ABSTRACT
Introduction Fundamental to the survival of most organisms, be they yeast, plants, shes, or mammals, are biological rhythms with periodic (daily, monthly or annual) changes in behavior and physiology [1]. e daily circadian rhythm is exemplied by opening/closing of owers or the daily sleep cycle in humans. e menstrual cycle of women is a typical monthly rhythm whereas circannual rhythms include bird migrations, hibernation in frogs and mammals. Marked reproductive seasonality in numerous vertebrate classes, including sh, ensures that reproduction and subsequent development of ospring is coordinated with optimal environmental
and nutritional conditions. It has long been accepted that external environmental inuences such as photoperiod [2], [3], [4] and temperature [4], [5], [6] exert dominant roles in biological rhythms, and internal neuroendocrine systems such as the pineal gland, hypothalamus and pituitary coordinate these signals [7], [8], [9], [10]. In this study, we use theoretical and experimental approaches to better understand global genomic regulation of the neuroendocrine system during seasonal reproduction.
