The second involves the function of nuclear hormone receptors. In the cascade controlling sexual differentiation we spent considerable time examining regulation of the transformer gene and are now examining the function of genes which control sexual behavior. Our work on nuclear receptors centers on the role of ultraspiracle , the Drosophila cognate of the retinoid X receptor, in development and differentiation, as well as functional interactions between ultraspiracle and other nuclear receptors. Control of Sexual Behavior Sexual behavior in Drosophila is complex enough to be interesting and simple enough to be experimentally approachable. Males show a stereotypic pattern of courtship in which they orient toward and follow a female, sing a species-specific courtship song by unilateral wing vibration, attempt copulation and copulate.
Female behavior is more subtle but at least as important to the process.
Early in courtship a female moves away from a courting male, forcing him to follow. She also analyzes the courtship song for general and species specific components. If the male both follows and sings well, the female slows and positions herself to facilitate copulation and copulation ensues. After copulation the male looks for additional females while the female becomes rejective of additional suitors. In addition, the female lays fertilized eggs in carefully chosen sites.