Meeting Abstract

S7-8  Monday, Jan. 6 11:30 - 12:00  Using an evolutionary model organism to reveal host genetic influence on host-microbe interactions MILLIGAN-MYHRE, KCA; University of Alaska Anchorage

Interactions between hosts and their microbiota involve multiple host systems and complex signaling between microbiota members. These interactions are balanced by host factors, including the immune system, hormones, diet, and more, and microbiota community interactions, both between members and between the microbiota and the host. When this balance is disrupted, the microbiota community shifts and the host often develops inflammatory or developmental diseases. Disruption can be caused by a combination of genetic or environmental factors. To determine the role of host genes in the ability of the microbiota to stimulate host immune responses and development, we adapted the evolutionary model threespine stickleback (Gasterosteus aculeatus). We characterized the microbiota in wild populations and determined that the host selects for and against specific members of the environmental microbiome based on their genetic background. We isolated over 300 microbes and created mock communities that reflect the microbiota identified by sequencing. We also manipulated the microbiota in developing fish from three different populations, and quantified immune system, somatic, and behavioral development in treated and untreated fish. We found that populations that shared ancestors but have evolved in different microbial and environmental conditions have different developmental trajectories when their microbiota is disrupted. These combined results indicate that populations are selecting for individual microbes, and may vary in their abilities to regulate microbial membership and response to microbes based on their genetic background.