小蔗螟Cytb基因序列的分析研究(鳞翅目:螟蛾总科:草螟亚科)  

Cytochrome b Gene Sequence of the Sugarcane Borer,Diatraea saccharalis(Lepidoptera:Pyraloidea:Crambidae)

作　　者：李玮玮[1] 张修月[1] 陈伟才[1] 岳碧松[1] 

机构地区：[1]四川大学生命科学学院,成都610064

出　　处：《四川动物》2009年第3期353-357,共5页Sichuan Journal of Zoology

摘　　要：扩增并测定了小蔗螟线粒体细胞色素b(Cytb)基因,其序列全长1146 bp,利用分子生物学软件分析了包括小蔗螟在内的4目(鳞翅目、双翅目、鞘翅目、缨尾目)共19条Cytb基因序列。分析结果显示:鳞翅目昆虫AT含量明显低于其它昆虫,其中小蔗螟AT含量为75.1%;AT含量与A或T碱基使用的偏倚没有明显的相关性;碱基替换主要发生在密码子第三位,并且颠换率远大于转换率;密码子使用频率与基因碱基组成AT偏倚有相关性;相比于核苷酸数据,氨基酸所显示的遗传距离更为准确;使用Cytb基因构建的系统进化树支持昆虫的单源进化学说。The mitochondrial cytochrome b gene of Diatraea saccharalis was amplified and sequenced and was found to be 1146 bp in length. The cyt b gene sequences from four orders including Diptera, Coleoptera, Thysanura, and Lepidoptera, were analyzed with molecular biology software. Nucleotide composition, transitions and transversions, amino acid composition, genetic distance, and the phylogenetic relationship among these insects were examined. The results indicated that Lepidopteran insects possessed a higher A ＋ T content, and was 75.1% in D. saccharalis. There was no conspicuous relationship between A ＋ T content and A/T-skewness. Nucleotide substitution occurred mostly at the third position, and transitions were greater than transversions. Codon usage could reflect base compositional bias of AT. The amino acid sequences were believed to be more accurate than nucleotide sequences in genetic distance. The phylogenetic analysis was performed using cyt b gene sequences, and the results supported a monophyletic Endopterygota （ Diptera ＋ Lepidoptera ＋ Coleoptera）, a monophyletic Mecopterida （ Diptera ＋ Lepidoptera）, a monophyletic Diptera, a monophyletic Lepidoptera, and a monophy- letic Coeloptera.

关 键 词：小蔗螟 鳞翅目 CYT B基因 序列分析 

分 类 号：Q963[生物学—昆虫学]