Gene expression and functional co-evolution in the Drosophila female reproductive tract
Authors: Rachel Thayer; David Begun
Affiliation: University of California, Davis
Keywords: Comparative genomics & genome evolution
One goal of evolutionary genetics is to understand the mechanisms and drivers of gene expression evolution and innovation. In Drosophila melanogaster, the male reproductive tissues that produce ejaculate exhibit rapid sequence and gene expression evolution, as well as high rates of genetic novelty. Sexual conflict over the optimal outcomes of female-ejaculate interactions is one favored explanation for this accelerated evolution. Importantly, this sexual conflict model predicts strong female co-evolution, which we sought to test. Using flies from high and low latitude populations in the classic North American cline, from which male gene expression has been previously characterized, we assayed gene expression divergence across five female tissues that are directly exposed to ejaculate products. To investigate female-ejaculate co-evolution, we measured post-mating gene expression in females with either a same-population or a diverged mate. If females and males are co-adapted, then mismatched matings should show aberrant gene expression. We are also working to characterize female reproductive gene expression at single-cell resolution for the first time, and to interpret functional gene expression divergence in this cellular context.