汉人不同区段头发的线粒体HVII异质性的序列分析

目的探讨汉族人不同区段头发线粒体DNA(mtDNA)HVII区的异质性。方法用5%Chelex100法提取7名汉族个体额、顶、枕及左、右颞部等5个不同部位的不同根不同段的头发mtDNA,同时取各自毛囊作为对照;以两步法扩增纯化后测序反应,3100型遗传分析仪检测。结果不同毛干区段的点异质性多发生于女性长发远段、儿童及老年人,不同区及同一根不同段均可发生点异质性,可多达4处,点异质性可能相同,可能不同,但一般多发生于相同个体毛囊mtDNA点突变处。不同区头发长度异质性不同,同一根头发不同段长度异质性相同。mtDNA点异质性有一定遗传倾向。稀释及混合样本mtDNA图谱也可表现为“点异质性”图谱。结论根据人头发毛干mtDNA测序结果得出“排除”结论时一定应慎重。

A Study on the mtDNA HVII heteroplasmy of Chinese human hair

Objective To study mtDNA HVII heteroplasmy of Chinese human hair in different parts (mtDNA HVII heteroplasmy). Methods The DNA in different parts of human hair in five places such as frontal,parietal,occipital,left and right temporal places were extracted from seven persons by 5%Chelex 100 method. After the two steps amplification of human hair shafts,the mtDNA HVII was sequenced by 3100 Genetic analyzer. ResultsThe heteroplasmy in different parts of human hair shafts were more susceptible to the distal sections of long hair of women,children and the old The same human hair but different shafts,and the same human hair shafts but different sections,point heteroplasmy was different and could be over four. The point heteroplasmy was the same,some times different,but most of point heteroplasmy loci were the mutation of hair follicles. The length heteroplasmy was different in the different place for the human hair of same person,but same in the different parts for the same hair shaft. It was found that the point heteroplasmy of mtDNA had heredity tendentiousness. Conclusion It must be careful to the result of exclusion on the basis of the mtDNA sequence of human hair shafts.