The Role of desat1 in Courtship and Pheromone Synthesis of Male and Female Drosophila Melanogaster



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Sexual reproduction has fascinated scientists for centuries. The analysis of animal sexual behavior in other animals has helped to enlighten us about human sexual behavior 1. However, it has been argued that our mating habits are not controlled by pure biological need. Some have stated that due to our higher order of thinking, we can override the base biological need to choose a mate based on pheromones. However, through studying model organisms, such as Drosophila melanogaster, we have learned that pheromones play a larger role in mate choice than was previously thought2. In this project, Drosophila melanogaster is used to study the role of pheromones in courtship. Drosophila males perform an intricate courtship dance that is primarily controlled through the pheromones that males and females emit. However, there are several mutations that affect the pheromones and how they are interpreted by Drosophila. A mutation of interest is desat1. desat1 is a mutation that affects male Drosophila. desat1 mutants lack desat1 desaturase. desat1 desaturase promotes desaturation of the fatty acids that contribute to the courtship stimulatory pheromones. Without desat1 desaturase, very few correct courtship stimulatory pheromones are produced. Beyond desat1 mutant’s tendency to mate quickly, not much is understood about the effects the lack of courtship stimulatory pheromones have on other flies3. Courtship assay between a desat1 male, desat1 female, and a wild-type female have been described4. If a desat1 male ispresented with both desat1 and wildtype females, the male will almost always choose the desat1 female. This phenomenon has not been widely studied and is the focus of my experiments. Published observations indicate that desat1 mutant females behave like wild-type females. When desat1 females are presented with wild-type males, their courtship behavior is identical to that of the wild-type/wild-type pairings. However, no research has been done on whether or not there is a difference in the pheromones desat1 females and wild-type females are emitting3. It is possible that they are emitting a pheromone that, under normal conditions, has no effect on mating but when this pheromone is encountered by the desat1 mutant, it overrides anything it sense from the wild-type female 4. In this project, I studied the courtship assays of desat1 males and females to learn how the mutation has the mutation has affected their sexual competence. I have also analyzed their pheromone profiles, using GC-mass spectroscopy to further elucidate my finding from the courtship assays.



Drosophila melanogaster, mating, courtship, GC-mass spec, crosses