Hajibabaei Mehrdad, Singer Gregory A C, Clare Elizabeth L, Hebert Paul D N
Biodiversity Institute of Ontario, Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
BMC Biol. 2007 Jun 13;5:24. doi: 10.1186/1741-7007-5-24.
The rapid and accurate identification of species is a critical component of large-scale biodiversity monitoring programs. DNA arrays (micro and macro) and DNA barcodes are two molecular approaches that have recently garnered much attention. Here, we compare these two platforms for identification of an important group, the mammals.
Our analyses, based on the two commonly used mitochondrial genes cytochrome c oxidase I (the standard DNA barcode for animal species) and cytochrome b (a common species-level marker), suggest that both arrays and barcodes are capable of discriminating mammalian species with high accuracy. We used three different datasets of mammalian species, comprising different sampling strategies. For DNA arrays we designed three probes for each species to address intraspecific variation. As for DNA barcoding, our analyses show that both cytochrome c oxidase I and cytochrome b genes, and even smaller fragments of them (mini-barcodes) can successfully discriminate species in a wide variety of specimens.
This study showed that DNA arrays and DNA barcodes are valuable molecular methods for biodiversity monitoring programs. Both approaches were capable of discriminating among mammalian species in our test assemblages. However, because designing DNA arrays require advance knowledge of target sequences, the use of this approach could be limited in large scale monitoring programs where unknown haplotypes might be encountered. DNA barcodes, by contrast, are sequencing-based and therefore could provide more flexibility in large-scale studies.
物种的快速准确鉴定是大规模生物多样性监测计划的关键组成部分。DNA阵列(微阵列和宏阵列)和DNA条形码是最近备受关注的两种分子方法。在此,我们比较这两种平台用于鉴定一个重要类群——哺乳动物。
我们基于两种常用的线粒体基因细胞色素c氧化酶I(动物物种的标准DNA条形码)和细胞色素b(一种常见的物种水平标记)进行分析,结果表明阵列和条形码都能够高精度地区分哺乳动物物种。我们使用了三个不同的哺乳动物物种数据集,包括不同的采样策略。对于DNA阵列,我们为每个物种设计了三个探针以应对种内变异。至于DNA条形码,我们的分析表明细胞色素c氧化酶I和细胞色素b基因,甚至它们的更小片段(微型条形码)都能在各种各样的样本中成功区分物种。
本研究表明DNA阵列和DNA条形码是生物多样性监测计划中有价值的分子方法。在我们的测试组合中,这两种方法都能够区分哺乳动物物种。然而,由于设计DNA阵列需要目标序列的先验知识,在可能遇到未知单倍型的大规模监测计划中,这种方法的使用可能会受到限制。相比之下,DNA条形码基于测序,因此在大规模研究中可以提供更大的灵活性。