Seasonal breeding as a neuroendocrine model for puberty in sheep
Jeremy T Smith, Lain J Clarke
MOLECULAR AND CELLULAR ENDOCRINOLOGY | ELSEVIER IRELAND LTD | Published : 2010
Puberty is defined as the awakening of the hypothalamic-pituitary gonadal axis. Sheep are seasonal breeders, experiencing an annual period of reproductive quiescence and renaissance that can be utilized as a model for the onset of puberty. Kisspeptin and gonadotropin-inhibitory hormone appear to be important for the seasonal shift in reproductive activity and the former is mandatory for puberty. The non-breeding season is characterized by an increase in the negative feedback effect of estrogen on GnRH and gonadotropin secretion, as is the case in the pre-pubertal period. This effect of estrogen may be transmitted by kisspeptin cells. Additionally, dopaminergic A14/A15 neurons facilitate the ..View full abstract
This work was supported by the National Health and Medical Research Council of Australia. JTS is supported by an Australian Research Council Future Fellowship and is a recipient of an ESA Postdoctoral Award.