荷斯坦奶牛STAT5A基因的SNPs检测及其与产奶性状的关联分析

根据GenBank公布的牛STAT5A基因的2个SNPs（AJ237937和AF079568）的引物序列,采用PCR-SS-CP方法对758头中国荷斯坦奶牛进行了STAT5A基因多态性检测,并将其与5个产奶性状进行了关联分析。在SNP1的9501碱基处发现A→G突变;SNP2中发现2个连锁点突变,即12 440位T→C和12 550位的CCT插入/缺失;方差分析结果表明：SNP1对乳蛋白率有显著影响（P〈0.05）;SNP2对产奶量有极显著影响（P〈0.01）,对乳脂量、乳蛋白量有显著影响（P〈0.05）;单倍型组合对产奶量和乳蛋白量有极显著影响（P〈0.01）,对乳脂量有显著影响（P〈0.05）。多重比较分析表明SNP2的AB基因型的产奶量、乳脂量和乳蛋白量的最小二乘均数极显著（P〈0.01）或显著（P〈0.05）高于基因型AA;而单倍型组合H1H2的产奶量、乳脂量和乳蛋白量的最小二乘均数显著（P〈0.05）或极显著（P〈0.01）高于其它4种单倍型组合;H3H4对产奶量和乳蛋白量的效应极显著高于其它4种单倍型组合（P〈0.01）。结果提示：STAT5A基因可以作为奶牛产奶性状的候选分子遗传标记。

SNPs Detection of STAT5A Gene and Association with Milk Production Traits in Holstein Cattle

Based on the primer sequences of two SNPs(AJ237937 and AF079568) of STAT5A gene from the GenBank database,polymorphisms on the two SNPs were detected in 758 Chinese Holstein cattles with PCR-SSCP and association between the polymorphisms and 5 milk production traits were analyzed.We found that the SNP1 was A/G(9501) and the SNP2 were T/C(12 440) and CCT insert/delete(12 550).Statistical results indicated that the SNP1 was significantly associated with protein percentage(P<0.05),the SNP2 was significantly associated with milk yield(P<0.01),fat yield(P<0.05) and protein yield(P<0.05),and the diplotype was associated with milk yield(P<0.01),protein yield(P<0.01) and fat yield(P<0.05).Duncan's multiple-range test showed that the cows with genotype AB of SNP2 had significantly higher milk yield(P<0.01),fat yield(P<0.05) and protein yield(P<0.05) than the cows with genotype AA.In addition,the least square mean for milk yield,fat yield,and protein yield of diplotype H1H2 was significantly higher than those of other four diplotypes(P<0.05 or P<0.01),respectively,and the least square mean for milk yield and protein yield of diplotype H3H4 was significantly higher than those of other four diplotypes(P<0.01).Our finding implied that STAT5A gene would be useful candidate gene in selection program on milk production traits in Holstein cattle.