扬子鳃蛭线粒体基因组全序列测定及其系统学地位——基于Pacbio和Illumina技术

利用Illumina和Pacbio测序技术对扬子鳃蛭（Ozobranchus jantseanus）线粒体基因组全序列进行测序及注释，并与NCBI数据库中蛭纲（Hirudinea）其他物种的线粒体全序列的排列方式和系统进化关系进行了比较，以确定其系统学地位.结果显示：获得的线粒体基因组序列长度为14 868 bp，蛋白编码基因存在2种起始密码子，分别为ATG和ATT；终止密码子共有4种，分别为TAA，TAG，TA和T；蛭纲10个物种的线粒体基因组全序列基因排序可分为2种类型，其差异表现在tRNAs的互换和长非编码区的长度的不同；扬子鳃蛭所属的吻蛭目（Rhynchobdellida）均为b型，绝大部分无吻蛭目（Arhynchobdellida）的排列方式为a型.基于蛭纲物种的13个蛋白编码基因(PCGs)的Neighbor-Joining（NJ）树进化分析显示，扬子鳃蛭与其他吻蛭目物种聚类.

Determination and Analysis of Complete Mitochondrial Genome of Ozobranchus jantseanus： Based on Pacbio and Illumina Sequencing

The complete mitochondrial genome of Ozobranchus jantseanus was sequenced and annotated accurately through a combination of Illumina and Pacbio technology, and the comparative analysis of the gene order and phylogenetic relationship with other species in the Hirudinea were performed. The results showed that the complete mitochondrial genome length of O. jantseanus was 14 868 bp, and there were two kinds of start codon, ATG and ATT, and four types of stop codon, TAA, TAG, TA and T in the coding gene of O. jantseanus. Comparative analysis showed that mitochondrial genes orders of 10 species in the Hirudinea were divided into two types, and the differences were reflected in the exchange of tRNA gene order and the length of long noncoding region (LNR). All Rhynchobdellida species, including O. jantseanus, belonged to the b-type, and most of the Arhynchobdellida species to a-type. The Neighbor-Joining (NJ) evolution analysis of 13 protein coding genes (PCGs) from species in the Hirudinea showed that O. jantseanus and others species in Rhynchobdellid formed a monophyletic group.