Novel FSH receptor heterodimer may be related to the high prolificacy of Jintang black goat

Follicle‐stimulating hormone (FSH) is the central hormone of the mammalian reproductive system. It targets the FSH receptor (FSHR), a member of the G protein‐coupled receptor family, to induce the FSH signal transduction. In the highly prolific Jintang black goat, gonadotropin level is not higher than that of Boer goat. However, two isoforms of FSHRs (FSHRA and FSHRB), generated from the alternative splicing of the same primary FSHR transcript, were expressed in the reproductive organs of Jintang black goat simultaneously. The mRNA level of FSHRB is 45.89, 3.80, and 13.81 times greater than that of FSHRA in the hypothalamus, pituitary, and ovary of the Jintang black goat, respectively. We found that FSHRA could interact with FSHRB protein, leading to augment of the FSH signaling transduction pathway. The enhancement of FSH signaling could increase the in vitro oocyte maturation rate. It implied that this might be the important reason for the high prolificacy in Jintang black goat.