Protein and mRNA expression of gonadotropin-releasing hormone receptor in yaks during estrus

ABSTRACT To demonstrate the role of gonadotropin-releasing hormone (GnRH) in yaks (Bos grunniens), we characterized the expression of gonadotropin-releasing hormone receptor (GnRHR) mRNA and protein. The level of GnRHR mRNA in the hypothalamus was higher than that in the pineal gland, pituitary gland, and ovary during estrus. Immunofluorescence analysis showed that GnRHR was expressed in the pinealocyte, synaptic ribbon, and synaptic spherules of the pineal gland and that melatonin interacts with GnRHR via nerve fibers. In the hypothalamus, GnRHR was expressed in the magnocellular neurons and parvocellular neurons. In the pituitary gland, GnRHR was expressed in acidophilic cells and basophilic cells. In the ovary, GnRHR was present in the ovarian follicle and Leydig cells. Gonadotropin-releasing hormone receptor is located in the pineal gland, hypothalamus, pituitary, and gonad during estrus of yaks and is mainly expressed in the hypothalamus and ovaries during the estrus period.

摘要 为阐明促性腺激素释放激素（gonadotropin-releasing hormone, GnRH）在牦牛（Bos grunniens）中的作用，本研究对促性腺激素释放激素受体（gonadotropin-releasing hormone receptor, GnRHR）的mRNA及蛋白表达特征进行了系统分析。发情期内，牦牛下丘脑内GnRHR mRNA的表达水平显著高于松果体、垂体与卵巢。免疫荧光检测结果显示，GnRHR在松果体的松果体细胞、突触带及突触小球中均有表达，且褪黑素可通过神经纤维与GnRHR产生相互作用。在下丘脑，GnRHR表达于大细胞神经元与小细胞神经元中；在垂体，GnRHR表达于嗜酸性细胞与嗜碱性细胞内；在卵巢，GnRHR存在于卵泡与莱迪希细胞（Leydig cells）中。在牦牛发情期，促性腺激素释放激素受体广泛分布于松果体、下丘脑、垂体及性腺中，且发情期内主要表达于下丘脑与卵巢。