绵羊LHR基因PCR-SSCP多态性与繁殖性状的关联分析

通过聚合酶链式反应-单链构象多态性(PCR-SSCP)分析方法检测绵羊品种(湖羊、晋中绵羊和陵川半细毛羊)促黄体素受体(luteinizing hormone receptor,LHR)基因外显子11核酸序列的单核苷酸多态性,并研究该基因多态性对湖羊性早熟和产羔数的影响。结果表明:在6对引物扩增产物中,只有引物P2和P6的扩增片段具有多态性,引物P2扩增区存在2种基因型,分别为LL和LM型,在3个绵羊品种中均未检测到MM型;引物P6扩增区存在6种不同的SSCP带型,经序列比对分析存在T2053A、A2044T和G2003A的错义突变。湖羊和晋中绵羊P2扩增区基因型分布差异不显著(P>0.05),而与陵川半细毛羊均存在极显著差异(P<0.01);P6扩增区的2 053、2 044、2 003位点各基因型分布在湖羊和晋中绵羊间差异不显著(P>0.05),而与陵川半细毛羊间存在显著差异。P2扩增位点仅陵川半细毛羊的基因分布不符合哈迪-温伯格定律;P6扩增区湖羊和晋中绵羊在各突变位点的等位基因频率处于群体平衡状态,陵川半细毛羊除2 003突变位点基因分布处于群体不平衡状态外,其余突变位点的等位基因频率分布符合哈迪-温伯格定律;LHR外显子11区不同基因型湖羊各胎次产羔数差异不显著(P>0.05),表明LHR外显子11对湖羊的性早熟和高繁殖力性状没有显著影响。

Correlation analysis between PCR-SSCP polymorphisms of luteinizing hormone receptor gene (LHR) and reproductive traits in sheep

The nucleotide sequence and single-strand conformation polymorphism(SSCP) in exon 11of luteinizing hormone receptor(LHR) gene were studied in Hu sheep(sexual precocity and high prolificacy breeds),Jinzhong sheep and Lingchuan semi-fine wool sheep(delayed puberty and low prolificacy breeds),as well as the effect of the gene polymorphism on the sexual precocity and prolificacy in Hu sheep.Results showed that products amplified by primer P2and P6had polymorphisms.Only two genotypes(LL and LM) were found for primer P2,and six SSCP types and three mutations(T2053A,A2044Tand G2003A) were detected for primer P6.There were no significant difference in genotype distribution between Hu sheep and Jinzhong sheep but extremely significant differences between Lingchuan semi-fine wool sheep and the other two breeds for primer P2.The distribution of SSCP types and genotypes in three mutation sites(2 053,2 044and 2 003) was no significant differences between Hu sheep and Jinzhong sheep but significant difference between Lingchuan semi-fine wool sheep and the other two for primer P6.The allele frequencies of mutation sites,except P2and 2 003mutation site of P6in Lingchuan semi-fine wool sheep,were accordant with Hardy-Weinberg law.Considering that litter sizes among all kinds of genotypes in Hu sheep had no significant difference,it could be preliminarily concluded that exon 11of LHRhad no significant influence on its sexual precocity and prolificacy.