近日，来自中国海洋大学水产学院的研究人员在美国《公共科学图书馆—综合》（PLoS ONE）上发表了题为“How DNA Barcodes Complement Taxonomy and Explore Species Diversity: The Case Study of a Poorly Understood Marine Fauna”的研究论文。
帘蛤科是海洋双壳贝类中物种数量最多的一个门类，命名的种类有500余种，其中许多种类具有重要经济价值。然而，由于种内和种间表型的多态性，一些帘蛤科贝类很难单靠形态特征来鉴定。近年来，人类活动带来的空前的生物多样性危机日益严重，为了准确评估生物多样性并进一步有效保护这些形态分类混乱的帘蛤贝类，亟需一种快速而且简单的方法来界定它们的种的界限。
该研究利用基于线粒体COI基因的DNA条形码技术，分析了中国沿海60种帘蛤贝类的315个体，发现几乎所有形态上能够鉴定到种的个体都形成独自的DNA条形码簇；形态上不能确定种名的26个体中，12个体被鉴定到已知种，其余14个体形成5个单独的支系，可能代表未描述的新种，或者至少是在国内未记录的种类。此外，在5个传统的形态种中发现隐存种的存在。该研究证实了DNA条形码技术能有效鉴定海洋贝类，同时能通过为分类修订提供有用信息、指示鉴别性的形态特征和标示隐存种，辅助分类和评估生物多样性。这是迄今为止国内外最大规模的海洋贝类DNA条形码研究。美国洛克菲勒大学Mark Stoeckle教授在DNA条形码博客（http://phe.rockefeller.edu/barcode/blog）中介绍了该研究成果，并对作者首次提出的DNA条形码除具有物种鉴定和隐存种发掘作用外，还具有“Taxonomy disentanglement”第三种作用的观点予以充分肯定。
该论文是在李琪教授的指导下，由博士研究生陈军等完成。该研究得到了国家863计划和国家自然科学基金课题的资助。(生物谷 Bioon.com)
doi:10.1016/j.cell.2005.08.020
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[标题]Tet Proteins Can Convert 5- Methylcytosine to 5-Formylcytosine and 5- Carboxylcytosine
John M. Dawes, Margarita Calvo, James R. Perkins, Kathryn J. Paterson, Hannes Kiesewetter, Carl Hobbs, Timothy K. Y. Kaan, Christine Orengo, David L. H. Bennett and Stephen B. McMahon
The species boundaries of some venerids are difficult to define based solely on morphological features due to their indistinct intra- and interspecific phenotypic variability. An unprecedented biodiversity crisis caused by human activities has emerged. Thus, to access the biological diversity and further the conservation of this taxonomically muddling bivalve group, a fast and simple approach that can efficiently examine species boundaries and highlight areas of unrecognized diversity is urgently needed. DNA barcoding has proved its effectiveness in high-volume species identification and discovery. In the present study, Chinese fauna was chosen to examine whether this molecular biomarker is sensitive enough for species delimitation, and how it complements taxonomy and explores species diversity.The present study shows that DNA barcoding is effective in species delimitation and can aid taxonomists by indicating useful diagnostic morphological traits, informing needful revision, and flagging unseen species. Moreover, the BOLD system, which deposits barcodes, morphological, geographical and other data, has the potential as a convenient taxonomic platform.
