The Hologenome Concept: Helpful or Hollow?

PLoS Biology, Journal Year: 2015, Volume and Issue: 13(12), P. e1002311 - e1002311

Published: Dec. 4, 2015

With the increasing appreciation for crucial roles that microbial symbionts play in development and fitness of plant animal hosts, there has been a recent push to interpret evolution through lens "hologenome"—the collective genomic content host its microbiome. But how evolve and, particularly, whether they undergo natural selection benefit hosts are complex issues associated with several misconceptions about evolutionary processes host-associated communities. Microorganisms can have intimate, ancient, and/or mutualistic associations without having undergone hosts. Likewise, observing host-specific community composition or greater similarity among more closely related does not imply coevolved let alone evolved host. Although at level symbiotic community, hologenome, occurs some cases, it should be accepted as null hypothesis explaining features host–symbiont associations.

Language: Английский

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Unraveling the processes shaping mammalian gut microbiomes over evolutionary time

Nature Communications, Journal Year: 2017, Volume and Issue: 8(1)

Published: Feb. 23, 2017

Abstract Whether mammal–microbiome interactions are persistent and specific over evolutionary time is controversial. Here we show that host phylogeny major dietary shifts have affected the distribution of different gut bacterial lineages did so on vastly phylogenetic resolutions. Diet mostly influences acquisition ancient large microbial lineages. Conversely, correlation with seen among more recently diverged lineages, consistent processes operating at similar timescales to evolution. Considering microbiomes appropriate scales allows us model their evolution along mammalian tree infer diets from predicted ancestors. Phylogenetic analyses support co-speciation as having a significant role in microbiome compositions. Highly co-speciating genera also associated immune diseases humans, laying path for future studies probe these bacteria signs co-evolution.

Language: Английский

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Caterpillars lack a resident gut microbiome

Proceedings of the National Academy of Sciences, Journal Year: 2017, Volume and Issue: 114(36), P. 9641 - 9646

Published: Aug. 22, 2017

Many animals are inhabited by microbial symbionts that influence their hosts' development, physiology, ecological interactions, and evolutionary diversification. However, firm evidence for the existence functional importance of resident microbiomes in larval Lepidoptera (caterpillars) is lacking, despite fact these insects enormously diverse, major agricultural pests, dominant herbivores many ecosystems. Using 16S rRNA gene sequencing quantitative PCR, we characterized gut wild leaf-feeding caterpillars United States Costa Rica, representing 124 species from 15 families. Compared with other vertebrates assayed using same methods, microbes detected caterpillar guts were unusually low-density variable among individuals. Furthermore, abundance composition leaf-associated reflected feces consuming plants. Thus, ingested food present (although possibly dead or dormant) gut, but host-specific, largely absent. To test whether transient might still contribute to feeding conducted an experiment on field-collected model Manduca sexta Antibiotic suppression bacterial activity did not significantly affect weight gain, survival. The high pH, simple structure, fast transit times typify digestive physiology may prevent colonization. Moreover, host-encoded detoxification mechanisms likely render unnecessary herbivory. Caterpillars illustrate potential benefits independence symbionts, a lifestyle be widespread animals.

Language: Английский

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Symbiont Acquisition and Replacement as a Source of Ecological Innovation

Trends in Microbiology, Journal Year: 2017, Volume and Issue: 25(5), P. 375 - 390

Published: March 21, 2017

Language: Английский

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Tick-Bacteria Mutualism Depends on B Vitamin Synthesis Pathways

Current Biology, Journal Year: 2018, Volume and Issue: 28(12), P. 1896 - 1902.e5

Published: June 1, 2018

Language: Английский

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Not all animals need a microbiome

FEMS Microbiology Letters, Journal Year: 2019, Volume and Issue: 366(10)

Published: May 1, 2019

ABSTRACT It is often taken for granted that all animals host and depend upon a microbiome, yet this has only been shown small proportion of species. We propose span continuum reliance on microbial symbionts. At one end are the famously symbiont-dependent species such as aphids, humans, corals cows, in which microbes abundant important to fitness. In middle may tolerate some colonization but minimally or facultatively dependent. other lack beneficial symbionts altogether. While their existence seem improbable, capable limiting growth bodies, microbially independent lifestyle be favored by selection under circumstances. There already evidence several ‘microbiome-free’ lineages represent distantly related branches animal phylogeny. discuss why these have received little attention, highlighting potential contaminants, transients, parasites masquerade also suggest ways explore microbiomes address limitations DNA sequencing. call further research microbiome-free taxa provide more complete understanding ecology evolution macrobe-microbe interactions.

Language: Английский

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The evolution of host-symbiont dependence

Nature Communications, Journal Year: 2017, Volume and Issue: 8(1)

Published: July 4, 2017

Organisms across the tree of life form symbiotic partnerships with microbes for metabolism, protection and resources. While some hosts evolve extreme dependence on their symbionts, others maintain facultative associations. Explaining this variation is fundamental to understanding when symbiosis can lead new higher-level individuals, such as during evolution eukaryotic cell. Here we perform phylogenetic comparative analyses 106 unique host-bacterial symbioses test correlations between symbiont function, transmission mode, genome size host dependence. We find that both mode function are correlated dependence, reductions in fitness being greatest nutrient-provisioning, vertically transmitted symbionts removed. also a negative correlation vertically, but not horizontally, symbionts. These results suggest population structure important driving irreversible

Language: Английский

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The on‐again, off‐again relationship between mitochondrial genomes and species boundaries

Molecular Ecology, Journal Year: 2016, Volume and Issue: 26(8), P. 2212 - 2236

Published: Dec. 20, 2016

The study of reproductive isolation and species barriers frequently focuses on mitochondrial genomes has produced two alternative almost diametrically opposed narratives. On one hand, mtDNA may be at the forefront speciation events, with co-evolved mitonuclear interactions responsible for some earliest genetic incompatibilities arising among isolated populations. other there are numerous cases introgression across boundaries even when nuclear gene flow is restricted. We argue that these seemingly contradictory patterns can result from a single underlying cause. Specifically, accumulation deleterious mutations in creates problem evolutionary solutions. In cases, compensatory or epistatic changes genome ameliorate effects mutations, thereby establishing coadapted genotypes within populations forming basis between Alternatively, high mutation loads rescued by replacement more fit, foreign haplotype. Coupled many nonadaptive mechanisms preferentially affect cytoplasmic genomes, this form adaptive contribute to widespread discordance genealogies. Here, we review recent advances related incompatibilities, including potential cointrogression interacting genes. also address an emerging controversy over classic assumption selection inefficient discuss lead lineages down paths response accumulation.

Language: Английский

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Repeated replacement of an intrabacterial symbiont in the tripartite nested mealybug symbiosis

Proceedings of the National Academy of Sciences, Journal Year: 2016, Volume and Issue: 113(37)

Published: Aug. 29, 2016

Significance Mealybugs are plant sap-sucking insects with a nested symbiotic arrangement, where one bacterium lives inside another bacterium, which together live insect cells. These two bacteria, along genes transferred from other bacteria to the genome, allow survive on its nutrient-poor diet. Here, we show that innermost in this symbiosis was replaced several times over evolutionary history. results highly integrated and interdependent systems can experience symbiont replacement suggest similar dynamics could have occurred building mosaic metabolic pathways seen mitochondria plastids.

Language: Английский

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Comparing Adaptive Radiations Across Space, Time, and Taxa

Journal of Heredity, Journal Year: 2019, Volume and Issue: 111(1), P. 1 - 20

Published: Oct. 28, 2019

Abstract Adaptive radiation plays a fundamental role in our understanding of the evolutionary process. However, concept has provoked strong and differing opinions concerning its definition nature among researchers studying wide diversity systems. Here, we take broad view what constitutes an adaptive radiation, seek to find commonalities disparate examples, ranging from plants invertebrate vertebrate animals, remote islands lakes continents, better understand processes shared across radiations. We surveyed many groups evaluate factors considered important large variety species In each these studies, ecological opportunity some form is identified as prerequisite for radiation. evolvability, which can be enhanced by hybridization between distantly related species, may play seeding entire Within radiations, that lead speciation depend largely on (1) whether primary drivers shifts are (a) external membership itself (mostly divergent or disruptive selection) (b) due competition within (interactions members) subsequent reproductive isolation similar environments, (2) extent timing admixture. These differences translate into different patterns accumulation radiations occur extraordinary ways, continue provide rich data diversification life.

Language: Английский

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