甘加藏羊发情周期下丘脑-垂体-卵巢轴KISS-1/GPR54的表达与分布

Expression and distribution of KISS-1/GPR54 on hypothalamic-pituitary-ovary axis in estrous cycle of Ganjia Tibetan sheep

为了研究高原甘加藏羊(Ovis aries)发情周期下丘脑-垂体-卵巢轴(hypothalamic-pituitary-ovary axis,HPOA)中肿瘤转移抑制基因(kisspeptins,KISS-1)/G蛋白偶联受体54(G protein-coupled receptors 54,GPR54)的表达及其对藏羊季节性发情周期的调控作用,本实验选取处于发情周期的甘加藏羊32只,应用qRT-PCR和免疫组织化学技术,检测其在发情周期HPOA组织中的表达和分布。qRT-PCR结果显示,甘加藏羊整个发情周期HPOA组织中均有KISS-1和GPR54 mRNA表达。下丘脑组织中发情前期KISS-1 mRNA相对表达量显著(P<0.05)高于其他3个发情时期;在垂体组织中发情前期和间情期的相对表达量较高,与发情后期差异显著(P<0.05);卵巢轴组织中间情期的相对表达量最高,显著(P<0.05)高于其他3个时期。下丘脑组织中发情期GPR54 mRNA相对表达量显著(P<0.05)高于其他3个时期;垂体组织中发情前期的相对表达量显著(P<0.05)高于其他时期;卵巢轴组织中发情后期的相对表达量显著(P<0.05)高于其他时期。免疫组织化学染色结果显示:Kisspeptin和GPR54阳性产物在下丘脑中主要分布于促垂体区的弓状核、脑室前腹侧区;腺垂体中主要在嗜碱性细胞和嫌色细胞中表达;卵巢轴中主要在卵泡颗粒层及卵泡内膜上表达。KISS-1和GPR54在藏羊发情周期HPOA中的差异表达,对藏羊季节性发情周期有一定的调控作用。

The aim of this study was to clarify the expression of KISS-1/GPR54 on the hypothalamus-pituitary-ovary axis(HPOA)of Ganjia Tibetan sheep during estrus cycle and its regulation function on seasonal estrus cycle in Ganjia Tibetan sheep.In this study,32 Ganjia Tibetan sheep in the estrus cycle were selected and the differences in the expressions and distribution of KISS-1/GPR54 on the hypothalamic-pituitary-ovary axis in the estrus cycle of Ganjia Tibetan sheep were detected by qRT-PCR and immunohistochemistry method.The qRT-PCR results showed that the expression of KISS-1 and GPR54 were found in HPOA tissues of Ganjia Tibetan sheep during the whole estrus cycle.In the hypothalamus,the relative expression levels of KISS-1 in proestrus were significantly(P<0.05)higher than the other three estrus stages.The relative expression levels of proestrus and interestrus in pituitary tissues were significantly(P<0.05)higher than that in metestrus.In the ovary axis tissue,the expression levels in the diestrus stage were significantly(P<0.05)higher than those in the other three estrus stages.The relative expression levels of GPR54 in the hypothalamus were the highest in the estrus stage,and were significantly(P<0.05)higher than those in the other three estrus stages;in the pituitary,the relative expression levels in the proestrus were significantly(P<0.05)higher than the other three estrus stages.The relative expression levels in the ovary axis tissues were the highest in proestrus,and were significantly(P<0.05)higher than that in other stages.Immunohistochemical staining results showed that kisspeptin and GPR54 positive products were mainly distributed in the cytoplasm and expressed in the arachnoid nucleus and the anterior ventral region of the ventricle in the hypothalamus.It was mainly expressed in basophil and chromophobe cells in adenohypophysis and in follicular granule layer and follicular intima in ovary axis.In conclusion,the differential expression of KISS-1 and GPR54 in the HPOA of Ganjia Tibetan sheep's estrus cycle had a certain regulatory effect on the seasonal estrus cycle of Tibetan sheep.