【摘要】 旨在研究安徽省中国荷斯坦奶牛群体κ-酪蛋白(CSN3)基因的多态性及其对奶牛生产性状及奶品质的影响。通过PCR克隆CSN3基因cDNA,使用DNA测序法检测402头中国荷斯坦奶牛CSN3基因的单核苷酸多态性(SNPs)位点，进行群体遗传信息分析并将检测出的SNPs位点基因型与奶牛产奶性能进行关联分析。结果显示：在中国荷斯坦奶牛CSN3基因CDs区序列中发现2个突变位点，即13 068 bp处C/T替换，13 124 bp处A/G替换。g.13068C>T位点CC型奶牛的基因型频率为0.52,日均产奶量比CT型奶牛高且差异极显著(P<0.01);TT型奶牛乳脂率最高，比CC型奶牛高且差异极显著(P<0.01),CT型奶牛乳脂率比CC型奶牛高且差异显著(P<0.05),CT型奶牛乳蛋白率最高，TT型奶牛牛奶尿素氮、群内级别指数(WHI)含量高于其他2个基因型奶牛，但差异均不显著。g.13124A>G位点AA型奶牛乳蛋白率比AG型奶牛高且差异显著(P<0.05);AG型奶牛日均产奶量比AA型奶牛高，乳脂率比AA型低，体细胞数比AA型高，牛奶尿素氮及WHI含量低于AA型，但均差异不显著。结论：g.13068C>T位点可作为中国荷斯坦奶牛产奶量及乳脂率的分子标记，g.13124A>G位点可作为中国荷斯坦奶牛乳蛋白率的分子标记，CSN3基因可能是影响中国荷斯坦奶牛产奶性能的主效或候选基因。更多还原

【Abstract】 In order to identify the polymorphism of the CSN3 gene and analyze their effects on dairy production traits and milk quality of Chinese Holstein cattle in Anhui Provence, DNA sequencing was performed, in this study, to detect SNPs in 402 Chinese Holstein cattle. Population genetic information analysis and the correlation of genotype and production traits were conducted. Two loci of the CSN3 gene in 402 Chinese Holstein cattle(g.13068C>T, g.13124A>G) were found. In the g.13068C>T locus, the genotype frequency of CC genotype cows at the g.13068C>T locus was 0.52; the CC genotype cattle had a significantly higher average daily milk production than the CT genotype dairy cattle(P<0.01). The TT genotype dairy cattle had significantly higher milk fat percentage than did the CC genotype dairy cattle(P<0.01). The milk fat content of the CT genotype cattle was higher than that of the CC genotype cattle(P<0.05). The protein content of milk was highest in the CT genotype cattle; the milk urea nitrogen(MUN) and WHI were higher in the TT genotype cattle, compared with those in the other two genotypes, but with no significant differences. In the g.13124A>G locus, the dairy cattle with the AA genotype cattle had significantly higher milk protein percentage than did the AG genotype dairy cattle(P<0.05). The daily average milk production of the AG genotype cattle was higher than that of the AA genotype cattle. The milk fat content of the AA genotype cattle was higher than that of the AG genotype cattle. The somatic cell count of the AG genotype cattle was higher than that of the AA genotype cattle. The MUN and WHI in the milk of the AA genotype cattle were higher than those of the AG genotype cattle, but with no significant differences. In summary, the g.13068C>T locus might be used as a molecular marker for milk production and fat rate in Chinese Holstein dairy cattle, the g.13124A>G locus might be used as a molecular marker for protein content of milk in Chinese Holstein dairy cattle, and the CSN3 gene could be a major or candidate gene influencing milk production performance in Chinese Holstein cattle.更多还原