基于线粒体COI基因的泰国近海有毒水母遗传多样性研究  

Genetic Diversity of the Venomous Medusae in Thai Waters Based on the Mitochondrial COI Gene Sequences

作　　者：缪晓翔 肖洁[1,2] 张学雷[1,2] 刘瑞娟[1,2] AUNGTONYA Charatsee 

机构地区：[1]国家海洋局第一海洋研究所,山东青岛266061 [2]海洋生态环境科学与工程国家海洋局重点实验室,山东青岛266061 [3]Phuket Marine Biological Center,Phuket83000,Thailand

出　　处：《海洋科学进展》2017年第4期535-546,共12页Advances in Marine Science

基　　金：中国-东盟海上合作基金项目--濒危海洋物种合作研究;国家自然科学青年基金项目--我国海水甲壳类中寄生性甲藻(Hematodinium)的种群遗传结构及其分子系统分类地位的研究(41206162)

摘　　要：利用编码线粒体细胞色素氧化酶I(COI)的基因片段序列,对泰国近海有毒水母69个样本进行遗传多样性研究,并探讨该片段作为DNA条形码对泰国近海有毒水母类进行快速分类鉴定的可行性,以期为后续有毒水母的监测和预警、生物学和生态学等的研究提供技术支撑。基因碱基组成分析表明,立方水母COI序列GC含量为42.1%,明显高于钵水母(37.1%)和水螅水母(36.9%)。COI基因编码氨基酸的密码子第3位点GC含量(30.2%)显著低于第1,2位点(分别为47.4%,42.1%),且该位点碱基替换频率最高,转换/颠换比值为1.0,表明该位点碱基突变趋于饱和;但去除密码子第3位点,对系统进化树的构建无显著影响。根据COI序列计算3个纲水母的K2P(Kimura 2-parameter)遗传距离,得出种内遗传差异为0.000~0.151,均值为0.036,同纲种间遗传差异为0.167~0.321,均值为0.263,纲间遗传差异为0.246~0.385,均值为0.334。该COI基因片段能够快速有效区分这些有毒水母种类。研究表明,泰国沿岸水母多样性较高,所获69个样品可以分为13个种,包括5种钵水母、6种立方水母和2种水螅水母,其中Carukiidae科存在新属新种。立方水母的地理分布具有明显的区域特征,马来半岛东西两岸存在物种和遗传多样性差异,其产生原因还有待于进一步研究。To explore the genetic diversity of the venomous medusae,the partial mitochondrial COI gene sequences were generated from 69 jellyfish specimens collected from the coastal waters of Thailand.And the feasibility of DNA barcoding using this gene fragment was further investigated,in order to provide technique supporting for the early warning of venomous medusae in Thailand,and for the future work on ecology and biology of these venomous jellyfish as well.The analysis of nucleotide composition of the sequences showed that G and C nucleotide percentage（GC%）of Cubozoa（42.1%）was significantly higher than those of Scyphozoa（37.1%）and Hydrozoa（36.9%）.GC% of the 3 rd condon position（30.2%）was much lower than those of the 1 st and 2 nd positions（47.4% and 42.1%,respectively）.Besides,the frequency of nucleotide substitution was highest at the 3 rd positions with the Rvalue（transition/transversion）of 1.0,indicating that the mutational rate at this position was prone to be saturated.Whereas,the topology of the phylogenetic tree was not significantly changed after the 3 rd condon positions were excluded from the analyses.The K2 P（Kimura 2-parameter）genetic distance was evaluated within and among the species based on the sequences of COI gene.The intra-specific genetic distances ranged from 0.000 to0.151,with the average of 0.036;the inter-specific distances varied from 0.167 to 0.321,with the average of 0.263,and inter-classes were from 0.246 to 0.385 with the average of 0.334.The COI gene fragments were proved to be able to discriminate these venomous jellyfish species fast and efficiently.Additionally,a high species diversity of the venomous jellyfish along the coasts of Thailand was revealed by this research.There were total 13 species identified from the 69 samples,including 5 Cubozoa species,6 scyphozoans and2 hydrozoans.A new genus of the family Carukiidae was suggested by this study.A regional distribution pattern of the cubozoan jellyfish in Thai waters was observed,which showed the speci

关 键 词：立方水母 钵水母 DNA条形码 COI序列 泰国 

分 类 号：Q344[生物学—遗传学]