Date of Award
Doctor of Philosophy (PhD)
To choose their mates, male and female vinegar flies (Drosophila melanogaster) perform a duet of stereotyped, sexually dimorphic courtship behaviors, a suite of sensory back-and-forth that offers an excellent model for studying the neural circuitry of complex behavior (Dickson, 2008). However, the study of Drosophila courtship has focused overwhelmingly on the male, and little is known about how the female evaluates male courtship to decide whether to mate and how she executes that decision by slowing down and opening vaginal plates, a process known as receptivity. To expand the mechanistic understanding of Drosophila receptivity, we set out to identify neurons directly involved in this behavior. Using a genome-wide neuronal RNAi screen, we identified a requirement for Abdominal-B (Abd-B), a homeobox transcription factor, in virgin female sexual receptivity. Silencing adult Abd-B neurons in the abdominal ganglion and reproductive tract decreased female receptivity. Whereas previous work measured copulation, we quantified movement using automated tracking and vaginal plate opening using magnified video recording. We show that “slowing down” is actually pausing, rather than walking more slowly. Silencing Abd-B neurons decreased pausing but did not affect vaginal plate opening, demonstrating that these two aspects of female sexual behavior are functionally separable. Synthetic activation of Abd-B neurons increased pausing, but playback of male courtship song alone was not sufficient to elicit this behavior. Therefore the female integrates multiple sensory cues from the male prior to copulation. We conclude that Abd-B neurons control female pausing in response to male courtship and that this is a key aspect of female sexual receptivity.
Bussell, Jennifer J., "Abdominal-B Neurons Control Drosophila Virgin Female Receptivity" (2014). Student Theses and Dissertations. 218.