澳系进口荷斯坦奶牛CXCR1基因遗传多态性与泌乳性状及体细胞评分的关联性分析

Genetic polymorphism of the CXCR1 gene and its associations with milk traits and SCS in Holstein imported from Australia

采用聚合酶链式反应-单链构象多态性(PCR-SSCP)技术对以海丰奶牛场588头澳系进口荷斯坦牛牛趋化因子受体1(Chemokine receptor 1,CXCR1)基因的遗传多态性进行分析;采用混合动物模型分析CXCR1基因2个突变位点与测定日产奶量、乳脂率、乳蛋白率、305d产奶量、305d乳脂量、305d乳蛋白量及体细胞评分7个性状的相关性,寻找可用于生产实际的分子标记。结果显示,CXCR1基因5′侧翼区-1830位点发生了A→G的突变,检测到AA、AG和GG 3种基因型,频率分别为0.684、0.289和0.027,等位基因A和G的频率分别为0.828和0.172;GG基因型奶牛的日产奶量、SCS和305d产奶量均极显著高于AA基因型(P<0.01),而其乳脂率和乳蛋白率却显著低于AA基因型奶牛(P<0.05)。编码区783位点仅发现AA和AC 2种基因型,基因型频率分别为0.886和0.114,等位基因A和C的频率分别为0.943和0.057。AA型的个体的日产奶量、305d脂肪产量和305d蛋白产量极显著高于AC型个体,而其乳脂率、乳蛋白率和SCS却极显著低于AC型个体(P<0.01)。结果表明,CXCR1基因遗传突变对澳系进口荷斯坦牛泌乳性状和乳房炎抗性有较大的遗传效应,可用于澳系进口荷斯坦牛的分子标记辅助选择。

The effects of two mutations in Chemokine receptor 1 （CXCR1） gene for 588 Holstein cows imported from Australia in Haifeng dairy cattle farm were investigated according to 7 mil- king performances.tested day milk yield, milk fat percentage, milk protein percentage, 305 d corrected milk yield,305 d milk fat yield,305 d milk protein yield and somatic cell score （SCS）. The aim was to explore the significant molecular marker in practical dairy production. The polymorphism of CXCR1 gene was analyzed using polymerase chain reaction-single strand conformation polymorphism （PCR-SSCP） technique, and with a mixed animal model, to verify the effects of the polymorphism on milking performances and SCS. The results showed three genotypes were identified in the 5r upstream of -1830（A/G）,and the genotypic frequencies of AA,AG and GG were 0. 684,0. 289 and 0. 027,respectively. The gene frequencies of A and G were 0. 828 and 0. 172. GGgenotype had significantly higher tested day milk yield, SCS and 305 d corrected milk yield than AA genotype （P^0.01） ,but its milk fat percentage,milk protein percentage were lower than AA （P（0.05）. Only two genotypes were found in the coding region at 783 site,and the genotypic frequencies of AA and AC were 0. 886 and 0. 114 ,respectively. The gene frequencies of A and C were 0. 943 and 0. 057. The tested day milk yield,305 d milk fat yield and 305 d milk protein yield of AA genotype were significantly higher than AC genotype. However,AA genotype had significantly lower milk fat percentage,milk protein percentage and SCS than AC genotype （P〈0.01）. The CXCR1 gene genetic diversity has a great genetic effect on milk traits and mastitis resistance and could be a useful genetic marker for Holstein cows imported from Australia.