Hanner Robert, Becker Sven, Ivanova Natalia V, Steinke Dirk
Department of Integrative Biology, Biodiversity Institute of Ontario, University of Guelph, Guelph, Ont, Canada.
Mitochondrial DNA. 2011 Oct;22 Suppl 1:106-22. doi: 10.3109/19401736.2011.588217.
The Fish Barcode of Life campaign involves a broad international collaboration among scientists working to advance the identification of fishes using DNA barcodes. With over 25% of the world's known ichthyofauna currently profiled, forensic identification of seafood products is now feasible and is becoming routine.
Driven by growing consumer interest in the food supply, investigative reporters from five different media establishments procured seafood samples (n = 254) from numerous retail establishments located among five Canadian metropolitan areas between 2008 and 2010. The specimens were sent to the Canadian Centre for DNA Barcoding for analysis. By integrating the results from these individual case studies in a summary analysis, we provide a broad perspective on seafood substitution across Canada.
Barcodes were recovered from 93% of the samples (n = 236), and identified using the Barcode of Life Data Systems "species identification" engine ( www.barcodinglife.org ). A 99% sequence similarity threshold was employed as a conservative matching criterion for specimen identification to the species level. Comparing these results against the Canadian Food Inspection Agency's "Fish List" a guideline to interpreting "false, misleading or deceptive" names (as per s 27 of the Fish Inspection regulations) demonstrated that 41% of the samples were mislabeled. Most samples were readily identified; however, this was not true in all cases because some samples had no close match. Others were ambiguous due to limited barcode resolution (or imperfect taxonomy) observed within a few closely related species complexes. The latter cases did not significantly impact the results because even the partial resolution achieved was sufficient to demonstrate mislabeling.
This work highlights the functional utility of barcoding for the identification of diverse market samples. It also demonstrates how barcoding serves as a bridge linking scientific nomenclature with approved market names, potentially empowering regulatory bodies to enforce labeling standards. By synchronizing taxonomic effort with sequencing effort and database curation, barcoding provides a molecular identification resource of service to applied forensics.
“鱼类生命条形码”计划涉及广泛的国际合作，众多科学家致力于利用DNA条形码推进鱼类识别工作。目前，全球已知鱼类中有超过25%已进行了条形码分析，海产品的法医鉴定现已可行且正逐渐成为常规操作。
受消费者对食品供应关注度不断提高的驱动，来自五家不同媒体机构的调查记者于2008年至2010年间，从加拿大五个大都市地区的众多零售机构采购了海产品样本（n = 254）。这些样本被送往加拿大DNA条形码中心进行分析。通过将这些个案研究的结果整合到一项汇总分析中，我们对加拿大全国范围内的海产品替代情况提供了一个全面的视角。
93%的样本（n = 236）成功获取了条形码，并使用生命条形码数据系统的“物种识别”引擎（www.barcodinglife.org）进行了识别。采用99%的序列相似性阈值作为将标本鉴定到物种水平的保守匹配标准。将这些结果与加拿大食品检验局的“鱼类清单”（这是一份解释“虚假、误导性或欺骗性”名称的指南，依据《鱼类检验条例》第27条）进行比较，结果表明41%的样本存在标签错误。大多数样本很容易被识别；然而，并非所有情况都是如此，因为有些样本没有相近的匹配物种。其他样本由于在一些亲缘关系较近的物种复合体中观察到条形码分辨率有限（或分类学不完善）而存在模糊性。后一种情况对结果没有显著影响，因为即使获得的部分分辨率也足以证明存在标签错误。
这项工作突出了条形码技术在识别各种市场样本方面的实用功能。它还展示了条形码如何作为一座桥梁，将科学命名法与认可的市场名称联系起来，有可能使监管机构能够执行标签标准。通过使分类学工作与测序工作以及数据库管理同步，条形码技术为应用法医学提供了一种分子识别资源服务。
