孕酮受体基因多态性及其与小尾寒羊产羔数的关系

Polymorphism of progesterone receptor gene and its relationship with litter size of Small Tail Han sheep

设计15对引物,采用PCR-SSCP技术检测孕酮受体(progesterone receptor,PGR)基因全部9个外显子在小尾寒羊、湖羊、特克塞尔和多赛特中的单核苷酸多态性,同时研究该基因对小尾寒羊产羔数的影响。只有引物P9扩增片段具有多态性。对于P9扩增片段,在小尾寒羊、湖羊和多赛特中均检测到AA、AG和GG型,在特克塞尔中只检测到AA和AG型。测序表明GG型与AA型相比在217 bp处有一单碱基突变(A→G),但未引起氨基酸变化。GG型和AG型小尾寒羊产羔数均值分别比AA型的多0.97只(P<0.05)和0.64只(P<0.05),GG型和AG型小尾寒羊产羔数差异不显著(P>0.05)。结果初步表明PGR基因的G等位基因是提高绵羊产羔数的一个潜在有效的DNA标记。

Fifteen pairs of primers were designed to detect single nucleotide polymorphisms of exon 1 to exon 9 of progesterone receptor（PGR） gene in Small Tail Han,Hu,Dorset and Texel sheep by PCR-SSCP.Only the products amplified by primer P9 displayed polymorphism.For primer P9,three genotypes（AA,AG and GG） were detected in Small Tail Han,Hu and Dorset sheep,and two genotypes（AA and AG） in Texel sheep.Sequencing revealed one mutation（217A→G） of PGR gene in the genotype GG in comparison to the genotype AA,and this mutation did not cause any amino acid changes.The ewes with genotype GG or AG had 0.97（P〈0.05） or 0.64（P〈0.05） lambs more than those with genotype AA,and the difference of the litter size between GG and AG genotypes was non-significant（P〈0.05） in Small Tail Han sheep.These results preliminarily indicated that allele G of PGR gene is a potential DNA marker for improving litter size in sheep.