大豆蚜线粒体基因组序列测定与分析

采用LongPCR和引物步移法测得大豆蚜Aphis glycines Matsumura线粒体基因组约90%的序列,并与蚜总科Aphidoidea已报道的3种蚜虫进行了比较。结果表明:已测得的序列长度为13696bp,AT含量为83.3%;蛋白质编码基因起始密码子都为ATN,COI、ND4、CYTB、ND2使用不完整终止密码子T,其余都使用常见终止密码子TAA;15个tRNA基因除tRNA-W外都能折叠成典型的三叶草二级结构。比较大豆蚜、豌豆蚜Acyrthosiphon pisum(Harris)、麦二叉蚜Schizaphis graminum(Rondani)和葡萄根瘤蚜Daktulosphaira vitifoliae(Fitch)的线粒体基因组,结果表明4个种均具有后生动物线粒体基因组中常见的基因,基因顺序与假想昆虫祖先的排列方式相同,但豌豆蚜包含3个tRNA-M;蛋白质编码基因的起始密码子都为ATN,除葡萄根瘤蚜外,其他3种蚜虫的COⅠ、ND4使用不完整终止密码子T;tRNA-W的二级结构中都存在TψC臂中"茎"的结构缺失,只有环的结构;而蛋白质编码基因使用最频繁的氨基酸略有不同,大豆蚜为Leu,豌豆蚜和麦二叉蚜为Ile;大豆蚜和麦二叉蚜的ND4/ND4L都存在7bp的重叠序列,而豌豆蚜和葡萄根瘤蚜没有发现此现象。

SEQUENCE AND ANALYSIS OF THE MITOCHONDRIAL GENOME OF APHIS GLYCINES (HEMIPTERA, APHIDIDAE)

The mitochondrial genome of Aphis glycines was sequenced using long PCR and primers walking approaches. About 90 % of the mitochondrial genome of A. glycines was obtained,that is 13 696 bp in length with 83.3 % A+T content. All protein-coding genes start with a typical ATN codon. The usual TAA termination codon is found in nine protein-coding genes. However,four genes,(COⅠ,ND4,CYTB and ND2) have an incomplete termination codon (T). Fifteen tRNA genes except tRNA-W fold into clover-leaf secondary structure. The absence of TψC arm of tRNA-W is observed in A. glycines. Comparing the mitochondrial genomes of Aphis glycines with other three aphids,Acyrthosiphon pisum (Harris),Schizaphis graminum (Rondani) and Daktulosphaira vitifoliae (Fitch),some conclusions are drawn in here. All the four aphids contain genes in metazoan mitochondrial genome generally,but the Acyrthosiphon pisum contains three tRNA-M the gene arrangement is consistent with the putative arthropoda ancestor. All protein-coding genes start with a typical ATN codon; the COⅠ and ND4 of A. glycines,A. pisum and S. graminum have an incomplete termination codon (T). The lost stem of TψC arm of tRNA-W is found in three among them except D. vitifoliae. The amino acids used frequently of A. glycines (Leu) are different from A. pisum and S. graminum (Ile). Gene overlap (TTAACAT) between ND4 and ND4L is found in A. glycines and S. graminum,but not in A. pisum and D. vitifoliae.