Development and evaluation of a DNA-barcoding approach for the rapid identification of nematodes
Development and evaluation of a DNA-barcoding approach for the rapid identification of nematodes
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DOI：
10.3354/meps320001
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发表时间：
2006-01-01
影响因子：
2.5
通讯作者：
Smerdon, Gary R.
中科院分区：
文献类型：
--
作者：
Bhadury, Punyasloke;Austen, Melanie C.;Smerdon, Gary R.
自由生活的线虫在所有海洋栖息地都很丰富，具有高度多样性，可用于监测人类活动对环境的影响。尽管有这样的属性，线虫有效地被许多海洋生态学家忽视，因为他们的耗时分类。线虫诊断传统上依赖于形态特征的详细比较，鉴于其丰富性，这是困难和费力的，这意味着该群体的生物多样性通常被低估。DNA条形码等分子方法为研究海洋线虫群落的生物多样性提供了潜在的有效替代方法，使这些生物体能够在生态调查和环境评估中得到更有效的利用。在这项研究中，一些核和线粒体基因组区域作为海洋线虫物种鉴定的潜在诊断位点进行了评估。其中，18S核糖体RNA基因从一系列分类群中扩增最可靠，因此作为DNA条形码进行评价。在分子和形态学鉴定的比较中，超过97%的测序标本基于18S rRNA序列的短片段（约345 bp）被正确分配，使其成为一个潜在的有用标记，用于未知线虫物种的快速分子分配，以及在生态调查或环境评估期间评估线虫物种丰富度。这项研究表明，基于扩增和测序的单一标记方法可能被证明是非常宝贵的，在生态调查过程中快速识别线虫，事实上，其他分类学上具有挑战性的无脊椎动物类群。
Free-living nematodes are abundant in all marine habitats, are highly diverse, and can be useful for monitoring anthropogenic impacts on the environment. Despite such attributes, nematodes are effectively ignored by many marine ecologists because of their time-consuming taxonomy. Nematode diagnostics has traditionally relied on detailed comparison of morphological characters which, given their abundance, is difficult and laborious, meaning that the biodiversity of the group is typically underestimated. Molecular methods such as DNA-barcoding offer potentially efficient alternative approaches to studying the biodiversity of marine nematode communities, allowing these organisms to be more effectively exploited in ecological surveys and environmental assessments. In this study, a number of nuclear and mitochondrial genomic regions were evaluated as potential diagnostic loci for marine nematode species identification. Of these, the 18S ribosomal RNA gene amplified most reliably from a range of taxa, and was therefore evaluated as a DNA barcode. In a comparison of molecular and morphological identifications, over 97 % of specimens sequenced were correctly assigned on the basis of a short stretch of 18S rRNA sequence (approximately 345 bp), making this a potentially useful marker for the rapid molecular assignment of unknown nematode species, and evaluation of nematode species richness during ecological surveys or environmental assessments. This study showed that a single marker approach based on amplification and sequencing may prove invaluable in the rapid identification of nematodes during ecological surveys and, indeed, other taxonomically challenging invertebrate taxa.