microbial ecology and evolution
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The oral microbiome plays key roles in human biology, health, and disease, but little is known about the global diversity, variation, or evolution of this microbial community. To better understand the evolution and changing ecology of the human oral microbiome, we analyzed 124 dental biofilm metagenomes from humans, including Neanderthals and Late Pleistocene to present-day modern humans, chimpanzees, and gorillas, as well as New World howler monkeys for comparison. We find that a core microbiome of primarily biofilm structural taxa has been maintained throughout African hominid evolution, and these microbial groups are also shared with howler monkeys, suggesting that they have been important oral members since before the catarrhine-platyrrhine split ca. 40 Mya. However, community structure and individual microbial phylogenies do not closely reflect host relationships, and the dental biofilms of Homo and chimpanzees are distinguished by major taxonomic and functional differences. Reconstructing oral metagenomes from up to 100 thousand years ago, we show that the microbial profiles of both Neanderthals and modern humans are highly similar, sharing functional adaptations in nutrient metabolism. These include an apparent Homo-specific acquisition of salivary amylase-binding capability by oral streptococci, suggesting microbial coadaptation with host diet. We additionally find evidence of shared genetic diversity in the oral bacteria of Neanderthal and Upper Paleolithic modern humans that is not observed in later modern human populations. Differences in the oral microbiomes of African hominids provide insights into human evolution, the ancestral state of the human microbiome, and a temporal framework for understanding microbial health and disease.
- Klíčová slova
- Neanderthal, dental calculus, microbiome, primate, salivary amylase,
- MeSH
- Bacteria klasifikace genetika MeSH
- biofilmy MeSH
- biologická evoluce * MeSH
- ekologie metody MeSH
- fylogeneze MeSH
- Gorilla gorilla mikrobiologie MeSH
- Hominidae klasifikace mikrobiologie MeSH
- lidé MeSH
- metagenom genetika MeSH
- mikrobiota genetika MeSH
- Pan troglodytes mikrobiologie MeSH
- ústa mikrobiologie MeSH
- zeměpis MeSH
- zubní plak mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Afrika MeSH
Stramenopiles represent a significant proportion of aquatic and terrestrial biota. Most biologists can name a few, but these are limited to the phototrophic (e.g. diatoms and kelp) or parasitic species (e.g. oomycetes, Blastocystis), with free-living heterotrophs largely overlooked. Though our attention is slowly turning towards heterotrophs, we have only a limited understanding of their biology due to a lack of cultured models. Recent metagenomic and single-cell investigations have revealed the species richness and ecological importance of stramenopiles-especially heterotrophs. However, our lack of knowledge of the cell biology and behaviour of these organisms leads to our inability to match species to their particular ecological functions. Because photosynthetic stramenopiles are studied independently of their heterotrophic relatives, they are often treated separately in the literature. Here, we present stramenopiles as a unified group with shared synapomorphies and evolutionary history. We introduce the main lineages, describe their important biological and ecological traits, and provide a concise update on the origin of the ochrophyte plastid. We highlight the crucial role of heterotrophs and mixotrophs in our understanding of stramenopiles with the goal of inspiring future investigations in taxonomy and life history. To understand each of the many diversifications within stramenopiles-towards autotrophy, osmotrophy, or parasitism-we must understand the ancestral heterotrophic flagellate from which they each evolved. We hope the following will serve as a primer for new stramenopile researchers or as an integrative refresher to those already in the field.
- Klíčová slova
- chromalveolate hypothesis, heterotrophic flagellates, microbial ecology and evolution, plastid evolution, protistology, rhodoplex hypothesis, stramenopiles,
- MeSH
- biologická evoluce MeSH
- fylogeneze MeSH
- Heterokontophyta * klasifikace genetika MeSH
- heterotrofní procesy * MeSH
- plastidy genetika MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Genomic reorganisation between species and horizontal gene transfer have been considered the most important mechanism of biological adaptation under selective pressure. Still, the impact of mobile genes in microbial ecology is far from being completely understood. Here we present the collection and characterisation of microbial consortia enriched from environments contaminated with emerging pollutants, such as non-steroidal anti-inflammatory drugs. We have obtained and further enriched two ibuprofen-degrading microbial consortia from two unrelated wastewater treatment plants. We have also studied their ability to degrade the drug and the dynamics of the re-organisations of the genetic information responsible for its biodegradation among the species within the consortium. Our results show that genomic reorganisation within microorganisms and species rearrangements occur rapidly and efficiently during the selection process, which may be facilitated by plasmids and/or transposable elements located within the sequences. We show the evolution of at least two different plasmid backbones on samples from different locations, showing rearrangements of genomic information, including genes encoding activities for IBU degradation. As a result, we found variations in the expression pattern of the consortia after evolution under selective pressure, as an adaptation process to the new conditions. This work provides evidence for changes in the metagenomes of microbial communities that allow adaptation under a selective constraint -ibuprofen as a sole carbon source- and represents a step forward in knowledge that can inspire future biotechnological developments for drug bioremediation.
- Klíčová slova
- biodegradation, consortia evolution, emerging pollutants, ibuprofen, microbial ecology,
- MeSH
- Bacteria * genetika metabolismus klasifikace MeSH
- biodegradace MeSH
- fylogeneze MeSH
- ibuprofen * metabolismus MeSH
- mikrobiální společenstva * genetika MeSH
- odpadní voda mikrobiologie MeSH
- plazmidy genetika MeSH
- přenos genů horizontální MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- ibuprofen * MeSH
- odpadní voda MeSH
The microbial eukaryotes known as protists are of immense importance for our understanding of eukaryotic biology. Although it is often difficult to convince funding bodies to sponsor research projects aimed at finding new protist lineages, such discoveries usually provide new and fundamental insights into cell and evolutionary biology, and ecology.
- MeSH
- biologická evoluce * MeSH
- ekologie * MeSH
- Publikační typ
- časopisecké články MeSH
- komentáře MeSH
Each Earth ecosystem has unique microbial communities. Pseudomonas bacteria have evolved to occupy a plethora of different ecological niches, including living hosts, such as animals and plants. Many genes necessary for the Pseudomonas-niche interaction and their encoded functions remain unknown. Here, we describe a comparative genomic study of 3,274 genomes with 19,056,667 protein-coding sequences from Pseudomonas strains isolated from diverse environments. We detected functional divergence of Pseudomonas that depends on the niche. Each group of strains from a certain environment harbored a distinctive set of metabolic pathways or functions. The horizontal transfer of genes, which mainly proceeded between closely related taxa, was dependent on the isolation source. Finally, we detected thousands of undescribed proteins and functions associated with each Pseudomonas lifestyle. This research represents an effort to reveal the mechanisms underlying the ecology, pathogenicity, and evolution of Pseudomonas, and it will enable clinical, ecological, and biotechnological advances. IMPORTANCE Microbes play important roles in the health of living beings and in the environment. The knowledge of these functions may be useful for the development of new clinical and biotechnological applications and the restoration and preservation of natural ecosystems. However, most mechanisms implicated in the interaction of microbes with the environment remain poorly understood; thus, this field of research is very important. Here, we try to understand the mechanisms that facilitate the differential adaptation of Pseudomonas-a large and ubiquitous bacterial genus-to the environment. We analyzed more than 3,000 Pseudomonas genomes and searched for genetic patterns that can be related with their coevolution with different hosts (animals, plants, or fungi) and environments. Our results revealed that thousands of genes and genetic features are associated with each niche. Our data may be useful to develop new technical and theoretical advances in the fields of ecology, health, and industry.
- Klíčová slova
- Pseudomonas, environmental microbiology, genomics, host-cell interactions, microbial ecology,
- MeSH
- ekosystém * MeSH
- fylogeneze MeSH
- fyziologická adaptace genetika MeSH
- genomika MeSH
- Pseudomonas * genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Ambrosia gall midges (AGMs) represent an intriguing group within the Cecidomyiidae, one of the most diversified dipteran families. AGMs form galls on plants, where they cultivate and consume fungal symbionts (phytomycetophagy). This mutualistic relationship may play a critical role in larval nutrition, gall morphogenesis, and protection against natural enemies. Although most other fungus-farming taxa have been intensively studied, AGMs have largely been neglected. This review synthesizes current knowledge on the diversity, biology, and ecological interactions of AGM, highlighting the intricate relationships with their fungal symbionts. The implications for adaptive radiation and speciation are critically considered, including how fungal associations may have facilitated ecological flexibility and diversification. We also tackle the processes of coevolution, not only between AGM and their fungal symbionts but also involving plants and parasitoids. We identify the most pressing issues and discrepancies in the current understanding the AGM-fungi interactions. Key areas of future research should include elucidating fungal acquisition and transmission mechanisms, determining the specificity and diversity of AGM-associated fungal communities, understanding the evolutionary pathways leading to phytomycetophagy, and addressing taxonomic challenges within the AGM group, where species identification has been complicated by reliance on gall morphology and host specificity.
- Klíčová slova
- ambrosia gall midges, fungal symbionts, fungus farming, host shift, host specialization, phytomycetophagy,
- MeSH
- biologická evoluce * MeSH
- Diptera * mikrobiologie fyziologie MeSH
- houby * fyziologie MeSH
- nádory rostlin parazitologie MeSH
- symbióza * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Termites are a clade of eusocial wood-feeding roaches with > 3000 described species. Eusociality emerged ~ 150 million years ago in the ancestor of modern termites, which, since then, have acquired and sometimes lost a series of adaptive traits defining of their evolution. Termites primarily feed on wood, and digest cellulose in association with their obligatory nutritional mutualistic gut microbes. Recent advances in our understanding of termite phylogenetic relationships have served to provide a tentative timeline for the emergence of innovative traits and their consequences on the ecological success of termites. While all "lower" termites rely on cellulolytic protists to digest wood, "higher" termites (Termitidae), which comprise ~ 70% of termite species, do not rely on protists for digestion. The loss of protists in Termitidae was a critical evolutionary step that fostered the emergence of novel traits, resulting in a diversification of morphology, diets, and niches to an extent unattained by "lower" termites. However, the mechanisms that led to the initial loss of protists and the succession of events that took place in the termite gut remain speculative. In this review, we provide an overview of the key innovative traits acquired by termites during their evolution, which ultimately set the stage for the emergence of "higher" termites. We then discuss two hypotheses concerning the loss of protists in Termitidae, either through an externalization of the digestion or a dietary transition. Finally, we argue that many aspects of termite evolution remain speculative, as most termite biological diversity and evolutionary trajectories have yet to be explored.
- Klíčová slova
- Bacteria, Fungi, Higher termites, Lower termites, Nutritional mutualism, Protists, Sociality, Symbiosis, Termitomyces,
- MeSH
- biologická evoluce * MeSH
- celulosa metabolismus MeSH
- fylogeneze MeSH
- Isoptera klasifikace genetika metabolismus MeSH
- střevní mikroflóra MeSH
- symbióza MeSH
- zkameněliny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- celulosa MeSH
Despite widespread variability and redundancy abounding animal immunity, little is currently known about the rate of evolutionary convergence (functionally analogous traits not inherited from a common ancestor) in host molecular adaptations to parasite selective pressures. Toll-like receptors (TLRs) provide the molecular interface allowing hosts to recognize pathogenic structures and trigger early danger signals initiating an immune response. Using a novel combination of bioinformatic approaches, here we explore genetic variation in ligand-binding regions of bacteria-sensing TLR4 and TLR5 in 29 species belonging to the tit family of passerine birds (Aves: Paridae). Three out of the four consensual positively selected sites in TLR4 and six out of 14 positively selected positions in TLR5 were located on the receptor surface near the functionally important sites, and based on the phylogenetic pattern evolved in a convergent (parallel) manner. This type of evolution was also seen at one N-glycosylation site and two positively selected phosphorylation sites, providing the first evidence of convergence in post-translational modifications in evolutionary immunology. Finally, the overall mismatch between phylogeny and the clustering of surface charge distribution demonstrates that convergence is common in overall TLR4 and TLR5 molecular phenotypes involved in ligand binding. Our analysis did not reveal any broad ecological traits explaining the convergence observed in electrostatic potentials, suggesting that information on microbial symbionts may be needed to explain TLR evolution. Adopting state-of-the-art predictive structural bionformatics, we have outlined a new broadly applicable methodological approach to estimate the functional significance of positively selected variation and test for the adaptive molecular convergence in protein-coding polymorphisms.
- Klíčová slova
- avian immunogenetics, innate immune genes, molecular co-evolution, pattern recognition receptors, post-translational modifications, surface electrostatic potential,
- MeSH
- fenotyp MeSH
- fylogeneze MeSH
- molekulární evoluce * MeSH
- Passeriformes * MeSH
- přirozená imunita genetika MeSH
- selekce (genetika) MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Ciliates are a diverse group of protists known for their ability to establish various partnerships and thrive in a wide variety of oxygen-depleted environments. Most anaerobic ciliates harbor methanogens, one of the few known archaea living intracellularly. These methanogens increase the metabolic efficiency of host fermentation via syntrophic use of host end-product in methanogenesis. Despite the ubiquity of these symbioses in anoxic habitats, patterns of symbiont specificity and fidelity are not well known. We surveyed two unrelated, commonly found groups of anaerobic ciliates, the Plagiopylea and Metopida, isolated from anoxic marine sediments. We sequenced host 18S rRNA and symbiont 16S rRNA marker genes as well as the symbiont internal transcribed spacer region from our cultured ciliates to identify hosts and their associated methanogenic symbionts. We found that marine ciliates from both of these co-occurring, divergent groups harbor closely related yet distinct intracellular archaea within the Methanocorpusculum genus. The symbionts appear to be stable at the host species level, but at higher taxonomic levels, there is evidence that symbiont replacements have occurred. Gaining insight into this unique association will deepen our understanding of the complex transmission modes of marine microbial symbionts, and the mutualistic microbial interactions occurring across domains of life.
- Klíčová slova
- Metopida, Plagiopylea, anaerobic protists, anoxic sediments, archaea, methanogens, symbiosis, syntrophy,
- MeSH
- anaerobióza MeSH
- Ciliophora * klasifikace genetika fyziologie MeSH
- DNA archebakterií genetika chemie MeSH
- fylogeneze * MeSH
- geologické sedimenty * mikrobiologie MeSH
- mořská voda mikrobiologie parazitologie MeSH
- RNA ribozomální 16S * genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA MeSH
- symbióza * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA archebakterií MeSH
- RNA ribozomální 16S * MeSH
- RNA ribozomální 18S MeSH
We identified emerging scientific, technological, and sociopolitical issues likely to affect how biological invasions are studied and managed over the next two decades. Issues were ranked according to their probability of emergence, pervasiveness, potential impact, and novelty. Top-ranked issues include the application of genomic modification tools to control invasions, effects of Arctic globalization on invasion risk in the Northern Hemisphere, commercial use of microbes to facilitate crop production, the emergence of invasive microbial pathogens, and the fate of intercontinental trade agreements. These diverse issues suggest an expanding interdisciplinary role for invasion science in biosecurity and ecosystem management, burgeoning applications of biotechnology in alien species detection and control, and new frontiers in the microbial ecology of invasions.
- Klíčová slova
- Arctic globalization, gene drives, global change, invasive species, microbial ecology, rapid evolution,
- MeSH
- ekosystém * MeSH
- zavlečené druhy * MeSH
- Publikační typ
- časopisecké články MeSH