Expression of a pheromone receptor in ovipositor sensilla of the female moth (Heliothis virescens)

Female moths release pheromones that influence various behavioral and physiological processes. The highly specific responses elicited by pheromones are mediated via specific chemosensory proteins, pheromone binding proteins and chemoreceptors, operating in the antennal sensory neurons. In Heliothis virescens, the response to the major pheromone component (Z)-11-hexadecenal (Z11-16:Al) is mediated by the pheromone binding protein PBP2 and the receptor type HR13. PCR experiments revealed that transcripts for relevant chemosensory molecules are also present in the abdomen suggesting an additional role. In the female, mRNA for HR13 as well as for the related PBP2 was found in the ovipositor tip and in an immunohistochemical analysis with a specific antiserum it was possible to visualize the receptor protein in distinct sensilla types surrounding the ovipositor tip. The expression of HR13 implies a chemosensory responsiveness of these sensilla types to pheromones possibly provided by PBP2. Due to the close vicinity of sensillar HR13 cells and pheromone producing cells in the ovipositor we propose that the HR13 cells might mediate abdominal responses to the emitted pheromones.