AUTHOR=de Fouchier Arthur , Sun Xiao , Monsempes Christelle , Mirabeau Olivier , Jacquin-Joly Emmanuelle , Montagné Nicolas TITLE=Evolution of two receptors detecting the same pheromone compound in crop pest moths of the genus Spodoptera JOURNAL=Frontiers in Ecology and Evolution VOLUME=3 YEAR=2015 URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2015.00095 DOI=10.3389/fevo.2015.00095 ISSN=2296-701X ABSTRACT=

In moths, mate finding strongly rely on the detection of sex pheromones by pheromone receptors (PRs). Any modification in the functional properties of these receptors can have a drastic impact on reproduction. In the course of characterizing candidate PRs in the noctuid moth Spodoptera littoralis, we expressed them in Drosophila olfactory sensory neurons and stimulated them with a large panel of moth pheromone compounds. We found that two PRs detect (Z,E)-9,12-14:OAc, a minor component of the female pheromone blend. Whereas SlitOR6 is highly specific to this component, SlitOR13 is less sensitive and not strictly specific as it also detects (Z)9-14:OAc, another minor component of the sex pheromone. Interestingly, SlitOR13 expression is restricted to the distal part of male antennae, where we could identify a novel functional class of pheromone-sensitive neurons whose response spectrum matches that of SlitOR13. Based on a phylogenetic analysis of Lepidoptera PRs, we found that the ability to bind (Z,E)-9,12-14:OAc appeared independently within three paralogous lineages, and an analysis of selective pressures revealed sites under positive selection that could have played a role in the emergence of functional properties of OR6 and OR13 in Spodoptera species.