Dopamine is critical for courtship behavior in Drosophila melanogaster

Male courtship in the fruit fly Drosophila melanogaster is an innate behavior influenced by sensory input and experience. Various aspects of male courtship behavior including motivation, pleasure, motor control, learning and memory are modulated by dopamine. For instance, the flies with increased dopamine levels show enhanced courtship activity. In Drosophila, there are four known types of dopamine receptors including D1 receptor dDA1, D2 receptor dD2R, D5 receptor DAMB, and the novel dopamine ecdysone receptor DopEcR that binds both dopamine and ecdysone steroid. The aim of this study is to elucidate the role of DopEcR in male courtship behavior. To investigate basal courtship behavior and courtship motivation, we examined 4-5 day old naïve males paired with either decapitated or intact virgin females. Courtship characteristics examined include latency of courtship initiation, courtship duration and bouts, and copulation latency. The genotypes used in this study are the male flies deficient in DopEcR (DER) and dopamine transporter DAT (fumin) as well as the wild-type Canton-S as a control. We hypothesize that DER (decreased dopamine signal only via DopEcR) or fumin (increased dopamine activity) will exhibit decreased or increased basal courtship levels, respectively, compared to wild-type males. Immunohistochemical studies are in progress to map the functional brain regions where the dopamine receptor DopEcR and DAT mediate courtship behavior. Knowledge obtained from this study will provide critical insights into the role of the dopamine system in Drosophila courtship behavior and its potential connections to behavioral plasticity