关于中国香鱼分类地位的线粒体DNA基因序列分析  

On the taxonomic status of Chinese sweetfish Plecoglossus sp. based on mitochondrial DNA analysis

作　　者：陈泉梅[1] 鲁延付[1] 章群[1] 

机构地区：[1]暨南大学生命科学技术学院水生生物研究所,广州510632

出　　处：《生态科学》2007年第2期143-145,共3页Ecological Science

基　　金：国家自然科学基金(项目编号:40106014);广东省自然科学基金(项目编号:000760)

摘　　要：测定了辽宁和广东香鱼的Cytb基因序列,与GenBank中日本和韩国香鱼分子数据合并比较。结果表明11尾香鱼402个碱基序列中变异位点8个,信息简约位点有2个,A+T与G+C含量分别为51.4%和48.6%,转换/颠换比为4.9。运用Kimura-2parameter模型,采用邻接法构建的分子系统树,发现中国香鱼与日本和韩国香鱼聚类在一起,不同地理种群的香鱼均未单独分群,表明中国和日、韩香鱼亲缘关系相当近。根据日、韩香鱼的地理分布,推测所分析的辽宁和广东种群可能亦为香鱼指名亚种,但该推论尚需与琉球香鱼亚种的序列进行比较后才能确定。研究虽未发现辽宁香鱼和广东香鱼间存在明显的种群结构差异,但由于中国海域辽阔,生境多样,中国沿海是否会有其它种下群体发生,则需要采用进化速度适中的线粒体和核基因标记,对中国香鱼不同的地理种群进行广泛的大样本分析来确定。The Sweetfish Plecoglossus is a kind of amphidromous fish endemic to east Asia. In order to determine taxonomic status of controversial Chinese sweetfish, mitochondrial cytochrome b gene sequences of 2 Chinese sweetfish from Liaoning and Guangdong were determined, combined with 9 GenBank-downloaded homologous sequences of the same genus from Japan and South Koea, 11 individual fishes were analyzed. Of the aligned 402bp nucleotide sequences, there existed 8 variable sites and 2 information sites. The contents of A＋T and G＋C of the gene are 51.4%, 48.6%, respectively. The ratio of transition verse transversional is 4.9. Kimura-2 parameter model based neighbour-joining tree indicated that Chinese sweetfish mosaic clustered with those from Japan and South Korea; no geographic structure within and between geographic populations were found, and genetic distance among different populations were equivalent, suggesting that they were closely related. According to the geographic distribution of abroad populations, they might belong to the same subspecies of P.altivelis altivelis. As Chinese sweetfish were nested within and genetic closely related to others, Liaoning and Guangdong sweetfish might belong to P.altivelis altivelis too. As no sequences from P.altivelis ryukyuensis were available to our study, this conclusion needs further research. Although no obvious genetic structure were found between Liaoning and Guangdong populations, it did not necessarily mean that all Chinese sweetfish belong to the same subspecies, as diversified coastal regions and habitats might exist in China, and sample size were limited and cytb is relatively conservative in this study. To determine the taxonomic status and populations structure of Chinese sweetfish, intensive and extensive population samples are needed using both mitochondrial and nuclear markers.

关 键 词：香鱼 细胞色素B 分类地位 

分 类 号：Q959.483[生物学—动物学]