What Drives Gut Microbial Diversity and Community Structure Among Closely-Related Host Species?

<p>The gut microbiome (GMB) of mammals hosts an important community of microbes that perform countless micro-ecosystem services for the host and are influenced by numerous factors including host physiology, environment, and phylogeny. Phylogeny may have a unique effect on GMB diversity and community structure (i.e., a GMB profile) via phylosymbiosis, a theory in which the evolution of hosts matches the evolution of their associated microbiota. Elucidating phylosymbiosis in mammals is difficult because multiple intrinsic and extrinsic factors collectively drive individual GMB variation. Thus, there is a need to simultaneously analyze the role of physiology, environment, and phylogeny on shaping host GMB profiles. I investigated this concept in 11 herbivore species across Etosha National Park (ENP), Namibia by extracting microbial DNA from fecal samples for 16S rRNA amplicon sequencing. I identified “core” bacterial taxa within herbivore species based on abundance and occurrence within samples. I discovered that certain bacterial taxa serve as environmental and physiological indicators in hosts. I found that GMB alpha diversity is influenced by sex and herbivore family, while GMB beta diversity is influenced by herbivore family and correlated with host divergence times in bovid species. However, ENP’s herbivore community did not exhibit phylosymbiosis, likely due to the influence of individual variation, dietary niche, and environment. This study fills knowledge gaps by quantifying the strength of multiple eco-evolutionary factors on GMB variation, and forms a foundation for future studies to incorporate GMB monitoring into conservation planning, which can serve as early warning signals for changes in host health.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2024

Author dc:creator

• Jensen, Rylee

Contributors dc:contributor

• Dr. Diana Lafferty

• gut microbiome
• herbivores
• Namibia
• amplicon sequencing
• phylosymbiosis
• conservation
• bioinformatics
• microbiology
• evolution
• mammal ecology
• Biology
• Ecology and Evolutionary Biology

Repository record dc:identifier

https://commons.nmu.edu/theses/863

OAI identifier oai:identifier

oai:commons.nmu.edu:theses-1918