BRCA1基因多态性及其与奶牛乳房炎抗性的相关性研究

Polymorphism of BRCA1 Gene and its Association with Mastitis Resistance in Holstein Dairy Cows

为了研究BRCA1基因突变与荷斯坦奶牛体细胞数和体细胞评分的关系,试验通过对BRCA1基因外显子13、14进行克隆、序列比对和挖掘已有突变的方法确定该基因的多态位点,采用SNaPshot技术检测了BRCA1基因25025T>A和46126G>T突变位点在北京郊区荷斯坦奶牛群体中的分布,并对突变位点与体细胞数和体细胞评分进行了关联分析。结果表明,荷斯坦奶牛BRCA1基因2个位点均检测到3种基因型,其中25025bp位点TT基因型为优势基因型,46126bp位点GT基因型为优势基因型。25025bp位点AA基因型个体体细胞数(P<0.05)和体细胞评分(P<0.01)都显著低于TT和TA基因型;46126bp位点TT基因型个体体细胞数显著低于GG和GT基因型个体(P<0.05),但3种基因型个体体细胞评分无显著差异(P>0.05)。本研究结果初步表明,BRCA1基因25025和46126bp位点可作为中国荷斯坦牛乳房炎抗性的标记辅助选择。

In order to study mutations of bovine breast cancer 1（BRCA1）gene and its association with somatic cell count and somatic cell score in Holstein dairy cows in Beijing.SNPs of BRCA1 gene exon 13 and 14were obtained by cloning,sequence alignment and searching for known mutations.In our research,25025T〉A of exon 9and 46126G〉T of exon 13 in BRCA1were detected by SNaPshot in Holstein dairy cows raised on the outskirts of Beijing city,as well as the association between SNPs and somatic cell count（SCC）or somatic cell score（SCS）were also analysed.The results showed that both 25025T〉A and 46126G〉T were detected in Holstein dairy cows.TT genotype at locus 25025T〉A and G〉T genotype at locus 46126G〉T were dominant geno-types,respectively.At locus 25025T〉A,least squares mean of SCC and SCS in individuals with AA genotype was significantly lower than that with TT and T〉A genotypes（P〈0.05;P〈0.01）.Least squares mean of SCC in individuals with TT genotype was significantly lower than that with GG and G〉T genotypes（P〈0.05）,while SCS of different genotypes showed no difference at locus46126G〉T（P〉0.05）.These results preliminarily indicated that the 25025T〉A and 46126G〉T mutations of BRCA1 gene could be used in molecular marker-assisted selection programs of mastitis resistance in Holstein dairy cows.