小尾寒羊黄体期和卵泡期生殖轴凋亡基因的表达研究及其与发情的关系

摘要

In order to identify the differential expression levels of Bad,Bax,Bcl-2 and Bcl-xL in hypothalamus-pituitary-gonadal (HPG) axis tissues during luteal and follicular periods,and to study the association of these genes with year-round estrus in Small Tail Han sheep.Year-round estrous Small Tail Han ewes were selected as tested subjects,and real-time PCR method was used to detect Bad,Bax,Bcl-2 and Bcl-xL mRNA expression by using 18S RNA as reference gene in hypothalamus-pituitary-gonadal axis tissues during luteal and follicular periods.The serum estradiol and progesterone contents were measured by RIA at the corresponding time points.The results showed that Bad,Bax,Bcl-2 and Bcl-xL genes were all expressed in hypothalamus,pituitary and ovary tissues.The expression levels of Bad and Bcl-2 genes in pituitary and ovary tissues in the luteal phase were higher than those in the follicular phase (P＜0.05).The expression levels of Bad and Bcl-2 genes in hypothalamus had no significant differences between the luteal phase and the follicular phase (P＞0.05).The expression levels of Bax and Bcl-xL genes in hypothalamus,pituitary and ovary tissues had no significant differences between the luteal phase and the follicular phase (P＞0.05).The concentration of progesterone in the luteal phase was significantly higher than that in the follicular phase (P＜0.05),while the estradiol concentration had no significant difference between the 2 stages (P＞0.05).The results indicated that the expression levels of Bad and Bcl-2 genes had great differences during the luteal and follicular periods of Small Tail Han sheep,which might regulate the stage transition from luteal to follicular periods,and the 2 genes were associated with estrus onset in Small Tail Han sheep.%旨在分析Bad、Bax、Bcl-2和Bcl-xL基因在小尾寒羊黄体期和卵泡期下丘脑-垂体-性腺轴各组织中的表达差异,并探究这些基因与绵羊常年发情性状的关系.以常年发情小尾寒羊为研究对象,采用实时荧光定量PCR(Real-time PCR)技术,对比分析了Bad、Bax、Bcl-2和Bcl-xL 4个基因在不同繁殖状态下(黄体期和卵泡期)小尾寒羊下丘脑-垂体-性腺轴各组织中的表达特征,采用放射免疫法(RIA)检测相应时期血清雌二醇和孕酮含量.结果表明,Bad、Bax、Bcl-2和Bcl-xL 4个基因在下丘脑、垂体、卵巢均有表达,Bad和Bcl-2在黄体期的垂体和卵巢中的表达量均显著高于卵泡期(P＜0.05),在下丘脑中2个时期表达量都没有显著差异(P＞0.05);Bax和Bcl-xL在黄体期下丘脑、垂体和卵巢中的表达量与卵泡期均无显著差异(P＞0.05).黄体期血清中孕酮含量显著高于卵泡期(P＜0.05),而2个时期血清中雌二醇含量没有显著差异(P＞0.05).Bad和Bcl-2基因在小尾寒羊黄体期和卵泡期的垂体和卵巢中差异表达,可能参与调控黄体期到卵泡期的发情状态转换,从而启动小尾寒羊发情.