To understand patterns of biodiversity it is essential to characterize the processes by which new species arise and are maintained in nature. Identifying the genetic basis of reproductive isolation provides insight into the underlying mechanisms of speciation.
My research focuses on the genetic basis of species divergence in house mice (Mus musculus). The three house mice subspecies (M. m. musculus, M. m. domesticus, M. m. castaneus) are genetically distinct but interbreed where they come in contact, and thus are considered to be in the early stages of speciation. Male hybrids from crosses between subspecies show reduced fertility, a common feature of reproductive barriers separating recently diverged species. I mapped quantitative trait loci contributing to testis expression variation (eQTL) in an F2 cross between M. m. musculus and M. m. domesticus. I am comparing eQTL results to sterility QTL that have already been mapped in this cross to identify the most promising candidate regions. To identify the underlying genes and mutations, I am using a combination of standard fine-mapping approaches, imaging and functional studies, and transgenics. My long-term goal is integrate this project with my previous research on sterility in a house mouse hybrid zone to: (1) identify genes and mutations contributing to reproductive isolation in natural populations, (2) infer the selective history of these mutations using population-genetic data and (3) characterize the effects of these genetic changes on protein abundance, structure, function, and interactions.