Biology subjects

Dauser, S.

Publications and source records attributed to Dauser, S..

2 recordsLinked to original sources

bioRxiv2020

Strong influence of vertebrate host phylogeny on gut archaeal diversity

Commonly used 16S rRNA gene primers miss much of the archaeal diversity present in the vertebrate gut, leaving open the question of which archaea are host associated, the specificities of such associations, and the major factors influencing archaeal diversity. We applied 16S rRNA amplicon sequencing with Archaea-targeting primers to a dataset of 311 fecal/gut samples spanning 5 taxonomic classes (Mammalia, Aves, Reptilia, Amphibia, and Actinopterygii) and obtained from mainly wild individuals (76% were wild). We obtained sufficient archaeal sequence data from 185 samples comprising 110 species that span all 5 classes. We provide evidence for novel Archaea-host associations, including Bathyarchaeia and Methanothermobacter -- the latter of which was prevalent among Aves and enriched in higher body temperatures. Host phylogeny more strongly explained archaeal diversity than diet, while specific taxa were associated with each factor. Co-phylogeny was significant and strongest for mammalian herbivores. Methanobacteria was the only class predicted to be present in the last command ancestors of mammals and all host species. Archaea-Bacteria interactions seem to have a limited effect on archaeal diversity. These findings substantially expand on the paradigm of Archaea-vertebrate associations and the factors that explain those associations. SignificanceArchaea play key roles in the vertebrate gut such as promoting bacterial fermentation via consumption of waste products. Moreover, gut-inhabiting methanogenic Archaea in livestock are a substantial source of greenhouse gas production. Still, much is not known of the archaeal diversity in most vertebrates, especially since 16S rRNA sequence surveys often miss much of the archaeal diversity that is present. By applying Archaea-targeted gut microbiome sequencing to a large collection of diverse vertebrates, we reveal new Archaea-host associations such as a high prevalence of Methanothermobacter in birds. We also show that host evolutionary history explains archaeal diversity better than diet, and certain genera in one particular class of Archaea (Methanobacteria) were likely pervasive in the ancestral vertebrate gut.

microbiology↗

bioRxiv2020

Large scale metagenome assembly reveals novel animal-associated microbial genomes, biosynthetic gene clusters, and other genetic diversity

Large-scale metagenome assemblies of human microbiomes have produced a vast catalogue of previously unseen microbial genomes; however, comparatively few microbial genomes derive from other vertebrates. Here, we generated 5596 metagenome-assembled genomes from the gut metagenomes of 180 predominantly wild animal species representing 5 classes, in addition to 14 existing animal gut metagenome datasets. The MAGs comprised 1522 species-level genome bins (SGBs); most of which were novel at the species, genus, or family levels, and the majority were enriched in host versus environment metagenomes. Many traits distinguished SGBs enriched in host or environmental biomes, including the number of antimicrobial resistance genes. We identified 1986 diverse biosynthetic gene clusters; only 23 clustered with any MIBiG database references. Gene-based assembly revealed tremendous gene diversity, much of it host- or environment-specific. Our MAG and gene datasets greatly expand the microbial genome repertoire and provide a broad view of microbial adaptations to the vertebrate gut. ImportanceMicrobiome studies on a select few mammalian species (e.g., humans, mice, and cattle) have revealed a great deal of novel genomic diversity in the gut microbiome. However, little is known of the microbial diversity in the gut of other vertebrates. We studied the gut microbiome of a large set of mostly wild animal species consisting of mammals, birds, reptiles, amphibians, and fish. Unfortunately, we found that existing reference databases commonly used for metagenomic analyses failed to capture the microbiome diversity among vertebrates. To increase database representation, we applied advanced metagenome assembly methods to our animal gut data and to many public gut metagenome datasets that had not been used to obtain microbial genomes. Our resulting genome and gene cluster collections comprised a great deal of novel taxonomic and genomic diversity, which we extensively characterized. Our findings substantially expand what is known of microbial genomic diversity in the vertebrate gut.

microbiology↗