Animals and plants host diverse microbial communities, collectively referred to as their microbiota. The members therein may pose a positive (mutualistic), negative (pathogenic), or neutral (commensal) effect on host fitness. Past work demonstrates that many hosts rely on mutualistic microbiota to provide functions such as enhanced resource utilization, defense against pathogenic microbiota or predators, and production of compounds and conditions which support host development. Therefore, understanding the identity and necessity of these functions, as well as the mechanisms evolved to maintain host-symbiont interactions, is crucial to understanding host evolution and ecology.
I am interested in how hosts with intricate life cycles (e.g., insects, plants, amphibians) maintain beneficial symbionts during development. Specifically, I am interested in investigating changes in microbiota community structure and function across different life stages.
Many hosts rely on the metabolic abilities of their microbiome in order to benefit from their diets. For example, ruminants, such as cows, have specialized stomachs to allow for the accumulation of large and diverse communities of microbes which ferment the nutrient-poor and hard to digest plant diet into simpler resources which the ruminant can utilize. Measuring the metabolic potential of an organism’s gut microbiome can help to understand how that organism has evolved to utilize its diet. Onthophagus taurus utilizes herbivore dung for reproduction and food yet herbivore dung is low in essential amino acids and high in complex polysaccharides, making it a difficult diet to digest. I am analyzing a project aiming to characterize the genes within the O. taurus gut microbiome to determine their potential function in allowing the beetles to consume herbivore dung as a diet.
How may the inheritance of beneficial, or commensal, symbionts influence a host's ability to defend against and overcome infectious pathogens? How might environmental conditions influence any of these affects? Has host reliance on microbiome-mediated immune responses diversified across micro and/or macroevolutionary scales?
Modern sequencing techniques allow researchers to gain large amounts of data on the compositional and functional aspects of the microbiome and to form hypotheses as to how those organisms interact with their hosts and environments. These techniques, however, are best supplemented with empirical testing to document the exact nature of these relationships. To test the hypothesis that host-associated microbes, implicated through amplicon/metagenomic sequencing studies are indeed beneficial, I aim to introduce these microbes into otherwise microbiome-free hosts and measure the resulting effects on host development and fitness.