鳄蜥线粒体基因组全序列及其结构分析

Mitochondrial Genomes of Shinisaurus crocodilurus and Its Structure

采用PCR扩增方法测定了鳄蜥(Shinisaurus crocodilurus Ahl.)线粒体基因组全序列。经测序其线粒体基因组全长16 585 bp,含有13个蛋白质编码基因、2个rRNA基因和22个tRNA基因和1个控制区。除tRNA-Ser(AGY)基因外,其余21个tRNA基因的二级结构均为典型的三叶草结构。鳄蜥的线粒体基因组碱基组成分别为:A(31.99%)、T(26.48%)、C(27.96%)、G(13.57%)。除了COI基因起始密码子是ATC,其余12个蛋白质编码基因的起始密码子都是ATG。9个基因(ND1,ND2,COI,ATP6,ATP8,ND4L,ND4,ND6,Cytb)均有完全的TAA、AGA或AGG终止密码子,其他4个基因终止密码子为不完整的TA(ND5)或T(COⅡ,COⅢ,ND3)。

The complete nucleotide sequence of the mitochondrial genome of Shinisaurus crocodilurus was determined by PCR. The complete mtDNA from S. crocodilurus was 16 585 bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 control region（D-loop）. The 22 tRNA genes can be fold in the typical cloverleaf structure except tRNA-Ser（AGY）gene. The average nucleotide composition was 31.99% A, 26.48% T, 27.96% C and 13.57% G. Among 13 protein-coding genes of the S. crocodilurus mitochondrial genome, the common start codon（ATG） could be assigned as the start codon for all protein-coding genes except for COI which started with ATC. Most of the protein-coding genes including ND1,ND2,COI,ATP6,ATP8,ND4L,ND4,ND6,Cytb had TAA, AGA or AGG as termination codon,while COⅡ, COⅢ, ND3 and ND5 had incomplete termination codons TA / T.