Meeting Abstract
While the evolutionary origins of novel morphologies is a fundamental question in evolutionary developmental biology, perhaps a greater challenge is to elucidate how novel co-evolving structures arise. Animal genitalia present a particularly interesting case for studying this problem, due to the rapidity with which these structures change form and their inherent requirement for interacting male and female morphologies. Although past research has generally focused on male anatomies, recent advances have revealed rapidly evolving complex structures in females as well. However, the degree to which these co-evolving genital structures are genetically independent is currently unknown. In the Drosophila melanogaster subgroup, males possess a novel genital outgrowth called the posterior lobe, which is used to clasp females during mating. It was recently discovered that females of this subgroup have a novel feature of their ovipositor that appears to interact with the posterior lobe. A gene network required for posterior lobe formation was found to be co-opted from a larval structure during the origin of the male structure. Surprisingly, we discovered that genes and enhancer regions from that network that contribute to the posterior lobe’s development are also involved in the patterning and formation of the corresponding female structure. These data suggest that the necessarily-shared genetic history between the two structures could in part explain the simultaneous origin of two seemingly morphologically autonomous sexual characters.
