P基因在中国汉族及藏族群体中的多态性研究

目的：研究中国汉族和藏族两个群体中P基因3个外显子多态性。方法：利用PCR－RFLP多态性方法扩增P基因的3个外显子10、14、24，对其产物分别用HaeⅢ、MboⅡ、MaeⅢ酶切，4％琼脂糖凝胶电泳确定基因型。结果：A355A和G780G的等位基因频率在两个群中的差异具有显著性（χ^2＝24．54，χ^2=37.05,P＜0．001），各基因型频率分布在两个群体间差异具有显著性（χ^2＝28．39，P＜0．001；χ^2=33.72,P＜0．001）；在两个群体内部男女基因型频率差异无显著性；IVS13－15的等位基因频率在两个群体中差异无显著性（χ^2＝2．06，P＜0．05）。汉族与藏族的基因型分布符合Hardy-Weinberg平衡。结论：P基因在不同的人群中具有很高的多态性。

High polymorphism at the human P gene locus in Chinese Han and Tibetan populations

OBJECTIVE: The authors studied two synonymous sites polymorphism (A355A, G780G) and one intervening sequence polymorphism(IVS13-15) of human P gene in 181 and 171 individuals sampled from Chinese Han and Tibetan populations respectively. METHODS: Genomic DNA was extracted from the ACD-blood specimens collected from 352 healthy unrelated individuals by phenol-chloro methods. The amplification of three fragments was performed using PCR technique; the product was digested with restricted enzyme. Agarose electrophoresis was used for typing the PCR product. RESULTS: There were two alleles at each exon variety locus; the allele frequencies in both A355A and G780G were of significant differences between the two populations ( chi(2)=24.54,chi(2)=37.05,P>0.001). No significant difference was found in allele frequency in IVS13-15 locus between the two populations (chi(2)=2.06,P>0.05). And in each of the populations, no significant difference was noted in the genotype frequency between the male and the female. The test for Hardy-Weinberg equilibrium showed that the genotype distributions observed in the two populations were correspondent with the expected. CONCLUSION: There is a remarkable difference in the distribution of allele frequencies at P gene locus between Chinese Han and Tibetan populations, which is related to the variation in skin pigmentation of these two Chinese population.