Maria Elena Pereyra, PhD - US grants

This action funds an NSF Minority Postdoctoral Research Fellowship for FY2002. The goal of the fellowship is to prepare minority scientists for positions of scientific leadership in academia and industry. To attain this goal, the fellowship provides opportunities for postdoctoral training of the highest quality to recent doctoral recipients. This program is an effort by the NSF to increase the number of research scientists from underrepresented minority groups, thereby contributing to the future vitality of the Nation's scientific enterprise. It is expected that Fellows trained through these fellowships will play important roles in training of the future workforce.

The research and training plan for this fellowship is entitled "Influence of Nutritional Cues on Reproduction in Nomadic Songbirds." The objectives of this project are to investigate the influence of nutritional cues on the neuroendocrine regulation of reproductive development in two closely related nomadic songbirds (pine siskin and lesser goldfinch) that depend heavily upon foods that vary widely in availability between years and across broad geographic ranges.

This action continues funding for a third year for a Minority Postdoctoral Research Fellowship. The research focuses on the regulation of reproductive development in nomadic finches, with emphasis on the neuroendocrine basis for the extent to which species adhere to a strictly seasonal schedule of breeding.

The regulation of breeding schedules is critical for determining reproductive success, particularly in seasonal environments. This project will determine breeding schedules of two closely related songbirds (the lesser goldfinch and the American goldfinch) to determine how hormones produced and released in specific neurons in the brain are impacted by photoperiod. Gonadotropin releasing hormone (GnRH) stimulates reproductive development, while gonadotropin-inhibitory hormone (GnIH) blocks this development when breeding condiotns are not favorable. This project will compare GnRH and GnIH in these two species as they transition from photosensitive to photostimulated phases during the fine-tuning of reproductive development in relation to local conditions. This project will provide information that will clarify the proximate physiological and molecular mechanisms through which different reproductive schedules in closely related species might arise from simple shifts in the extent to which neural inhibition supresses GnRH release. The project will also provide training for undergraduate and graduate students and will provide unique instruction in field and laboratory techniques.