovirus. The promotion of leukemia development by commensals is due to suppression of the adaptive immune response through upregulation of several negative regulators of immunity. These negative regulators include Serpinb9b and Rnf128, which are associated with a poor prognosis of some spontaneous human cancers. Upregulation of Serpinb9b is mediated by sensing of bacteria by the NOD1/NOD2/RIPK2 pathway. This work describes a mechanism by which the microbiota enhances tumorigenesis within gut-distant organs and points at potential targets for cancer therapy.

RevDate: 2022-09-14

Gasser M, Alloisio N, Fournier P, et al (2022)

A non specific Lipid Transfer Protein with potential functions in infection and nodulation.

Molecular plant-microbe interactions : MPMI [Epub ahead of print].

The response of Alnus glutinosa to Frankia alni ACN14a is driven by several sequential physiological events from calcium spiking and root hair deformation to the development of the nodule. Early stages of actinorhizal symbiosis were monitored at the transcriptional level to observe plant host responses to Frankia. Forty-two genes were significantly upregulated in inoculated compared to non-inoculated roots. Most of these genes encode proteins involved in biological processes induced during microbial infection such as oxidative stress or response to stimuli but a large part of them are not differentially modulated or downregulated later in the process of nodulation. In contrast, several of them remained upregulated in mature nodules, and this included the gene most upregulated, which encodes a non-specific lipid transfer protein (nsLTP). Classified as an antimicrobial peptide, this nsLTP, was immunolocalized on the deformed root hair surfaces that are points of contact for Frankia during infection. Later in nodules, it binds to the surface of Frankia's vesicles, which are the specialized cells for nitrogen fixation. This nsLTP, named AgLTP24, was biologically produced in a heterologous host and purified for assay on F. alni ACN14a to identify physiological effects. Thus, the activation of the plant immunity response occurs upon first contact, while the recognition of Frankia switches off part of the defense system during nodulation. AgLTP24 constitutes a part of the defense system that is maintained all along the symbiosis with potential functions such as the formation of infection threads or nodule primordia to the control of Frankia proliferation.

RevDate: 2022-09-17

Li G, Sun J, Meng Y, et al (2022)

The Impact of Environmental Habitats and Diets on the Gut Microbiota Diversity of True Bugs (Hemiptera: Heteroptera).

Biology, 11(7):.

Insects are generally associated with gut bacterial communities that benefit the hosts with respect to diet digestion, limiting resource supplementation, pathogen defense, and ecological niche expansion. Heteroptera (true bugs) represent one of the largest and most diverse insect lineages and comprise species consuming different diets and inhabiting various ecological niches, even including underwater. However, the bacterial symbiotic associations have been characterized for those basically restricted to herbivorous stink bugs of the infraorder Pentatomomorpha. The gut microbiota associated with the megadiverse heteropteran lineages and the implications of ecological and diet variance remain largely unknown. Here, we conducted a bacterial 16S rRNA amplicon sequencing of the gut microbiota across 30 species of true bugs representative of different ecological niches and diets. It was revealed that Proteobacteria and Firmicute were the predominant bacterial phyla. Environmental habitats and diets synergistically contributed to the diversity of the gut bacterial community of true bugs. True bugs living in aquatic environments harbored multiple bacterial taxa that were not present in their terrestrial counterparts. Carnivorous true bugs possessed distinct gut microbiota compared to phytophagous species. Particularly, assassin bugs of the family Reduviidae possessed a characterized gut microbiota predominantly composed of one Enterococcus with different Proteobacteria, implying a specific association between the gut bacteria and host. Overall, our findings highlight the importance of the comprehensive surveillance of gut microbiota association with true bugs for understanding the molecular mechanisms underpinning insect-bacteria symbiosis.

RevDate: 2022-09-15
CmpDate: 2022-09-15

Tanaka H, Sasaki D, Choi J, et al (2022)

Two new species of mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) from Japan.

Zootaxa, 5168(3):306-318.

Two new mealybug species (Hemiptera: Coccomorpha: Pseudococcidae), namely, Dysmicoccus kunaw Tanaka sp. nov. and Phenacoccus miruku Tanaka Choi sp. nov., collected in Japan, are described based on the morphological characteristics of the adult females. Dysmicoccus kunaw resembles D. trispinosus (Hall 1923) and D. furcillosus Williams 2004, but differs from them in having two conical cerarian setae in each anal lobe cerarius, a considerable number of dorsal multilocular pores on the abdominal segments, and two types of oral collar tubular ducts on the venter. Phenacoccus miruku is similar to P. sisymbriifolium Granara de Willink 2007 and P. similis Granara de Willink 1983, but differs by lacking quinqelocular pores anterior to the mouthparts and translucent pores on the hind tibiae, and in the shape of the circulus. A molecular phylogenetic analysis was used to investigate the phylogenetic placements of the two new species. Keys to the species of Dysmicoccus Ferris and Phenacoccus Cockerell found in Japan are provided.

RevDate: 2022-09-17
CmpDate: 2022-09-15

Duchenne F, Wüest RO, CH Graham (2022)

Seasonal structure of interactions enhances multidimensional stability of mutualistic networks.

Proceedings. Biological sciences, 289(1982):20220064.

Community ecologists have made great advances in understanding how natural communities can be both diverse and stable by studying communities as interaction networks. However, focus has been on interaction networks aggregated over time, neglecting the consequences of the seasonal organization of interactions (hereafter 'seasonal structure') for community stability. Here, we extended previous theoretical findings on the topic in two ways: (i) by integrating empirical seasonal structure of 11 plant-hummingbird communities into dynamic models, and (ii) by tackling multiple facets of network stability together. We show that, in a competition context, seasonal structure enhances community stability by allowing diverse and resilient communities while preserving their robustness to species extinctions. The positive effects of empirical seasonal structure on network stability vanished when using randomized seasonal structures, suggesting that eco-evolutionary dynamics produce stabilizing seasonal structures. We also show that the effects of seasonal structure on community stability are mainly mediated by changes in network structure and productivity, suggesting that the seasonal structure of a community is an important and yet neglected aspect in the diversity-stability and diversity-productivity debates.

RevDate: 2022-09-13

Muñoz E, J Carneiro (2022)

Plant-microbe symbiosis widens the habitability range of the Daisyworld.

Journal of theoretical biology pii:S0022-5193(22)00266-1 [Epub ahead of print].

Plant-microbe symbiosis is pervasive in the Earth's ecosystems and dates back to the early land colonisation by plants. Mutualistic partnership with rhizobia bacteria and mycorrhizal fungi promotes plant nutrition, growth and diversity, impacting important ecosystem functions. However, how the global behaviour and dynamical properties of an ecosystem are modified by plant-microbe symbiosis is still unclear. To tackle this theoretical question, we resorted to the Daisyworld as a toy model of the global ecosystem. We redesigned the original model to allow accounting for seed production, spreading, germination, and seedling development to mature seed-producing plants to describe how symbiotic and non-symbiotic daisy species differ in these key processes. Using the steady-state and bifurcation analysis of this model, we demonstrate that symbiosis with microbes broadens the habitability range of the Daisyworld by enhancing plant growth and/or facilitating plant access to otherwise uninhabitable nutrient-poor regions.

RevDate: 2022-09-13

Bove CB, Ingersoll MV, SW Davies (2022)

Help me, symbionts, you're my only hope: Approaches to accelerate our understanding of coral holobiont interactions.

Integrative and comparative biology pii:6696962 [Epub ahead of print].

Tropical corals construct the three-dimensional framework for one of the most diverse ecosystems on the planet, providing habitat to a plethora of species across taxa. However, these ecosystem engineers are facing unprecedented challenges, such as increasing disease prevalence and marine heatwaves associated with anthropogenic global change. As a result, major declines in coral cover and health are being observed across the world's oceans, often due to the breakdown of coral-associated symbioses. Here, we review the interactions between the major symbiotic partners of the coral holobiont - the cnidarian host, algae in the family Symbiodiniaceae, and the microbiome - that influence trait variation, including the molecular mechanisms that underlie symbiosis and the resulting physiological benefits of different microbial partnerships. In doing so, we highlight the current framework for the formation and maintenance of cnidarian-Symbiodiniaceae symbiosis, and the role that immunity pathways play in this relationship. We emphasize that understanding these complex interactions is challenging when you consider the vast genetic variation of the cnidarian host and algal symbiont, as well as their highly diverse microbiome, which is also an important player in coral holobiont health. Given the complex interactions between and among symbiotic partners, we propose several research directions and approaches focused on symbiosis model systems and emerging technologies that will broaden our understanding of how these partner interactions may facilitate the prediction of coral holobiont phenotype, especially under rapid environmental change.

RevDate: 2022-09-15
CmpDate: 2022-09-15

Chelpachenko OE, Danilova EI, Perunova NB, et al (2022)

Quantitative method for the determination of antibiotic-resistant gut bacterial strains for the early diagnosis of chronic arthritis.

Klinicheskaia laboratornaia diagnostika, 67(9):525-529.

Based on the clinical and microbiological monitoring of two groups of children aged 3 to 17 years with acute (n=78) and chronic (n=46) course of reactive arthritis (ReA), a method for early diagnosis of chronic arthritis was developed by determining the number of antibiotic-resistant coprostrains in patients with ReA, characterized by the absence of the need to isolate a pure culture of the pathogen and its identification; inoculation of faeces at a dilution of 10-5 on solid 1.5% GRM-agar with an antibacterial agents used in the treatment of a particular patient, at a minimum inhibitory concentration in the resistance range, followed by incubation and counting of the colonies of microorganisms grown on the plate. A significant relationship between the number of antibiotic-resistant gut bacterial strains and the course of arthritis (acute, chronic) was revealed, and the borderline value of the number of antibiotic-resistant gut bacterial strains was determined - 5×103 CFU/g, which allows differentiating the acute course from the chronic one: in the acute course< 5×103 CFU/g, with chronic - ≥ 5×103 CFU/g. The method allows, at the stage of completion of anti-inflammatory therapy in the active phase of the disease, to identify a risk group for the development of a chronic course of arthritis among patients with ReA, which can contribute to timely therapeutic measures aimed at preventing recurrence of the disease and making the patient disabled.

RevDate: 2022-09-13

Sun D, Zhang X, Liao D, et al (2022)

Novel Mycorrhiza-Specific P Transporter PvPht1;6 Contributes to As Accumulation at the Symbiotic Interface of As-Hyperaccumulator Pteris vittata.

Environmental science & technology [Epub ahead of print].

Arsenic (As) is toxic and ubiquitous in the environment, posing a growing threat to human health. As-hyperaccumulator Pteris vittata has been used for phytoremediation of As-contaminated soil. Symbiosis with arbuscular mycorrhizal fungi (AMF) enhances As accumulation by P. vittata, which is different from As inhibition in typical plants. In this study, P. vittata seedlings inoculated with or without AMF were cultivated in As-contaminated soils for 2 months. AMF-root symbiosis enhanced plant growth, with 64.5% greater As contents in the fronds. After exposure to AsV for 2 h, the arsenate (AsV) and arsenite (AsIII) contents in AMF-roots increased by 1.8- and 3.6-fold, suggesting more efficient As uptake by P. vittata with AMF-roots. Plants take up and transport AsV via phosphate transporters (Phts). Here, for the first time, we identified a novel mycorrhiza-specific Pht transporter, PvPht1;6, from P. vittata. The transcripts of PvPht1;6 were strongly induced in AMF-roots, which were localized to the plasma membrane of arbuscule-containing cells. By complementing a yeast mutant lacking 5-Phts, we confirmed PvPht1;6's transport activity for both P and AsV. In contrast to typical AMF-inducible phosphate transporter LePT4 from tomato, PvPht1;6 showed greater AsV transport capacity. The results suggest that PvPht1;6 is probably critical for AsV transport at the periarbuscular membrane of P. vittata root cells, revealing the underlying mechanism of efficient As accumulation in P. vittata with AMF-roots.

RevDate: 2022-09-13

Bhattacharjee O, Raul B, Ghosh A, et al (2022)

Nodule INception (NIN)-independent epidermal events lead to bacterial entry during nodule development in peanut (Arachis hypogaea).

The New phytologist [Epub ahead of print].

Legumes can host nitrogen-fixing rhizobia inside root nodules. In model legumes, rhizobia enter via infection threads (ITs) and develop nodules where infection-zone contains a mixture of infected and uninfected cells. Peanut (Arachis hypogaea) diversified from model legumes ~50-55 million years ago. Rhizobia enter through 'cracks' to form nodules in peanut roots where the cells of infection-zone are uniformly infected. Phylogenomic studies indicated symbiosis as a labile trait in peanut. These atypical features prompted us to investigate the molecular mechanism of peanut nodule development. Combining cell biology, genetics, and genomic tools, we visualized the status of hormonal signaling in peanut nodule primordia. Moreover, we dissected the signaling modules of Nodule INception (NIN), a master regulator of both epidermal infection and cortical organogenesis. Cytokinin signaling operates in a broad zone, from the epidermis to the pericycle inside nodule primordia, while auxin signaling is narrower and focused. NIN is involved in the nodule organogenesis, but not in the crack entry. Nodulation Pectate Lyase (NPL), which remodels cell walls during IT-formation, is not required. Whereas Nodule enhanced Glycosyl Hydrolases (AhNGHs) is recruited for cell wall modification during crack entry. While the hormonal regulation is conserved, the function of the NIN signaling modules is diversified in peanut.

RevDate: 2022-09-13

Gao C, SA Blum (2022)

Silyl Radical Cascade Cyclization of 2-Isocyanothioanisole toward 2-Silylbenzothiazoles through Radical Initiator-Inhibitor Symbiosis.

The Journal of organic chemistry [Epub ahead of print].

A demethylative silyl radical cascade cyclization of 2-isocyanothioanisoles toward 2-silylated benzothiazole building blocks has been developed. The development of a "radical initiator-inhibitor symbiosis" system solves the challenge of otherwise dominant methyl radical-triggered side reactions brought about by kinetically unfavored generation of reactive silyl radical species. The products accessed in this protocol are amendable to various downstream functionalization reactions, including the quick construction of a topoisomerase II inhibitor via a Hiyama cross-coupling reaction and of an antiviral agent via a fluoride-/hydroxide-free nucleophilic substitution to acyl chloride.

RevDate: 2022-09-13

Noh S, Capodanno BJ, Xu S, et al (2022)

Reduced and Nonreduced Genomes in Paraburkholderia Symbionts of Social Amoebas.

mSystems [Epub ahead of print].

The social amoeba Dictyostelium discoideum is a predatory soil protist frequently used for studying host-pathogen interactions. A subset of D. discoideum strains isolated from soil persistently carry symbiotic Paraburkholderia, recently formally described as P. agricolaris, P. bonniea, and P. hayleyella. The three facultative symbiont species of D. discoideum present a unique opportunity to study a naturally occurring symbiosis in a laboratory model protist. There is a large difference in genome size between P. agricolaris (8.7 million base pairs [Mbp]) versus P. hayleyella and P. bonniea (4.1 Mbp). We took a comparative genomics approach and compared the three genomes of D. discoideum symbionts to 12 additional Paraburkholderia genomes to test for genome evolution patterns that frequently accompany host adaptation. Overall, P. agricolaris is difficult to distinguish from other Paraburkholderia based on its genome size and content, but the reduced genomes of P. bonniea and P. hayleyella display characteristics indicative of genome streamlining rather than deterioration during adaptation to their protist hosts. In addition, D. discoideum-symbiont genomes have increased secretion system and motility genes that may mediate interactions with their host. Specifically, adjacent BurBor-like type 3 and T6SS-5-like type 6 secretion system operons shared among all three D. discoideum-symbiont genomes may be important for host interaction. Horizontal transfer of these secretion system operons within the amoeba host environment may have contributed to the unique ability of these symbionts to establish and maintain a symbiotic relationship with D. discoideum. IMPORTANCE Protists are a diverse group of typically single cell eukaryotes. Bacteria and archaea that form long-term symbiotic relationships with protists may evolve in additional ways than those in relationships with multicellular eukaryotes such as plants, animals, or fungi. Social amoebas are a predatory soil protist sometimes found with symbiotic bacteria living inside their cells. They present a unique opportunity to explore a naturally occurring symbiosis in a protist frequently used for studying host-pathogen interactions. We show that one amoeba-symbiont species is similar to other related bacteria in genome size and content, while the two reduced-genome-symbiont species show characteristics of genome streamlining rather than deterioration during adaptation to their host. We also identify sets of genes present in all three amoeba-symbiont genomes that are potentially used for host-symbiont interactions. Because the amoeba symbionts are distantly related, the amoeba host environment may be where these genes were shared among symbionts.

RevDate: 2022-09-14
CmpDate: 2022-09-14

Abd El-Raheem AM, Abdelazeem Elmasry AM, Elbrense H, et al (2022)

Photorhabdus and Xenorhabdus as Symbiotic Bacteria for Bio-Control Housefly (Musca domestica L.).

Pakistan journal of biological sciences : PJBS, 25(7):586-601.

Background and Objective: The housefly poses a threat to the public health of humans and domestic animals since it can carry and transmit pathogens. Despite there are many attempts to control this insect, most of them depend on conventional pesticides. Thus, the current study aimed to evaluate the efficacy of whole-cell suspension, cell-free supernatant and crude cells of the symbiotic bacteria Photorhabdus sp. and Xenorhabdus sp., as bio-control agents for housefly stages. Materials and Methods: The Photorhabdus sp. and Xenorhabdus sp., were isolated from the entomopathogenic nematodes, Heterorhabditis indica and Steinernema feltiae, respectively. The phenotypic, as well as the enzymatic characterizations of both bacteria, were determined. In addition, histopathological changes of the alimentary canal of M. domestica adults treated with whole-cell suspensions (at 3×108 cells mL1) of both bacteria were carefully examined using transmission electron microscopy. Results: The results showed that both symbiotic bacteria significantly suppressed larvae, pupae and adults of M. domestica, particularly when they were applied as whole-cell suspensions. For example, the highest concentration of whole-cell suspension, cell-free supernatant and crude cells of Photorhabdus sp., induced larval mortalities by 94.7, 64.0 and 45.3%, while those of Xenorhabdus sp., induced larval mortalities by 58.7, 46.7 and 30.7% at 96 hrs, respectively. The results also showed that whole-cell suspensions of both symbiotic bacteria caused severe histopathological changes in the ultrastructure of the treated adults' alimentary canal. Conclusion: Both symbiotic bacteria can be effectively used, particularly the whole-cell suspension, as bio-control agents against the housefly either in the larval or adult stage.

RevDate: 2022-09-14
CmpDate: 2022-09-14

He JG, Jiang WX, He ZY, et al (2022)

[Analysis of Microbial Interaction Law of Mud Membrane in IFAS Process for Treating Low Carbon Source Sewage in South China].

Huan jing ke xue= Huanjing kexue, 43(9):4736-4747.

To assess the problem of sewage treatment under the condition of low carbon sources, we carried out a study of activated sludge and a biofilm symbiosis system (IFAS). The occurrence characteristics and interaction law of microorganisms in two phases of sludge membrane under low carbon source conditions were discussed, and their niche and influence on treatment efficiency were clarified. Through a pilot-scale experiment in actual water plants, the biofilm characteristics, sludge membrane activity, and succession law of flora were analyzed, and the microbial structure and interaction in sludge membrane in two phases under the control of different activated sludge ages were compared. The results showed that the sludge concentration in the reactor increased with the increase in SRT under variable SRT. Because the microbial concentration in SRT-H was much higher than that in SRT-L, the competition between mud films in SRT-H was more intense than that in SRT-L, and the pollutant removal efficiency in SRT-H was lower than that in SRT-L. Under the condition of low-carbon feed water, the sludge activity in the IFAS process decreased with the increase in SRT. Under the condition of low SRT(5 d), the nitrification, denitrification, phosphorus accumulation, and phosphorus absorption rate of activated sludge increased by 122%, 88%, 34%, and 44%, respectively, compared with that of high SRT (25 d). However, SRT had little effect on biofilm activity, and there was little difference in nitrification activity and denitrification activity between the two SRTs. Microbial sequencing analysis showed that the functional bacteria of the IFAS process were enriched and transferred with the change in SRT between the two phases of mud membrane. In SRT-L, the functional bacteria that were enriched and transferred between the two phases of mud film owing to the "seeding" effect were mainly unclassified_g__Enterobacteriaceae, whereas in SRT-H, Acinetobacter was mainly used. At the same time, by analyzing the distribution of dominant functional bacteria, it was found that there was some competition between denitrifying bacteria and phosphorus-accumulating bacteria in activated sludge. Under the condition of a lack of organic substrate in the influent, the relative abundance of denitrifying bacteria was obviously higher than that of phosphorus-accumulating bacteria, which indicated that denitrifying bacteria could better adapt to low-carbon source conditions. Thus, they could occupy a dominant competition position, which was mainly reflected in the increase in the relative abundance of aerobic denitrifying bacteria. In addition, the SRT change in the mud phase reacted in the membrane phase, making the residence time of biofilm change correspondingly, thus changing the flora structure, screening out different dominant bacteria genera, and further increasing the difference.

RevDate: 2022-09-14
CmpDate: 2022-09-14

Zarnowski R, Sanchez H, Jaromin A, et al (2022)

A common vesicle proteome drives fungal biofilm development.

Proceedings of the National Academy of Sciences of the United States of America, 119(38):e2211424119.

Extracellular vesicles mediate community interactions among cells ranging from unicellular microbes to complex vertebrates. Extracellular vesicles of the fungal pathogen Candida albicans are vital for biofilm communities to produce matrix, which confers environmental protection and modulates community dispersion. Infections are increasingly due to diverse Candida species, such as the emerging pathogen Candida auris, as well as mixed Candida communities. Here, we define the composition and function of biofilm-associated vesicles among five species across the Candida genus. We find similarities in vesicle size and release over the biofilm lifespan. Whereas overall cargo proteomes differ dramatically among species, a group of 36 common proteins is enriched for orthologs of C. albicans biofilm mediators. To understand the function of this set of proteins, we asked whether mutants in select components were important for key biofilm processes, including drug tolerance and dispersion. We found that the majority of these cargo components impact one or both biofilm processes across all five species. Exogenous delivery of wild-type vesicle cargo returned mutant phenotypes toward wild type. To assess the impact of vesicle cargo on interspecies interactions, we performed cross-species vesicle addition and observed functional complementation for both biofilm phenotypes. We explored the biologic relevance of this cross-species biofilm interaction in mixed species and mutant studies examining the drug-resistance phenotype. We found a majority of biofilm interactions among species restored the community's wild-type behavior. Our studies indicate that vesicles influence the development of protective monomicrobial and mixed microbial biofilm communities.

RevDate: 2022-09-13

Tulsyan S, Aftab M, Sisodiya S, et al (2022)

Molecular basis of epigenetic regulation in cancer diagnosis and treatment.

Frontiers in genetics, 13:885635.

The global cancer cases and mortality rates are increasing and demand efficient biomarkers for accurate screening, detection, diagnosis, and prognosis. Recent studies have demonstrated that variations in epigenetic mechanisms like aberrant promoter methylation, altered histone modification and mutations in ATP-dependent chromatin remodelling complexes play an important role in the development of carcinogenic events. However, the influence of other epigenetic alterations in various cancers was confirmed with evolving research and the emergence of high throughput technologies. Therefore, alterations in epigenetic marks may have clinical utility as potential biomarkers for early cancer detection and diagnosis. In this review, an outline of the key epigenetic mechanism(s), and their deregulation in cancer etiology have been discussed to decipher the future prospects in cancer therapeutics including precision medicine. Also, this review attempts to highlight the gaps in epigenetic drug development with emphasis on integrative analysis of epigenetic biomarkers to establish minimally non-invasive biomarkers with clinical applications.

RevDate: 2022-09-13

Giacaman RA, Fernández CE, Muñoz-Sandoval C, et al (2022)

Understanding dental caries as a non-communicable and behavioral disease: Management implications.

Frontiers in oral health, 3:764479.

New paradigms in caries conceptualization have emerged during the last decades, leading to intense debate and discussion on how to approach the disease, both from a preventive and a therapeutic perspective. Among many new ideas, research discoveries and technologies, one major concept can be highlighted that created a deep frontier between the old and the new paradigm in caries conceptualization; the non-communicable nature of the disease, firmly associated with behaviors and lifestyles. This article synthetizes the conceptual construction of dental caries as a non-communicable disease (NCD) based on the current evidence and discusses the appropriate management of the disease in this context. Dental caries has shifted from being considered transmissible and infectious to an ecological and non-communicable disease. Environmental factors such as frequent sugars intake, disrupt the symbiosis of the dental biofilm leading to a dysbiosis, which favors caries lesion initiation and progression. As an NCD, dental caries shares characteristics with other NCDs such as cardiovascular and chronic respiratory diseases, cancer and diabetes, including long duration and slow progression, not being transmissible from person-to-person, being strongly related to modifiable behavioral risk factors, and affecting preferentially disadvantaged populations with a strong inequality gradient. Given the high prevalence of dental caries, and its consequences on people's health and quality of life, a recognizable conceptual view of caries as a NCD is required to target an effective management. Current understanding of dental caries supports prevention through acting on the modifiable risk factors (behaviors) and involves management based on an interdisciplinary approach. Communicating these modern concepts among researchers, clinicians and policymakers is needed to decrease the global high burden of the disease.

RevDate: 2022-09-13
CmpDate: 2022-09-13

Lari S, Jonnalagadda PR, Yamagani P, et al (2022)

Assessment of dermal exposure to pesticides among farmers using dosimeter and hand washing methods.

Frontiers in public health, 10:957774.

Inappropriate use of pesticides followed by unsafe handling practices to control the insect infestation among the farming groups in developing countries has resulted in a high exposure risk. The use of personal protective equipment is also negligible among Indian farmers due to their affordability to access the same. Very little research has been conducted to establish an exposure assessment procedure through dermal penetration of pesticide residues. Therefore, to quantify the contamination of pesticide residues through dermal exposure along with detailed field observations and pesticide management practices, a field study was conducted in Rangareddy district, Telangana, Southern India, to assess the dermal exposure based on dosimeter and hand washing methods. The analytical method was modified and validated in-house for performance parameters such as limit of detection, quantification, linear range, recovery, and precision. The potential dermal exposure values ranged from 0.15 to 13.45 μg, while a reduction was found in exposure levels as actual dermal exposure values ranged from 0 to 0.629 μg. Contamination through hand washing was the major contributor to overall dermal exposure. Statistical analysis revealed a significant difference in the exposed dermal regions of the leg and torso after the use of PPE. Penetration factor for each anatomical region and risk evaluation in terms of the Margin of Safety implies unsafe handling of pesticides. The findings of the present study confirm the increased exposure to organophosphate pesticides among operators and highlight the importance of the use of protective measures, especially among those that focus on dermal exposure mitigation.

RevDate: 2022-09-13

Gokak AJH, Mehendale S, SM Bhāle (2022)

Modelling and analysis for higher education shadow institutions in Indian context: an ISM approach.

Quality & quantity [Epub ahead of print].

The Indian education sector is booming with increasing number of students enrolling for various educational courses for acquiring higher education. The competition for lucrative jobs adds to the pressure on students to perform in competitive exams for higher education and other skill development courses.Query As a result, students turn to Private Coaching Classes also called Shadow Education and Private Supplementary Tutoring for additional help. Equally competitive environment exists for shadow or coaching institutes. They too face demanding customers which exerts a lot of pressure on them to achieve academic excellence. In this study, quality management perspective was applied to institutional practices along with Interpretive Structural Model methodology and MICMAC technique for developing a framework to enhance students' learning and academic performance in shadow institutes for higher education. Attempt has been made to construct a hierarchical structural model for decision making which takes into account all strategic issues and their interrelationships encountered by shadow institutions. This model or structure if implemented can also help shadow institutes to achieve sustained growth in a highly competitive and dynamic environment.

RevDate: 2022-09-13

Morales-Quintana L, Moya M, Santelices-Moya R, et al (2022)

Improvement in the physiological and biochemical performance of strawberries under drought stress through symbiosis with Antarctic fungal endophytes.

Frontiers in microbiology, 13:939955.

Strawberry is one of the most widely consumed fruit, but this crop is highly susceptible to drought, a condition strongly associated with climate change, causing economic losses due to the lower product quality. In this context, plant root-associated fungi emerge as a new and novel strategy to improve crop performance under water-deficiency stress. This study aimed to investigate the supplementation of two Antarctic vascular plant-associated fungal endophytes, Penicillium brevicompactum and Penicillium chrysogenum, in strawberry plants to develop an efficient, effective, and ecologically sustainable approach for the improvement of plant performance under drought stress. The symbiotic association of fungal endophytes with strawberry roots resulted in a greater shoot and root biomass production, higher fruit number, and an enhanced plant survival rate under water-limiting conditions. Inoculation with fungal endophytes provokes higher photosynthetic efficiency, lower lipid peroxidation, a modulation in antioxidant enzymatic activity, and increased proline content in strawberry plants under drought stress. In conclusion, promoting beneficial symbiosis between plants and endophytes can be an eco-friendly strategy to cope with drought and help to mitigate the impact of diverse negative effects of climate change on crop production.

RevDate: 2022-09-13

Russell KA, QS McFrederick (2022)

Floral nectar microbial communities exhibit seasonal shifts associated with extreme heat: Potential implications for climate change and plant-pollinator interactions.

Frontiers in microbiology, 13:931291.

Floral nectar contains vital nutrients for pollinators, including sugars, amino acids, proteins, and secondary compounds. As pollinators forage, they inoculate nectar with bacteria and fungi. These microbes can colonize nectaries and alter nectar properties, including volume and chemistry. Abiotic factors, such as temperature, can influence microbial community structure and nectar traits. Considering current climate change conditions, studying the effects of increased temperature on ecosystem processes like pollination is ever more important. In a manipulative field experiment, we used a passive-heating technique to increase the ambient temperature of a California native plant, Penstemon heterophyllus, to test the hypothesis that temperatures elevated an average of 0.5°C will affect nectar properties and nectar-inhabiting microbial communities. We found that passive-heat treatment did not affect nectar properties or microbial communities. Penstemon heterophyllus fruit set also was not affected by passive-heat treatments, and neither was capsule mass, however plants subjected to heat treatments produced significantly more seeds than control. Although we conducted pollinator surveys, no pollinators were recorded for the duration of our experiment. A naturally occurring extreme temperature event did, however, have large effects on nectar sugars and nectar-inhabiting microbial communities. The initially dominant Lactobacillus sp. was replaced by Sediminibacterium, while Mesorhizobium, and Acinetobacter persisted suggesting that extreme temperatures can interrupt nectar microbiome community assembly. Our study indicates that the quality and attractiveness of nectar under climate change conditions could have implications on plant-pollinator interactions.

RevDate: 2022-09-21

Yun HS, Sul WJ, Chung HS, et al (2022)

Secretory membrane traffic in plant-microbe interactions.

The New phytologist [Epub ahead of print].

Plant defense responses include the extracellular release of defense-related molecules, such as pathogenesis-related proteins and secondary metabolites, as well as cell wall materials. This primarily depends on the trafficking of secretory vesicles to the plasma membrane, where they discharge their contents into the apoplastic space via soluble N-ethylmaleimide sensitive factor attachment protein receptor-assisted exocytosis. However, some pathogenic and symbiotic microbes have developed strategies to manipulate host plant exocytic pathways. Here, we discuss the mechanisms by which plant exocytic pathways function in immunity and how microbes have evolved to manipulate those pathways.

RevDate: 2022-09-11

Li J, Weinberger F, de Nys R, et al (2022)

A pathway to improve seaweed aquaculture through microbiota manipulation.

Trends in biotechnology pii:S0167-7799(22)00221-9 [Epub ahead of print].

Eukaryotic hosts are associated with microbial communities that are critical to their function. Microbiota manipulation using beneficial microorganisms, for example, in the form of animal probiotics or plant growth-promoting microorganisms (PGPMs), can enhance host performance and health. Recently, seaweed beneficial microorganisms (SBMs) have been identified that promote the growth and development and/or improve disease resistance of seaweeds. This knowledge coincides with global initiatives seeking to expand and intensify seaweed aquaculture. Here, we provide a pathway with the potential to improve commercial cultivation of seaweeds through microbiota manipulation, highlighting that seaweed restoration practices can also benefit from further understanding SBMs and their modes of action. The challenges and opportunities of different approaches to identify and apply SBMs to seaweed aquaculture are discussed.

RevDate: 2022-09-21

Zhang J, Xia A, Yao D, et al (2022)

Removal of oxytetracycline and ofloxacin in wastewater by microalgae-bacteria symbiosis for bioenergy production.

Bioresource technology, 363:127891 pii:S0960-8524(22)01221-4 [Epub ahead of print].

The development of microalgae-bacteria symbiosis for treating wastewater is flourishing owing to its high biomass productivity and exceptional ability to purify contaminants. A nature-selected microalgae-bacteria symbiosis, mainly consisting of Dictyosphaerium and Pseudomonas, was used to treat oxytetracycline (OTC), ofloxacin (OFLX), and antibiotic-containing swine wastewater. Increased antibiotic concentration gradually reduced biomass productivity and intricately changed symbiosis composition, while 1 mg/L OTC accelerated the growth of symbiosis. The symbiosis biomass productivity reached 3.4-3.5 g/L (5.7-15.3 % protein, 18.4-39.3 % carbohydrate, and 2.1-3.9 % chlorophyll) when cultured in antibiotic-containing swine wastewater. The symbiosis displayed an excellent capacity to remove 76.3-83.4 % chemical oxygen demand, 53.5-62.4 % total ammonia nitrogen, 97.5-100.0 % total phosphorus, 96.3-100.0 % OTC, and 32.8-60.1 % OFLX in swine wastewater. The microbial community analysis revealed that the existence of OTC/OFLX increased the richness and evenness of microalgae but reduced bacteria species in microalgae-bacteria, and the toxicity of OFLX to bacteria was stronger than that of OTC.

RevDate: 2022-09-21

Li X, Su K, Mou Y, et al (2022)

Enhancement of nutrients removal and biomass accumulation of algal-bacterial symbiosis system by optimizing the concentration and type of carbon source in the treatment of swine digestion effluent.

Chemosphere, 308(Pt 2):136335 pii:S0045-6535(22)02828-4 [Epub ahead of print].

The algae-bacteria symbiosis system (ABS) is used to effectively solve the problems of low carbon/nitrogen (C/N) ratio, low biodegradability and high ammonia toxicity in swine digestion effluent. This study examined the effects of the concentration and type of carbon source on ABS in the pollutants removal especially ammonia. When C/N ratio was 30:1 and carbon source was sodium acetate, the ABS was most conducive to the removal of nitrogen, phosphorus and COD, and to the accumulation of biomass and lipids. To make the wastewater discharge meet the relevant standard, the ABS + mono-cultivation of algae reprocessing system (MAS), was applied to actual swine digestion effluent. Through adjusting the C/N ratio in ABS to 30:1, the biomass concentration was 2.06 times higher than that of raw wastewater, and the removal efficiencies of NH4+-N, TN, TP and COD increased by 1.43, 1.46, 1.95 and 1.28 times, respectively. The final concentrations of NH4+-N, TN, TP and COD after the treatment of ABS (C/N ratio of 30:1) + MAS, were 16.98 ± 1.07 mg L-1, 18.72 ± 1.81 mg L-1, 0.48 ± 0.01 mg L-1 and 263.49 ± 11.89 mg L-1, respectively, reached the Chinese discharge standards for livestock and poultry wastewater. Bacterial community analysis showed that the dominant species of the ABS (C/N ratio of 30:1) was Corynebacterium (genus level). This study revealed that adjusting the concentration and type of carbon source was helpful to the nutrient cycling and resource utilization of ABS, indicating a feasible technique for treating high ammonia nitrogen digestate.


RJR Experience and Expertise


Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.


Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.


Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.


Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.


While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.


Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.


Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.


Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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In this comprehensive history of symbiosis theory--the first to be written--Jan Sapp masterfully traces its development from modest beginnings in the late nineteenth century to its current status as one of the key conceptual frameworks for the life sciences. The symbiotic perspective on evolution, which argues that "higher species" have evolved from a merger of two or more different kinds of organisms living together, is now clearly established with definitive molecular evidence demonstrating that mitochondria and chloroplasts have evolved from symbiotic bacteria. In telling the exciting story of an evolutionary biology tradition that has effectively challenged many key tenets of classical neo-Darwinism, Sapp sheds light on the phenomena, movements, doctrines, and controversies that have shaped attitudes about the scope and significance of symbiosis. Engaging and insightful, Evolution by Association will be avidly read by students and researchers across the life sciences.

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Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

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Curriculum Vitae for R J Robbins

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