中文摘要：

设计5对引物，采用PCR-SSCP技术检测催乳素（prolactin，PRL）基因外显子1至外显子5在高繁殖力绵羊品种（小尾寒羊和湖羊）和低繁殖力绵羊品种（多赛特、特克塞尔和考力代）中的单核苷酸多态性，同时研究该基因对小尾寒羊高繁殖力的影响。通过克隆测序首次获得了绵羊PRL基因外显子全序列。结果表明，外显子2在5个绵羊品种中均存在单核苷酸多态性，而其它4个外显子只在湖羊中存在单核苷酸多态性。研究初步表明，小尾寒羊PRL基因外显子2的CC型平均产羔数分别比CD型和DD型多0．39只（P〈0．05）和0．98只（P〈0．05），CD型和DD型小尾寒羊平均产羔数差异不显著（P〉0．05）。

英文摘要：

The prolactin （PRL） gene was studied as a candidate gene for the prolificacy of Small Tail Han sheep. Single nucleotide polymorphisms （SNPs） ofexon 1 to exon 5 ofPRL gene were detected in high fecundity breeds （Small Tail Han and Hu sheep） and low fecundity breeds （Dorset, Texel and Corriedale sheep） with five pairs of primers by PCR-SSCP. The entire exon sequence of ovine PRL gene was obtained firstly by means of cloning and sequencing. SNPs of the exon 2 were detected in five sheep breeds and the other exons （exon 1, exon 3 to exon 5） only in Hu sheep. For the exon 2 ofPRL gene, the Small Tail Han ewes with genotype CC had 0.39 （P 〈0.05） or 0.98 （P 〈0.05） lambs more than those with genotype CD or DD; the Small Tail Han ewes with genotype CD had 0.59 （P〉0.05） lambs more than those with genotype DD.