贵州地方猪种UCP3基因多态性与肉质性状的相关性分析

解耦联蛋白3(uncoupling protein 3,UCP3)是调节能量和脂肪代谢的重要因子。以商品猪(杂交猪)为对照,采用SSCP方法对贵州地方猪品种糯谷猪和萝卜猪的UCP3基因进行了多态性分析。结果表明:3个猪群体中,都检测到了3种基因型(AA、BB、AB),χ2独立性检验结果显示,3种基因型在3个群体间的分布不一致,糯谷猪和萝卜猪以AB基因型为主,杂交猪以BB基因型占优势,杂交猪与地方猪种之间的差异显著(P<0.01);对纯合基因型的UCP3基因片段进行克隆测序,证实AA基因型中UCP3基因外显子6编码区第842位碱基发生了单碱基突变(T→C),导致编码的氨基酸从苏氨酸突变为甲硫氨酸。进一步分析3种基因型与胴体和肉质性状之间的相关性,证明AB基因型个体的肉质最优,贵州地方猪种的大理石纹、肌内脂肪含量和嫩度3项指标显著优于商品猪(P<0.01),因此推测UCP3基因与贵州地方猪种的肉质性状具有相关性,可能是贵州地方猪种肉质性状的候选基因。

Correlation between the Polymorphism of UCP3 Gene and Meat Traits in Guizhou Native Pigs

Uncoupling protein 3, expressed in muscle, belongs to the UCP family, which is important in the metabolism of energy and fat. Taking a control of hybrids breed, the aim of the present study was to investigate the polymorphism of UCP3 gene and its correlation with meat traits by single strand conformation polymorphism(SSCP) method in the two-local pig breeds: Nuogu pig and Luobo pig. Three different genotypes, AA, BB and AB, were detected in three pig populations. Furthermore, the three genotypes were detected in three pig breeds analyzing by chi (χ2) test. The two local pig breeds in Guizhou had dominant genotype of AB, but in hybrids breed the dominant genotype was BB. Both of the frequencies of AB genotypes in the two local pig breeds were significantly different with hybrid breed(P < 0.01); after cloning the DNA fragment of exon 6 in UCP3 gene from AA and BB genotypes, a single nucleotide mutation (T/C) was confirmed in the 842 base of coding region, which resulted in the amino acid change from threonine to methionine. Analyzing the three genotypes of UCP3 gene and its correlation with meat traits, the individual with AB genotype had the most excellent meat traits; three meat quality traits in local porcine of Guizhou, marble score, intramuscular fat content, tenderness, were significantly better than those in BB and AA genotypes(P < 0.01). These results suggested that the single nucleotide polymorphisms of exon 6 in UCP3 gene were related to the good meat traits of Nuogu and Luogo pig breeds. UCP3 gene could be a molecular marker for the selection and breeding of Nuogu and Luobo pig.