长臂虾科线粒体基因组特征分析及分子标记探讨

Analysis of Mitochondrial Genome Characteristics and Exploration of Molecular Markers in Palaemonidae

通过常规PCR和长PCR扩增获得脊尾白虾的线粒体DNA,采用鸟枪法测序、序列组装获得脊尾白虾的线粒体基因组全序列。结合罗氏沼虾和沼虾的线粒体基因组,分析了长臂虾线粒体基因组的基本特征、基因排列、蛋白质编码基因和基因变异程度等。与泛甲壳动物线粒体基因组的原始排列相比,2个沼虾的线粒体基因组的基因排列完全一致;而脊尾白虾线粒体基因组却存在2个tRNA基因的易位。长臂虾科线粒体基因组主编码基因的变异特征分析揭示了cox1基因多态位点的比例最低,仅为25.5%;而3个基因(nad2、nad4和nad5)不仅多态位点的比例较高,而且基因的长度较长,从而拥有最丰富的多态位点。因此,nad2、nad4和nad5基因可以作为分子标记,用于分析长臂虾不同群体之间的遗传多样性,为长臂虾生物多样性的保护及合理利用其生物资源提供更多保障。

Mitochondrial DNA was obtained from prawn Exopalaemon carinicauda by conventional PCR and long PCR amplification, and then the mitochondrial genome was acquired using shotgun sequencing and sequence assembly. Altogether with freshwater prawn Macrobrachium rosenbergii and M. lanchesteri mitochondrial genomes, the basic features of mitochondrial genome, including gene order, protein-coding genes and gene mutation were analyzed in Palaemonidae. Two Macrobrachium mitochondrial genomes have same arrangement with the pan-crustacean ground pattern, while E. carinicauda mitochondrial genome have two tRNA gene translocation. Gene variation analysis of Palaemonoidea mitochondrial genes revealed that coxl has the lowest proportion of polymorphic loci（only 25.5%）. While the proportion of polymorphic loci in three genes（nad2 ,nad4 and nad5）is higher,and the length of those genes is longer,resulting in most extensive polymorphic sites in those genna. Therefore,nad2,nad4 and nad5 genes can be used as molecular markers to analyze genetic diversity among different groups in Palaemonoidea,which provides more protection for conservation of Palaemonoidea biodiversity and for rational utilization of biological resources.