National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20892, USA.
Proc Natl Acad Sci U S A. 2012 Apr 17;109(16):6241-6. doi: 10.1073/pnas.1117018109. Epub 2012 Mar 27.
Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups.
六个 DNA 区域被一个多国多实验室的联合团队评估为真菌（真核生物界第二大连锁）的潜在 DNA 条形码。线粒体细胞色素 c 氧化酶亚基 1 区被排除作为潜在的标记，因为它在真菌中难以扩增，通常包含较大的内含子，并且变异性不足。三个核核糖体 RNA 顺式作用区与三个代表蛋白编码基因（RNA 聚合酶 II 大亚基、RNA 聚合酶 II 第二大亚基和微染色体维持蛋白）的区域一起进行了比较。尽管与核糖体标记相比，蛋白编码基因区域通常具有更高的正确鉴定百分比，但低 PCR 扩增和测序成功率使它们无法成为通用真菌条形码的候选者。在核糖体顺式作用区中，内部转录间隔区（ITS）具有最广泛的真菌成功鉴定的最高概率，并且在种间和种内变异之间具有最明确的条形码差距。核核糖体大亚基是某些群体中流行的系统发育标记，在某些分类群中具有较高的物种分辨率，例如早期分化的谱系和子囊酵母，但在其他方面略逊于 ITS。核核糖体小亚基在真菌中具有较差的种水平分辨率。ITS 将被正式提议作为生命条形码联盟的主要真菌条形码标记，并且可能为特定的狭义分类群开发补充条形码。
