南海金线鱼属Nemipterus鱼类COⅠ和Cyt b基因片段的比较分析

基于线粒体细胞色素b(Cyt b)和细胞色素氧化酶Ⅰ基因(COⅠ)片段,运用PCR直接测序法,对采自南海的金线鱼(Nemipterus virgatus)、日本金线鱼(N.japonicus)、深水金线鱼(N.bathybius)、红棘金线鱼(N.nemurus)和苏门答腊金线鱼(N.mesoprion)及GenBank中的六齿金线鱼(N.hexodon)、裴氏金线鱼(N.peronii)及红金线鱼(N.furcosus)的序列进行了分析,并比较分析了它们间的序列差异。Cyt b基因序列片段(425 bp)和COⅠ基因序列片段(507 bp)的分析均显示日本金线鱼和红棘金线鱼之间序列差异和遗传距离均最小,COⅠ基因片段中为分别0.25%和0.003,Cyt b基因片段中为0和0,两者亲缘关系非常近;几种金线鱼之间尚未达到属的水平,裴氏金线鱼仍属于金线鱼属;两目的片段的NJ系统树均显示,日本金线鱼和红棘金线鱼混杂在一起聚为一支,而日本金线鱼和苏门答腊金线鱼属于不同的发育分支;红棘金线鱼和日本金线鱼是最新分化种,金线鱼则是最早分化种;几种金线鱼类的分化时间大约在中更新世时期。比较属间的系统发育关系,旨在为金线鱼属鱼类分类提供依据,进而对鱼类资源的评估与保护措施提供基础参考。

Sequence analysis of mitochondrial CO Ⅰ and Cyt b gene of Nemipterus species in South China Sea

We sequenced and analyzed partial nucleotide sequences of Cyt b and COⅠgene for Nemipterus spe-cies,including Nemipterus virgatus,N.japonicus,N.bathybius,N.nemurus,N.mesoprion,and the COⅠgene of N.hexodon,N.peronii and N.furcosus from GenBank.The results show that there are little different in nucleotide base of Cyt b(425 bp) and COⅠ(507 bp).The divergence of sequences and genetic distances are tiny in N.ja-ponicus and N.nemurus(COⅠ0.25% and 0.003,Cyt b 0 and 0) which suggest they have very closed relationship.And the Nemipterus species belongs to one genus,including N.peronii since the N.japonicus and N.mesoprion are in different branches.From the NJ phylogenetic trees,N.japonicus and N.nemurus are the latest differentiation species,N.virgatus is the oldest one.Molecular evolution rate(2% every million year in Cyt b) showed the di-vergence of Nemipterus species occurred during the middle pleistocene epoch.It is a reference of the classification of Nemipterus species.