广西壮族人群线粒体DNA单个碱基突变的分析

ANALYSIS OF THE POINT MUTATIONS IN THE MITOCHONDRIAL DNA SEQUENCES FROM GUANGXI ZHUNAG ETHNIC GROUP

目的 :探讨广西壮族人群的线粒体 DNA (m t DNA)单个碱基的突变 ,了解突变的频率 ,为进一步研究壮族人群的遗传基础和相关的线粒体遗传病提供基础资料。方法 :从 83例广西壮族人血液标本中提取 DNA,通过 PCR扩增、分离和回收 ,用 377全自动序列分析仪进行序列测定 ,分析了 mt DNA第一高变区单个碱基的突变。结果 :来自南宁等四个地区的 76个样本共有 6 6个单倍型 ,71个多态位点 ,共发生了 2 98次转换、 39次颠换和 1个缺失 ,88%的碱基替换为转换 ,12 %为颠换。南宁、百色、柳州和河池地区的转换、颠换和缺失的频率分别为 6 .31% ,6 .4 0 % ,6 .79和 5 .90 %。对上述频率进行多样本率比较的卡方检验 ,均无显著性差异 (P >0 .0 5 )。结论 :壮族人群 mt DNA的单个碱基突变比较丰富。

Objective:To study the point mutations in the Mitochondrial DNA(mtDNA) sequences from Guangxi Zhuang ethnic group, to acquaint the mutation frequencies, as well as to provide basic data for research of the mitochondrial genetic structure and the diseases related to mitochondrion from Guangxi Zhuang ethnic group Methods: Genomic DNA was extracted from the whole blood of 83 unrelated individuals of Guangxi Zhuang by standard phenol/chloroform methods After the mtDNA hypervariable segment I sequences (515 bp) were amplified, the PCR products were separated, purified and sequenced with ABI PRISMTM DNA Sequence Analysis 377 The mutation frequencies among the groups from the 4 geographic regions ( Nanning, Hechi, Baise and Liuzhou ) in Guangxi were counted up and compared with the PEMS software Results: 66 haplotypes were identified in the 76 samples with 71 sites showing polymorphism There were 298 transitions, 39 transversions and 1 deletion 88% of base substitutions were transitions,and 12% were transversions The mutational frequencies of transitions, transversions and deletion among the groups form the 4 geographic regions added up to 6 31%, 6 40%, 6 79% and 5 90% respectively These differences were not statistically significant (P>0 05) Conclusion:There were many point mutations and the mutation frequencies occurred at the different sites of the mtDNA sequences from Zhuang ethnic groups were not in concordance