Overexpression of a CREB repressor isoform enhances the female sexual receptivity in Drosophila.

The cAMP responsive transcriptional factor, CREB, is highly conserved among animal species, and its activity affects their behavior. In Drosophila melanogaster, one of alternatively spliced products of the CREB gene, dCREB2-a, is a transcriptional activator, while another isoform, dCREB2-b, is a repressor of dCREB2-a. Here, we demonstrate that overexpression of dCREB2-b in virgin females enhances their sexual receptivity. We studied the role of dCREB2 in female mating behavior using two transgenic lines, hs-dCREB2-a and hs-dCREB2-b, which overexpress respective products with heat-shock treatment. Wild-type males started their courtship behavior and mated more quickly with heat-shocked hs-dCREB2-b females than with non-heat-shocked hs-dCREB2-b females. Overexpression of dCREB2-a in females affected neither their courtship behavior nor mating frequency. The effects of overexpressed dCREB2-b were not due to elevated locomotor activities of heat-shocked females nor due to more vigorous courtship behavior of paired wild-type males. CREB might be involved in female sexual behavior of animals.