Bavarian State Collection of Zoology (SNSB - ZSM), München, Germany.
Department Biology II and GeoBioCenter, Ludwig-Maximilians-University, München, Germany.
Mol Ecol Resour. 2017 Nov;17(6):1293-1307. doi: 10.1111/1755-0998.12683. Epub 2017 Jun 27.
Mayflies, stoneflies and caddisflies (Ephemeroptera, Plecoptera and Trichoptera) are prominent representatives of aquatic macroinvertebrates, commonly used as indicator organisms for water quality and ecosystem assessments. However, unambiguous morphological identification of EPT species, especially their immature life stages, is a challenging, yet fundamental task. A comprehensive DNA barcode library based upon taxonomically well-curated specimens is needed to overcome the problematic identification. Once available, this library will support the implementation of fast, cost-efficient and reliable DNA-based identifications and assessments of ecological status. This study represents a major step towards a DNA barcode reference library as it covers for two-thirds of Germany's EPT species including 2,613 individuals belonging to 363 identified species. As such, it provides coverage for 38 of 44 families (86%) and practically all major bioindicator species. DNA barcode compliant sequences (≥500 bp) were recovered from 98.74% of the analysed specimens. Whereas most species (325, i.e., 89.53%) were unambiguously assigned to a single Barcode Index Number (BIN) by its COI sequence, 38 species (18 Ephemeroptera, nine Plecoptera and 11 Trichoptera) were assigned to a total of 89 BINs. Most of these additional BINs formed nearest neighbour clusters, reflecting the discrimination of geographical subclades of a currently recognized species. BIN sharing was uncommon, involving only two species pairs of Ephemeroptera. Interestingly, both maximum pairwise and nearest neighbour distances were substantially higher for Ephemeroptera compared to Plecoptera and Trichoptera, possibly indicating older speciation events, stronger positive selection or faster rate of molecular evolution.
蜉蝣目、石蝇目和毛翅目（蜉蝣目、石蝇目和毛翅目）是水生大型无脊椎动物的重要代表，通常被用作水质和生态系统评估的指示生物。然而，蜉蝣目、石蝇目和毛翅目物种的明确形态鉴定，尤其是其幼虫阶段的鉴定，是一项具有挑战性但又至关重要的任务。需要建立一个基于分类学精心整理标本的全面 DNA 条码库，以克服鉴定中的问题。一旦获得了该库，它将支持快速、经济高效和可靠的基于 DNA 的鉴定，并评估生态状况。本研究代表了迈向 DNA 条码参考库的重要一步，因为它涵盖了德国三分之二的蜉蝣目、石蝇目和毛翅目物种，包括 363 个已鉴定物种的 2613 个个体。因此，它涵盖了 44 个科中的 38 个科（86%）和几乎所有主要的生物指标物种。从分析的标本中回收了符合 DNA 条码要求的序列（≥500 bp），占 98.74%。虽然大多数物种（325 种，即 89.53%）通过 COI 序列被明确分配到单个 Barcode Index Number（BIN），但 38 个物种（18 种蜉蝣目、9 种石蝇目和 11 种毛翅目）被分配到总共 89 个 BIN。这些额外的 BIN 中的大多数形成最近的邻域聚类，反映了当前认可的物种的地理亚群的区分。BIN 共享并不常见，仅涉及两对蜉蝣目物种。有趣的是，最大的种间和最近的邻域距离对于蜉蝣目都明显高于石蝇目和毛翅目，这可能表明更早的物种形成事件、更强的正选择或更快的分子进化速度。
