Harrison 9700704 Pheromones are used by a large number of insects to attract mates. In the Lepidoptera pheromone binding proteins (PBPs) play a role in the binding and transpmrting of pheromones in the male antennae. PBPs should be subject to directional selection to bind new pheromones efficiently when a pheromone changes, but this prediction has not been tested rigorously. Three different methods will be used to detect selection; each method involves comparison of PBP gene sequences obtained from a set of moth species. The first approach uses population genetic test that detect excess nonsynonymous substitutions that may occur in response to a change in pheromone. A second method uses relative rates test to look for increases in nonsynonymous substitution along branches along which a change in pheromone has occurred. Several different classes of changes in pheromones will be examined. The final method for detecting selection involves analysis of PBPs in species which have independently evolved to use the same pheromone; the goal is identify convergence in the amino acid sequences of these PBPs. Demonstration of selection acting upon these PBPs would be important for the study of protein evolution and pheromone communication.
