中文摘要：

采用PCR—SSCP技术检测抑制素A（inhibin A，INHA）基因外显子1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（多赛特羊、特克塞尔羊和德国肉用美利奴羊）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。结果表明，在所有5个绵羊品种中都存在2种基因型（AA和AB）。高繁殖力的小尾寒羊和湖羊等位基因B的频率分别为0．21和0．47，低繁殖力的多赛特、特克塞尔和德国肉用美利奴3个绵羊品种B等位基因频率分别为0．07、0．10和0．02。测序表明AB型和AA型相比在INHA基因外显子1中第877位发生T—c的碱基突变。独立性检验表明高繁殖力绵羊品种与低繁殖力绵羊品种之间INHA基因型分布差异显著（P〈0．05）。AB型小尾寒羊平均产羔数比AA型多0．57只（P〈0．01）。

英文摘要：

Inhibin A （INHA） gene was studied as a candidate gene for the prolificacy of Small Tail Han sheep Single nucleotide polymorphism of exon 1 oflNHA gene was detected in both high fecundity breeds （Small Tail Hart and Hu sheep） and low fecundity breeds （Dorset, Texel and German Mutton Merino sheep） by PCR-SSCP. Results indicated that there were two genotypes （AA and AB ） in all five sheep breeds tested. Frequency of allele B was 0.21 and 0.47 in prolific Small Tail Han and Hu sheep, respectively. Frequency of allele B was 0.07, 0.10 and 0.02 in Dorset, Texel and German Mutton Merino sheep, respectively. Sequencing revealed a T-＊C mutation at 877 bp of exon 1 oflNHA gene in the AB genotype in comparison to the AA genotype. The INHA genotype distributions were significantly different （P〈0.05） among high fecundity sheep breeds and low fecundity sheep breeds. The Small Tail Han ewes with heterozygous genotype AB had 0.57 （P〈0.01） lambs more than those with genotype AA.