摘要:SummaryThe sex pheromone processing system of moths has been a major focus of research on olfaction and speciation, as it is highly specific and closely related to reproductive isolation. The two noctuid mothsHeliothis virescensandHeliothis subflexahave been used as a model for deciphering the mechanisms underlying differentiation in pheromone communication, but no information exist regarding the functions of the pheromone receptors (PRs) ofH. subflexa. Here, we functionally characterized all candidate PRs ofH. subflexa, and found that only the response profile of OR6 differed between the two species.Through domain swapping and site-directed mutation followed by functional characterization, we identified a critical amino acid in OR6 caused a one-way alteration in specificity. This result suggests HsubOR6 evolved from an ancestral OR6 gene with a HvirOR6-like function and implies that the evolutionary direction of the receptor specificity was from theH. virescens-like pattern toH. subflexa-like pattern.Graphical abstractDisplay OmittedHighlights•Six pheromone receptors (PRs) were functionally characterized inHeliothis subflexa•Function of one orthologous PR-OR6 differed betweenH. subflexaandH. virescens•A critical amino acid residue caused one-way alteration of OR6 specificity•This suggests HsubOR6 evolved from an ancestral gene with a HvirOR6-like functionEcology; Biological sciences; Zoology; Neuroscience; Sensory neuroscience