小梅山猪LHR基因第11外显子PCR-RFLP多态性及其与产仔数的关联分析

Polymorphism of PCR-RFLP in exon 11 of LHR gene and its relationship with litter size in Xiaomeishan pigs

采用混合基因池和直接测序方法,寻找猪LHR基因第11外显子区域的SNP;利用PCR-RFLP技术对小梅山猪、枫泾猪和大白猪3个群体218头繁殖母猪进行大规模检测,并采用最小二乘法分析其与616窝小梅山猪繁殖记录的关系。结果表明,在猪LHR基因第11外显子1 351bp处发现1个SNP(C→T);利用错配PCR技术产生1个新的酶切位点SphⅠ,经RFLP分析,在小梅山猪群体中检测到3种基因型:MM、MN、NN,其中MN基因型频率最高(0.69),而枫泾猪和大白猪中只检测到MM型个体;关联分析及方差分析结果表明,对于小梅山猪母猪,2胎以上中,MN型的总产仔数(TNB)显著高于NN型(P<0.05);所有胎次中,MN型的TNB和活产仔数(NBA)均显著高于NN型(P<0.05);初步表明,MN基因型为优势基因型,TNB和NBA的遗传主要受基因的显性效应的影响;LHR基因第11外显子可作为小梅山猪辅助选择的遗传标记。

The present study was to detect the polymorphism of exon 11 of luteinizing hormone receptor gene（LHR） and investigate the relationship between LHR gene and litter size in pigs. SNPs of exon 11 of LHR gene were searched by DNA pooling and DNA sequencing methods,which were then large-scale detected by PCR-RFLP in Xi- aomeishan,Fengjing and Large White pigs of about 218 breeding sows. And the effects of genotypes of LHR on re- productive records of 616 litters of Xiaomeishan piglets were analyzed by the least square analysis. The results showed that 1 novel SNP were detected at 1 351 bp locus of exon 11 of pig LHR gene,which caused C mutation for T,and produced a new restrict enzyme site（Sph I ） by mismatch PCR. Three genotypes were detected by RFLP technology in Xiaomeishan pigs, which were called MM, MN and NN genotype respectively, and in which the MN genotype frequency was the highest（0.69）. And there was only MM genotype founding in Fengjing and Large White pigs. The results of correlation analysis and analysis of variance showed that in Xiaomeishan pigs MN genotype had significantly higher TNB than NN genotype in more than 2 parities（P〈0.05） ,while in all parities MN genotype had significantly higher TNB and NBA than NN genotype（P〈0.05）. The preliminary results suggested that MN geno- type was the dominant genotype in Xiaomeishan pigs,and the heredity of TNB and NBA were mostly influenced by the genetic dominant effect. The exon 11 of LHR gene could be used as a genetic marker in assisted selection of Xi- aomeishan pigs.