中文摘要：

设计6对引物，用聚合酶链式反应-单链构象多态性（PCR-SSCP）和序列分析方法检测促黄体素受体（1uteinizing hormone receptor，LHR）基因外显子11在性早熟、高繁殖力山羊（Capmhircus）品种（济宁青山羊）和性晚熟、低繁殖力品种（波尔山羊、安哥拉山羊和内蒙古绒山羊）中的单核苷酸多态性，同时研究该基因对济宁青山羊性早熟和高繁殖力的影响。结果发现，仅引物P3和P6的扩增片段具有多态性。引物P3在波尔山羊中检测到AA、AB和BB基因型，在济宁青山羊和安哥拉山羊中均检测到从和AB基因型，在内蒙古绒山羊中只检测到AA基因型；测序发现BB基因型与AA基因型相比存在1个突变（G1522A），导致505位氨基酸由缬氨酸变为甲硫氨酸（V505M）；济宁青山羊AA和AB基因型频率分别为0．919和0．081，在P3位点上处于哈迪-温伯格平衡状态（X^2=0．26，P=0．877）；济宁青山羊与波尔山羊、安哥拉山羊和内蒙古绒山羊之间LHR基因型分布差异分别达到极显著（P〈0．001）、显著（P〈0．05）和不显著（P〉0．05）水平；济宁青山羊AA和AB基因型之间产羔数差异不显著（P〉0．05）。引物P6在4个山羊品种中均检测到CC和CD基因型；测序发现CD与CC基因型相比发生了A2039G突变，导致677位氨基酸由谷氨酰胺变为精氨酸（Q677R）；济宁青山羊CC和CD基因型频率分别为0．161和0．839，在P6位点上处于哈迪-温伯格不平衡状态（X^2=77．79，P=0．000）；济宁青山羊与波尔山羊、安哥拉山羊和内蒙古绒山羊之间LHR基因型分布差异分别达到极显著（P〈0．001）、极显著（P〈0．001）和显著（P〈0．05）水平；济宁青山羊CC和CD基因型之间产羔数差异不显著（P〉0．05）。研究结果初步表明LHR基因外显子11对济宁青山羊的性早熟和高繁殖力没有显著影响。

英文摘要：

The luteinizing hormone receptor （LHR） gene was studied as a candidate gene for the sexual precocity of Jining Grey goats （Capra hircus）. Six pairs of primers were designed to detect single nucleotide polymorphisms of LHR gene exon 11 in sexual precocity and high prolificacy breed （Jining Grey goat） and delayed puberty and low prolificacy breeds （Boer, Angora and Inner Mongolia Cashmere goats） by sequence analysis and PCR-SSCP. The results showed that only the products amplified by primers P3 and P6 displayed polyrnorphisms. For primer P3, three genotypes （AA, AB and BB） were detected in Boer goats, two genotypes （AA and AB） were in Jining Grey and Angora goats, only AA genotype was in Inner Mongolia Cashmere goats. Sequencing revealed one mutation （G1522A） in genotype BB compared with genotype AA, which caused valine substitution with methionine （V505M）. The frequency of AA and AB genotypes was 0.919 and 0.081 in Jining Grey goats. The fitness tests showed that the Jining Grey goat population was in Hardy-Weinberg equilibrium （X^2 =0.26, P =0.877）. Genotype distributions of LHR gene were at different levels （P 〈0.001, P 〈0.05, P 〉0.05） between Jining Grey goats and Boer, Angora and Inner Mongolia Cashmere goats. No significant difference （P 〉0.05） was found in litter size between AA and AB genotypes in Jining Grey goats. For primer P6, CC and CD genotypes were detected in four goat breeds. Sequencing revealed one mutation （A2039G） of genotype CD compared with genotype CC, which resulted in amino acid substitution of Q677R. The frequency of CC and CD genotypes was 0.161 and 0.839 in Jining Grey goats. The fitness tests showed that the Jining Grey goat population was not in Hardy-Weinberg equilibrium （X^2 =77.79, P =0.000）. Genotype distributions of LHR gene were at different levels （P 〈0.001, P 〈0.001, P 〈0.05） between Jining Grey goats and Boer, Angora and Inner Mongolia Cashmere goats. No significant difference （P 〉0.05） was found in li