scholarly journals Horizontal acquisition followed by expansion and diversification of toxin-related genes in deep-sea bivalve symbionts

2019 ◽  
Author(s):  
Lizbeth Sayavedra ◽  
Rebecca Ansorge ◽  
Maxim Rubin-Blum ◽  
Nikolaus Leisch ◽  
Nicole Dubilier ◽  
...  
Keyword(s):  
Deep Sea ◽  
Molecular Mechanisms ◽  
Secretion Systems ◽  
Heterogeneous Distribution ◽  
Adaptive Selection ◽  
Evolutionary Origins ◽  
Microbe Interactions ◽  
Sulfur Oxidizing ◽  
Animal Hosts ◽  
Host Microbe Interactions

AbstractDeep-sea bathymodioline mussels gain their nutrition from intracellular bacterial symbionts. Their sulfur-oxidizing (SOX) symbionts were recently shown to encode abundant toxin-related genes (TRGs) in their genomes, which may play a role in beneficial host-microbe interactions. Here, we compared TRGs in the genomes of SOX symbionts from 10 bathymodioline mussel and two sponge species to better understand their potential functions and evolutionary origins. Despite the close phylogenetic relatedness of these symbionts, the number and classes of encoded toxins varied greatly between host species. One of the TRG classes, YDs, has experienced gene expansions multiple times, suggesting that these genes are under adaptive selection. Some symbiont genomes contained secretion systems, which can play a role in host-microbe interactions. Both TRGs and secretion systems had a heterogeneous distribution, suggesting that these closely related bacteria have acquired different molecular mechanisms for interacting with the same family of animal hosts, possibly through convergent evolution.

scholarly journals A New C-Type Lectin Similar to the Human Immunoreceptor DC-SIGN Mediates Symbiont Acquisition by a Marine Nematode

2006 ◽  
Vol 72 (4) ◽  
pp. 2950-2956 ◽  
Author(s):  
Silvia Bulgheresi ◽  
Irma Schabussova ◽  
Tie Chen ◽  
Nicholas P. Mullin ◽  
Rick M. Maizels ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Marine Nematode ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Marine Symbiosis ◽  
Microbe Interactions ◽  
Sulfur Oxidizing ◽  
Host Microbe Interactions ◽  
Symbiont Acquisition

ABSTRACT Although thiotrophic symbioses have been intensively studied for the last three decades, nothing is known about the molecular mechanisms of symbiont acquisition. We used the symbiosis between the marine nematode Laxus oneistus and sulfur-oxidizing bacteria to study this process. In this association a monolayer of symbionts covers the whole cuticle of the nematode, except its anterior-most region. Here, we identify a novel Ca2+-dependent mannose-specific lectin that was exclusively secreted onto the posterior, bacterium-associated region of L. oneistus cuticle. A recombinant form of this lectin induced symbiont aggregation in seawater and was able to compete with the native lectin for symbiont binding in vivo. Surprisingly, the carbohydrate recognition domain of this mannose-binding protein was similar both structurally and functionally to a human dendritic cell-specific immunoreceptor. Our results provide a molecular link between bacterial symbionts and host-secreted mucus in a marine symbiosis and suggest conservation in the mechanisms of host-microbe interactions throughout the animal kingdom.

scholarly journals A Microbial Perspective on the Grand Challenges in Comparative Animal Physiology

mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Kevin D. Kohl
Keyword(s):  
Microbial Communities ◽  
Vertical Integration ◽  
Temporal Integration ◽  
Data Sets ◽  
Grand Challenges ◽  
Animal Physiology ◽  
Physiological Processes ◽  
Microbe Interactions ◽  
Animal Hosts ◽  
Host Microbe Interactions

ABSTRACTInteractions with microbial communities can have profound influences on animal physiology, thereby impacting animal performance and fitness. Therefore, it is important to understand the diversity and nature of host-microbe interactions in various animal groups (invertebrates, fish, amphibians, reptiles, birds, and mammals). In this perspective, I discuss how the field of host-microbe interactions can be used to address topics that have been identified as grand challenges in comparative animal physiology: (i) horizontal integration of physiological processes across organisms, (ii) vertical integration of physiological processes across organizational levels within organisms, and (iii) temporal integration of physiological processes during evolutionary change. Addressing these challenges will require the use of a variety of animal models and the development of systems approaches that can integrate large, multiomic data sets from both microbial communities and animal hosts. Integrating host-microbe interactions into the established field of comparative physiology represents an exciting frontier for both fields.

scholarly journals Multiple evolutionary origins reflect the importance of sialic acid transporters in the colonisation potential of bacterial pathogens and commensals

2021 ◽  
Author(s):  
Emmanuele Severi ◽  
Michelle Rudden ◽  
Andrew Bell ◽  
Tracy Palmer ◽  
Nathalie Juge ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Sialic Acid ◽  
Classification Scheme ◽  
Sialic Acids ◽  
Evolutionary Selection ◽  
Evolutionary Origins ◽  
Mucosal Surfaces ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Cell Surface Glycoconjugates

AbstractLocated at the tip of cell surface glycoconjugates, sialic acids are at the forefront of host-microbe interactions and, being easily liberated by sialidase enzymes, are used as metabolites by numerous bacteria, particularly by pathogens and commensals living on or near diverse mucosal surfaces. These bacteria rely on specific transporters for the acquisition of host-derived sialic acids. Here, we present the first comprehensive genomic and phylogenetic analysis of bacterial sialic acid transporters, leading to the identification of multiple new families and subfamilies. Our phylogenetic analysis suggests that sialic acid-specific transport has evolved independently at least 8 times during the evolution of bacteria, from within 4 of the major families/superfamilies of bacterial transporters, and we propose a robust classification scheme to bring together a myriad of different nomenclatures that exist to date. The new transporters discovered occur in diverse bacteria including Spirochaetes, Bacteroidetes, Planctomycetes, and Verrucomicrobia, many of which are species that have not been previously recognised to have sialometabolic capacities. Two subfamilies of transporters stand out in being fused to the sialic acid mutarotase enzyme, NanM, and these transporter fusions are enriched in bacteria present in gut microbial communities. We also provide evidence for a possible function of a sialic acid transporter component in chemotaxis that is independent of transport. Our analysis supports the increasing experimental evidence that competition for host-derived sialic acid is a key phenotype for successful colonisation of complex mucosal microbiomes, such that a strong evolutionary selection has occurred for the emergence of sialic acid specificity within existing transporter architectures.

scholarly journals Host-Microbe Interactions in the Chemosynthetic Riftia pachyptila Symbiosis

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Tjorven Hinzke ◽  
Manuel Kleiner ◽  
Corinna Breusing ◽  
Horst Felbeck ◽  
Robert Häsler ◽  
...  
Keyword(s):  
Deep Sea ◽  
Population Control ◽  
Sequence Information ◽  
Riftia Pachyptila ◽  
Content Type ◽  
Intracellular Symbiont ◽  
Energy Limitation ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Substrate Transfer

ABSTRACT The deep-sea tubeworm Riftia pachyptila lacks a digestive system but completely relies on bacterial endosymbionts for nutrition. Although the symbiont has been studied in detail on the molecular level, such analyses were unavailable for the animal host, because sequence information was lacking. To identify host-symbiont interaction mechanisms, we therefore sequenced the Riftia transcriptome, which served as a basis for comparative metaproteomic analyses of symbiont-containing versus symbiont-free tissues, both under energy-rich and energy-limited conditions. Our results suggest that metabolic interactions include nutrient allocation from symbiont to host by symbiont digestion and substrate transfer to the symbiont by abundant host proteins. We furthermore propose that Riftia maintains its symbiont by protecting the bacteria from oxidative damage while also exerting symbiont population control. Eukaryote-like symbiont proteins might facilitate intracellular symbiont persistence. Energy limitation apparently leads to reduced symbiont biomass and increased symbiont digestion. Our study provides unprecedented insights into host-microbe interactions that shape this highly efficient symbiosis. IMPORTANCE All animals are associated with microorganisms; hence, host-microbe interactions are of fundamental importance for life on earth. However, we know little about the molecular basis of these interactions. Therefore, we studied the deep-sea Riftia pachyptila symbiosis, a model association in which the tubeworm host is associated with only one phylotype of endosymbiotic bacteria and completely depends on this sulfur-oxidizing symbiont for nutrition. Using a metaproteomics approach, we identified both metabolic interaction processes, such as substrate transfer between the two partners, and interactions that serve to maintain the symbiotic balance, e.g., host efforts to control the symbiont population or symbiont strategies to modulate these host efforts. We suggest that these interactions are essential principles of mutualistic animal-microbe associations.

scholarly journals Social interaction-induced activation of RNA splicing in the amygdala of microbiome-deficient mice

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Roman M Stilling ◽  
Gerard M Moloney ◽  
Feargal J Ryan ◽  
Alan E Hoban ◽  
Thomaz FS Bastiaanssen ◽  
...  
Keyword(s):  
Social Interaction ◽  
Social Behaviour ◽  
Rna Splicing ◽  
Molecular Mechanisms ◽  
Autism Spectrum ◽  
Gene Expression Response ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Expression Response ◽  
Multiple Species

Social behaviour is regulated by activity of host-associated microbiota across multiple species. However, the molecular mechanisms mediating this relationship remain elusive. We therefore determined the dynamic, stimulus-dependent transcriptional regulation of germ-free (GF) and GF mice colonised post weaning (exGF) in the amygdala, a brain region critically involved in regulating social interaction. In GF mice the dynamic response seen in controls was attenuated and replaced by a marked increase in expression of splicing factors and alternative exon usage in GF mice upon stimulation, which was even more pronounced in exGF mice. In conclusion, we demonstrate a molecular basis for how the host microbiome is crucial for a normal behavioural response during social interaction. Our data further suggest that social behaviour is correlated with the gene-expression response in the amygdala, established during neurodevelopment as a result of host-microbe interactions. Our findings may help toward understanding neurodevelopmental events leading to social behaviour dysregulation, such as those found in autism spectrum disorders (ASDs).

scholarly journals Multiple evolutionary origins reflect the importance of sialic acid transporters in the colonization potential of bacterial pathogens and commensals

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Emmanuele Severi ◽  
Michelle Rudden ◽  
Andrew Bell ◽  
Tracy Palmer ◽  
Nathalie Juge ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Sialic Acid ◽  
Sialic Acids ◽  
Content Type ◽  
Link Type ◽  
Evolutionary Origins ◽  
Mucosal Surfaces ◽  
Colonization Potential ◽  
Microbe Interactions ◽  
Host Microbe Interactions

Located at the tip of cell surface glycoconjugates, sialic acids are at the forefront of host–microbe interactions and, being easily liberated by sialidase enzymes, are used as metabolites by numerous bacteria, particularly by pathogens and commensals living on or near diverse mucosal surfaces. These bacteria rely on specific transporters for the acquisition of host-derived sialic acids. Here, we present the first comprehensive genomic and phylogenetic analysis of bacterial sialic acid transporters, leading to the identification of multiple new families and subfamilies. Our phylogenetic analysis suggests that sialic acid-specific transport has evolved independently at least eight times during the evolution of bacteria, from within four of the major families/superfamilies of bacterial transporters, and we propose a robust classification scheme to bring together a myriad of different nomenclatures that exist to date. The new transporters discovered occur in diverse bacteria, including Spirochaetes , Bacteroidetes , Planctomycetes and Verrucomicrobia , many of which are species that have not been previously recognized to have sialometabolic capacities. Two subfamilies of transporters stand out in being fused to the sialic acid mutarotase enzyme, NanM, and these transporter fusions are enriched in bacteria present in gut microbial communities. Our analysis supports the increasing experimental evidence that competition for host-derived sialic acid is a key phenotype for successful colonization of complex mucosal microbiomes, such that a strong evolutionary selection has occurred for the emergence of sialic acid specificity within existing transporter architectures.

scholarly journals Spatial Analyses of Specialized Metabolites: The Key to Studying Function in Hosts

mSystems ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Melissa M. Galey ◽  
Laura M. Sanchez
Keyword(s):  
Analytical Chemistry ◽  
Molecular Mechanisms ◽  
Imaging Mass Spectrometry ◽  
Analytical Techniques ◽  
Spatial Analyses ◽  
Biological Functions ◽  
Specialized Metabolites ◽  
Microbe Interactions ◽  
Host Microbe Interactions

ABSTRACT Microbial communities contribute to a wide variety of biological functions in hosts and have the ability to specifically influence the health of those organisms through production of specialized metabolites. However, the structures or molecular mechanisms related to health or disease in host-microbe interactions represent a knowledge gap. In order to close this gap, we propose that a combinatory approach, pulling from microbiology and analytical chemistry, be considered to investigate these interactions so as to gain a better understanding of the chemistry being produced. We hypothesize that bacteria alter their chemistry in order to survive and induce specific states in their host organisms. Our lab makes use of imaging mass spectrometry and other analytical techniques to study this chemistry in situ , which provides actionable information to test hypotheses.

Bacterial receptors for host transferrin and lactoferrin: molecular mechanisms and role in host–microbe interactions

2013 ◽  
Vol 8 (12) ◽  
pp. 1575-1585 ◽  
Author(s):  
Ari Morgenthau ◽  
Anastassia Pogoutse ◽  
Paul Adamiak ◽  
Trevor F Moraes ◽  
Anthony B Schryvers
Keyword(s):  
Molecular Mechanisms ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Bacterial Receptors

scholarly journals Interplays between human microbiota and microRNAs in COVID-19 pathogenesis: a literature review

2021 ◽  
Vol 25 (2) ◽  
pp. 1-7
Author(s):  
Bok Sil Hong ◽  
Myoung-Ryu Kim
Keyword(s):  
Molecular Mechanisms ◽  
Host Immune System ◽  
Host Gene Expression ◽  
Human Microbiota ◽  
Inflammatory Status ◽  
Bidirectional Association ◽  
Comprehensive Picture ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Gut Microbiota Composition

[Purpose] Recent studies have shown that COVID-19 is often associated with altered gut microbiota composition and reflects disease severity. Furthermore, various reports suggest that the interaction between COVID-19 and host-microbiota homeostasis is mediated through the modulation of microRNAs (miRNAs). Thus, in this review, we aim to summarize the association between human microbiota and miRNAs in COVID-19 pathogenesis.[Methods] We searched for the existing literature using the keywords such “COVID-19 or microbiota,” “microbiota or microRNA,” and “COVID-19 or probiotics” in PubMed until March 31, 2021. Subsequently, we thoroughly reviewed the articles related to microbiota and miRNAs in COVID-19 to generate a comprehensive picture depicting the association between human microbiota and microRNAs in the pathogenesis of COVID-19.[Results] There exists strong experimental evidence suggesting that the composition and diversity of human microbiota are altered in COVID-19 patients, implicating a bidirectional association between the respiratory and gastrointestinal tracts. In addition, SARS-CoV-2 encoded miRNAs and host cellular microRNAs modulated by human microbiota can interfere with viral replication and regulate host gene expression involved in the initiation and progression of COVID-19. These findings suggest that the manipulation of human microbiota with probiotics may play a significant role against SARS-CoV-2 infection by enhancing the host immune system and lowering the inflammatory status.[Conclusion] The human microbiota-miRNA axis can be used as a therapeutic approach for COVID-19. Hence, further studies are needed to investigate the exact molecular mechanisms underlying the regulation of miRNA expression in human microbiota and how these miRNA profiles mediate viral infection through host-microbe interactions.

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