线粒体基因是研究生物系统进化的重要分子标记,本文对迁飞昆虫稻纵卷叶螟Cnaphalocrocis medinalis线粒体DNA进行扩增及注释,结果表明:稻纵卷叶螟线粒体基因组全长15377bp,AT含量为82%,基因组结构为鳞翅目所特有的CR-M-I-Q结构。以细胞色素C氧化酶基因(COX)为分子标记,对有翅类昆虫22个物种进行系统树构建,发现与昆虫翅的发生高度吻合。对存在于PCGs终止密码子判定的争议予以阐明并提出注释建议,有利于今后动物线粒体基因组序列注释的统一规范。
Mitochondrial genes represent important molecular clocks for phylogenetic analysis. In present study, the complete mitochondrial genome of Cnaphalocrocis medinalis was sequenced, which is a circular molecule with 15 377 bp length ( AT 82% ). The genome structure shows a lepidopteron-unique CR-M-I-Q arrangement. Based on COX gene, we speculated phylogenetic relationship among 22 pterygotan insects species. The result suggests the evolution of insects was highly related to the divergence of their wings. Three types of model are proposed for the first time, to determine the termination codon of the animal mtDNAs.