人与动物mtDNA细胞色素b基因的序列差异

目的 探讨人与动物之间mtDNA细胞色素b(Cyt-b)基因序列差异及其种属鉴定。方法 采用1对Cyt-b基因通用引物对人和19种动物共171例样本的mtDNA进行PCR扩增,琼脂糖凝胶检测扩增产物,ABI 377测序仪及荧光测序技术分析扩增产物的DNA序列。结果 所有样本均检测到1条358bp的扩增片段;任何两种动物扩增片段的序列都不相同,人与19种动物的序列差异在18.9％-30.0％,19种动物之间的序列差异在5.9％-32.9％。同种动物不同个体间只有人、驴及小白鼠存在变异,最多有4个碱基变异位点(1.3％),其它动物未发现种内变异。结论 人与不同种动物的Cyt-b基因序列存在差异,以此可区分不同种属的动物。

Cytochrome b DNA Sequence Difference in Species Identity

Objective To establish a new species identification method by cytochrome b sequencing of samples from different species of animals. Methods mtDNA of 171 samples from human to 19 species of animals were tested by a pair of universal cyto b PCR primer. The PCR products were examined by agarose electrophoresis, and then were sequenced by ABI 377. Results All samples produced a 358bp PCR fragment, but different species of animals have different Cyt-b sequence. The sequence comparision showed that the percentage of sequence diversity among human and other 19 species of animals as 18. 9% -30.0% , and that between 19 species of animals was 5. 9% - 32.9%. DNA sequence variation in the same species of animals was only observed in human, donkey and mouse, and the number is less than 4 (1.3%), other animals showed no intraspecies variation. Conclusion Different species of animals can be identified by their different Cyt-b sequence.