Gene CG15630 (fipi) is involved in regulation of the interpulse interval in Drosophila courtship song.

To study the central pattern generators functioning, previously we identified genes, whose neurospecific knockdowns led to deviations in the courtship song of Drosophila melanogaster males. Reduced expression of the gene CG15630 caused a decrease in the interpulse interval. To investigate the role of CG15630, which we have called here fipi (factor of interpulse interval), in the courtship song production, at first, we have characterized fipi transcripts and protein (FIPI) in the mutant flies carrying P insertion and deletions in this gene and in flies with its RNAi knockdown. FIPI is homologous to the mammalian NCAM2 protein, an important factor of neuronal development in the olfactory system. In this study, we have revealed that local fipi knockdown in the antennal olfactory sensory neurons (OR67d and IR84a), which are responsible for reception of chemosignals modulating courtship behavior, alters the interpulse interval in the opposite directions. Thus, a proper fipi expression seems to be necessary for perception of sexual chemosignals, and the effect of fipi knockdown on IPI value depends on the type of chemoreceptor neurons affected.