Chapter 6 - Sertoli Cell Biology in Seasonal Breeders

Abstract

This chapter discusses Sertoli cell biology in seasonal breeders and summarizes the structural responses of Sertoli cells in relation to changing endocrine status at different phases of gonadal activity. The primary environmental cue for stimulating gonadal activity and reproductive behavior during the appropriate time of the year for the majority of animals is the seasonal changes in day length. Supplementary cues such as temperature, food and water availability, and social factors from members of the same species (pheromones and vomeronasal mediation supplemented with tactile cues), through fine-tuning of the initial, general reproductive response to photoperiod, can also affect seasonal reproduction. A very popular model for the study of seasonality of reproduction in mammals is the golden (Syrian) hamster. The seasonally breeding golden (Syrian) hamster exhibits photoperiod-dependent transitions from reproductively active to quiescence and to recrudescence. The striking changes in Sertoli cell morphology between active and inactive states of spermatogenesis in golden hamster are structural manifestations of alterations in the function of these cells in response to concomitant endocrine changes in the testis and indicate a virtual shutdown of Sertoli cell function during short-photoperiod induced testicular regression.