Polymorphism of LHβgene and its relationship with litter number of goat | 山羊LHβ基因多态性与产羔数的相关分析

chinois. 研究布尔山羊和西农萨能奶山羊LHβ基因多态性及其与产羔数的相关性。采集布尔山羊和西农萨能奶山羊的血样，针对LHβ基因5′调控区及3个外显子设计6对引物，利用PCR-SSCP技术检测LHβ基因在6个位点上的多态性，并用最小二乘法研究该基因多态性与产羔数的关系。引物P1与P5扩增片段具有多态性，引物P1扩增产物有PP、PQ和QQ 3种基因型，P5扩增产物有LL和LM 2种基因型，其余4对引物的扩增片段没有多态性。LHβ基因P1引物位点PP与QQ基因型相比，PP型在第153 bp处发生了C→A突变；引物P5位点LL与LM基因型相比，LL型在第64 bp处发生了 T→C突变，2处突变均未导致氨基酸变化，为沉默突变。在引物P1位点，布尔山羊PP型个体第3，4胎产羔数均极显著高于PQ型个体(P0.01)，西农萨能奶山羊PP型个体第4，5胎产羔数均显著高于PQ型个体（P0.05）；在引物P5位点，布尔山羊LL型个体第4，5胎产羔数分别极显著(P0.01)和显著（P0.05）高于LM型个体，西农萨能奶山羊LL型个体第5胎产羔数极显著高于LM型个体(P0.01)。引物P1与P5扩增片段具有多态性，引物P1和P5位点可能对山羊的产羔数有影响。

anglais. This experiment studied the relationship between the genetic polymorphisms of the LHβ gene and the litter number of Boer and Xinong Saneng dairy goat. Blood samples were collected from Boer goat and Xinong Saneng dairy goat, PCR-SSCP and sequencing were applied to analyze the effect of the genetic variation, and least square was applied to analyze the correlation of different genotypes and the litter number. Six pairs of primers were designed to detect single nucleotide polymorphisms of LHβgene by PCR-SSCP. The results revealed that there were three genotypes (PP, PQ and QQ ) for P1 and two genotypes (LL and LM ) for P5 respectively. The mutations did not cause any amino acid change and were silence mutations. For primer 1, the difference of the least squares mean showed that only the products amplified by primer P1 and P5 displayed polymorphisms. Sequencing (LSM) for litter size between PP and PQ was significant (P0.01). The litter number of individuals with genotype PP was higher than that with genotype PQ in the third and the fourth litter of Boer goat and in the fourth and fifth litter of Xinong Saanen dairy goat. For primer P5, the litter number of individuals with genotype LL was higher than that with genotype LM in the fourth litter of Boer goat and Xinong Saanen dairy goat. The result showed that only the products amplified by primer P1 and P5 displayed polymorphisms, and had significant effect on goat litter number. The LHβ gene can be regarded as an effective molecular marker on MAS program for litter number of goat.