Gonadotrophin subunit and GnRH receptor gene expression in the pars distalis of the equine pituitary.

In the horse, pronounced changes in fertility occur annually in response to photoperiod. However, the mechanisms regulating gonadotrophin synthesis and release in this species remain unclear. Here, we investigated the expression of gonadotrophin subunits and GnRH receptor (GnRH-R) mRNA in the pituitary glands of Thoroughbred horses during the breeding (BS) and non-breeding (NBS) season.