quick-to-court, a Drosophila mutant with elevated levels of sexual behavior, is defective in a predicted coiled-coil protein

Remarkably little is known about the molecular mechanisms that drive sexual behavior. We have identified a new gene, quick-to-court (qtc), whose mutat ions cause males to show high levels of male-male courtship. qtc males also show a novel phenotype: when placed in the presence of a virgin female, th ey begin courtship abnormally quickly. qtc mutations are striking in their specificity, in that many aspects of male sexual behavior are normal. Mle h ave cloned the qtc gene and found that it encodes a predicted coiled-coil p rotein and is expressed in the olfactory organs, central nervous system, an d male reproductive tract.