DISSERTATION RESEARCH: The Role of Chemical Signaling in the Evolution of Reproductive Isolation in Terrestrial Salamanders

Oregon State University, Corvallis OR

Investigators

Abstract

THE ROLE OF CHEMICAL SIGNALING IN THE EVOLUTION OF REPRODUCTIVE ISOLATION IN TERRESTRIAL SALAMANDERS Lynne D. Houck and Catherine A. Palmer Terrestrial salamanders communicate by using chemical odors, termed pheromones. Certain pheromones are used only during courtship. These courtship pheromones are produced by the male and delivered to the female during courtship. These male courtship pheromones typically function to increase female receptivity, as indicated by a more rapid completion of the courtship. These same pheromones may also be used by the female to identify incorrect mating partners (males from other species), and hence prevent hybridization between species. The male courtship pheromones are comprised of proteins. One protein in particular can act alone to substantially increase female receptivity. The gene for that protein was identified, and was found to be expressed in a series of closely-related terrestrial salamander species. This setting, for which the ancestry of the species is known, offers an opportunity to investigate the evolution of changes that occur from gene to protein to behavior. This study will focus on genetic and biochemical variation in courtship pheromones. This information will be compared with existing data on female behavioral response to courtships with males of her own and of different species. The results of this investigation will provide a novel perspective on the evolution of female response to a male chemical signal.