4种鳕鱼线粒体16SrRNA、COI和Cytb基因片段序列的比较研究  

Sequence comparison of mtDNA 16S rRNA,COI and Cyt b gene fragments in four species of Gadidae fish

作　　者：毕潇潇[1] 高天翔[1] 肖永双[1] 李永振[2] 

机构地区：[1]中国海洋大学海水养殖教育部重点实验室,山东青岛266003 [2]中国水产科学研究院南海水产研究所,广东广州510300

出　　处：《南方水产》2009年第3期46-52,共7页South China Fisheries Science

基　　金：国家高技术研究发展计划(863计划)项目(2006AA09Z418 );国家重点基础研究发展计划(973计划)项目(2005CB422306);国家科技基础条件平台工作项目(2006DKA30470-016)

摘　　要：对狭鳕(Theragra chalcogramma)、太平洋鳕(Gadus macrocephalus)、蓝鳕(Micromesistius poutassou)和远东宽突鳕(Eleginus gracilis)4种不同属鳕鱼的线粒体16S rRNA、Cytochrome oxidase subunit I(COI)和细胞色素b(Cytb)基因片段序列进行了测定,分析比较了不同鳕鱼种间的序列差异。通过PCR扩增和序列测定,得到4种鳕鱼线粒体3个基因片段的总长度分别为539bp(16S rRNA)、601bp(COI)和385bp(Cytb),其基因片段的A+T含量都较高。4种鳕鱼种内个体间序列变异较小,3个基因片段的核苷酸替代速率依次为Cytb>COI>16S rRNA。Cytb基因片段序列的分析结果显示太平洋鳕和狭鳕间分歧时间约为219万年,发生于中新世(Mio-cene);宽突鳕与蓝鳕间分歧时间约为653万年,发生在上新世(Pliocene)。根据遗传距离构建的NJ系统树表明,狭鳕与太平洋鳕的亲缘关系较近,与蓝鳕的亲缘关系较远。In order to identify differentiation of species of Gadidae fishes and evaluate the genetic variance, sequence comparison of mtDNA 16S rRNA, COI and Cyt b gene fragments were employed for Theragra chalcogramma, Gadus macrocephalus, Micromesistius poutassou and Eleginus gracilis. Nucleotide sequences of 539 bp for 16S rRNA, 601 bp for COI and 385 bp for Cyt b genes were obtained. The percentage of A ＋ T content was high. Sequence analysis indicated that the variation level of intra-species was low. The nu- cleotide substitution rates of three gene segments arranged from high to low was Cyt b 〉COI 〉 16S rRNA. The estimated time of divergence between G. macrocephalus and T. chalcogramma was about 2. 19 million years based on Cyt b gene sequence, which was apparently lower than that between E. gracilis and M. poutassou （ about 6. 53 million years）. The result indicated a Miocene divergence and a Pliocene divergence of the four species. Based on the senetic distances, NJ phylogenetic tree was made and indicated that there was a closer relationship between G. macrocephalus and T. chalcogramma.

关 键 词：鳕鱼 16S rRNA基因 COI基因 CYT b基因 序列分析 

分 类 号：Q244[生物学—细胞生物学] Q522.6