中国5个群体D20S85基因座的遗传多态性

目的 了解中国5个群体D20S85基因座的群体遗传学数据,比较它们之间的遗传学差异,探讨其在法医学应用中的意义。方法 分别收集5个群体622名无关个体的血样,Chelex-100快速抽提法或饱和酚/氯仿法抽提DNA;扩增后经PAGE垂直板电泳、银染,进行D20S85基因座分型。结果 在5个群体622名无关个体中,共检出9个等位基因,并首次在广东汉族和广西壮族群体中检出等位基因14;每个群体基因频率大于0.05的均为6个,D20S85*6为最常见等位基因。5个群体共观察到35种基因型,群体内基因型频率分布均符合Hardy-Weinberg氏平衡,各群体间基因型构成比无显著性差异。观察140次减数分裂未发现突变。各群体的期望杂合度为0.7720～0.7912;非父排除率,在三联体为0.7538～0.7594,二联体为0.3988～0.4297;个人识别率为0.9175～0,9272;多态信息含量为0.7442～0.7656。应用于亲子鉴定和个人识别案例,效果满意。结论 D20S85基因座是法医学应用价值较高的遗传标记系统。

Study on genetic polymorphisms of STR locus D20S85 in five Chinese populations and forensic application

Objective To study the genetic polymorphisms of STR locus D20S85 and to obtain the genetic data of Guangdong Han, Guangxi Zhuang, Huadong Han,Neimenggu Han and Meng populations. Method Using PCR and silver - staining methods, the alleles of D20S85 locus were detected and analysed. Results 9 alleles and 35 genotypes were found in those populations. The highest allele frequency was D20S85* 6. The results of Hardy - Wein-berg equilibrium test showed that the genotype distributions observed in five populations were correspondent with the expected. The expected heterozygosity was 0.7720 - 0.7912; the exclusion probability of paternity was 0.7538-0.7594(triplet) and 0.3988 -0.4297 (biplet) ; the discrimination power 0.9175 -0.9272 and the polymorphism information content 0.7442 - 0.7656. Conclusion STR D20S85 locus is a useful genetic marker for forensic application .