A male-specific and circadian regulated fatty acid omega-hydroxylase, SXE1, is necessary for efficient male mating in Drosophila melanogaster

In Drosophila, sexual differentiation, physiology and behavior are thought to be mediated by numerous male and female-specific effector genes whose expression is controlled by sex-specifically expressed transcriptional regulators. One such downstream effector gene, sex-specific enzyme 1 (sxe1, cyp4d21), has been identified in a screen for genes with sex-biased expression in the head. Sxe1 was also identified in another screen as a circadian regulated gene. Here, we analyzed the spatial and temporal regulation of sxe1 and identified a function for this gene in male courtship. We show that male-specific transcriptional regulator DSX^M and the clock genes are necessary for cycling of sxe1 mRNA during the diurnal cycle. Similar to sxe1 mRNA, expression of SXE1 protein oscillates in a diurnal fashion, with highest protein levels occurring around midnight. SXE1 protein expression is restricted to non-neuronal cells associated with diverse sensory bristles of both the chemo- and mechanosensory systems. Suppression or knockout of sxe1 significantly reduces mating success throughout the diurnal cycle. Finally, the metabolomic profile of wild type and sxe1 mutant males revealed that sxe1 functions as a fatty acid omega-hydroxylase, suggesting that male courtship and mating success is mediated by small compounds generated by this enzyme.

Key Words: Drosophila courtship, circadian rhythm, homologous recombination, male-specific cytochrome p450, omega-hydroxylase

Online ISS 1091-6490
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