大通牦牛DRB3.2基因的遗传多样性

Polymorphism of DRB3.2 gene in Datong yak

为研究大通牦牛DRB3.2基因的遗传多样性,对69头大通牦牛的DRB3.2基因进行半巢式PCR扩增及序列测定,与GenBank下载的牛亚科其他群体对应基因序列进行比较分析。结果表明,大通牦牛DRB3.2基因在核苷酸组成上与其他牛种无明显差异,变异主要源于碱基的颠换,以T/G和C/G为主,等位基因多样性为0.991,平均核苷酸差异数为5.30,核苷酸多样性为2.01%,非同义替换与同义替换的比率(ω)为3.487 0,氨基酸分析结果表明发生变异的位点主要集中在该基因的抗原结合区及其相邻区域。正向检验结果表明,大通牦牛正受到强烈的正向选择,这种变异可能与该基因适应环境因子的特殊功能有关。

The To study the polymorphism of major histocompatibility complex DRB3. 2 gene in Datong yak, the hemi nested PCR and sequencing technique were employed to examine the polymorphism levels in Datong yak （n =69）, and the sequence was compared with other populations of bovine from the GenBank. The sequence analysis results indicated that they were similar in content of nucleotide, and the mutations dominated by T/ G and C/ G were mainly caused by transversion. The allele diversity was 0.991, the average number of nucleotide differences was 5. 30, the single nucleotide polymorphism was 2.01%, and the ratio （棕） of non-synonymous substitutions to synonymous substitutions was 3. 487 0. The amino acid variations mainly occurred in antigen-binding regions and adjacent regions. The positive test results showed that Datong yak was facing strong positive selection and the variations were mainly associated with its special functions.