南方地区中国荷斯坦牛DGAT1基因多态性与泌乳性状的关联分析

 【目的】探索南方地区中国荷斯坦牛DGAT1基因多态性与泌乳性状的相关性。【方法】以上海光明乳业集团金山奶牛场30个公牛家系的605头中国荷斯坦牛为试验材料,采用PCR-SSCP法分析DGAT1基因K232A位点遗传多态性,采用混合动物模型分析DGAT1基因K232A位点突变对测定日产奶量、乳脂率、乳蛋白率、305 d校正产奶量、乳脂量、乳蛋白量及体细胞评分7个泌乳性状的影响。【结果】共检测到KK、KA和AA三种基因型,频率分别为0.7918、0.1917和0.0165,等位基因K和A的频率分别为0.8876和0.1124。该位点突变对测定日产奶量、乳脂率、乳蛋白率、305 d校正产奶量、乳蛋白量的影响达到极显著水平(P＜0.01),对乳脂量的影响达到显著水平(P＜0.05),对乳中体细胞评分影响不显著(P＞0.05)。多重比较表明,KK和KA型测定日产奶量、305 d校正产奶量和乳蛋白量极显著高于AA型(P＜0.01),AA型乳脂率和乳蛋白率极显著高于KK和KA型(P＜0.01)。【结论】DGAT1基因K232A位点突变对中国荷斯坦牛泌乳性状有较大的遗传效应,可用于其泌乳性状的分子标记辅助选择。

Analysis of Association Between DGAT1 Gene and Milking Traits in Chinese Holstein in the South of China

【Objective】 Analysis of association between DGAT1 gene and milking traits for Chinese Holstein in the south of China was investigated. 【Method】 The polymorphism of the K232A site in exon 8 of DGAT1 gene was investigated in 605 Chinese Holstein cows from 30 bull families in Jinshan Dairy Farm of Shanghai Bright Dairy Group using PCR-SSCP, and with a mixed animal model, the effects of the polymorphism of the K232A site on test-day milk yield, fat percentage, milk protein percentage, 305 days corrected milk yield, milk fat yield, milk protein yield and SCS were analysed. 【Result】 Three genotypes were found and the genotypic frequencies of KK, KA and AA were 0.7918, 0.1917, and 0.0165, respectively. The gene frequencies of K and A were 0.8876 and 0.1124. The very significant association of the DGAT1 K232A with tested day milk yield, milk fat percentage, 305 days corrected milk yield and milk protein yield (P＜0.01), and significant association with milk fat yield were identified, and had no significant effect on the SCS in milk (P＞0.05). LSD showed that the cows with KK and KA genotypes had higher tested day milk yield, 305 days corrected milk yield and milk protein yield than those with AA genotype (P＜0.01),while had lower milk fat percentage and milk protein percentage (P＜0.01). 【Conclusion】 The DGAT1 K232A subsitution has a great genetic effect on milking traits and could be a useful genetic marker for Chinese Holsteion breeding.