核糖体转录间隔子2应用于鱼类种属的鉴别

为了防止珍稀鱼类的非法捕捞和销售, 鱼类种属的鉴别就成为非常关键的问题, 特别是形态学方法无法区分的样品(如鱼苗、鱼鳞、鱼卵、鱼肉及其加工产品等)。为了帮助珍稀鱼类资源的管理和保护, 文章报道了一种利用核糖体基因的转录间隔子2鉴别鱼类种属的分子遗传学方法: (1) 利用同一目鱼类5.8S rRNA和28S rRNA基因的保守性, 设计出扩增鲤形目鱼类这两个基因间转录间隔子2 DNA片段, 测序获得它们的碱基排列顺序; (2) 再根据不同鱼类转录间隔子2序列的差异, 设计出每种鱼的种属特异引物、种属鉴别标准物, 构建鱼类分子分类图谱, 利用PCR复合扩增技术鉴别鱼类种属。通过对国内不同地方采集的5种鲤形目鱼类的210个单一品种样本和40个混合样本的鉴别检验, 该方法能够准确、灵敏和快速鉴别这5种鱼, 可用于鱼类资源保护和评估、管理和开发, 特别是在渔业管理人员渔业执法、海关打击珍稀鱼类走私、防止商业欺诈和外来有害生物入侵等方面非常有用

Identification of fish species based on ribosomal DNA ITS2 locus

To prevent illegal fishing and sale, the most difficult problem is identification of marketed fish species, especially the parts that are difficult to be differentiated with morphological method (e.g., larval, eggs, scales, meat, products etc. To assist conservation and management of fishery resources, this paper reported a molecular genetic approach based on ribosomal internal transcribed spacer 2 locus. The method includes two steps: (1) the order general primers were designed according to the conservative nature of 5.8SrRAN and 28SrRNA genes within an order, and the DNA ribosomal internal transcribed spacer 2 locus fragment were then amplified and sequenced. (2) The species-specific ladders and the species-specific primers for each species were designed according to the sequencing results. The map of molecular taxonomy was constructed. This approach employs multiplex PCR that is formatted for fish species identification. We tested 210 sin-gle-species samples and 40 mix-species samples from different regions of China. The approach distinguished accurately and sensitively samples from each of the five species. This genetic and molecular approach will be useful for fish conservation, assessment, management and exploitation, strengthen in law enforcement of fishery manager, combat rare and endangered fish smuggling, and prevent commercial fraud and biological invasion by harmful nonnative species.