优良的BMPR-IB基因型可提高绵羊冷冻胚胎的受胎效果

以控制BooroolaMerino羊高繁殖力的BMPR-IB基因为候选基因,以小尾寒羊及其杂交羊、东北半细毛羊、澳洲美利奴羊、德国肉用美利奴羊、萨福克羊、特克塞尔羊、夏洛莱羊为试验对象,采用PCR-限制性片段长度多态性(PCR-RFLP)方法进行基因单核苷酸多态性(SNP)检测和基因型分析,同时研究基因对高繁殖力的影响.研究结果表明:小尾寒羊及其杂交羊、东北半细毛羊和夏洛莱羊群体中发现了与BooroolaMerino羊相同的A746G碱基突变,而小尾寒羊及其杂交羊群体的B等位基因频率明显高于其他2个品种.另外4个品种中未发现此突变.携带B等位基因的群体较非携带B等位基因群体排出更多的卵子,排卵后黄体直径较小.移植入冷冻胚胎后, 、B 和BB3种基因型群体的妊娠率分别为38.78%、45.71%和66.67%.由此推断,BMPR-IB基因突变很有可能从增加卵巢排卵数和提高胚胎着床及妊娠建立效率两个方面同时影响绵羊高繁殖力性状.所得BB型群体冻胚移植妊娠率明显高于 和B 型群体,已接近鲜胚移植水平,通过PCR-RFLP方法进行基因型分析,选用合适基因型群体作为胚胎移植受体,有可能为提高绵羊胚胎移植受胎率提供新的方向.

Preponderance Genotype of BMPR-IB Improves The Pregnant Rate of Embryo-transfer in Sheep

Bone morphogenetic protein receptor-IB gene(BMPR-IB)which controls the fecundity of Booroola Merino ewes was studied as candidate genes on the high prolificacy in sheep. Seven sheep breeds, small tail han sheep and its crosses, Northeastern Half-fuzz sheep, Australian Merino sheep, German Mutton Merino sheep, Suffork sheep, Texel sheep and Charolais sheep, were used. Single nucleotide polymorphism of BMPR-IB gene was detected in all sheep breeds by PCR-RFLP. The results showed that there was a same A746G mutation in BMPR-IB gene as that of Booroola Merino ewe, the frequency of B allele in the small tail han sheep and its crosses was significantly higher than that of the other two breeds, and the same mutation did not exist in other four breeds. The sheep carrying the B allele were able to ovulate more ova than non-gene carriers, and ovulating at a smaller diameter. The pregnant rates with respect to frozen embryo were 38.78%, 45.71% and 66.67% for the , B and BB animals, respectively. However, the results of present study showed that the A/G mutation in BMPR-IB gene appeared to positively affect both ova number and pregnancy process, which suggests that BMPR-IB gene play an important role in the regulation of sheep prolificacy. So ideal genotype sheep by PCR-RFLP as recipient is selected. It provides a new approach to improve pregnancy rate of embryo transfer.