Hajibabaei Mehrdad, McKenna Charly
Biodiversity Institute of Ontario & Integrative Biology, University of Guelph, Guelph, ON, Canada.
Methods Mol Biol. 2012;858:339-53. doi: 10.1007/978-1-61779-591-6_15.
Conventional DNA barcoding uses an approximately 650 bp DNA barcode of the mitochondrial gene COI for species identification in animal groups. Similar size fragments from chloroplast genes have been proposed as barcode markers for plants. While PCR amplification and sequencing of a 650 bp fragment is consistent in freshly collected and well-preserved specimens, it is difficult to obtain a full-length barcode in older museum specimens and samples which have been preserved in formalin or similar DNA-unfriendly preservatives. A comparable issue may prevent effective DNA-based authentication and testing in processed biological materials, such as food products, pharmaceuticals, and nutraceuticals. In these cases, shorter DNA sequences-mini-barcodes-have been robustly recovered and shown to be effective in identifying majority of specimens to a species level. Furthermore, short DNA regions can be utilized via high-throughput sequencing platforms providing an inexpensive and comprehensive means of large-scale species identification. These properties of mini-barcodes, coupled with the availability of standardized and universal primers make mini-barcodes a feasible option for DNA barcode analysis in museum samples and applied diagnostic and environmental biodiversity analysis.
传统的DNA条形码技术利用线粒体基因COI中一段约650 bp的DNA条形码对动物群体进行物种鉴定。叶绿体基因中类似大小的片段已被提议作为植物的条形码标记。虽然对新鲜采集且保存良好的标本进行650 bp片段的PCR扩增和测序是一致的，但对于保存在福尔马林或类似不利于DNA保存的防腐剂中的老博物馆标本和样本，很难获得全长条形码。类似的问题可能会阻碍对加工过的生物材料（如食品、药品和营养保健品）进行有效的基于DNA的鉴定和检测。在这些情况下，较短的DNA序列——微型条形码——已被成功回收，并显示在将大多数标本鉴定到物种水平方面是有效的。此外，短DNA区域可通过高通量测序平台加以利用，提供一种廉价且全面的大规模物种鉴定方法。微型条形码的这些特性，再加上标准化通用引物的可用性，使得微型条形码成为博物馆样本DNA条形码分析以及应用诊断和环境生物多样性分析的可行选择。
