不同繁殖力湖羊垂体组织BMP/Smad信号通路基因mRNA表达量

mRNA expression levels of genes encoding BMP/Smad pathway molecules in pituiaries of Hu sheep with different fecundity

湖羊是世界著名的多胎绵羊品种,BMP/Smad信号通路与绵羊生殖有密切关系,为探讨高繁殖力和低繁殖力湖羊垂体组织中BMP/Smad信号通路基因mRNA表达水平差异,本试验选取16只经产湖羊母羊,分为产单羔组和多羔组,发情后屠宰记录卵巢排卵数,并采取垂体组织,利用荧光定量PCR技术对湖羊BMP/Smad信号通路各信号分子基因(包括BMP蛋白家族基因:BMP2、BMP4、BMP7;BMP受体基因:BMPRⅠA、BMPRⅠB、BMPRⅡ;细胞内Smad蛋白家族基因:Smad1、Smad4、Smad5)mRNA在垂体组织中的表达水平进行分析。结果显示,多羔组卵巢排卵数极显著高于单羔组(P<0.01);在垂体组织中,BMP2、BMP7、BMPRⅠA、BMPRⅡ、Smad1和Smad4基因表达量在单羔组和多羔组间没有显著差异(P>0.05),但是,多羔组BMP4、BMPRⅠB和Smad5基因表达量显著低于单羔组(P<0.01),且与卵巢排卵数分别呈不同程度的负相关,说明发情期湖羊垂体组织BMP4、BMPRⅠB和Smad5基因表达量差异可能是引起湖羊较高产羔数的原因之一。

Hu sheep is famous for its hyper-prolificacy in the world,and the BMP/Smad pathway is shown to have close relationships with reproduction in sheep. The present study was performed to determine the expressional differences of mRNAs encoding BMP/Smad pathway molecules in pituitaries of Hu sheep between high-fecundity and lowfecundity and to further investigate the relationships between their expressions and ovulation number. Sixteen adult H u ewes,grouped as high-fecundity （HF） and low-fecundity （LF）,were treated for synchronized estrous and sacrificed for tissue sampling and recording ovulation number. Expression levels in the pituitary of Hu sheep for BMP/ Smad pathway molecule genes, including BMP2, BMP4, BMP7, BMPR Ⅰ A, BMPR Ⅰ B, BMPR Ⅱ , Smadl, Smad5 and Smad4 were investigated by real-time PCR. The results showed that there were no significant differences in BMP2, BMP7, BMPR ⅠA, BMPR Ⅱ, Smadl and Smad4 mRNA abundance in the pituitary between H F and LF group （P〉 0. 05）, respectively. But BMP4, BMPR Ⅰ B and Smad5 mRNA abundances in the pituitary were respectively higher in HF group than those in LF group （P〈0.01） and negatively correlated with ovulation number. It is suggested that the expressional differences of BMP4, BMPR I B and Smad5 in the pituitary between high-fecundity and low-fecundity group might he one of factors for high fecundity in Hu sheep.