CXCR2基因多态性与奶牛体细胞评分的关联性

Association with CXCR2 gene polymorphism and SCS in dairy cow

利用基因测序技术对CXCR2基因进行了多态性筛查,结果发现存在+612A→G、+684G→A、+777G→C、+855G→A、+858C→A和+861G→A等6个突变位点,其中+855为新发现的SNP。6个位点都处于连锁不平衡状态,+684与+861位点之间和+777与+858之间的相关程度高(r2分别为0.635和0.541)。基因效应模型分析表明:+855和+861位点不同基因型对奶牛体细胞评分的影响没有显著性差异(P>0.05)。+612位点不同基因型对体细胞评分的影响具有显著性差异(P<0.05),AA基因型个体的体细胞评分最低为4.19,乳房炎抗性最强。+777位点不同基因型对体细胞评分的影响差异性显著(P<0.05),GG基因型个体体细胞评分最低为4.17,对乳房炎的抗性较强,说明该基因+612和+777SNPs可作为奶牛乳房炎抗性分子标记位点。

DNA sequencing technology were used to detect the polymorphism of CXCR2 gene, results showed that, there were six polymorphism loci called＋612A→G, ＋ 684G→A, ＋ 777G→C, ＋855G→A, ＋858C→A and ＋861G →A in the amplified segment,and ＋855 SNP was the new discovery. Linkage disequilibrium analysis results showed that the six SNPs were mutually independent in the heredity. The degree of correlation with ＋684 and ＋861, ＋777 and ＋858 were high so they can represent each other well. Linear modle analysis indicated： the two loci ＋855 and ＋861 had no significant effects on SCS（P〉0.05）. Different genotypes in ＋612 had significant effect on SCS（P〈0.05） ,SCS LSM of AA genotype individuals had the lowest SCS 4.19 and better mastitis resistance. Different genotypes in ＋777 locus had significant effect on SCS（P〈0.05）,SCS LSM of GG genotype was 4. 17 and had relative mastitis resistance. ＋612 and ＋777 SNPs can be used as the molecular markers for rnastitis resistance.