摘要：
利用现代分子标记技术寻找影响猪产仔数的标记基因座，为应用标记辅助选择培育高繁殖率猪的品种或品系提供依据。试验采用PCR-SSCP技术检测了安徽4个地方品种猪(安庆六白猪、皖南黑猪、皖南花猪、定远黑猪)OB基因第2、第3外显子的多态性，同时探讨该基因对安徽4个地方品种猪产仔性能的效应。结果显示：①安徽4个地方品种猪的OB基因外显子2上没有检测到多态性突变位点，而在外显子3上两对引物的扩增片段均存在多态性突变位点；经克隆测序分析发现，外显子3在3 469 bp处存在T→C突变，在3 714 bp处存在G→T突变，但这两个突变位点均属于同义突变。②T3469C突变位点上检测到AA、AB、BB 3种基因型，其中安庆六白猪、皖南黑猪、皖南花猪与定远黑猪等位基因A基因频率分别为0.617 6、0.637 3、0.527 3、0.609 6；G3714T突变位点上检测到CC、CD、DD 3种基因型，其中安庆六白猪、皖南黑猪、皖南花猪与定远黑猪等位基因的C频率分别为0.705 9、0.578 4、0.663 6、O.637 0；A、C等位基因占主导地位。③最小二乘分析表明，T3469C和G3714T位点上3种基因型对4个地方品种猪在头胎产活仔数和经产产活仔数上的效应均为BB＞AB＞AA、DD＞CD＞CC。初步推断OB基因可能是影响安徽地方猪产仔性状的候选基因之一或该基因与主基因相连锁，因此可以用该标记位点对安徽地方猪产仔性状进行标记辅助选择。%Modern molecular marker techniques were used to seek the marker loci which affect the litter size of pig and provide the foundation for selecting or breeding pigs with high reproduction rate. The PCR-SSCP technique was used to analyse the polymorphism of the second and third exon in OB gene in four Anhui indigenous pig breeds (Anqingliubai pig, Wannan black pig, Wannanhua pig, Dingyuan black pig) , and the effects of OB gene on litter performance of the four pig breeds. The results were showed as follows; ① There was no polymorphism mutation in the second exon of OB gene in the four Anhui indigenous pig breeds, while there existed two polymorphism mutations in two pairs of amplification primers in the third exon. By sequencing, the two polymorphism mutations were found in 3 469 bp (T→C) arid 3 714 bp (G→T) inthe third exon, respectively, but both of them belonged to silent mutations.②Three genotypes of AA, AB, BB were detected in the T3469C mutation and the A allele frequencies were 0.617 6, 0.637 3, 0.527 3, 0.609 6 in Anqingliubai pig, Wannan black pig, Wannanhua pig and Dingyuan black pig, respectively. CC, CD, DD genotypes were detected in the G3714T mutation and the C allele frequencies were 0.705 9, 0.578 4, 0.663 6, 0.637 0 in Anqingliubai pig, Wannan black pig, Wannanhua pig, and Dingyuan black pig, respectively. In addition, A and C alleles played important roles. ③ Least-square analysis revealed that these three genotypes in T3469C and G3714T loci showed the same trend with BB＞AB＞AA and DD＞CD＞CC in the effects on the number born alive (NBA) of the first parity and the NBA of the latter parities in the four indigenous pig breeds. It was concluded that OB gene was probably one of candidate genes, or one linked with major genes, which affected litter traits in Anhui indigenous pigs. Therefore, this marker locus could be used for marker assisted selection of litter traits in Anhui indigenous pigs.
