This project aims to identify genetic variation responsible for the evolution of elaborate male traits. Head shape of stalk-eyed flies will be studied because this trait can exhibit extreme sexual dimorphism. In some species the eyes of males are separated by a stalk that is longer than the body. Genes and genetic pathways that exhibit sexually dimorphic expression during eye-stalk development will be identified and then DNA sequence variation at several candidate genes will be examined to elucidate the functional roles of these genes. Candidate genes will be chosen using microarrays, a technology that compares expression of thousands of genes between two samples, such as males and females. Those genes with sexually dimorphic expression will be implicated in eyestalk development by comparing closely related species with or without dimorphic eyestalks. The functional significance of these genes will be confirmed by detecting associations between sequence variation and eyestalk lengths of individuals in a large pedigree.
Despite having most of their DNA in common, males and females often exhibit dramatic differences in shape and form. Which pathways create these differences and how these pathways evolve over time is poorly understood. This research will examine, at the level of the entire genome, variation in gene expression associated with a specific sexually dimorphic character. Overall, the results from this project will provide insight into the relationships between selection, the evolution of sexual dimorphism and DNA variation.
