猪PRDX6基因编码区的多态性及遗传效应分析

Polymorphism in coding region of pig PRDX6 gene and its genetic effects analysis

PRDX6基因属于抗氧化蛋白超家族,主要在应答氧化压力、脂分解代谢、磷脂分解代谢中发挥作用。根据PRDX6基因的生理生化功能,文章选择其为影响猪肉质性状的候选基因,探索PRDX6基因的多态性与猪肉质性状的关系。首先分离了猪PRDX6的部分编码区序列,并在不同猪种间进行序列比对,发现编码区第4外显子有2个潜在的SNPs分别位于第417 bp处(C/T突变)和第423 bp处(A/G突变),但均没有引起氨基酸的改变。采用Pyrosequencing焦磷酸测序方法对这两个位点在6个猪种和247头F2"大白×梅山"资源家系中进行了遗传变异分析和性状关联分析。结果表明:417C/T位点国外品种均以C等位基因为主,而国内品种均以T等位基因为主,该位点与肌内脂肪、肌肉水分存在显著关联(P<0.05);423A/G位点国外品种均以A等位基因为主,国内品种以G等位基因为主,该位点与失水率、系水力、肌内脂肪及肌肉水分存在显著关联(P<0.05)。由此推断:这两个位点很可能是影响猪肉质性状(尤其是肌肉嫩度)的分子标记。

PRDX6,a member of antioxidant protein superfamily,plays an important role in oxidative stress,catabolism of lipids and phospholipid lipisomes.Therefore,we used PRDX6 as an important candidate gene for meat quality according to its physiological and biochemical function.Partial coding sequence of porcine PRDX6 was isolated and two potenial SNPs,one at 417 bp（C/T） and the other at 423 bp（A/G）,were found in the fourth exon by comparison of the obtained sequence from different pig breeds.In order to explore the relationship between PRDX6 polymorphism and meat quality,genetic variation and trait association of these two SNPs were separately performed in 6 purebred pig population and 247 F2 ＂Large White × Meishan＂ resource population by pyrosequencing.The results showed that allele C was predominant in western pig breeds,while allele T was predominant in Chinese indigenous breeds at 417 bp（C/T）.This SNP was significantly associated with the intramuscular fat and water moisture（P0.05）.The A/G mutation at 423 bp was significantly associated with drip water rate,water holding capacity,intramuscular fat,and water moisture（P0.05）.Allele A was predominant in western pig breeds,while allele G was predominant in Chinese indigenous breeds.These two SNPs were likely to be important markers affecting meat quality traits（especially the muscle tenderness）.