中华鳖线粒体基因组序列分析

Complete Mitochondrial Genome Sequence Analysis of Chinese Softshell Turtle(Pelodiscus sinensis)

参照近源物种线粒体基因组序列,设计17对特异引物,采用PCR产物直接测序法测得中华鳖线粒体基因组全序列.初步分析其基因组特点和各基因的定位,用pDRAW32软件预测12种限制性酶对其的酶切图谱.结果表明,中华鳖线粒体基因组全长17364bp,核苷酸组成为35.23%A、27.26%T、25.73%C、11.78%G,包括13个蛋白质编码基因、2个rRNA基因、22个tRNA基因和1个非编码控制区.基于线粒体基因组编码的13个蛋白质的氨基酸序列,用NJ法和MP法构建系统进化树,分析6种龟鳖类动物之间的亲缘关系,与传统的系统分类基本一致,初步确定淡水龟科与海龟科的亲缘关系比与龟科的亲缘关系要近.

The complete mitochondrial genome of Chinese softshell turtle Pelodiscus sinensis was determined by DNA sequencing based on the PCR fragments of 17 pairs of primers. The entire genome was 17 364 bp containing 37 genes （13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes） , as well as a non-coding control region. The gene order is identical to that observed in most other vertebrates. The overall base composition of the light strand is 35.23% A, 27.26% T, 25.73% C, 11.78% G. The pDRAW32 software was used for restriction enzyme mapping. Based on the deduced amino acid sequences of 13 proteincoding genes, the phylogenetic tree was constructed with Neighbor-joining（NJ） and Maximum parsimony（MP） methods and the phylogenetic relationships of six turtles was discussed. The results demonstrated that Cheloniidae and Bataguridae have closer phylogenetic relationship.