Rôle d’un récepteur à double affinité Ecdysone/Dopamine (DopEcR) et d’un facteur de transcription (Krüppel) dans la plasticité de l’olfaction chez un papillon de nuit (Thèse de Doctorat d'Université)

Abstract

Most animals including insects rely mainly on olfaction to find their mating partners. In moths, males are attracted by female-produced sex pheromones inducing stereotyped sexual behaviour. Olfactory processes involved in chemical communication can be modulated by biotic factors such as age, physiological state or experience, leading to structural and functional changes of the sensory system. Evidence is now accumulating that hormones and catecholamines play a key role in pathways controlling olfactory plasticity. In this context we investigated the putative involvement of the G- protein-coupled dopamine/ecdysteroid receptor DopEcR, in the olfactory plasticity of pheromone- communication in Agrotis ipsilon males using an RNA interference strategy. Through the combination of biochemical, electrophysiological and behavioural approaches we identified the membrane receptor AipsDopEcR, which is predominantly expressed in both primary and secondary olfactory centres. Our results show that this GPCR modulates male sexual behaviour by controlling the central nervous processing of sex- pheromone through the action of ecdysone and dopamine. In parallel we identified the transcriptional factor Krüppel, which was found to mediate the modulatory action of juvenile hormone in the behavioural responses to sex pheromone in A. ipsilon males