【摘要】 采用PCR-RFLP技术,用限制性内切酶BstYⅠ对河北省489头荷斯坦母牛和40头荷斯坦公牛白细胞抗原-DRB3基因(BoLA-DRB3)外显子2的284bp扩增产物进行多态性分析。荷斯坦母牛经BstYⅠ酶切产生3种基因型AA、AB和BB,其频率分别为0.078、0.380和0.542;荷斯坦公牛经BstYⅠ酶切产生2种基因型AB和BB,其频率分别为0.250和0.750;荷斯坦母牛和公牛在该酶切位点均处于Hardy-Weinberg平衡状态(母牛:χ2=0.45,P=0.799>0.05;公牛:χ2=0.82,P=0.665>0.05);用最小二乘法分析BoLA-DRB3基因外显子2的多态性与荷斯坦母牛体细胞评分(somatic cell score,SCS)的关系,结果表明AA基因型SCS最小二乘均值极显著低于AB基因型所对应的值(P=0.0098<0.01),极显著低于BB基因型所对应的值(P=0.00009<0.0001);AB基因型SCS最小二乘均值极显著低于BB基因型所对应的值(P=0.0096<0.01);对乳房炎抗性,AA是最有利基因型,BB是最不利基因型。研究结果表明BoLA-DRB3基因外显子2的多态性是提高奶牛乳房炎抗性的一个潜在的DNA标记。更多还原

【Abstract】 The exon 2 of bovine lymphocyte antigen-DRB3 gene(BoLA-DRB3)in 489 Holstein cows and 40 Holstein bulls from Hebei Province was amplified and a unique fragment of 284 bp was obtained.The 284 bp PCR product was digested with restriction endonuclease BstYⅠ,and genetic polymorphism was investigated by PCR-RFLP.Three genotypes(AA,AB and BB) were found in 489 Holstein cows,and the frequency of AA,AB and BB genotypes was 0.078,0.380 and 0.542,respectively.Two genotypes(AB and BB) were found in 40 Holstein bulls,and the frequency of AB and BB genotypes was 0.250 and 0.750,respectively.Chi-square test showed that both Holstein cows and bulls were in Hardy-Weinberg equilibrium(cows:χ2 = 0.45,P = 0.799 > 0.05;bulls:χ2 = 0.82,P = 0.665 > 0.05).The relationship between the polymorphism in exon 2 of BoLA-DRB3 gene and somatic cell score(SCS) in Holstein cows was analyzed by least square linear model.Least square mean of SCS for AA was significantly lower than that for AB(P = 0.0098 < 0.01) or BB(P = 0.00009 < 0.0001),and least square mean of SCS for AB was significantly lower than that for BB(P = 0.0096 < 0.01).AA was the most favorable genotype,BB was the most unfavorable genotype for mastitis resistance.The results indicated that the polymorphism in exon 2 of BoLA-DRB3 gene is a potential DNA marker for improving mastitis resistance in dairy cattle.更多还原