翘嘴鳜线粒体基因组全序列的克隆与特征分析

Characterization of the Complete Mitochondrial Genome Sequence in Siniperca chuatsi

通过直接测序的方法获得翘嘴鳜线粒体DNA基因组全序列(GenBank:JF972568)。翘嘴鳜线粒体基因组全长为16 496 bp,其包含13个编码蛋白基因、22个tRNA基因、2个rRNA基因和1个Control region区域。整个翘嘴鳜线粒体DNA利用率非常高,仅仅只有32 bp的基因间隔和35 bp的基因重叠。翘嘴鳜线粒体的编码蛋白基因具有明显的A+T偏好性,同时整个基因组中G碱基含量非常低,仅有16.2%。翘嘴鳜线粒体基因起始密码子以ATG为主,但终止密码子却呈现多样性。翘嘴鳜22个tRNA基因只有tRNA-leu(UUR、CUN)和tRNA-Ser(UCN、AGY)有2个密码子,22个tRNA按位置可分为3个基因簇(IQM、WANCY、HSL)。翘嘴鳜rRNA的位置和大小与其他鱼类相似,D-Loop区域具有明显的A+T碱基偏好性。翘嘴鳜线粒体全序列的克隆对进一步确定鳜类分类地位和多样性保护具有重要意义。

The complete mitochondrial DNA （mtDNA） of Siniperca chuatsi was cloned and sequenced. The mitochondrial genomes is 16 496 bp in length and contains 37 genes （13 protein-coding genes,2 ribosomal RNA,and 22 transfer tRNAs） and a major non-coding region. There are only 32 bp nucleotides gap and 35 bp nucleotides overlap in the mitochondrial genome. The mitochondrial genome has a better A ＋T bias and the G content is relatively low. Except for cytochrome coxidase subunit 1 （CO1） ,which began with GTG as an initiation codon,all proteins started with an ATG codon. However,the stop codons of the mitochondrial genomes examined differed from the initiation codons with variety. The tRNA-leu nd tRNA-Ser are double style genes. The three tRNA clusters-IQM, WANCY, and HSL whose base composition is very similar to those reported in bony fish. The 12SrRNA and the 16SrRNA genes,as in other bony fishes,were located between the tRNA-Phe and tRNA-Leu （UUR）,and were separated by the tRNA-Val. The control region was observed to have a better A＋T bias. These results were helpful for further understanding the phylogenetic classification and evolution of sinipercine fishes. Genetic structure of the three Siniperca fishes could be used as a basis for its genetic conversation and utilization.