Meeting Abstract
The genetic basis of cellular immunity has long been a focus of immunological research. While mounting a successful cellular immune response has obvious fitness benefits, cellular immunity can be energetically costly and only functions as a reactive strategy to infection. There is a growing understanding that behavioral immune defenses are a common strategy that hosts employ to avoid and treat infection. However, the genetic mechanisms underlying these behavioral strategies remain largely uncharacterized. Drosophila melanogaster and their parasitoid wasps offer a unique opportunity to understand the genetic and neural mechanisms of behavioral immunity in an ecologically relevant context. These wasps lay their eggs inside fly larvae and eventually consume fly hosts from the inside out. Fly larvae can mount a cellular immune response to encapsulate and kill the wasp egg, but adult wasps inject virulence proteins with their eggs to suppress host cellular immunity. As a supplement to this imperfect cellular immune response, female flies sense the presence of wasps by sight and reduce oviposition, effectively reducing the exposure of offspring to infection. We are conducting a genome-wide association study (GWAS) using the Drosophila Genetic Reference Panel to identify candidate polymorphisms affecting this oviposition reduction behavior. Our screen has uncovered candidate genes expressed in the central nervous system and the reproductive tract. Functional tests of these candidates using available mutants, including knockdown and overexpression, will be used to confirm our GWAS results, leading to a novel understanding of how environmental stimuli can alter an organism’s physiology and behavior.
