【摘要】 设计5对引物P1～P5,采用PCR-SSCP技术检测210头荷斯坦母牛DNA依赖性蛋白激酶(DNA-dependent protein kinase,PRKDC)基因部分序列的多态性。结果发现P2扩增的外显子区域存在G34126A1个突变位点,导致丝氨酸变为天冬酰胺;P3的扩增产物存在C77353T、T77384G、C77406T和77408bp处C缺失4个突变位点。P2扩增产物经SSCP分析有AA、AB和BB3种基因型,其频率分别为0.186、0.433和0.381;P3扩增片段经SSCP分析有CC、CD、DD、CE和DE5种基因型,其频率分别为0.786、0.129、0.009、0.067和0.009。用最小二乘法分析PRKDC基因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:对于P2扩增产物多态位点,AA基因型SCS最小二乘均值显著低于AB和BB基因型所对应的值(均为P<0.05),AB和BB基因型SCS最小二乘均值差异不显著(P>0.05);对乳房炎抗性,AA是最有利基因型,BB是最不利基因型;对于P3扩增产物多态位点,CC、CD、DD、CE和DE基因型SCS最小二乘均值差异均不显著(P>0.05)。研究结果初步表明PRKDC基因G34126A多态位点的A等位基因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 genetic polymorphisms of partial sequence of DNA-dependent protein kinase gene(PRKDC) in 210 Holstein cows were detected by PCR-SSCP with five pairs of primers P1～P5.Five polymorphic sites,i.e.G34126A,C77353T,T77384G,C77406T and indel(C) at site of 77408 bp were found,and G34126A mutation caused an amino acid change of serine to asparagine.Forthe amplified fragment of P2,three genotypes(AA,AB and BB) were found in 210 Holstein cows,and the genotype frequency of AA,AB and BB was 0.186,0.433 and 0.381,respectively.For the amplified fragment of P3,five genotypes(CC,CD,DD,CE and DE) were found in 210 Holstein cows,and the genotype frequency of CC,CD,DD,CE and DE was 0.786,0.129,0.009,0.067 and 0.009,respectively.The relationship between polymorphisms of PRKDC gene and somatic cell score(SCS) in Holstein cows was analyzed by least squares linear model.Results showed that least squares mean of SCS for AA was significantly lower than that for AB or BB(both P<0.05),and the difference of the least squares means for SCS between AB and BB was not significant(P>0.05).AA was the most favorable genotype,BB was the most unfavorable genotype for mastitis resistance.The difference of the least squares means for SCS among CC,CD,DD,CE and DE was not significant(P>0.05).The results preliminarily indicated that allele A of G34126A polymorphic site of PRKDC gene is a potential DNA markerforimproving mastitis resistance in cows.更多还原