Meeting Abstract

P3.89  Wednesday, Jan. 6  Seasonal influence of kisspeptin on fine-tuning reproduction in the Puget Sound white-crowned sparrow (Zonotrichia leucophrys pugetensis) CLEMONS, A*; FREESTONE, C; TONETTI, J; O’BRIEN, S; WINGFIELD, JC; Marian University; Marian University; Marian University; Marian University; University of California, Davis sobrien@marian.edu

All organisms must time breeding to appropriate times of the year that ensure the possibility for maximizing offspring survival. Migratory birds must time the onset of reproduction while making their way to their breeding grounds, which may or may not be conducive to breeding once they have arrived. Thus, individuals with challenges such as these must fine-tune the onset of full reproductive capability. Historically, the neuropeptide gonadotropin-releasing hormone (GnRH) was seen as the major player in beginning the orchestration of such events. However, the recently discovered neuropeptide, kisspeptin (KiSS) as been shown to be implicated in influencing GnRH-mediated release of the reproductive gonadotropin hormones, luteinizing hormone and follicle-stimulating hormone (LH and FSH respectively). Recent studies have shown peripheral and central injections of KiSS to have rapid and lasting effects on plasma LH levels in a variety of vertebrates. Here we examine whether jugular injections of KiSS in wild-caught Puget Sound white-crowned sparrows (Zonotrichia leucophrys pugetensis) influences plasma LH levels. We captured birds on their breeding grounds early and late in the breeding season, took a pre-injection blood sample at time 0, gave a bolus injection of KiSS, then subsequently took blood samples at 5, 10 and 15 minutes post-injection. Results show KiSS to have a rapid effect on plasma LH early in the breeding season when LH levels are highest, though KiSS fails to have an effect on plasma LH later in the breeding season as LH levels are dropping. These preliminary results may identify KiSS as a key player in the mechanisms that fine-tune early breeding events for a variety of seasonally breeding organisms.