9733237 Tsai Gonadotropin-releasing hormone (GnRH) is central to the initiation and maintenance of reproduction in vertebrates. It stimulates the release of two hormones from the pituitary that directly regulate the growth of ovaries and testes and the production of sex steroid hormones, such as estrogen and testosterone. Defects in GnRH production and/or release will invariably lead to sterility. Despite this hormone's importance in the reproduction of vertebrates, very little is known about when GnRH originally arose in evolution and when it began to assume the role of a central reproductive regulator. Dr. Tsai has shown that GnRH-like molecules exist in a protostome, Aplysia californica. The evolutionary implication of these results is extremely exciting since it suggest that GnRH may have already been present in a primitive invertebrate ancestor that gave rise to diverse group of vertebrates and invertebrates. Such extraordinary conservation over the course of evolution opens up the door to many possibilities regarding the functional roles that GnRH had assumed over the course of evolution. Dr. Tsai will integrative molecular, physiological and evolutionary approaches to examine structural and functional conservation of GnRH. As part of this CAREER award, she will use the same multidisciplinary approach to design a new laboratory course on comparative reproductive biology. Moreover, Dr. Tsai will actively recruit students interested in addressing evolutionary questions with molecular techniques from regional campuses to initiate research projects. The information gained from her research program will have profound implications concerning how the system of reproductive regulation presently seen in humans and other vertebrates has evolved over many millions of years.
