直翅目昆虫线粒体基因组研究进展

Research progress in mitochondrial genomes of the Orthoptera insects

本文总结了本实验室对40余种直翅目昆虫的线粒体基因组序列的研究方法和主要结果。直翅目线粒体基因组研究中最重要的发现包括:(1)在直翅目昆虫线粒体基因组中发现了3种基因排列次序。蝗亚目除蜢总科外都具有DK排列。蜢总科的变色乌蜢为KD排列,与蝗亚目其他总科不同,而与螽亚目昆虫的排序方式相同。已测出的螽亚目大多数昆虫的KD排列顺序与典型节肢动物的完全相同,但在黄脸油葫芦Teleogryllus emma发生了tRNAGlu,tRNASer和tRNAAsn的倒置;(2)在疑钩额螽Ruspolia dubia中发现了一种到目前为止具有最短控制区(70bp)的线粒体基因组;(3)采用多种方法分析了昆虫A+T富集区存在的调控序列和二级结构特征,获得了昆虫A+T富集区保守序列的一致结构。采用Z曲线分析蝗虫的A+T富集区,表明也存在与原核生物复制起点类似的信号;(4)构建了30种蝗虫12S rRNA和16S rRNA的二级结构。在昆虫线粒体基因组非编码链中发现了一些类tRNA结构和tRNA异构体;(5)构建了基于线粒体基因组数据的直翅目昆虫主要亚科以上分类单元之间的系统发育关系。

The sequencing strategies and analysis results of 40 complete mitochondrial genomes from Orthoptera were summarized. The most important findings include： （ 1） three types of gene order in Orthoptera were found. The gene order of Erianthus versicolor is the same as that of Ensifera species,and the gene order of tRNAGlu,tRNASerand tRNAAsn in Teleogryllus emma （ Gryllidae） are located in the minor strand. （ 2） The mitochondrial DNA of Ruspolia dubia contains a short A ＋ T-rich region with 70 bp in length. （ 3） The conserved consensus structures of A ＋ T-rich region were determined. The Z-curve method was applied to analyze the A ＋ T-rich region,and the results showed that signals similar to prokaryote duplication origin exist in A ＋ T-rich region. （ 4） The secondary structures of 16S sRNA and 12S rRNA from 30 species were predicted and compared with those of other insects. Some tRNA-like or tRNA isotype structures were found in noncoding regions of mitochondrial genomes of Orthoptera. （ 5） The phylogenetic relationships at families and superfamilies of Orthoptera were reconstructed based on the data of the 40 complete mitochondrial genomes.