中国荷斯坦牛DGAT2基因第4外显子与产奶性状的关联分析

本试验以宁夏地区8个公牛家系的各8头女儿共计64头中国荷斯坦母牛为研究对象．利用AB13730测序仪对DGAT2基因Exon4进行了基因型检测后发现三个突变位点474bp（C／G）、48lbp（G／A）、621bp（C／T），各个位点发现有两种基因型，分别为CC型、GC型，GG型、GA型，CC型和CT型，基因型频率分别为0．484、0．516，0．687、0．313，0．484和0．516。通过SAS软件（8．02）对4个产奶性状与DGAT2基因Exon4的关联分析表明．474bp（C／G）CG型305d产奶量和乳脂率显著高于CC型（P〈0．05），乳蛋白率、体细胞数影响不显著（P〉0．05）；481bp（G／A）GA型305d产奶量显著高于GG型，与乳脂率、乳蛋白率、体细胞数无显著的相关性（P〉0．05）；621bp（C／T）CT型305d产奶量、乳蛋白率、体细胞数都显著高于CC型（P〈0．05），乳脂率影响不显著（P〉O．05）。

Genetic Effects of DGAT2 Gene Exon4 on Milk Production Traits in Chinese Holstein Cows

With the ABI3730 DNA Squeneer, three mutations of DGAT2 Exon4 had been detected in 64 Chinese Holstein cows from eight sire famailies. The three SNPs including 474bp（C/G） ,481 bp （G/A） and 621bp（C/T） had been genotyped as CC, GC ; GG, GA; CC, CT and their frequency were 0.484,0.516;0.687,0.313;0.484,0.516 respectively; Further, the genetic effects of the DGAT2 Exon4 mutations on four milk production traits were estimated using SAS（8.02）soflware. Statistical results indicated that 305-day milk yield and fat ratio of CG genotype cows were higher than CC genotype（P〈0.05）in 474bp（C/G） mutation; 305-day milk yield of the genotype GA was higher than GG genotype（P〈0.05） in 481bp（G/A） mutation; 305-day milk yield, protein ratio and somatic cell count of the genotype CT were higher than CC genotype（P〈0.05） in 621bp（C/T） mutation.