人类线粒体基因控制区序列的变异频率与碱基构成特点分析

Variation frequency and base composition characterization types of human mitochondrial DNA control region

目的 探讨人类线粒体基因控制区的多态频率和变异类型。方法 搜集基因文库记录的 86个人类线粒体基因D环控制区序列 ,并与标准剑桥序列进行比对分析。结果 86个序列中共在 181个位点发现 12 5 3个碱基变异 ,主要变异形式为碱基转换 (占 71.75 % ) ,其次为碱基插入 (16 .0 4 % )和缺失 (8.6 2 % ) ,碱基颠换较少 ,仅占3.5 9%。核酸位点 16 189、30 3～ 315、5 14～ 5 2 3是变异频率较高 ,且具有基因长度不稳定的区域。结论 线粒体基因D环区为高度多态变异区 ,其变异频率的确定可为针对线粒体基因多态性与疾病发生风险评估的其他研究提供参考。

Objective To explore the variation frequency and base composition characterization of mitochondrial DNA (mtDNA) control region in human beings. Methods Eighty-six sequences of human mtDNA D-loop region from GenBank were collected and compared with Cambridge sequence. Results A total of 1 253 variations in 181 sites were found in 86 sequences. The dominant type of variation was nucleotide transition (71.75%), followed by insertion (16.04%) and deletion (8.62%). The nucleotide transversion only accounted for 3.59%. The nucleotide sites 16、189,303-315,and 514-523 were the ones with high variation frequency and length instability. Conclusion The mitochondrial control region is a hypervariable area with high frequency of polymorphism. The evaluation of variation frequency in this region provides a good reference for the studies aiming at the relationship between mitochondrial DNA polymorphism and pathogenetic risk of diseases.