中文摘要：

【目的】分析不同繁殖状态阿勒泰羊下丘脑褪黑素受体1A（MTNR1A）基因表达情况与其季节性繁殖之间的关系，为深入研究绵羊季节性繁殖的调控机理奠定基础。【方法】采用RT-PCR对发情盛期阿勒泰羊不同组织中的MTNR1A基因表达情况进行检测，并以qRT-PcR测定分析乏情期及发情初期、发情盛期、发情末期和间情期阿勒泰羊下丘脑MTNR1A基因的表达变化情况。【结果】MTNR1A基因在发情盛期阿勒泰羊的下丘脑、垂体、卵巢和脾脏中高表达，而在心肌、肺脏和骨骼肌中不表达或表达量极低。秋季发情季节阿勒泰羊下丘脑中MTNR1A基因的表达量极显著高于夏季乏情季节（P〈0．01），但在发情前期、发情盛期、发情末期和间情期的表达量差异不显著（P〉0．05）；夏至后20d下丘脑中MTNR1A基因的表达量显著高于夏至前20d（P〈0．05）。【结论】褪黑素及其受体在阿勒泰羊发情启动过程中发挥重要的调控作用。

英文摘要：

[Objective]The present experiment was conducted to investigate relationship between melatonin recptor IA （MTNR1A） gene expression in hypothalamus of Altay sheep and its seasonal reproduction, in order to lay the foundation for further study on regulation mechanism of seasonal reproduction for sheep. [Method]The expression of MTNRIA gene in different tissues of estrous Ahay sheep were detected by using RT-PCR technique, and its expression change in hy- pothalamus at proestrus, estrus fastigium, metoestrus and anoestrus stages were detected using qRT-PCR. [Result]The results showed that the MTNRIA gene was expressed at high level in hypothalamus, pituitary, ovary and spleen, while was at lower level in cardiac muscle, lung and skeletal muscle. The expression level of MTNRIA gene in autumn estrous season was extremely significantly higher than that in summer anoestrus season（P〈0.01）, but there were non-significant dif- ferences in expression level of MTNR1A gene among proestrus, estrus fastigium, metoestrus and anoestrus （P〉0.05）. The expression level of MTNR1A gene in hypothalamus on the 20th day after summer solstice was significantly higher than that on the 20th day before summer solstice （P〈0.05）. [Conclusion ]The melatonin and its receptor play vital regulatory role for actuat- ing oestrus of sheep.