Antennal-specific pheromone-degrading aldehyde oxidases from the moths Antheraea polyphemus and Bombyx mori

Female moths produce blends of odorant chemicals, called pheromones. These precise chemical mixtures both attract males and elicit appropriate mating behaviors. To locate females, male moths must rapidly detect changes in environmental pheromone concentration. Therefore, the regulation of pheromone concentration within antennae, their chief organ of smell, is important. We describe antennal-specific aldehyde oxidases from the moths Antheraea polyphemus and Bombyx mori that are capable of catabolizing long chain, unsaturated aldehydes such as their aldehyde pheromones. These soluble enzymes are associated uniquely with male and female antennae and have molecular masses of 175 and 130 kDa, respectively. The A. polyphemus aldehyde oxidase has been localized to the olfactory sensilla which contain the pheromone receptor cell dendrites. These same sensilla contain a previously described sensilla-specific esterase that degrades the acetate ester component of A. polyphemus pheromone. We propose that sensillar pheromone-degrading enzymes modulate pheromone concentration in the receptor space and hence play a dynamic role in the pheromone-mediated reproductive behaviors of these animals.