中国地鼠线粒体Cyt b基因测序及其分子进化

Sequence Analysis of Mitochondrial Cyt b and Estimation of the Molecular Evolution of Cricetulus griseus

目的测定中国地鼠线粒体DNA细胞色素b基因部分序列,分析其分子系统进化关系。方法提取中国地鼠肝脏的总基因组DNA。设计合成特异引物进行PCR扩增,经检测进行测序。用Blast与GenBank中啮齿类其他常用实验动物的物种细胞色素b基因进行同源序列比较,分析其碱基组成及变异情况,并用邻接法、最大简约法、最小进化法构建了分子系统树,在分子水平上探讨中国地鼠和常用啮齿类实验动物的进化关系。结果获得了中国地鼠线粒体Cytb基因的部分序列,共936bp。结论中国地鼠和金黄地鼠的亲缘关系最近,与小鼠、大鼠存在的差异相对大,与豚鼠的亲缘关系最远,与传统的分类地位基本吻合。

Objective To sequence the mitochondrial cytochrome b （cyt b ） gene and compare the homologous sequences between Cricetulus griseus and Mesocricetus auratus , Microtus kikuchii , Microtus rossiaemeridionalis , Rattus norvegicus , Mus musculus, Canis lupus familiaris and Carla porcellus. Methods Total DNA from the liver tissue of Cricetulus griseus was extracted and a pair of specific primers was designed and processed for PCR amplification. Compared with the sequence of cyt b genes in GenBank of BLAST, the base composition and variance among these regions were calculated. Based on cyt b sequences the molecular phylogenetic trees were constructed by neighbor-joining method, maximum parsimony and minimum evolution, and the taxonomic status of Cricetulus griseus among the animals was estimated at molecular level. Results The part sequences of cyt b gene in Cricetulus griseus were obtained. Conclusion The results show that genetic difference between Cricetulus griseus and Microtus kikuchii , Microtus rossiaemeridionalis , Rattus norvegicus , Mus musculus , Canis lupus are comparatively larger than that between Cricetulus griseus and Mesocricetus auratus. The evolution tree built from the homology of cyt b genes of Cricetulus griseus and other 7 kinds of laboratory animals is consistent with the traditional taxonomic results.