Minority Postdoctoral Research Fellowship for FY 2007

Saporito Ralph A, Coral Gables FL

Investigators

Abstract

This action funds an NSF Minority Postdoctoral Research Fellowship for FY 2007. The goal of the fellowship is to increase the participation of minority scientists at the postdoctoral level and to prepare them for positions of scientific leadership in US science. To attain this goal, the fellowship provides opportunities for postdoctoral training and research of the highest quality to recent doctoral recipients. It is expected that Fellows supported through these fellowships will play important roles in training of the future workforce. The research and training plan is entitled "Geographic variation in sequestered chemical defenses." Rhabdophis tigrinus (an Asian snake)possesses bufadienolide toxins that serve an antipredatory function and that are acquired solely from toads (Bufo japonicus) that are consumed as prey. Recent studies have revealed that there is geographic variation in the bufadienolides of R. tigrinus, which may have important functional implications for chemical defense in this species. Both R. tigrinus and B. japonicus are broadly sympatric on the main islands of Japan, and geographic variation in the bufadienolides of R. tigrinus likely reflects variation in the toxins of B. japonicus. This research examines the geographic structure and trophic interactions that underlie patterns of chemical defense in species that sequester their defensive compounds. Objectives are (1) to study geographic variation in bufadienolide-based chemical defenses of R. tigrinus and B. japonicus throughout Japan and (2) to determine whether variation in bufadienolides observed in R. tigrinus reflects the pattern of chemical variation in it prey, B. japonicus. By testing the hypothesis that the geographic structure of bufadienolide composition in R. tigrinus is a consequence of similar variation within B. japonicus, it will clarify the evolutionary and ecological interactions that have shaped this newly discovered and complex system of vertebrate chemical defense. The sponsoring scientist is Dr. Alan H. Savitzky (Old Dominion University) and will involve collaboration with Dr. Akira Mori (Kyoto University, Japan) and Drs. Jerrold Meinwald and Frank Schroeder (Cornell University). The training goals include broadening the Fellow's experience in chemical ecology by studying a different class of defensive compounds and using new analytical techniques.