河南汉族人群线粒体DNA(CA)n重复子的多态性及法医学应用

Polymorphism of the mitochondrial CA dinucleotide repeats in Henan Han population and its application to forensic casework

目的：探讨河南汉族人群线粒体（mt）DNA514～523位置（CA）n重复子的遗传多态性及应用。方法：应用PCR扩增、聚丙烯酰胺凝胶电泳分离、银染技术，对河南汉族214例无关个体血样进行mtDNA（CA）n重复子分型。并对5例腐败肌肉及5例角化组织用Chelex-100、二硫苏糖醇（DTT）联合Chelex-100法和PCR缓冲液法分型技术效果进行比较。结果：河南汉族214例无关个体中检出4种等位基因，重复5～8次，基因差异度0．5013。腐败肌肉及角化组织用DTT联合Chelex-100法和PCR缓冲液法均分型成功。结论：mtDNA（CA）n重复子多态性在河南汉族人群具有一定的法医学应用价值，尤其对于腐败肌肉及角化组织。

Aim ： To study the polymorphism of the mitochondrial DNA （mtDNA） CA dinucleotide repeats in Henan Han population and its application in forensic medicine. Methods： The CA dinucleotide repeats region （nucleotide position： 514 -523） of mtDNA was amplified by PCR using total DNA samples from 214 unrelated individuals of Henan Han population. The amplification products were analyzed by polyacrylamide gel electrophoresis followed by silver staining. Genotyping techniques including Chelex-100, Chelex-100 with DTT, and PCR buffer were compared using 5 cases of decomposed tissue and 5 cases of keratinized tissue. Results： A total of 4 alleles with 5 - 8 repeat units were observed and the genetic diversity was estimated to be 0. 501 3. Decomposed and keratinized samples were typed successfully by using the methods of Chelex-100 with DTT and PCR buffer,respectively. Conclusion： The polymorphism of mtDNA CA dinucleotide repeats is useful in forensic genetics, especially for decomposed and keratinized samples.