Host: Dr. Galit Shohat-Ophir
Neural Basis of Sexual Behaviours in Fruit Flies
After mating, females of many species change their behaviour to ensure the survival of their progeny. In Drosophila, mated females undergo a remarkable phenotypic switch resulting in decreased sexual receptivity and increased egg laying. These post-mating responses are induced by sex-peptide, a male protein that is transferred to the female reproductive system during copulation. Yet, how does the mating signal get to the female brain to induce changes in behaviour?
Using intersectional genetics and functional mapping, we showed that the neuronal circuitry expressing the sex determination gene doublesex is essential for the post-mating behavioural switch. Our findings suggest that the doublesex neuronal circuitry induces female post-mating responses, first by responding to sex-peptide in the reproductive system, and second by relaying the signal to the central nervous system prior to higher-order processing centers in the brain. More recently, I studied the role of higher order doublesex neurons in driving female courtship behaviours. Surprisingly, I found that activation of doublesex neurons in the brain induces Drosophila females to behave like males. What makes this finding so exciting is that it shows that neuronal circuitry for male behaviours exists in the female fly brain but remains dormant.
My studies represent a key step forward in defining the neuronal circuitry underlying sex-specific behaviours, and offer great potential for understanding fundamental neuronal mechanisms that are present across species.