微型DNA条形码在鱼类物种鉴定中的适用性研究

Suitability of mini-DNA barcoding for classification of fishes

以台湾海峡11目38科66属85种355个鱼类样品为研究对象,选取线粒体COⅠ基因中长为313 bp的序列为微型条形码,探讨微型DNA条形码技术在鱼类分类鉴定中的适用性。共获取355条基因序列,序列中T、C、A、G碱基的平均含量占比分别为29.50%、30.10%、24.90%和15.50%;AT含量占比均高于50%。样品种内、种间、属间、科间和目间的K2P(Kimrua-2-Parameter)遗传距离分别为0.37%、18.10%、22.10%、25.40%和27.80%,遗传距离随着分类阶元的提高而增大,种间遗传距离是种内遗传距离的49倍,表明该微型DNA条形码可用于鱼类的分类鉴定,可有助于渔业资源调查和生物多样性保护。

In this study we selected 313 bp sequence of cytochrome C oxidase subunitⅠ(COⅠ)gene as mini-DNA barcode to evaluate the applicability of barcode in the identification of fishes at the species level.A total of 355 barcode sequences were obtained from 85 species in 66 genera of 38 families and 11 orders of fishes in Taiwan Strait.The average contents of T,C,A and G were 29.50%,30.10%,24.90%and 15.50%,respectively.The AT content was higher than 50%in each species.The average Kimura two parameter(K2P)distances within species,genera,families,orders and classes were 0.37%,18.10%,22.10%,25.40%and 27.80%,respectively.The mean interspecific distance was 49-fold higher than the mean intraspecific distance.The K2P neighbor-joining trees based on the sequence generally clustered species in accordance with their taxonomic classifications.High efficiency of species identification was demonstrated in the present study by mini-DNA barcoding.Thus,we conclude that mini-DNA barcoding can be used for the classification of fishes.