DISSERTATION RESEARCH: Pheromone signaling and molecular dissection of olfactory neurons in red-legged salamanders

University Of Louisville Research Foundation Inc, Louisville KY

Investigators

Abstract

Courtship and mating in animals involves intricate sets of behaviors that often involve sensory cues. When pheromones are utilized, the receiver of the pheromone signal must detect and interpret the signal - usually relying on a sensory organ that in turn connects to areas of the brain involved in reproductive behavior. To sense and recognize protein pheromones, most vertebrates have a specialized olfactory organ, the vomeronasal organ (VNO). The VNO is composed of thousands of neurons that are finely tuned such that each neuron only recognizes a small number of possible pheromones by using a set of molecular receptors. In mouse models, nearly two decades after these receptors were first identified (and a Nobel Prize awarded), only a small number of specific pheromone:receptor pairs have been reported. In the red-legged salamander (P. shermani), as part of a unique courtship ritual, male salamanders deliver protein pheromones to females in order to enhance female receptivity. These protein pheromones were among the first to be biochemically characterized and this salamander has served as a valuable model system for studying how pheromones affect mating behavior in vertebrates. However, the specific molecular receptors in the salamander VNO that bind these pheromones remain to be identified and characterized. Using two state-of-the-art techniques - laser capture microdissection and high throughput DNA sequencing - the aim of this project is to identify the receptors that bind male pheromones in P. shermani. This study will provide novel insights into understanding the molecular mechanisms of pheromone:receptor interactions in salamanders and possibly all vertebrates (including humans). Additionally, the methodologies to be employed have never been applied to studying olfactory neurons, and may significantly advance the rate of research progress in this area of the neurosciences. Undergraduate research training is a key goal, and students will be actively included in all elements of the project. Gene date will be made available at: NCBI Genbank (http://www.ncbi.nlm.nih.gov/genbank)