IDENTIFICATION OF PARTIAL MUTATIONAL SITES IN HUMAN MITOCHONDRIAL DNA IN THE CHINESE AND ITS SIGNIFICANCE

A simple method for the identification of mutational sites in human mitochondrial DNA (mtDNA) was described. It was based on the human Cambridge sequence as a relative standard sequence and a single base pair substitution in mtDNA as a unique mutational form. The partial mutational sites can be determined using this method which was characterized by combining the restriction mapping with the analysis for the table of human mtDNA potential mutational sites with rapidity and simplicity. In the meanwhile, six mtDNA mutational sites found in Chinese population were identified by means of this method.     

中国汉族、维吾尔族、哈萨克族和回族群体线粒体DNA多态性的研究

本文应用线粒体(mtDNA)作为研究工具,对我国汉族、维吾尔族、哈萨克族和回族群体的遗传结构进行了系统分析。通过对四个民族群体mtDNA限制性类型的调查,发现了一批新的类型,其中包括一些只存在于某一种族和民族中的突变类型,表明mtDNA限制酶切片段多态性类型的分布在不同民族和种族中有显著差别。在与灵长类动物比较后发现,现代世界上只有少数东方人种中保留着mtDNA的祖先类型,这为亚洲可能是人类的起源地之一提供了间接证据。我们根据限制性位点差计算出各民族间的遗传距离,绘制成系统树,表明维吾尔族和哈萨克族群体最先汇聚成一支,而汉族与回族汇聚成一支,最后两支再汇聚在一起。同时发现,维吾尔族和哈萨克族群体内部交异比汉族和回族大,从分子水平揭示了这四个民族群体问的相互关系。     

MITOCHONDRIAL DNA POLYMORPHISM IN CHINESE

Human mitochondrial DNA (mtDNA) restriction endonuclease fragment patterns were analyzed using placenta DNA isolated from 273 individuals representing four different nationalities, the Han, the Uygur, the Kazakh and the Hui populations. Thirty-eight fragment patterns (morphs) were observed with the enzyme ApaI, BamHI, EcoRl, HindIII, HinfI, HhaI, HapII, KpnI, MboI, PstI, PvuII, SacI, ScaL and XhoI. Fourteen new morphs, including some only existing in individual racial and national populations were observed, which indicates that there is a significant difference in the distribution of mtDNA morphs among various national and racial populations. By comparison with the mtDNA sequences in primate species, some mtDNA ancestral morphs were found to be retained in Oriental population today. This result provided indirect evidence that Asia may be one of the human original sources. Genetic distances among four national populations computed and employed in construction of an average linkage tree suggested that the     

中国人群线粒体DNA部分突变位点的测定和意义

本文报道了一种简易的人体线粒体DNA(mtDNA)突变位点测定方法。这一方法以剑桥顺序为标准顺序。在确定不同限制酶的识别位置及其片段大小后,用不同限制酶对不同个体的酶切图谱作比较。在发现长度突变型后,利用已知限制酶识别顺序,确定人mtDNA剑桥顺序上所具有的潜在性突变位点。根据标准的剑桥顺序和被检酶切片段大小以及潜在性突变情况,估计出被检mtDNA发生突变的确切位置或大概位置。应用这一方法,我们对在中国汉族、维吾尔族、哈萨克族和回族人群中发现的六种 mtDNA变异型的突变位点进行了分析。