Shen Xin, Sun Ming'an, Wu Zhigang, Tian Mei, Cheng Hanliang, Zhao Fangqing, Meng Xueping
Jiangsu Key Laboratory of Marine Biotechnology/College of Marine Science, Huaihai Institute of Technology, Lianyungang, 222005, China.
Gene. 2009 May 15;437(1-2):1-8. doi: 10.1016/j.gene.2009.02.014. Epub 2009 Mar 5.
The complete mitochondrial (mt) DNA sequence was determined for a ridgetail white prawn, Exopalaemon carinicauda Holthuis, 1950 (Crustacea: Decopoda: Palaemonidae). The mt genome is 15,730 bp in length, encoding a standard set of 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, which is typical for metazoans. The majority-strand consists of 33.6% A, 23.0% C, 13.4% G, and 30.0% T bases (AT skew=0.057; GC skew=-0.264). A total of 1045 bp of non-coding nucleotides were observed in 16 intergenic regions, including a major A+T rich (79.7%) noncoding region (886 bp). A novel translocation of tRNA(Pro) and tRNA(Thr) was found when comparing this genome with the pancrustacean ground pattern indicating that gene order is not conserved among caridean mitochondria. Furthermore, the rate of Ka/Ks in 13 protein-coding genes between three caridean species is much less than 1, which indicates a strong purifying selection within this group. To investigate the phylogenetic relationship within Malacostraca, phylogenetic trees based on currently available malacostracan complete mitochondrial sequences were built with the maximum likelihood and Bayesian models. All analyses based on nucleotide and amino acid data strongly support the monophyly of Decapoda. The Penaeidae, Reptantia, Caridea, and Meiura clades were also recovered as monophyletic groups with strong statistical support. However, the phylogenetic relationships within Pleocyemata are unstable, as represented by the inclusion or exclusion of Caridea.
测定了中华管鞭虾（Exopalaemon carinicauda Holthuis，1950）（甲壳纲：十足目：长臂虾科）的完整线粒体（mt）DNA序列。该线粒体基因组长度为15730 bp，编码一套标准的13个蛋白质编码基因、2个核糖体RNA基因和22个转运RNA基因，这是后生动物的典型特征。重链由33.6%的A、23.0%的C、13.4%的G和30.0%的T碱基组成（A偏斜=0.057；G偏斜=-0.264）。在16个基因间隔区共观察到1045 bp的非编码核苷酸，包括一个主要的富含A+T（79.7%）的非编码区（886 bp）。将该基因组与泛甲壳动物基本模式进行比较时，发现了tRNA(Pro)和tRNA(Thr)的一种新的易位，这表明在长臂虾线粒体中基因顺序并不保守。此外，三种长臂虾物种的13个蛋白质编码基因中的Ka/Ks比率远小于1，这表明该类群内存在强烈的纯化选择。为了研究软甲纲内的系统发育关系，基于目前可用的软甲纲完整线粒体序列，采用最大似然法和贝叶斯模型构建了系统发育树。基于核苷酸和氨基酸数据的所有分析都强烈支持十足目的单系性。对虾科、爬行亚目、长臂虾亚目和美尾亚目分支也被恢复为具有强统计支持的单系类群。然而，真虾下目内的系统发育关系不稳定，以长臂虾亚目的包含或排除为代表。
