中文摘要：

已经测定的昆虫线粒体基因组中,直翅目草螽亚科的疑钩额螽Ruspolia dubia线粒体控制区长度最短,仅70bp。为此,本研究采用L-PCR结合二次PCR扩增策略对另一种草螽亚科昆虫斑翅草螽Conocephalus maculates线粒体基因组序列进行了测定。序列注释发现：斑翅草螽线粒体基因组序列全长15 898 bp,A＋T含量为72.05%,基因排列与典型的节肢动物线粒体基因组一致。全部蛋白质编码基因以典型的ATN作为起始密码子,9个蛋白质编码基因具有完整的终止密码子,其余4个以不完整的T作为终止信号。除trnSAGN外,其余21个tRNAs均可折叠形成典型的三叶草结构,依照Steinberg等（1997）线粒体特殊tRNA结构类型-9,trnSAGN的DHU臂形成一个7 nt环,反密码子臂则长达9 bp,含1个突起碱基,而不是正常的5 bp。斑翅草螽与其他直翅目昆虫线粒体基因组的主要区别在于,在trnSUCN和nad1,nad1和trnLCUN基因间各存在一段罕见的、大段的基因间隔序列,长度分别为78 bp和360 bp。其中,位于nad1和trnLCUN之间的基因间隔序列N链可形成一个包含完整起始、终止密码子（ATT/TAA）、编码103个氨基酸的未知开放阅读框。同义密码子使用偏好与线粒体基因组编码的tRNA反密码子匹配情况无关,但与密码子第3位点的碱基组成紧密相关;相对密码子使用频率（relative synonymous codon usage,RSCU）大于1的密码子,其第3位点全部是A或T。在已经测定的直翅目昆虫线粒体基因组tRNAs中,均存在一定数量的碱基错配,且以G-U弱配对为主,表明G-U配对在线粒体基因组中可能是一种正常的碱基配对形式。本研究测定的斑翅草螽线粒体基因组序列,和先前已经测定的直翅目线粒体基因组序列一起,可以为重建直翅目的进化历史提供数据资源。

英文摘要：

The mitochondrial genome（mitogenome） of Ruspolia dubia（Orthoptera： Conocephalinae） contains a short control region with 70 bp in length.So,the mitogenome of Conocephalus maculates come from Conocephalinae was sequenced by using long-PCR and sub-PCR techniques.The mitogenome of C.maculates is 15 898 bp in size,its A＋T content is 72.05% and the genome organization follows the ancestral insect gene arrangement.All protein-coding genes（PCGs） start with a typical ATN codon,while nine of the 13 PCGs end with TAA or TAG,and the remainder have incomplete termination codons T.Except for trnSAGN,all 21 tRNAs have the typical clover-leaf structures.According to the unusual Type-9 of Steinberg et al.（1997）,the DHU arm of trnSAGN forms a simple 7-nt loop and the anticodon stem has nine base-pairs with a bulged nucleotide in the middle in contrast to the normal five base-pairs.The main differences between C.maculatus and other orthopteran mitogenomes was that two novel larger intergenic spacers（78 bp and 360 bp） between trnSUCN and nad1,nad1 and trnLCUN,respectively.The intergenic spacer between nad1 and trnLCUN has been labeled unidentified open reading frame（UORF） because N strand comprises an open reading frame（103 amino acids） complete with start and termination codons（ATT/TAA）.The usage of synonymous codon markedly is correlated with the nucleotide at the 3rd codon position,but has no relation to the anticodon of mitogenome tRNA.Generally,for all codons with their relative synonymous codon usage（RSCU） more than 1,the 3rd codon positions are A or T.Noncanonical matches of G-U base pairs accounts for the overwhelming majority of total unmatched base pairs in the orthopteran mitogenome tRNAs.The results suggest that the G-U may be one cognitive base pairing in mitogenome.The C.maculates mitogenome sequences,as well as the previously determined orthopteran mitogenomes,provide sequence source to reconstruct Orthoptera evolutionary history.