Effect of High Fat/High Sugar Diets on fruitless Gene Expression and Copulatory Behavior in Drosophila melanogaster

Abstract

A diet high in fat has been shown to cause Diabetes, Cardiovascular Disease, and different types of Cancer in humans. In the model organism Drosophila melanogaster, a diet high in fat and sugar has been shown to decrease sexual functioning significantly. The fruitless gene in Drosophila is a neuronal gene that codes for a transcription factor whose functional role is to control the mating ability of male fruit flies. Through our research, we attempted to answer the question: Does a diet high in fat and sugar change sexual functioning in Drosophila - and is this change caused by decreased expression of the fruitless gene? For the experiment, we exposed our experimental group of Drosophila to a diet high in fat and sugar in their larval stage. We then examined the sexual behavior of these larvae once they reached a sexually-mature stage and compared their behavior to a control group of Drosophila that were grown under normal conditions. Male-male and male-female pairs were observed for orientation, tapping, wing song, licking, curling and copulation attempts. To analyze expression of the fruitless gene in both the control and experimental Drosophila cultures, we used quantitative Polymerase Chain Reaction (qPCR). Because the flies were exposed to the change in diet in their larval stage, we hypothesized that there would be a significant change in their sexual functioning in their adolescent and adult stages because of a decreased functioning of the fruitless gene.