SAN2020

In animals, neuropeptidergic signaling is essential for the regulation of survival and reproductive-related processes. Among arthropod neuropeptide systems, Orcokinins are poorly studied, in despite of its high level of conservation in different Orders. There are currently no reports on the role of Orcokinins in the experimental insect model Drosophila melanogaster. In the present work, we exploited genetic tools available in this species in order to elucidate functional roles of Orcokinins in the regulation of different innate behaviors; ecdysis, sleep, circadian activity and courtship. We found that a reduction in Orcokinin gene expression provoked a slight shortening in pre-ecdysis, a reduction in daytime locomotor activity and an increased duration of total daytime sleep, occurring in a smaller number of sleep episodes that were of greater average duration. The strongest effect was observed in courtship behavior, where OKs RNAi-mediated gene silencing provoked a marked disinhibition in male courtship, both toward a female and a male target. Orcokinin is emerging as an important neuropeptide family in the regulation of vital processes in insects, such as reproduction and post-embryonic development. In the case of the fruit fly, our results suggest an important role in courtship inhibition.