A carboxylesterase, Esterase-6, modulates sensory physiological and behavioral response dynamics to pheromone in DrosophilaReport as inadecuate




A carboxylesterase, Esterase-6, modulates sensory physiological and behavioral response dynamics to pheromone in Drosophila - Download this document for free, or read online. Document in PDF available to download.

* Corresponding author 1 PISC - Physiologie de l-Insecte, Signalisation et Communication Versailles 2 Faculty of Pharmacy, Unit of Medicinal Chemistry 3 Department of Plant Protection Biology 4 PISC - Physiologie de l-Insecte : Signalisation et Communication

Abstract : Background: Insects respond to the spatial and temporal dynamics of a pheromone plume, which implies not only a strong response to -odor on-, but also to -odor off-. This requires mechanisms geared toward a fast signal termination. Several mechanisms may contribute to signal termination, among which odorant-degrading enzymes. These enzymes putatively play a role in signal dynamics by a rapid inactivation of odorants in the vicinity of the sensory receptors, although direct in vivo experimental evidences are lacking. Here we verified the role of an extracellular carboxylesterase, esterase-6 Est-6, in the sensory physiological and behavioral dynamics of Drosophila melanogaster response to its pheromone, cis-vaccenyl acetate cVA. Est-6 was previously linked to post-mating effects in the reproductive system of females. As Est-6 is also known to hydrolyze cVA in vitro and is expressed in the main olfactory organ, the antenna, we tested here its role in olfaction as a putative odorant-degrading enzyme. Results: We first confirm that Est-6 is highly expressed in olfactory sensilla, including cVA-sensitive sensilla, and we show that expression is likely associated with non-neuronal cells. Our electrophysiological approaches show that the dynamics of olfactory receptor neuron ORN responses is strongly influenced by Est-6, as in Est-6 degrees null mutants lacking the Est-6 gene cVA-sensitive ORN showed increased firing rate and prolonged activity in response to cVA. Est-6 degrees mutant males had a lower threshold of behavioral response to cVA, as revealed by the analysis of two cVA-induced behaviors. In particular, mutant males exhibited a strong decrease of male-male courtship, in association with a delay in courtship initiation. Conclusions: Our study presents evidence that Est-6 plays a role in the physiological and behavioral dynamics of sex pheromone response in Drosophila males and supports a role of Est-6 as an odorant-degrading enzyme ODE in male antennae. Our results also expand the role of Est-6 in Drosophila biology, from reproduction to olfaction, and highlight the role of ODEs in insect olfaction.

Keywords : carboxylesterase pheromone esterase 6 olfaction signal termination





Author: Thomas Chertemps - Adrien François - Gloria Rosell - Teun Dekker - Philippe Lucas - Martine Maibeche Coisne - Nicolas Durand -

Source: https://hal.archives-ouvertes.fr/



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