荷斯坦牛GHR基因多态与产奶性状关联分析

Association between the Polymorphism of GHR and Milk Production Traits in Chinese Holstein Cows

本研究采用PIRA-PCR和RFLP方法检测了1 145头中国荷斯坦牛生长激素受体基因(GHR)外显子8的F279Y多态位点及其与产奶性状的关联性。关联分析结果表明该突变位点与305天产奶量(P<0.01)、乳脂率(P<0.05)和乳蛋白率(P<0.01)关联显著。Bonferronit检验多重比较结果显示:基因型TT和AT在305天产奶量和乳脂率上差异显著(P<0.05);基因型TT和AT在乳蛋白率上差异极显著(P<0.01);基因型TT和AA在乳蛋白率上差异显著(P<0.05)。A等位基因对乳蛋白率的加性效应为-0.025 8%(P<0.01);产奶量和乳蛋白量的显性效应分别为-214.005(P<0.01)和-5.515 kg(P<0.05);乳脂率和乳蛋白率的等位基因替代效应分别为-0.047 5%(P<0.05)和-0.029%(P<0.01)。因此,T等位基因是提高乳成份的优势等位基因,A等位基因是提高产奶量的优势等位基因。本研究表明GHR基因的F279Y突变可望应用于我国荷斯坦牛产奶性状的标记辅助选择育种。

Primer-Introduced Restriction Analysis-Polymerase Chain Reaction （PIRA-PCR） and Restriction Fragment Length Polyrnorphism（RFLP）were developed to identify the F279Y mutation witlSin the exon8 of GHR gene. Further, the association between F279Y and five milk production traits were investigated in a population of 1 145 Chinese Holstein cows. Statistical results indicated that 305-day milk yield and protein percentage（P〈0. 01）and fat percentage（P〈0. 05）was significantly associated with the F279Y mutation of GHR, respectively. The results of Bonferroni t-test showed that the difference between genotypes TT and AT were significant for 305-day milk yield and fat percentage（P〈 0. 05）. Also, the difference between genotypes TT and AT was significant（P〈0. 01）for protein percentage and the difference of protein percentage between genotypes TT and AA was significant（P〈0. 05）. The additive effect of A allele for protein percentage was -0. 025 8%（P〈 0. 01） and dominance effects were -214. 005 （P〈0. 01）and -5. 515 kg （P〈0. 05）for 305-day milk yield and protein yield. The substitution effects for fat percentage and protein percentage were -0. 047 5% （P〈0. 05） and -0. 029% （P〈0. 01）, respectively. Therefore, allele T is the dominant allele for milk composition, while allele A is the dominant allele for milk yield. Our findings in the present study implied that F279Y mutation of GHR gene could be of considerable in marker-assisted selection programs of milk production traits in Chinese Holstein cows.