猪钙蛋白酶抑制蛋白基因的基因型与肉质性状的关联性分析

钙蛋白酶抑制蛋白基因是影响猪肉质性状的候选基因之一。本研究以125头地方猪和117头外来猪为材料，研究CAST基因的多态性。结果在CAST基因上检测到一个多态性位点(A876G)，并引起了氨基酸残基的改变Lys250 Arg。在地方猪种中仅检测到G (Arg)等位基因，而在外来猪种中A (Lys) 和 G (Arg)两个等位基因均检测到。基因型与肉质性状的关联性分析结果表明，CAST基因型与肌肉的嫩度，屠宰45 min后的pH值及滴水损失存在强相关，又由于地方猪种与外来猪种的肉质性状间存在显著差异。因此，在CAST基因上检测到的多态型位点Lys250Arg的基因型效应有待于进一步研究，并将其有效应用于商品猪生产中。

Calpastatin Genotype is Associated with the Meat Quality Traits in Pigs

Calpastatin (CAST) gene was considered to be a good candidate for meat quality traits. Total of 242 animals, including 125 from two Chinese and 117 from two Western pig lines were genotyped on CAST gene. One substitutions (A876G) in the porcine CAST gene was detected causing substitution of Lys at position 250 with Arg .. The results show that only allele G (Arg) was examined in Chinese pigs, whereas allele A (Lys) and allele G (Arg) in Western pigs, indicating these two groups of pigs diverged at this locus during genetic evolution of the breed. Association analyses between genotypes and meat quality traits demonstrated that one CAST genotype was significantly associated with higher tenderness, higher pH at postmortem 45 min, and lower drip loss and, therefore, this genotype is associated with higher eating quality. Because marked differences in meat quality exist between Western and Chinese pig breeds, this Lys250Arg variation in the CAST gene deserves further evaluation to determine its phenotypic effect on meat quality traits in commercial pig populations.