中国地鼠线粒体基因组的序列分析与分子进化

目的 获得中国地鼠线粒体基因组序列,为线粒体疾病模型提供分子数据.方法 参照近缘物种的线粒体基因组序列,设计27对特异引物,采用TD-PCR及测序技术获得了中国地鼠的线粒体全基因组序列,分析了其基因组特点和各基因的定位.还结合GenBank中已发表的其他5种啮齿类动物的线粒体基因组序列,探讨啮齿类动物不同科间的系统进化关系.结果 中国地鼠线粒体基因组全长为16 283 bp,碱基组成为33.53％A、30.50％T、12.98％G、22.80％C,包括13个蛋白质编码基因、2个rRNA基因、22个tRNA基因和1个非编码基因控制区.中国地鼠和金黄地鼠亲缘关系最近.结论 中国地鼠线粒体基因组各基因长度、位置与典型的啮齿类动物相似,其编码蛋白质区域和rRNA基因与其他啮齿类动物具有很高的同源性,显示线粒体基因组在进化上十分保守.5种动物的分子系统进化树与传统分类地位一致.

Sequence analysis of the complete mitochondrial genome and molecular evolution of Cricetulus griseus

Objective To obtain the nucleotide sequence of the complete mitochondrial DNA （mtDNA） of Cricetulus griseus to provide molecular data for mitochondrial disease models. Methods The complete mitochondrial genome of Cricetulus griseus was sequenced with 27 primers and their PCR amplications, the genomic structural characteristics and gene mapping were analyzed, and to discuss the phylogenetic relationship among 5 rodent species whose complete mitochon- drial genome sequences are available in the published databases. Results The complete genome contains 16 283 base pairs and encodes 37 genes,including 13 protein-coding,2 ribosomal RNA and 22 transfer RNA genes. The base composi- tion for the four nucleotides is 33.53 % A, 30. 50% T, 12.98 % G and 22.80% C. Conclusions The genome of Cricetulus griseus is very similar to that of other vertebrate mitochondrial genomes. Some of the protein-coding regions and the tR- NA genes are highly homologous to those of other rodents. The evolution tree built from the homology of 5 kinds of laboratory animals is consistent with the traditional taxonomic results.