Expression analysis of , , and genes in year-round estrous and seasonally estrous rams.

The expression characteristics of the hypothalamic-pituitary-gonadal (HPG) axis-related candidate genes, , , and , were analyzed in year-round estrous rams (small-tail Han sheep, STH) and seasonally estrous rams (Sunite sheep, SNT) using qPCR. The results were as follows: was mainly expressed in pituitary, and was specifically expressed in hypothalamus in the two groups. However, and were widely expressed in the cerebrum, cerebellum, hypothalamus, pituitary, testis, epididymis, vas deferens and adrenal gland tissues in both breeds, with significant differences in the cerebellum, hypothalamus, pituitary, testis and vas deferens tissues. We speculated that and may have positive roles in different regions in ram year-round estrus. Moreover, the expression patterns of and suggested that they may regulate the estrous mode of ram via testis and vas deferens. This is the first study to systematically analyze the expression patterns of HPG axis-related genes in rams.