Behaviour 2019
Examining the links between host genotype, symbiotic bacterial communities, and chemical signals in a songbird
Joel W.G. Slade1, Andrew D. Winters2, Helena A. Soini3, Cody R. Lambert3, Milos V. Novotny3, Kevin R. Theis2, Danielle J. Whittaker1. 1Michigan State University - BEACON Center for the Study of Evolution in Action, East Lansing, Michigan, United States; 2Wayne State University, Detroit, Michigan, United States; 3Indiana University, Bloomington, Indiana, United States

In birds, including the dark-eyed junco (Junco hyemalis), volatile compounds given off by preen oil may be an important chemical signal involved in reproductive behavior. While studies have found a connection between host microbiomes and semiochemicals, there is scant evidence on how individual genotype may mediate the abundance and types of semiochemical-producing bacteria within a host. A candidate gene family that may mediate host microbiomes is the major histocompatibility complex (MHC). In this study, we investigate intrasubspecific and intersexual variation of preen oil in the slate-colored junco (Junco hyemalis hyemalis) and the Carolina junco (Junco hyemalis carolinensis). We then compare variation in the preen gland microbiome to variation in the chemical composition of preen oil. Finally, we test if host genotype at MHC mediates the preen gland microbiome and preen oil composition. Ultimately, our goal is achieving a clearer picture of how host genotype mediates the role of bacteria in songbird chemical signaling, resulting in reliable signaling of information about the host.