Meeting Abstract
Seasonally breeding animals maximize reproductive success by reproducing only when there are sufficient resources available; when resources are scarce, reproduction is not energetically supported. Similarly, delayed reproductive development in response to undernutrition is a well-demonstrated phenomenon in mammals. The peptide hormone kisspeptin is known to both coordinate reproductive development and to play a role in triggering seasonal reproductive activity. A lack of kisspeptin action is associated with undernutrition during development; therefore, we hypothesized that seasonally breeding animals that experience a nutritional challenge early in life may exhibit altered seasonal responses as adults as a result of modified kisspeptin activity. We delayed reproductive development in male and female Siberian hamsters (Phodopus sungorus) by providing restricted food (70% of ad libitum intake) during a period from weaning until early adulthood. We assessed changes in body mass, timing of puberty, and reproductive masses at postnatal day 60. Food-restricted animals exhibited delays in development compared to ad lib.-fed animals; this effect was more dramatic in females than in males. Ongoing work is aimed at examining underlying differences in mRNA expression of kisspeptin and its receptor in relevant brain areas, as well as circulating reproductive hormones. The results of this study complement similar studies of reproductive development in mammals while contributing to our knowledge of the mechanisms of seasonal reproduction.
