Evolution and Tinkering in Olfactory Systems - Heather Eisthen

Wednesday, 4 September, 2013 - 09:30 to 11:00
The origin of signals and their detection mechanisms present intriguing problems in animal behavior, as the signaler and receiver must co-evolve for communication to occur. We are studying chemical communication in amphibians as a model for understanding the origin and diversification of pheromones and their detection mechanisms. The moist skin of many amphibians contains compounds that are used in antipredator defense as well as in managing interactions with microbial communities. Such species-typical compounds are ripe for cooption in signaling. I will discuss two examples of such signals: tetrodotoxin, a lethal neurotoxin that is broadly used in antipredator defense but is secondarily used in intraspecific signaling in newts in the genus Taricha; and a group of peptides that generally function as antimicrobials and have been coopted for use as pheromones in several families of salamanders. I will describe our recent results concerning both the mechanisms of production and detection of tetrodotoxin and peptide pheromones in salamanders. These examples serve as potent reminders that biological systems do not arise de novo, but through cooption and reassembly of existing structures.