松辽黑猪RBP4基因多态性及其与繁殖性状的关联分析

为探究松辽黑猪视黄醇结合蛋白4（RBP4）基因多态性及其与繁殖性状的关联性，试验选取132头松辽黑猪作为研究对象，以与猪繁殖性状相关的RBP4基因为候选基因，采用PCR-HRM分析与PCR产物直接测序相结合的方法检测松辽黑猪RBP4基因部分外显子的单核苷酸多态性（SNP），分析RBP4基因SNP与母猪总产仔数、产活仔数、乳头数及仔猪初生重、3周龄重、断奶重的关联性。结果显示，松辽黑猪RBP4基因第3、5外显子上各存在1个SNP位点，分别命名为为G45A和C170T，其中在G45A位点检测到GG、GA和AA 3种基因型，在C170T位点检测到CC和CT 2种基因型。群体遗传参数分析及卡方适合性检验结果显示，RBP4基因G45A位点在松辽黑猪群体中分布较为均匀，遗传变异程度处于中等水平，偏离Hardy-Weinberg平衡（P<0.01）；C170T位点在松辽黑猪群体中分布不均匀，遗传变异程度较低，未偏离Hardy-Weinberg平衡（P>0.05）。关联分析结果表明，在RBP4基因G45A位点上，3种基因型的总产仔数及产活仔数均表现为：GG > GA > AA，其中GG基因型的总产仔数、产活仔数显著高于AA基因型（P<0.05）；GG基因型仔猪3周龄重显著低于GA基因型（P<0.05）；GG基因型仔猪断奶重显著低于GA及AA基因型（P<0.05）；各基因型在仔猪初生重及母猪乳头数上未表现出显著差异（P>0.05）。在C170T位点上，不同基因型松辽黑猪的总产仔数、产活仔数、乳头数及仔猪初生重、3周龄重、断奶重均无显著差异（P>0.05）。综上，RBP4基因G45A位点对松辽黑猪产仔数具有显著影响，但该位点是否可作为松辽黑猪产仔数相关的遗传标记，有待进一步研究；RBP4基因C170T位点可能不是松辽黑猪繁殖性状相关的突变位点，在后期工作中需扩大群体做进一步验证。

Polymorphism of RBP4 Gene and Its Association with Reproductive Traits in Songliao Black Pigs

This study was aimed to investigate the association of the polymorphism of retinol-binding protein 4 (RBP4) gene with reproductive traits in Songliao Black pigs.132 Songliao Black pigs were selected,the single nucleotide polymorphism (SNP) of RBP4 gene in Songliao Black pigs were screened by PCR-HRM combined with DNA sequencing,and the correlation between SNPs and reproductive traits (total number born,number born alive,number of nipples,birth weight,3-week weight and weaning weight) were analyzed.The results showed that two SNPs (G45A and C170T) of RBP4 gene were detected,which were located in exons 3 and 5,respectively.There were three genotypes (GG,GA and AA) in the G45A site,and two genotypes (CC and CT) in the C170T site.The G45A site was uniform in Songliao Black pigs,and its variation and polymorphism were moderate,while it was not in Hardy-Weinberg equilibrium (P<0.01).The C170T site was uneven in Songliao Black pigs,and its variation and polymorphism were low,it was in Hardy-Weinberg equilibrium (P>0.05).In the G45A site,the total number born and number born alive were showed as GG > GA > AA,the total born and number born alive of GG genotype were significantly higher than AA genotype (P<0.05),the 3-week weight of GG genotype was significantly lower than GA genotype (P<0.05),the weaning weight of GG genotype was significant lower than GA and AA genotypes (P<0.05),there was no significant difference of birth weight and number of nipples in different genotypes (P>0.05).In the C170T site,there was no significant difference of all reproductive traits in different genotypes (P>0.05).In conclusion,the G45A site of RBP4 gene had a great influence on the litter size in Songliao Black pigs,it needed to further explore whether the G45A site could be used as a genetic marker for the litter size in Songliao Black pigs.The C170T site might not be a mutation site associated with reproductive traits in Songliao Black pigs,it needed to expand the number of pig for further verify.