551
|
Kreisinger J, Kropáčková L, Petrželková A, Adámková M, Tomášek O, Martin JF, Michálková R, Albrecht T. Temporal Stability and the Effect of Transgenerational Transfer on Fecal Microbiota Structure in a Long Distance Migratory Bird. Front Microbiol 2017; 8:50. [PMID: 28220109 PMCID: PMC5292904 DOI: 10.3389/fmicb.2017.00050] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 01/06/2017] [Indexed: 12/20/2022] Open
Abstract
Animal bodies are inhabited by a taxonomically and functionally diverse community of symbiotic and commensal microorganisms. From an ecological and evolutionary perspective, inter-individual variation in host-associated microbiota contributes to physiological and immune system variation. As such, host-associated microbiota may be considered an integral part of the host’s phenotype, serving as a substrate for natural selection. This assumes that host-associated microbiota exhibits high temporal stability, however, and that its composition is shaped by trans-generational transfer or heritable host-associated microbiota modulators encoded by the host genome. Although this concept is widely accepted, its crucial assumptions have rarely been tested in wild vertebrate populations. We performed 16S rRNA metabarcoding on an extensive set of fecal microbiota (FM) samples from an insectivorous, long-distance migratory bird, the barn swallow (Hirundo rustica). Our data revealed clear differences in FM among juveniles and adults as regards taxonomic and functional composition, diversity and co-occurrence network complexity. Multiple FM samples from the same juvenile or adult collected within single breeding seasons exhibited higher similarity than expected by chance, as did adult FM samples over two consecutive years. Despite low effect sizes for FM stability over time at the community level, we identified an adult FM subset with relative abundances exhibiting significant temporal consistency, possibly inducing long-term effects on the host phenotype. Our data also indicate a slight maternal (but not paternal) effect on FM composition in social offspring, though this is unlikely to persist into adulthood. We discuss our findings in the context of both evolution and ecology of microbiota vs. host interactions and barn swallow biology.
Collapse
Affiliation(s)
- Jakub Kreisinger
- Department of Zoology, Faculty of Science, Charles University Prague, Czechia
| | - Lucie Kropáčková
- Department of Zoology, Faculty of Science, Charles University Prague, Czechia
| | - Adéla Petrželková
- Department of Ecology, Faculty of Science, Charles University Prague, Czechia
| | - Marie Adámková
- Institute of Vertebrate Biology, Czech Academy of Sciences, Studenec Czechia
| | - Oldřich Tomášek
- Department of Zoology, Faculty of Science, Charles UniversityPrague, Czechia; Institute of Vertebrate Biology, Czech Academy of Sciences, StudenecCzechia
| | - Jean-François Martin
- Montpellier-SupAgro, UMR Centre de Biologie pour la Gestion des Populations Montferrier-sur-Lez, France
| | - Romana Michálková
- Department of Zoology, Faculty of Science, Charles University Prague, Czechia
| | - Tomáš Albrecht
- Department of Zoology, Faculty of Science, Charles UniversityPrague, Czechia; Institute of Vertebrate Biology, Czech Academy of Sciences, StudenecCzechia
| |
Collapse
|
552
|
Newton ILG. Getting at the "what" and the "how" in symbiosis. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:11-13. [PMID: 27718334 DOI: 10.1111/1758-2229.12486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Symbioses are ubiquitous and have had a tremendous impact on the evolution of life on the planet. Indeed, endosymbiosis lead to the generation of the first eukaryotic cell and from that point onwards, eukaryotes have interacted with the other domains of life, sometimes forming persistent and necessary relationships that span generations. However, because the majority of hosts and symbionts are not easily manipulated, the intricate details of these symbioses, an understanding of the molecular underpinnings of these interactions, have not been elucidated. It is difficult to ask questions about the details of a host-microbe symbiosis if either member cannot be cultured, genetically manipulated, or even housed in a laboratory. Several technological advances in recent years may address these difficulties, making it easier for researchers to ask mechanistic questions in symbiotic systems.
Collapse
Affiliation(s)
- Irene L G Newton
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| |
Collapse
|
553
|
Macke E, Tasiemski A, Massol F, Callens M, Decaestecker E. Life history and eco-evolutionary dynamics in light of the gut microbiota. OIKOS 2017. [DOI: 10.1111/oik.03900] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Emilie Macke
- Laboratory Aquatic Biology, KU Leuven (Kulak), Dept of Biology; E. Sabbelaan 53, BE-8500 Kortrijk Belgium
| | | | - François Massol
- Univ. Lille; CNRS UMR 8198 Evo-Eco-Paleo SPICI group Lille France
| | - Martijn Callens
- Laboratory Aquatic Biology, KU Leuven (Kulak), Dept of Biology; E. Sabbelaan 53, BE-8500 Kortrijk Belgium
| | - Ellen Decaestecker
- Laboratory Aquatic Biology, KU Leuven (Kulak), Dept of Biology; E. Sabbelaan 53, BE-8500 Kortrijk Belgium
| |
Collapse
|
554
|
Dinan TG, Cryan JF. Gut instincts: microbiota as a key regulator of brain development, ageing and neurodegeneration. J Physiol 2017; 595:489-503. [PMID: 27641441 PMCID: PMC5233671 DOI: 10.1113/jp273106] [Citation(s) in RCA: 449] [Impact Index Per Article: 64.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/13/2016] [Indexed: 12/16/2022] Open
Abstract
There is a growing realisation that the gut-brain axis and its regulation by the microbiota may play a key role in the biological and physiological basis of neurodevelopmental, age-related and neurodegenerative disorders. The routes of communication between the microbiota and brain are being unravelled and include the vagus nerve, gut hormone signalling, the immune system, tryptophan metabolism or by way of microbial metabolites such as short chain fatty acids. The importance of early life gut microbiota in shaping future health outcomes is also emerging. Disturbances of this composition by way of antibiotic exposure, lack of breastfeeding, infection, stress and the environmental influences coupled with the influence of host genetics can result in long-term effects on physiology and behaviour, at least in animal models. It is also worth noting that mode of delivery at birth influences microbiota composition with those born by Caesarean section having a distinctly different microbiota in early life to those born per vaginum. At the other extreme of life, ageing is associated with a narrowing in microbial diversity and healthy ageing correlates with a diverse microbiome. Recently, the gut microbiota has been implicated in a variety of conditions including depression, autism, schizophrenia and Parkinson's disease. There is still considerable debate as to whether or not the gut microbiota changes are core to the pathophysiology of such conditions or are merely epiphenomenal. It is plausible that such neuropsychiatric disorders might be treated in the future by targeting the microbiota either by microbiota transplantation, antibiotics or psychobiotics.
Collapse
Affiliation(s)
- Timothy G. Dinan
- APC Microbiome InstituteUniversity College CorkIreland
- Department of Psychiatry and Neurobehavioural ScienceUniversity College CorkIreland
| | - John F. Cryan
- APC Microbiome InstituteUniversity College CorkIreland
- Department of Anatomy and NeuroscienceUniversity College CorkIreland
| |
Collapse
|
555
|
|
556
|
The hologenome concept: we need to incorporate function. Theory Biosci 2016; 136:89-98. [DOI: 10.1007/s12064-016-0240-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 11/29/2016] [Indexed: 02/07/2023]
|
557
|
Beckmann JS, Lew D. Reconciling evidence-based medicine and precision medicine in the era of big data: challenges and opportunities. Genome Med 2016; 8:134. [PMID: 27993174 PMCID: PMC5165712 DOI: 10.1186/s13073-016-0388-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This era of groundbreaking scientific developments in high-resolution, high-throughput technologies is allowing the cost-effective collection and analysis of huge, disparate datasets on individual health. Proper data mining and translation of the vast datasets into clinically actionable knowledge will require the application of clinical bioinformatics. These developments have triggered multiple national initiatives in precision medicine—a data-driven approach centering on the individual. However, clinical implementation of precision medicine poses numerous challenges. Foremost, precision medicine needs to be contrasted with the powerful and widely used practice of evidence-based medicine, which is informed by meta-analyses or group-centered studies from which mean recommendations are derived. This “one size fits all” approach can provide inadequate solutions for outliers. Such outliers, which are far from an oddity as all of us fall into this category for some traits, can be better managed using precision medicine. Here, we argue that it is necessary and possible to bridge between precision medicine and evidence-based medicine. This will require worldwide and responsible data sharing, as well as regularly updated training programs. We also discuss the challenges and opportunities for achieving clinical utility in precision medicine. We project that, through collection, analyses and sharing of standardized medically relevant data globally, evidence-based precision medicine will shift progressively from therapy to prevention, thus leading eventually to improved, clinician-to-patient communication, citizen-centered healthcare and sustained well-being.
Collapse
Affiliation(s)
- Jacques S Beckmann
- Clinical Bioinformatics, SIB Swiss Institute of Bioinformatics, CH-1015, Lausanne, Switzerland.
| | - Daniel Lew
- Clinical Bioinformatics, SIB Swiss Institute of Bioinformatics, CH-1015, Lausanne, Switzerland
| |
Collapse
|
558
|
Quistad SD, Grasis JA, Barr JJ, Rohwer FL. Viruses and the origin of microbiome selection and immunity. ISME JOURNAL 2016; 11:835-840. [PMID: 27983723 DOI: 10.1038/ismej.2016.182] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/15/2016] [Accepted: 11/10/2016] [Indexed: 02/07/2023]
Abstract
The last common metazoan ancestor (LCMA) emerged over half a billion years ago. These complex metazoans provided newly available niche space for viruses and microbes. Modern day contemporaries, such as cnidarians, suggest that the LCMA consisted of two cell layers: a basal endoderm and a mucus-secreting ectoderm, which formed a surface mucus layer (SML). Here we propose a model for the origin of metazoan immunity based on external and internal microbial selection mechanisms. In this model, the SML concentrated bacteria and their associated viruses (phage) through physical dynamics (that is, the slower flow fields near a diffusive boundary layer), which selected for mucin-binding capabilities. The concentration of phage within the SML provided the LCMA with an external microbial selective described by the bacteriophage adherence to mucus (BAM) model. In the BAM model, phage adhere to mucus protecting the metazoan host against invading, potentially pathogenic bacteria. The same fluid dynamics that concentrated phage and bacteria in the SML also concentrated eukaryotic viruses. As eukaryotic viruses competed for host intracellular niche space, those viruses that provided the LCMA with immune protection were maintained. If a resident virus became pathogenic or if a non-beneficial infection occurred, we propose that tumor necrosis factor (TNF)-mediated programmed cell death, as well as other apoptosis mechanisms, were utilized to remove virally infected cells. The ubiquity of the mucosal environment across metazoan phyla suggest that both BAM and TNF-induced apoptosis emerged during the Precambrian era and continue to drive the evolution of metazoan immunity.
Collapse
Affiliation(s)
- Steven D Quistad
- Department of Biology, San Diego State University, San Diego, CA, USA.,Laboratoire de Colloïdes et Matériaux Divisés (LCMD), Institute of Chemistry, Biology, and Innovation, ESPCI ParisTech/CNRS UMR 8231/PSL Research University, Paris, France.,Laboratoire de Colloïdes et Matériaux Divisés (LCMD), Institute of Chemistry, Biology, and Innovation, ESPCI ParisTech/CNRS UMR 8231/PSL Research University, Paris, France
| | - Juris A Grasis
- Department of Biology, San Diego State University, San Diego, CA, USA
| | - Jeremy J Barr
- Department of Biology, San Diego State University, San Diego, CA, USA.,School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Forest L Rohwer
- Department of Biology, San Diego State University, San Diego, CA, USA
| |
Collapse
|
559
|
Gopal M, Gupta A. Microbiome Selection Could Spur Next-Generation Plant Breeding Strategies. Front Microbiol 2016; 7:1971. [PMID: 28003808 PMCID: PMC5141590 DOI: 10.3389/fmicb.2016.01971] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 11/24/2016] [Indexed: 12/16/2022] Open
Abstract
“No plant is an island too…” Plants, though sessile, have developed a unique strategy to counter biotic and abiotic stresses by symbiotically co-evolving with microorganisms and tapping into their genome for this purpose. Soil is the bank of microbial diversity from which a plant selectively sources its microbiome to suit its needs. Besides soil, seeds, which carry the genetic blueprint of plants during trans-generational propagation, are home to diverse microbiota that acts as the principal source of microbial inoculum in crop cultivation. Overall, a plant is ensconced both on the outside and inside with a diverse assemblage of microbiota. Together, the plant genome and the genes of the microbiota that the plant harbors in different plant tissues, i.e., the ‘plant microbiome,’ form the holobiome which is now considered as unit of selection: ‘the holobiont.’ The ‘plant microbiome’ not only helps plants to remain fit but also offers critical genetic variability, hitherto, not employed in the breeding strategy by plant breeders, who traditionally have exploited the genetic variability of the host for developing high yielding or disease tolerant or drought resistant varieties. This fresh knowledge of the microbiome, particularly of the rhizosphere, offering genetic variability to plants, opens up new horizons for breeding that could usher in cultivation of next-generation crops depending less on inorganic inputs, resistant to insect pest and diseases and resilient to climatic perturbations. We surmise, from ever increasing evidences, that plants and their microbial symbionts need to be co-propagated as life-long partners in future strategies for plant breeding. In this perspective, we propose bottom–up approach to co-propagate the co-evolved, the plant along with the target microbiome, through – (i) reciprocal soil transplantation method, or (ii) artificial ecosystem selection method of synthetic microbiome inocula, or (iii) by exploration of microRNA transfer method – for realizing this next-generation plant breeding approach. Our aim, thus, is to bring closer the information accrued through the advanced nucleotide sequencing and bioinformatics in conjunction with conventional culture-dependent isolation method for practical application in plant breeding and overall agriculture.
Collapse
Affiliation(s)
- Murali Gopal
- Microbiology Section, ICAR-Central Plantation Crops Research Institute Kasaragod, India
| | - Alka Gupta
- Microbiology Section, ICAR-Central Plantation Crops Research Institute Kasaragod, India
| |
Collapse
|
560
|
Brooks AW, Kohl KD, Brucker RM, van Opstal EJ, Bordenstein SR. Phylosymbiosis: Relationships and Functional Effects of Microbial Communities across Host Evolutionary History. PLoS Biol 2016; 14:e2000225. [PMID: 27861590 PMCID: PMC5115861 DOI: 10.1371/journal.pbio.2000225] [Citation(s) in RCA: 313] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 10/20/2016] [Indexed: 02/07/2023] Open
Abstract
Phylosymbiosis was recently proposed to describe the eco-evolutionary pattern, whereby the ecological relatedness of host-associated microbial communities parallels the phylogeny of related host species. Here, we test the prevalence of phylosymbiosis and its functional significance under highly controlled conditions by characterizing the microbiota of 24 animal species from four different groups (Peromyscus deer mice, Drosophila flies, mosquitoes, and Nasonia wasps), and we reevaluate the phylosymbiotic relationships of seven species of wild hominids. We demonstrate three key findings. First, intraspecific microbiota variation is consistently less than interspecific microbiota variation, and microbiota-based models predict host species origin with high accuracy across the dataset. Interestingly, the age of host clade divergence positively associates with the degree of microbial community distinguishability between species within the host clades, spanning recent host speciation events (~1 million y ago) to more distantly related host genera (~108 million y ago). Second, topological congruence analyses of each group's complete phylogeny and microbiota dendrogram reveal significant degrees of phylosymbiosis, irrespective of host clade age or taxonomy. Third, consistent with selection on host–microbiota interactions driving phylosymbiosis, there are survival and performance reductions when interspecific microbiota transplants are conducted between closely related and divergent host species pairs. Overall, these findings indicate that the composition and functional effects of an animal's microbial community can be closely allied with host evolution, even across wide-ranging timescales and diverse animal systems reared under controlled conditions. Studies on the assembly and function of host-microbiota symbioses are inherently complicated by the diverse effects of diet, age, sex, host genetics, and endosymbionts. Central to unraveling one effect from the other is an experimental framework that reduces confounders. Using common rearing conditions across four animal groups (deer mice, flies, mosquitoes, and wasps) that span recent host speciation events to more distantly related host genera, this study tests whether microbial community assembly is generally random with respect to host relatedness or "phylosymbiotic," in which the phylogeny of the host group is congruent with ecological relationships of their microbial communities. Across all four animal groups and one external dataset of great apes, we apply several statistics for analyzing congruencies and demonstrate phylosymbiosis to varying degrees in each group. Moreover, consistent with selection on host–microbiota interactions driving phylosymbiosis, transplanting interspecific microbial communities in mice significantly decreased their ability to digest food. Similarly, wasps that received transplants of microbial communities from different wasp species had lower survival than those given their own microbiota. Overall, this experimental and statistical framework shows how microbial community assembly and functionality across related species can be linked to animal evolution, health, and survival.
Collapse
Affiliation(s)
- Andrew W. Brooks
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Genetics Institute, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Kevin D. Kohl
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Robert M. Brucker
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- The Rowland Institute at Harvard, Harvard University, Cambridge, Massachusetts, United States of America
| | - Edward J. van Opstal
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Seth R. Bordenstein
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
| |
Collapse
|
561
|
Neubauer EF, Poole AZ, Weis VM, Davy SK. The scavenger receptor repertoire in six cnidarian species and its putative role in cnidarian-dinoflagellate symbiosis. PeerJ 2016; 4:e2692. [PMID: 27896028 PMCID: PMC5119243 DOI: 10.7717/peerj.2692] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/15/2016] [Indexed: 01/01/2023] Open
Abstract
Many cnidarians engage in a mutualism with endosymbiotic photosynthetic dinoflagellates that forms the basis of the coral reef ecosystem. Interpartner interaction and regulation includes involvement of the host innate immune system. Basal metazoans, including cnidarians have diverse and complex innate immune repertoires that are just beginning to be described. Scavenger receptors (SR) are a diverse superfamily of innate immunity genes that recognize a broad array of microbial ligands and participate in phagocytosis of invading microbes. The superfamily includes subclades named SR-A through SR-I that are categorized based on the arrangement of sequence domains including the scavenger receptor cysteine rich (SRCR), the C-type lectin (CTLD) and the CD36 domains. Previous functional and gene expression studies on cnidarian-dinoflagellate symbiosis have implicated SR-like proteins in interpartner communication and regulation. In this study, we characterized the SR repertoire from a combination of genomic and transcriptomic resources from six cnidarian species in the Class Anthozoa. We combined these bioinformatic analyses with functional experiments using the SR inhibitor fucoidan to explore a role for SRs in cnidarian symbiosis and immunity. Bioinformatic searches revealed a large diversity of SR-like genes that resembled SR-As, SR-Bs, SR-Es and SR-Is. SRCRs, CTLDs and CD36 domains were identified in multiple sequences in combinations that were highly homologous to vertebrate SRs as well as in proteins with novel domain combinations. Phylogenetic analyses of CD36 domains of the SR-B-like sequences from a diversity of metazoans grouped cnidarian with bilaterian sequences separate from other basal metazoans. All cnidarian sequences grouped together with moderate support in a subclade separately from bilaterian sequences. Functional experiments were carried out on the sea anemone Aiptasia pallida that engages in a symbiosis with Symbiodinium minutum (clade B1). Experimental blocking of the SR ligand binding site with the inhibitor fucoidan reduced the ability of S. minutum to colonize A. pallida suggesting that host SRs play a role in host-symbiont recognition. In addition, incubation of symbiotic anemones with fucoidan elicited an immune response, indicating that host SRs function in immune modulation that results in host tolerance of the symbionts.
Collapse
Affiliation(s)
- Emilie F. Neubauer
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Angela Z. Poole
- Department of Biology, Western Oregon University, Monmouth, OR, United States
| | - Virginia M. Weis
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States
| | - Simon K. Davy
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| |
Collapse
|
562
|
Díaz-Muñoz SL, Boddy AM, Dantas G, Waters CM, Bronstein JL. Contextual organismality: Beyond pattern to process in the emergence of organisms. Evolution 2016; 70:2669-2677. [PMID: 27704542 PMCID: PMC5132100 DOI: 10.1111/evo.13078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 09/06/2016] [Accepted: 09/24/2016] [Indexed: 12/19/2022]
Abstract
Biologists have taken the concept of organism largely for granted. However, advances in the study of chimerism, symbiosis, bacterial‐eukaryote associations, and microbial behavior have prompted a redefinition of organisms as biological entities exhibiting low conflict and high cooperation among their parts. This expanded view identifies organisms in evolutionary time. However, the ecological processes, mechanisms, and traits that drive the formation of organisms remain poorly understood. Recognizing that organismality can be context dependent, we advocate elucidating the ecological contexts under which entities do or do not act as organisms. Here we develop a “contextual organismality” framework and provide examples of entities, such as honey bee colonies, tumors, and bacterial swarms, that can act as organisms under specific life history, resource, or other ecological circumstances. We suggest that context dependence may be a stepping stone to the development of increased organismal unification, as the most integrated biological entities generally show little context dependence. Recognizing that organismality is contextual can identify common patterns and testable hypotheses across different entities. The contextual organismality framework can illuminate timeless as well as pressing issues in biology, including topics as disparate as cancer emergence, genomic conflict, evolution of symbiosis, and the role of the microbiota in impacting host phenotype.
Collapse
Affiliation(s)
- Samuel L Díaz-Muñoz
- Center for Genomics and Systems Biology and Department of Biology, New York University, New York, New York, 10003
| | - Amy M Boddy
- Department of Psychology, Arizona State University, Tempe, Arizona, 85281
| | - Gautam Dantas
- Department of Pathology and Immunology, Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Christopher M Waters
- Department of Microbiology and Molecular Genetics, 5180 Biomedical Physical Sciences, Michigan State University, East Lansing, Michigan, 48824
| | - Judith L Bronstein
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721
| |
Collapse
|
563
|
Kopac SM, Klassen JL. Can They Make It on Their Own? Hosts, Microbes, and the Holobiont Niche. Front Microbiol 2016; 7:1647. [PMID: 27818648 PMCID: PMC5073103 DOI: 10.3389/fmicb.2016.01647] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/04/2016] [Indexed: 11/18/2022] Open
Abstract
Virtually all multicellular organisms host a community of symbionts composed of mutualistic, commensal, and pathogenic microbes, i.e., their microbiome. The mechanism of selection on host-microbe assemblages remains contentious, particularly regarding whether selection acts differently on hosts and their microbial symbionts. Here, we attempt to reconcile these viewpoints using a model that describes how hosts and their microbial symbionts alter each other's niche and thereby fitness. We describe how host-microbe interactions might change the shape of the host niche and/or reproductive rates within it, which are directly related to host fitness. A host may also alter the niche of a symbiotic microbe, although this depends on the extent to which that microbe is dependent on the host for reproduction. Finally, we provide a mathematical model to test whether interactions between hosts and microbes are necessary to describe the niche of either partner. Our synthesis highlights the phenotypic effects of host-microbe interactions while respecting the unique lifestyles of each partner, and thereby provides a unified framework to describe how selection might act on a host that is associated with its microbiome.
Collapse
Affiliation(s)
| | - Jonathan L. Klassen
- Department of Molecular and Cell Biology, University of ConnecticutStorrs, CT, USA
| |
Collapse
|
564
|
Berg M, Zhou XY, Shapira M. Host-Specific Functional Significance of Caenorhabditis Gut Commensals. Front Microbiol 2016; 7:1622. [PMID: 27799924 PMCID: PMC5066524 DOI: 10.3389/fmicb.2016.01622] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 09/29/2016] [Indexed: 12/27/2022] Open
Abstract
The gut microbiota is an important contributor to host health and fitness. Given its importance, microbiota composition should not be left to chance. However, what determines this composition is far from clear, with results supporting contributions of both environmental factors and host genetics. To gauge the relative contributions of host genetics and environment, specifically the microbial diversity, we characterized the gut microbiotas of Caenorhabditis species spanning 200-300 million years of evolution, and raised on different composted soil environments. Comparisons were based on 16S rDNA deep sequencing data, as well as on functional evaluation of gut isolates. Worm microbiotas were distinct from those in their respective soil environment, and included bacteria previously identified as part of the C. elegans core microbiota. Microbiotas differed between experiments initiated with different soil communities, but within each experiment, worm microbiotas clustered according to host identity, demonstrating a dominant contribution of environmental diversity, but also a significant contribution of host genetics. The dominance of environmental contributions hindered identification of host-associated microbial taxa from 16S data. Characterization of gut isolates from C. elegans and C. briggsae, focusing on the core family Enterobacteriaceae, were also unable to expose phylogenetic distinctions between microbiotas of the two species. However, functional evaluation of the isolates revealed host-specific contributions, wherein gut commensals protected their own host from infection, but not a non-host. Identification of commensal host-specificity at the functional level, otherwise overlooked in standard sequence-based analyses, suggests that the contribution of host genetics to shaping of gut microbiotas may be greater than previously realized.
Collapse
Affiliation(s)
- Maureen Berg
- Department of Integrative Biology, University of California, Berkeley Berkeley, CA, USA
| | - Xiao Ying Zhou
- Department of Integrative Biology, University of California, Berkeley Berkeley, CA, USA
| | - Michael Shapira
- Department of Integrative Biology, University of California, BerkeleyBerkeley, CA, USA; Graduate Group in Microbiology, University of California, BerkeleyBerkeley, CA, USA
| |
Collapse
|
565
|
May G. Here come the commensals. AMERICAN JOURNAL OF BOTANY 2016; 103:1709-1711. [PMID: 27671530 DOI: 10.3732/ajb.1600265] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/29/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Georgiana May
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, Minnesota 55108 USA
| |
Collapse
|
566
|
Dittmer J, van Opstal EJ, Shropshire JD, Bordenstein SR, Hurst GDD, Brucker RM. Disentangling a Holobiont - Recent Advances and Perspectives in Nasonia Wasps. Front Microbiol 2016; 7:1478. [PMID: 27721807 PMCID: PMC5033955 DOI: 10.3389/fmicb.2016.01478] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/05/2016] [Indexed: 12/18/2022] Open
Abstract
The parasitoid wasp genus Nasonia (Hymenoptera: Chalcidoidea) is a well-established model organism for insect development, evolutionary genetics, speciation, and symbiosis. The host-microbiota assemblage which constitutes the Nasonia holobiont (a host together with all of its associated microbes) consists of viruses, two heritable bacterial symbionts and a bacterial community dominated in abundance by a few taxa in the gut. In the wild, all four Nasonia species are systematically infected with the obligate intracellular bacterium Wolbachia and can additionally be co-infected with Arsenophonus nasoniae. These two reproductive parasites have different transmission modes and host manipulations (cytoplasmic incompatibility vs. male-killing, respectively). Pioneering studies on Wolbachia in Nasonia demonstrated that closely related Nasonia species harbor multiple and mutually incompatible Wolbachia strains, resulting in strong symbiont-mediated reproductive barriers that evolved early in the speciation process. Moreover, research on host-symbiont interactions and speciation has recently broadened from its historical focus on heritable symbionts to the entire microbial community. In this context, each Nasonia species hosts a distinguishable community of gut bacteria that experiences a temporal succession during host development and members of this bacterial community cause strong hybrid lethality during larval development. In this review, we present the Nasonia species complex as a model system to experimentally investigate questions regarding: (i) the impact of different microbes, including (but not limited to) heritable endosymbionts, on the extended phenotype of the holobiont, (ii) the establishment and regulation of a species-specific microbiota, (iii) the role of the microbiota in speciation, and (iv) the resilience and adaptability of the microbiota in wild populations subjected to different environmental pressures. We discuss the potential for easy microbiota manipulations in Nasonia as a promising experimental approach to address these fundamental aspects.
Collapse
Affiliation(s)
- Jessica Dittmer
- Rowland Institute at Harvard, Harvard University, Cambridge MA, USA
| | | | - J Dylan Shropshire
- Department of Biological Sciences, Vanderbilt University, Nashville TN, USA
| | - Seth R Bordenstein
- Department of Biological Sciences, Vanderbilt University, NashvilleTN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University, NashvilleTN, USA
| | - Gregory D D Hurst
- Institute of Integrative Biology, University of Liverpool Liverpool, UK
| | - Robert M Brucker
- Rowland Institute at Harvard, Harvard University, Cambridge MA, USA
| |
Collapse
|
567
|
Eisthen HL, Theis KR. Animal-microbe interactions and the evolution of nervous systems. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150052. [PMID: 26598731 DOI: 10.1098/rstb.2015.0052] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Animals ubiquitously interact with environmental and symbiotic microbes, and the effects of these interactions on animal physiology are currently the subject of intense interest. Nevertheless, the influence of microbes on nervous system evolution has been largely ignored. We illustrate here how taking microbes into account might enrich our ideas about the evolution of nervous systems. For example, microbes are involved in animals' communicative, defensive, predatory and dispersal behaviours, and have likely influenced the evolution of chemo- and photosensory systems. In addition, we speculate that the need to regulate interactions with microbes at the epithelial surface may have contributed to the evolutionary internalization of the nervous system.
Collapse
Affiliation(s)
- Heather L Eisthen
- Department of Integrative Biology, Michigan State University, 288 Farm Lane Rm 203, East Lansing, MI 48824, USA BEACON Center for the Study of Evolution in Action, 567 Wilson Road Rm 1441, East Lansing, MI 48824, USA
| | - Kevin R Theis
- BEACON Center for the Study of Evolution in Action, 567 Wilson Road Rm 1441, East Lansing, MI 48824, USA Department of Internal Medicine, University of Michigan Medical School, 1150 West Medical Center Drive, MSRB I Rm 1510A, Ann Arbor, MI 48109, USA
| |
Collapse
|
568
|
Cong X, Xu W, Romisher R, Poveda S, Forte S, Starkweather A, Henderson WA. Gut Microbiome and Infant Health: Brain-Gut-Microbiota Axis and Host Genetic Factors. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2016; 89:299-308. [PMID: 27698614 PMCID: PMC5045139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The development of the neonatal gut microbiome is influenced by multiple factors, such as delivery mode, feeding, medication use, hospital environment, early life stress, and genetics. The dysbiosis of gut microbiota persists during infancy, especially in high-risk preterm infants who experience lengthy stays in the Neonatal intensive care unit (NICU). Infant microbiome evolutionary trajectory is essentially parallel with the host (infant) neurodevelopmental process and growth. The role of the gut microbiome, the brain-gut signaling system, and its interaction with the host genetics have been shown to be related to both short and long term infant health and bio-behavioral development. The investigation of potential dysbiosis patterns in early childhood is still lacking and few studies have addressed this host-microbiome co-developmental process. Further research spanning a variety of fields of study is needed to focus on the mechanisms of brain-gut-microbiota signaling system and the dynamic host-microbial interaction in the regulation of health, stress and development in human newborns.
Collapse
Affiliation(s)
- Xiaomei Cong
- School of Nursing, University of Connecticut, Storrs, Connecticut, USA
- Institute for Systems Genomics, University of Connecticut, Farmington, Connecticut, USA
| | - Wanli Xu
- School of Nursing, University of Connecticut, Storrs, Connecticut, USA
| | - Rachael Romisher
- School of Nursing, University of Connecticut, Storrs, Connecticut, USA
| | - Samantha Poveda
- School of Nursing, University of Connecticut, Storrs, Connecticut, USA
| | - Shaina Forte
- School of Nursing, University of Connecticut, Storrs, Connecticut, USA
| | | | - Wendy A. Henderson
- Digestive Disorders Unit, Biobehavioral Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
569
|
Mitter B, Pfaffenbichler N, Sessitsch A. Plant-microbe partnerships in 2020. Microb Biotechnol 2016; 9:635-40. [PMID: 27418200 PMCID: PMC4993182 DOI: 10.1111/1751-7915.12382] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 11/30/2022] Open
Abstract
The plant holobiont comprises the plant and its associated microbiota, which interact with each other and determine holobiont functioning and plant performance. We have started to understand the complexity of the involved microorganisms and their interactions, however, we need more research on plant-microbiome interactions to understand holobiont functioning. By 2020 we expect that our knowledge on these interactions will have considerably increased facilitating crop management practices based on the interactions of the plant holobiont.
Collapse
Affiliation(s)
- Birgit Mitter
- Bioresources Unit, Health & Environment Department, AIT Austrian Institute of Technology GmbH, A-3430, Tulln, Austria
| | - Nikolaus Pfaffenbichler
- Bioresources Unit, Health & Environment Department, AIT Austrian Institute of Technology GmbH, A-3430, Tulln, Austria
| | - Angela Sessitsch
- Bioresources Unit, Health & Environment Department, AIT Austrian Institute of Technology GmbH, A-3430, Tulln, Austria
| |
Collapse
|
570
|
Hahn MA, Dheilly NM. Experimental Models to Study the Role of Microbes in Host-Parasite Interactions. Front Microbiol 2016; 7:1300. [PMID: 27602023 PMCID: PMC4993751 DOI: 10.3389/fmicb.2016.01300] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/08/2016] [Indexed: 01/09/2023] Open
Abstract
Until recently, parasitic infections have been primarily studied as interactions between the parasite and the host, leaving out crucial players: microbes. The recent realization that microbes play key roles in the biology of all living organisms is not only challenging our understanding of host-parasite evolution, but it also provides new clues to develop new therapies and remediation strategies. In this paper we provide a review of promising and advanced experimental organismal systems to examine the dynamic of host-parasite-microbe interactions. We address the benefits of developing new experimental models appropriate to this new research area and identify systems that offer the best promises considering the nature of the interactions among hosts, parasites, and microbes. Based on these systems, we identify key criteria for selecting experimental models to elucidate the fundamental principles of these complex webs of interactions. It appears that no model is ideal and that complementary studies should be performed on different systems in order to understand the driving roles of microbes in host and parasite evolution.
Collapse
Affiliation(s)
- Megan A Hahn
- School of Marine and Atmospheric Sciences, Stony Brook University Stony Brook, NY, USA
| | - Nolwenn M Dheilly
- School of Marine and Atmospheric Sciences, Stony Brook University Stony Brook, NY, USA
| |
Collapse
|
571
|
Wolbachia Endosymbionts Modify Drosophila Ovary Protein Levels in a Context-Dependent Manner. Appl Environ Microbiol 2016; 82:5354-63. [PMID: 27342560 PMCID: PMC4988175 DOI: 10.1128/aem.01255-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/18/2016] [Indexed: 11/20/2022] Open
Abstract
Endosymbiosis is a unique form of interaction between organisms, with one organism dwelling inside the other. One of the most widespread endosymbionts is Wolbachia pipientis, a maternally transmitted bacterium carried by insects, crustaceans, mites, and filarial nematodes. Although candidate proteins that contribute to maternal transmission have been identified, the molecular basis for maternal Wolbachia transmission remains largely unknown. To investigate transmission-related processes in response to Wolbachia infection, ovarian proteomes were analyzed from Wolbachia-infected Drosophila melanogaster and D. simulans. Endogenous and variant host-strain combinations were investigated. Significant and differentially abundant ovarian proteins were detected, indicating substantial regulatory changes in response to Wolbachia. Variant Wolbachia strains were associated with a broader impact on the ovary proteome than endogenous Wolbachia strains. The D. melanogaster ovarian environment also exhibited a higher level of diversity of proteomic responses to Wolbachia than D. simulans. Overall, many Wolbachia-responsive ovarian proteins detected in this study were consistent with expectations from the experimental literature. This suggests that context-specific changes in protein abundance contribute to Wolbachia manipulation of transmission-related mechanisms in oogenesis. IMPORTANCE Millions of insect species naturally carry bacterial endosymbionts called Wolbachia. Wolbachia bacteria are transmitted by females to their offspring through a robust egg-loading mechanism. The molecular basis for Wolbachia transmission remains poorly understood at this time, however. This proteomic study identified specific fruit fly ovarian proteins as being upregulated or downregulated in response to Wolbachia infection. The majority of these protein responses correlated specifically with the type of host and Wolbachia strain involved. This work corroborates previously identified factors and mechanisms while also framing the broader context of ovarian manipulation by Wolbachia.
Collapse
|
572
|
Biodiversity, the Human Microbiome and Mental Health: Moving toward a New Clinical Ecology for the 21st Century? ACTA ACUST UNITED AC 2016. [DOI: 10.1155/2016/2718275] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Advances in research concerning the brain-related influences of the microbiome have been paradigm shifting, although at an early stage, clinical research involving beneficial microbes lends credence to the notion that the microbiome may be an important target in supporting mental health (defined here along the continuum between quality of life and the criteria for specific disorders). Through metagenomics, proteomics, metabolomics, and systems biology, a new emphasis to personalized medicine is on the horizon. Humans can now be viewed as multispecies organisms operating within an ecological theatre; it is important that clinicians increasingly see their patients in this context. Historically marginalized ecological aspects of health are destined to become an important consideration in the new frontiers of practicing medicine with the microbiome in mind. Emerging evidence indicates that macrobiodiversity in the external environment can influence mental well-being. Local biodiversity may also drive differences in human-associated microbiota; microbial diversity as a product of external biodiversity may have far-reaching effects on immune function and mood. With a focus on the microbiome as it pertains to mental health, we define environmental “grey space” and emphasize a new frontier involving bio-eco-psychological medicine. Within this concept the ecological terrain can link dysbiotic lifestyles and biodiversity on the grand scale to the local human-associated microbial ecosystems that might otherwise seem far removed from one another.
Collapse
|
573
|
Weinersmith KL, Earley RL. Better with your parasites? Lessons for behavioural ecology from evolved dependence and conditionally helpful parasites. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
574
|
González-Guerrero M, Escudero V, Saéz Á, Tejada-Jiménez M. Transition Metal Transport in Plants and Associated Endosymbionts: Arbuscular Mycorrhizal Fungi and Rhizobia. FRONTIERS IN PLANT SCIENCE 2016; 7:1088. [PMID: 27524990 PMCID: PMC4965479 DOI: 10.3389/fpls.2016.01088] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/11/2016] [Indexed: 05/03/2023]
Abstract
Transition metals such as iron, copper, zinc, or molybdenum are essential nutrients for plants. These elements are involved in almost every biological process, including photosynthesis, tolerance to biotic and abiotic stress, or symbiotic nitrogen fixation. However, plants often grow in soils with limiting metallic oligonutrient bioavailability. Consequently, to ensure the proper metal levels, plants have developed a complex metal uptake and distribution system, that not only involves the plant itself, but also its associated microorganisms. These microorganisms can simply increase metal solubility in soils and making them more accessible to the host plant, as well as induce the plant metal deficiency response, or directly deliver transition elements to cortical cells. Other, instead of providing metals, can act as metal sinks, such as endosymbiotic rhizobia in legume nodules that requires relatively large amounts to carry out nitrogen fixation. In this review, we propose to do an overview of metal transport mechanisms in the plant-microbe system, emphasizing the role of arbuscular mycorrhizal fungi and endosymbiotic rhizobia.
Collapse
Affiliation(s)
- Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Madrid, Spain
| | | | | | | |
Collapse
|
575
|
Kohl KD, Dearing MD. The Woodrat Gut Microbiota as an Experimental System for Understanding Microbial Metabolism of Dietary Toxins. Front Microbiol 2016; 7:1165. [PMID: 27516760 PMCID: PMC4963388 DOI: 10.3389/fmicb.2016.01165] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 07/13/2016] [Indexed: 01/22/2023] Open
Abstract
The microbial communities inhabiting the alimentary tracts of mammals, particularly those of herbivores, are estimated to be one of the densest microbial reservoirs on Earth. The significance of these gut microbes in influencing the physiology, ecology and evolution of their hosts is only beginning to be realized. To understand the microbiome of herbivores with a focus on nutritional ecology, while evaluating the roles of host evolution and environment in sculpting microbial diversity, we have developed an experimental system consisting of the microbial communities of several species of herbivorous woodrats (genus Neotoma) that naturally feed on a variety of dietary toxins. We designed this system to investigate the long-standing, but experimentally neglected hypothesis that ingestion of toxic diets by herbivores is facilitated by the gut microbiota. Like several other rodent species, the woodrat stomach has a sacculated, non-gastric foregut portion. We have documented a dense and diverse community of microbes in the woodrat foregut, with several genera potentially capable of degrading dietary toxins and/or playing a role in stimulating hepatic detoxification enzymes of the host. The biodiversity of these gut microbes appears to be a function of host evolution, ecological experience and diet, such that dietary toxins increase microbial diversity in hosts with experience with these toxins while novel toxins depress microbial diversity. These microbial communities are critical to the ingestion of a toxic diet as reducing the microbial community with antibiotics impairs the host's ability to feed on dietary toxins. Furthermore, the detoxification capacity of gut microbes can be transferred from Neotoma both intra and interspecifically to naïve animals that lack ecological and evolutionary history with these toxins. In addition to advancing our knowledge of complex host-microbes interactions, this system holds promise for identifying microbes that could be useful in the treatment of diseases in humans and domestic animals.
Collapse
Affiliation(s)
- Kevin D. Kohl
- Department of Biological Sciences, Vanderbilt University, NashvilleTN, USA
| | | |
Collapse
|
576
|
Alberdi A, Aizpurua O, Bohmann K, Zepeda-Mendoza ML, Gilbert MTP. Do Vertebrate Gut Metagenomes Confer Rapid Ecological Adaptation? Trends Ecol Evol 2016; 31:689-699. [PMID: 27453351 DOI: 10.1016/j.tree.2016.06.008] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/18/2016] [Accepted: 06/21/2016] [Indexed: 12/14/2022]
Abstract
During times of rapid environmental change, survival of most vertebrate populations depends on their phenomic plasticity. Although differential gene-expression and post-transcriptional processes of the host genome receive focus as the main molecular mechanisms, growing evidence points to the gut microbiota as a key driver defining hosts' phenotypes. We propose that the plasticity of the gut microbiota might be an essential factor determining phenomic plasticity of vertebrates, and that it might play a pivotal role when vertebrates acclimate and adapt to fast environmental variation. We contemplate some key questions and suggest methodological approaches and experimental designs that can be used to evaluate whether gut microorganisms provide a boost of plasticity to vertebrates' phenomes, thereby increasing their acclimation and adaptation capacity.
Collapse
Affiliation(s)
- Antton Alberdi
- EvoGenomics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark.
| | - Ostaizka Aizpurua
- EvoGenomics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - Kristine Bohmann
- EvoGenomics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark; School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7UG, UK
| | - Marie Lisandra Zepeda-Mendoza
- EvoGenomics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark
| | - M Thomas P Gilbert
- EvoGenomics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen, Denmark; Trace and Environmental DNA Laboratory, Department of Environment and Agriculture, Curtin University, Perth, Western Australia 6102, Australia; NTNU University Museum, N-7491 Trondheim, Norway.
| |
Collapse
|
577
|
Abstract
In most animals, digestive tracts harbor the greatest number of bacteria in the animal that contribute to its health: by aiding in the digestion of nutrients, provisioning essential nutrients and protecting against colonization by pathogens. Invertebrates have been used to enhance our understanding of metabolic processes and microbe-host interactions owing to experimental advantages. This review describes how advances in DNA sequencing technologies have dramatically altered how researchers investigate microbe-host interactions, including 16S rRNA gene surveys, metagenome experiments, and metatranscriptome studies. Advantages and challenges of each of these approaches are described herein. Hypotheses generated through omics studies can be directly tested using site-directed mutagenesis, and findings from transposon studies and site-directed experiments are presented. Finally, unique structural aspects of invertebrate digestive tracts that contribute to symbiont specificity are presented. The combination of omics approaches with genetics and microscopy allows researchers to move beyond correlations to identify conserved mechanisms of microbe-host interactions.
Collapse
Affiliation(s)
- Joerg Graf
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut 06269;
| |
Collapse
|
578
|
Wagner MR, Lundberg DS, del Rio TG, Tringe SG, Dangl JL, Mitchell-Olds T. Host genotype and age shape the leaf and root microbiomes of a wild perennial plant. Nat Commun 2016; 7:12151. [PMID: 27402057 PMCID: PMC4945892 DOI: 10.1038/ncomms12151] [Citation(s) in RCA: 416] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 06/06/2016] [Indexed: 01/01/2023] Open
Abstract
Bacteria living on and in leaves and roots influence many aspects of plant health, so the extent of a plant's genetic control over its microbiota is of great interest to crop breeders and evolutionary biologists. Laboratory-based studies, because they poorly simulate true environmental heterogeneity, may misestimate or totally miss the influence of certain host genes on the microbiome. Here we report a large-scale field experiment to disentangle the effects of genotype, environment, age and year of harvest on bacterial communities associated with leaves and roots of Boechera stricta (Brassicaceae), a perennial wild mustard. Host genetic control of the microbiome is evident in leaves but not roots, and varies substantially among sites. Microbiome composition also shifts as plants age. Furthermore, a large proportion of leaf bacterial groups are shared with roots, suggesting inoculation from soil. Our results demonstrate how genotype-by-environment interactions contribute to the complexity of microbiome assembly in natural environments.
Collapse
Affiliation(s)
- Maggie R. Wagner
- Program in Genetics and Genomics, Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Derek S Lundberg
- Department of Biology, Curriculum in Genetics and Molecular Biology, Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Tijana G. del Rio
- Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Susannah G. Tringe
- Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Jeffery L. Dangl
- Department of Biology, Curriculum in Genetics and Molecular Biology, Carolina Center for Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Thomas Mitchell-Olds
- Program in Genetics and Genomics, Department of Biology, Duke University, Durham, North Carolina 27708, USA
| |
Collapse
|
579
|
Bourne DG, Morrow KM, Webster NS. Insights into the Coral Microbiome: Underpinning the Health and Resilience of Reef Ecosystems. Annu Rev Microbiol 2016; 70:317-40. [PMID: 27482741 DOI: 10.1146/annurev-micro-102215-095440] [Citation(s) in RCA: 339] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Corals are fundamental ecosystem engineers, creating large, intricate reefs that support diverse and abundant marine life. At the core of a healthy coral animal is a dynamic relationship with microorganisms, including a mutually beneficial symbiosis with photosynthetic dinoflagellates (Symbiodinium spp.) and enduring partnerships with an array of bacterial, archaeal, fungal, protistan, and viral associates, collectively termed the coral holobiont. The combined genomes of this coral holobiont form a coral hologenome, and genomic interactions within the hologenome ultimately define the coral phenotype. Here we integrate contemporary scientific knowledge regarding the ecological, host-specific, and environmental forces shaping the diversity, specificity, and distribution of microbial symbionts within the coral holobiont, explore physiological pathways that contribute to holobiont fitness, and describe potential mechanisms for holobiont homeostasis. Understanding the role of the microbiome in coral resilience, acclimation, and environmental adaptation is a new frontier in reef science that will require large-scale collaborative research efforts.
Collapse
Affiliation(s)
- David G Bourne
- Marine Biology and Aquaculture, College of Science and Engineering, James Cook University, Townsville, Queensland, Australia 4811; .,Australian Institute of Marine Science, Townsville, Queensland, Australia 4810
| | - Kathleen M Morrow
- Australian Institute of Marine Science, Townsville, Queensland, Australia 4810.,Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824
| | - Nicole S Webster
- Australian Institute of Marine Science, Townsville, Queensland, Australia 4810
| |
Collapse
|
580
|
Kelley JL, Brown AP, Therkildsen NO, Foote AD. The life aquatic: advances in marine vertebrate genomics. Nat Rev Genet 2016; 17:523-34. [DOI: 10.1038/nrg.2016.66] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
581
|
O'Callaghan TF, Ross RP, Stanton C, Clarke G. The gut microbiome as a virtual endocrine organ with implications for farm and domestic animal endocrinology. Domest Anim Endocrinol 2016; 56 Suppl:S44-55. [PMID: 27345323 DOI: 10.1016/j.domaniend.2016.05.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 05/06/2016] [Accepted: 05/11/2016] [Indexed: 12/21/2022]
Abstract
The gut microbiome exerts a marked influence on host physiology, and manipulation of its composition has repeatedly been shown to influence host metabolism and body composition. This virtual endocrine organ also has a role in the regulation of the plasma concentrations of tryptophan, an essential amino acid and precursor to serotonin, a key neurotransmitter within both the enteric and central nervous systems. Control over the hypothalamic-pituitary-adrenal axis also appears to be under the influence of the gut microbiota. This is clear from studies in microbiota-deficient germ-free animals with exaggerated responses to psychological stress that can be normalized by monocolonization with certain bacterial species including Bifidobacterium infantis. Therapeutic targeting of the gut microbiota may thus be useful in treating or preventing stress-related microbiome-gut-brain axis disorders and metabolic diseases, much the same way as redirections of metabolopathies can be achieved through more traditional endocrine hormone-based interventions. Moreover, the implications of these findings need to be considered in the context of farm and domestic animal physiology, behavior, and food safety.
Collapse
Affiliation(s)
- T F O'Callaghan
- Department of Biosciences, Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Microbiology, University College Cork, Cork, Ireland
| | - R P Ross
- APC Microbiome Institute, University College Cork, Cork, Ireland; College of Science Engineering and Food Science, University College Cork, Cork, Ireland
| | - C Stanton
- Department of Biosciences, Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork, Ireland
| | - G Clarke
- APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork, Ireland.
| |
Collapse
|
582
|
Hyland NP, Cryan JF. Microbe-host interactions: Influence of the gut microbiota on the enteric nervous system. Dev Biol 2016; 417:182-7. [PMID: 27343895 DOI: 10.1016/j.ydbio.2016.06.027] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 12/20/2022]
Abstract
The enteric nervous system (ENS), considered a separate branch of the autonomic nervous system, is located throughout the length of the gastrointestinal (GI) tract as a series of interconnected ganglionated plexi. Given the proximity of the intestinal microbiota to the ENS, it is perhaps not surprising that the gut microbiota can influence its development and function. However, these interactions are complex and may be either direct or indirect, often involving signalling initiated by microbe-derived components, metabolites or host-derived intermediaries which subsequently affect enteric nerve excitability and GI function. Individual microbes and strains can differentially influence ENS activity and neurochemistry. In this review we will briefly summarise the role of the microbiota on ENS development, and, in some more detail, explore the mechanisms by which the microbiota can influence ENS activity and function.
Collapse
Affiliation(s)
- Niall P Hyland
- APC Microbiome Institute, University College Cork, Cork, Ireland; Departments of Pharmacology & Therapeutics, University College Cork, Cork, Ireland.
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork, Ireland; Anatomy & Neuroscience, University College Cork, Cork, Ireland
| |
Collapse
|
583
|
Estrela S, Kerr B, Morris JJ. Transitions in individuality through symbiosis. Curr Opin Microbiol 2016; 31:191-198. [DOI: 10.1016/j.mib.2016.04.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 11/29/2022]
|
584
|
Dirksen P, Marsh SA, Braker I, Heitland N, Wagner S, Nakad R, Mader S, Petersen C, Kowallik V, Rosenstiel P, Félix MA, Schulenburg H. The native microbiome of the nematode Caenorhabditis elegans: gateway to a new host-microbiome model. BMC Biol 2016; 14:38. [PMID: 27160191 PMCID: PMC4860760 DOI: 10.1186/s12915-016-0258-1] [Citation(s) in RCA: 245] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/19/2016] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Host-microbe associations underlie many key processes of host development, immunity, and life history. Yet, none of the current research on the central model species Caenorhabditis elegans considers the worm's natural microbiome. Instead, almost all laboratories exclusively use the canonical strain N2 and derived mutants, maintained through routine bleach sterilization in monoxenic cultures with an E. coli strain as food. Here, we characterize for the first time the native microbiome of C. elegans and assess its influence on nematode life history characteristics. RESULTS Nematodes sampled directly from their native habitats carry a species-rich bacterial community, dominated by Proteobacteria such as Enterobacteriaceae and members of the genera Pseudomonas, Stenotrophomonas, Ochrobactrum, and Sphingomonas. The C. elegans microbiome is distinct from that of the worm's natural environment and the congeneric species C. remanei. Exposure to a derived experimental microbiome revealed that bacterial composition is influenced by host developmental stage and genotype. These experiments also showed that the microbes enhance host fitness under standard and also stressful conditions (e.g., high temperature and either low or high osmolarity). Taking advantage of the nematode's transparency, we further demonstrate that several Proteobacteria are able to enter the C. elegans gut and that an Ochrobactrum isolate even seems to be able to persist in the intestines under stressful conditions. Moreover, three Pseudomonas isolates produce an anti-fungal effect in vitro which we show can contribute to the worm's defense against fungal pathogens in vivo. CONCLUSION This first systematic analysis of the nematode's native microbiome reveals a species-rich bacterial community to be associated with C. elegans, which is likely of central importance for our understanding of the worm's biology. The information acquired and the microbial isolates now available for experimental work establishes C. elegans as a tractable model for the in-depth dissection of host-microbiome interactions.
Collapse
Affiliation(s)
- Philipp Dirksen
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
| | - Sarah Arnaud Marsh
- Institute of Biology of the Ecole Normale Supérieure (IBENS), CNRS, Inserm, 46 rue d'Ulm, 75230, Paris Cedex 05, France
- Institut Pasteur, 25-28 rue du Docteur Roux, 75724, Paris Cedex 15, France
| | - Ines Braker
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
| | - Nele Heitland
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
| | - Sophia Wagner
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
| | - Rania Nakad
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Joseph-Stelzmann-Str. 26, 50931, Cologne, Germany
| | - Sebastian Mader
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
| | - Carola Petersen
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
| | - Vienna Kowallik
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Strasse 2, 24306, Plön, Germany
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, Christian-Albrechts University, Am Botanischen Garten 1-3, 24118, Kiel, Germany
| | - Marie-Anne Félix
- Institute of Biology of the Ecole Normale Supérieure (IBENS), CNRS, Inserm, 46 rue d'Ulm, 75230, Paris Cedex 05, France
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Am Botanischen Garten 3-9, 24118, Kiel, Germany.
| |
Collapse
|
585
|
Kohl KD, Sadowska ET, Rudolf AM, Dearing MD, Koteja P. Experimental Evolution on a Wild Mammal Species Results in Modifications of Gut Microbial Communities. Front Microbiol 2016; 7:634. [PMID: 27199960 PMCID: PMC4854874 DOI: 10.3389/fmicb.2016.00634] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/18/2016] [Indexed: 01/15/2023] Open
Abstract
Comparative studies have shown that diet, life history, and phylogeny interact to determine microbial community structure across mammalian hosts. However, these studies are often confounded by numerous factors. Selection experiments offer unique opportunities to validate conclusions and test hypotheses generated by comparative studies. We used a replicated, 15-generation selection experiment on bank voles (Myodes glareolus) that have been selected for high swim-induced aerobic metabolism, predatory behavior toward crickets, and the ability to maintain body mass on a high-fiber, herbivorous diet. We predicted that selection on host performance, mimicking adaptive radiation, would result in distinct microbial signatures. We collected foregut and cecum samples from animals that were all fed the same nutrient-rich diet and had not been subjected to any performance tests. We conducted microbial inventories of gut contents by sequencing the V4 region of the 16S rRNA gene. We found no differences in cecal microbial community structure or diversity between control lines and the aerobic or predatory lines. However, the cecal chambers of voles selected for herbivorous capability harbored distinct microbial communities that exhibited higher diversity than control lines. The foregut communities of herbivorous-selected voles were also distinct from control lines. Overall, this experiment suggests that differences in microbial communities across herbivorous mammals may be evolved, and not solely driven by current diet or other transient factors.
Collapse
Affiliation(s)
- Kevin D Kohl
- Department of Biological Sciences, Vanderbilt University Nashville, TN, USA
| | - Edyta T Sadowska
- Institute of Environmental Sciences, Jagiellonian University Kraków, Poland
| | - Agata M Rudolf
- Institute of Environmental Sciences, Jagiellonian University Kraków, Poland
| | - M Denise Dearing
- Department of Biology, University of Utah Salt Lake City, UT, USA
| | - Paweł Koteja
- Institute of Environmental Sciences, Jagiellonian University Kraków, Poland
| |
Collapse
|
586
|
English translation of Heinrich Anton de Bary’s 1878 speech, ‘Die Erscheinung der Symbiose’ (‘De la symbiose’). Symbiosis 2016. [DOI: 10.1007/s13199-016-0409-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
587
|
Brereton NJB, Gonzalez E, Marleau J, Nissim WG, Labrecque M, Joly S, Pitre FE. Comparative Transcriptomic Approaches Exploring Contamination Stress Tolerance in Salix sp. Reveal the Importance for a Metaorganismal de Novo Assembly Approach for Nonmodel Plants. PLANT PHYSIOLOGY 2016; 171:3-24. [PMID: 27002060 PMCID: PMC4854704 DOI: 10.1104/pp.16.00090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/20/2016] [Indexed: 05/09/2023]
Abstract
Metatranscriptomic study of nonmodel organisms requires strategies that retain the highly resolved genetic information generated from model organisms while allowing for identification of the unexpected. A real-world biological application of phytoremediation, the field growth of 10 Salix cultivars on polluted soils, was used as an exemplar nonmodel and multifaceted crop response well-disposed to the study of gene expression. Sequence reads were assembled de novo to create 10 independent transcriptomes, a global transcriptome, and were mapped against the Salix purpurea 94006 reference genome. Annotation of assembled contigs was performed without a priori assumption of the originating organism. Global transcriptome construction from 3.03 billion paired-end reads revealed 606,880 unique contigs annotated from 1588 species, often common in all 10 cultivars. Comparisons between transcriptomic and metatranscriptomic methodologies provide clear evidence that nonnative RNA can mistakenly map to reference genomes, especially to conserved regions of common housekeeping genes, such as actin, α/β-tubulin, and elongation factor 1-α. In Salix, Rubisco activase transcripts were down-regulated in contaminated trees across all 10 cultivars, whereas thiamine thizole synthase and CP12, a Calvin Cycle master regulator, were uniformly up-regulated. De novo assembly approaches, with unconstrained annotation, can improve data quality; care should be taken when exploring such plant genetics to reduce de facto data exclusion by mapping to a single reference genome alone. Salix gene expression patterns strongly suggest cultivar-wide alteration of specific photosynthetic apparatus and protection of the antenna complexes from oxidation damage in contaminated trees, providing an insight into common stress tolerance strategies in a real-world phytoremediation system.
Collapse
Affiliation(s)
- Nicholas J B Brereton
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| | - Emmanuel Gonzalez
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| | - Julie Marleau
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| | - Werther Guidi Nissim
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| | - Michel Labrecque
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| | - Simon Joly
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| | - Frederic E Pitre
- Institut de recherche en biologie végétale, University of Montreal, Montreal QC H1X 2B2, Canada (N.J.B.B., E.G., J.M., M.L., S.J., F.E.P.); andMontreal Botanical Garden, Montreal, QC H1X 2B2, Canada (W.G.N., M.L., S.J., F.E.P.)
| |
Collapse
|
588
|
Parrish NF, Tomonaga K. Endogenized viral sequences in mammals. Curr Opin Microbiol 2016; 31:176-183. [PMID: 27128186 DOI: 10.1016/j.mib.2016.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/15/2016] [Accepted: 03/15/2016] [Indexed: 12/13/2022]
Abstract
Reverse-transcribed RNA molecules compose a significant portion of the human genome. Many of these RNA molecules were retrovirus genomes either infecting germline cells or having done so in a previous generation but retaining transcriptional activity. This mechanism itself accounts for a quarter of the genomic sequence information of mammals for which there is data. We understand relatively little about the causes and consequences of retroviral endogenization. This review highlights functions ascribed to sequences of viral origin endogenized into mammalian genomes and suggests some of the most pressing questions raised by these observations.
Collapse
Affiliation(s)
- Nicholas F Parrish
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States.
| | - Keizo Tomonaga
- Department of Viral Oncology, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan; Department of Tumor Viruses, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan; Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan.
| |
Collapse
|
589
|
Abstract
A paradigm shift has recently transformed the field of biological science; molecular advances have revealed how fundamentally important microorganisms are to many aspects of a host’s phenotype and evolution. In the process, an era of “holobiont” research has emerged to investigate the intricate network of interactions between a host and its symbiotic microbial consortia. Marine sponges are early-diverging metazoa known for hosting dense, specific, and often highly diverse microbial communities. Here we synthesize current thoughts about the environmental and evolutionary forces that influence the diversity, specificity, and distribution of microbial symbionts within the sponge holobiont, explore the physiological pathways that contribute to holobiont function, and describe the molecular mechanisms that underpin the establishment and maintenance of these symbiotic partnerships. The collective genomes of the sponge holobiont form the sponge hologenome, and we highlight how the forces that define a sponge’s phenotype in fact act on the genomic interplay between the different components of the holobiont.
Collapse
|
590
|
Plant-Microbiota Interactions as a Driver of the Mineral Turnover in the Rhizosphere. ADVANCES IN APPLIED MICROBIOLOGY 2016; 95:1-67. [PMID: 27261781 DOI: 10.1016/bs.aambs.2016.03.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A major challenge facing agriculture in the 21st century is the need to increase the productivity of cultivated land while reducing the environmentally harmful consequences of mineral fertilization. The microorganisms thriving in association and interacting with plant roots, the plant microbiota, represent a potential resource of plant probiotic function, capable of conjugating crop productivity with sustainable management in agroecosystems. However, a limited knowledge of the organismal interactions occurring at the root-soil interface is currently hampering the development and use of beneficial plant-microbiota interactions in agriculture. Therefore, a comprehensive understanding of the recruitment cues of the plant microbiota and the molecular basis of nutrient turnover in the rhizosphere will be required to move toward efficient and sustainable crop nutrition. In this chapter, we will discuss recent insights into plant-microbiota interactions at the root-soil interface, illustrate the processes driving mineral dynamics in soil, and propose experimental avenues to further integrate the metabolic potential of the plant microbiota into crop management and breeding strategies for sustainable agricultural production.
Collapse
|
591
|
Abstract
Species are fundamental units of comparison in biology. The newly discovered importance and ubiquity of host-associated microorganisms are now stimulating work on the roles that microbes can play in animal speciation. We previously synthesized the literature and advanced concepts of speciation by symbiosis with notable attention to hybrid sterility and lethality. Here, we review recent studies and relevant data on microbes as players in host behavior and behavioral isolation, emphasizing the patterns seen in these analyses and highlighting areas worthy of additional exploration. We conclude that the role of microbial symbionts in behavior and speciation is gaining exciting traction and that the holobiont and hologenome concepts afford an evolving intellectual framework to promote research and intellectual exchange between disciplines such as behavior, microbiology, genetics, symbiosis, and speciation. Given the increasing centrality of microbiology in macroscopic life, microbial symbiosis is arguably the most neglected aspect of animal and plant speciation, and studying it should yield a better understanding of the origin of species.
Collapse
|
592
|
Abstract
The advent of relatively inexpensive tools for characterizing microbial communities has led to an explosion of research exploring the diversity, ecology, and evolution of microbe-host systems. Some now question whether existing conceptual frameworks are adequate to explain microbe-host systems. One popular paradigm is the "holobiont-hologenome," which argues that a host and its microbiome evolve as a single cooperative unit of selection (i.e., a superorganism). We argue that the hologenome is based on overly restrictive assumptions which render it an approach of little research utility. A host plus its microbiome is more effectively viewed as an ecological community of organisms that encompasses a broad range of interactions (parasitic to mutualistic), patterns of transmission (horizontal to vertical), and levels of fidelity among partners. The hologenome requires high partner fidelity if it is to evolve as a unit. However, even when this is achieved by particular host-microbe pairs, it is unlikely to hold for the entire host microbiome, and therefore the community is unlikely to evolve as a hologenome. Both mutualistic and antagonistic (fitness conflict) evolution can occur among constituent members of the community, not just adaptations at the "hologenome" level, and there is abundant empirical evidence for such divergence of selective interests among members of host-microbiome communities. We believe that the concepts and methods of ecology, genetics, and evolutionary biology will continue to provide a well-grounded intellectual framework for researching host-microbiome communities, without recourse to the limiting assumption that selection acts predominantly at the holobiont level.
Collapse
|
593
|
Shapira M. Gut Microbiotas and Host Evolution: Scaling Up Symbiosis. Trends Ecol Evol 2016; 31:539-549. [PMID: 27039196 DOI: 10.1016/j.tree.2016.03.006] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 02/18/2016] [Accepted: 03/05/2016] [Indexed: 02/07/2023]
Abstract
Our understanding of species evolution is undergoing restructuring. It is well accepted that host-symbiont coevolution is responsible for fundamental aspects of biology. However, the emerging importance of plant- and animal-associated microbiotas to their hosts suggests a scale of coevolutionary interactions many-fold greater than previously considered. This review builds on current understanding of symbionts and their contributions to host evolution to evaluate recent data demonstrating similar contributions of gut microbiotas. It further considers a multilayered model for microbiota to account for emerging themes in host-microbiota interactions. Drawing on the structure of bacterial genomes, this model distinguishes between a host-adapted core microbiota, and a flexible, environmentally modulated microbial pool, differing in constraints on their maintenance and in their contributions to host adaptation.
Collapse
Affiliation(s)
- Michael Shapira
- University of California, Berkeley, department of Integrative Biology and Graduate Group in Microbiology. Valley Life Sciences Building, room 5155, Berkeley, CA 94720, USA.
| |
Collapse
|
594
|
Getting the Hologenome Concept Right: an Eco-Evolutionary Framework for Hosts and Their Microbiomes. mSystems 2016; 1:mSystems00028-16. [PMID: 27822520 PMCID: PMC5069740 DOI: 10.1128/msystems.00028-16] [Citation(s) in RCA: 280] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Given the complexity of host-microbiota symbioses, scientists and philosophers are asking questions at new biological levels of hierarchical organization—what is a holobiont and hologenome? When should this vocabulary be applied? Are these concepts a null hypothesis for host-microbe systems or limited to a certain spectrum of symbiotic interactions such as host-microbial coevolution? Critical discourse is necessary in this nascent area, but productive discourse requires that skeptics and proponents use the same lexicon. Given the complexity of host-microbiota symbioses, scientists and philosophers are asking questions at new biological levels of hierarchical organization—what is a holobiont and hologenome? When should this vocabulary be applied? Are these concepts a null hypothesis for host-microbe systems or limited to a certain spectrum of symbiotic interactions such as host-microbial coevolution? Critical discourse is necessary in this nascent area, but productive discourse requires that skeptics and proponents use the same lexicon. For instance, critiquing the hologenome concept is not synonymous with critiquing coevolution, and arguing that an entity is not a primary unit of selection dismisses the fact that the hologenome concept has always embraced multilevel selection. Holobionts and hologenomes are incontrovertible, multipartite entities that result from ecological, evolutionary, and genetic processes at various levels. They are not restricted to one special process but constitute a wider vocabulary and framework for host biology in light of the microbiome.
Collapse
|
595
|
Greer R, Dong X, Morgun A, Shulzhenko N. Investigating a holobiont: Microbiota perturbations and transkingdom networks. Gut Microbes 2016; 7:126-35. [PMID: 26979110 PMCID: PMC4856449 DOI: 10.1080/19490976.2015.1128625] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The scientific community has recently come to appreciate that, rather than existing as independent organisms, multicellular hosts and their microbiota comprise a complex evolving superorganism or metaorganism, termed a holobiont. This point of view leads to a re-evaluation of our understanding of different physiological processes and diseases. In this paper we focus on experimental and computational approaches which, when combined in one study, allowed us to dissect mechanisms (traditionally named host-microbiota interactions) regulating holobiont physiology. Specifically, we discuss several approaches for microbiota perturbation, such as use of antibiotics and germ-free animals, including advantages and potential caveats of their usage. We briefly review computational approaches to characterize the microbiota and, more importantly, methods to infer specific components of microbiota (such as microbes or their genes) affecting host functions. One such approach called transkingdom network analysis has been recently developed and applied in our study. (1) Finally, we also discuss common methods used to validate the computational predictions of host-microbiota interactions using in vitro and in vivo experimental systems.
Collapse
Affiliation(s)
- Renee Greer
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Xiaoxi Dong
- College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | - Andrey Morgun
- College of Pharmacy, Oregon State University, Corvallis, OR, USA
| | | |
Collapse
|
596
|
|
597
|
|
598
|
Abstract
Concepts and definitions of species have been debated by generations of biologists and remain controversial. Microbes pose a particular challenge because of their genetic diversity, asexual reproduction, and often promiscuous horizontal gene transfer (HGT). However, microbes also present an opportunity to study and understand speciation because of their rapid evolution, both in nature and in the lab, and small, easily sequenced genomes. Here, we review how microbial population genomics has enabled us to catch speciation "in the act" and how the results have challenged and enriched our concepts of species, with implications for all domains of life. We describe how recombination (including HGT and introgression) has shaped the genomes of nascent microbial, animal, and plant species and argue for a prominent role of natural selection in initiating and maintaining speciation. We ask how universal is the process of speciation across the tree of life, and what lessons can be drawn from microbes? Comparative genomics showing the extent of HGT in natural populations certainly jeopardizes the relevance of vertical descent (i.e., the species tree) in speciation. Nevertheless, we conclude that species do indeed exist as clusters of genetic and ecological similarity and that speciation is driven primarily by natural selection, regardless of the balance between horizontal and vertical descent.
Collapse
Affiliation(s)
- B. Jesse Shapiro
- Département de sciences biologiques, Université de Montréal, Montréal, Quebec, Canada
| | - Jean-Baptiste Leducq
- Département de sciences biologiques, Université de Montréal, Montréal, Quebec, Canada
| | - James Mallet
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| |
Collapse
|
599
|
Benjamino J, Graf J. Characterization of the Core and Caste-Specific Microbiota in the Termite, Reticulitermes flavipes. Front Microbiol 2016; 7:171. [PMID: 26925043 PMCID: PMC4756164 DOI: 10.3389/fmicb.2016.00171] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/01/2016] [Indexed: 02/01/2023] Open
Abstract
The hindgut of the termite Reticulitermes flavipes harbors a complex symbiotic community consisting of protists, bacteria, and archaea. These symbionts aid in the digestion of lignocellulose from the termite’s wood meal. Termite hindguts were sampled and the V4 hyper-variable region of the 16S rRNA gene was sequenced and analyzed from individual termites. The core microbiota of worker termites consisted of 69 OTUs at the 97% identity level, grouped into 16 taxa, and together accounted for 67.05% of the sequences from the bacterial community. The core was dominated by Treponema, which contained 36 different OTUs and accounted for ∼32% of the sequences, which suggests Treponema sp. have an important impact on the overall physiology in the hindgut. Bray–Curtis beta diversity metrics showed that hindgut samples from termites of the same colony were more similar to each other than to samples from other colonies despite possessing a core that accounted for the majority of the sequences. The specific tasks and dietary differences of the termite castes could have an effect on the composition of the microbial community. The hindgut microbiota of termites from the alate castes differed from the worker caste with significantly lower abundances of Treponema and Endomicrobia, which dominated the hindgut microbiota in workers and soldiers. Protist abundances were also quantified in the same samples using qPCR of the 18S rRNA gene. Parabasalia abundances dropped significantly in the winged alates and the Oxymonadida abundances dropped in both alate castes. These data suggest that the changes in diet or overall host physiology affected the protist and bacterial populations in the hindgut. The in-depth bacterial characterization and protist quantification in this study sheds light on the potential community dynamics within the R. flavipes hindgut and identified a large and complex core microbiota in termites obtained from multiple colonies and castes.
Collapse
Affiliation(s)
- Jacquelynn Benjamino
- Department of Molecular and Cell Biology, University of Connecticut, Storrs CT, USA
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, StorrsCT, USA; Institute for Systems Genomics, University of Connecticut, StorrsCT, USA
| |
Collapse
|
600
|
Fonseca-García C, Coleman-Derr D, Garrido E, Visel A, Tringe SG, Partida-Martínez LP. The Cacti Microbiome: Interplay between Habitat-Filtering and Host-Specificity. Front Microbiol 2016; 7:150. [PMID: 26904020 PMCID: PMC4751269 DOI: 10.3389/fmicb.2016.00150] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/27/2016] [Indexed: 01/19/2023] Open
Abstract
Cactaceae represents one of the most species-rich families of succulent plants native to arid and semi-arid ecosystems, yet the associations Cacti establish with microorganisms and the rules governing microbial community assembly remain poorly understood. We analyzed the composition, diversity, and factors influencing above- and below-ground bacterial, archaeal, and fungal communities associated with two native and sympatric Cacti species: Myrtillocactus geometrizans and Opuntia robusta. Phylogenetic profiling showed that the composition and assembly of microbial communities associated with Cacti were primarily influenced by the plant compartment; plant species, site, and season played only a minor role. Remarkably, bacterial, and archaeal diversity was higher in the phyllosphere than in the rhizosphere of Cacti, while the opposite was true for fungi. Semi-arid soils exhibited the highest levels of microbial diversity whereas the stem endosphere the lowest. Despite their taxonomic distance, M. geometrizans and O. robusta shared most microbial taxa in all analyzed compartments. Influence of the plant host did only play a larger role in the fungal communities of the stem endosphere. These results suggest that fungi establish specific interactions with their host plant inside the stem, whereas microbial communities in the other plant compartments may play similar functional roles in these two species. Biochemical and molecular characterization of seed-borne bacteria of Cacti supports the idea that these microbial symbionts may be vertically inherited and could promote plant growth and drought tolerance for the fitness of the Cacti holobiont. We envision this knowledge will help improve and sustain agriculture in arid and semi-arid regions of the world.
Collapse
Affiliation(s)
- Citlali Fonseca-García
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados Irapuato, Mexico
| | - Devin Coleman-Derr
- Department of Energy Joint Genome InstituteWalnut Creek, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA; Plant Gene Expression Center, United States Department of Agriculture-Agricultural Research ServiceAlbany, CA, USA
| | - Etzel Garrido
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados Irapuato, Mexico
| | - Axel Visel
- Department of Energy Joint Genome InstituteWalnut Creek, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA; Molecular Cell Biology, School of Natural Sciences, University of California, MercedMerced, CA, USA
| | - Susannah G Tringe
- Department of Energy Joint Genome InstituteWalnut Creek, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National LaboratoryBerkeley, CA, USA; Molecular Cell Biology, School of Natural Sciences, University of California, MercedMerced, CA, USA
| | - Laila P Partida-Martínez
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados Irapuato, Mexico
| |
Collapse
|