Katano Izumi, Harada Ken, Doi Hideyuki, Souma Rio, Minamoto Toshifumi
School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji Japan.
Faculty of Science, Nara Women's University, Kitauoyahigashi-machi, Nara, Japan.
PLoS One. 2017 May 17;12(5):e0176541. doi: 10.1371/journal.pone.0176541. eCollection 2017.
Environmental DNA (eDNA) has recently been used for detecting the distribution of macroorganisms in various aquatic habitats. In this study, we applied an eDNA method to estimate the distribution of the Japanese clawed salamander, Onychodactylus japonicus, in headwater streams. Additionally, we compared the detection of eDNA and hand-capturing methods used for determining the distribution of O. japonicus. For eDNA detection, we designed a qPCR primer/probe set for O. japonicus using the 12S rRNA region. We detected the eDNA of O. japonicus at all sites (with the exception of one), where we also observed them by hand-capturing. Additionally, we detected eDNA at two sites where we were unable to observe individuals using the hand-capturing method. Moreover, we found that eDNA concentrations and detection rates of the two water sampling areas (stream surface and under stones) were not significantly different, although the eDNA concentration in the water under stones was more varied than that on the surface. We, therefore, conclude that eDNA methods could be used to determine the distribution of macroorganisms inhabiting headwater systems by using samples collected from the surface of the water.
环境DNA（eDNA）最近已被用于检测各种水生栖息地中大型生物的分布。在本研究中，我们应用eDNA方法来估计日本大鲵（Onychodactylus japonicus）在源头溪流中的分布。此外，我们比较了用于确定日本大鲵分布的eDNA检测方法和手工捕捉方法。对于eDNA检测，我们利用12S rRNA区域设计了一套针对日本大鲵的qPCR引物/探针组。在所有地点（除了一个地点外）我们都检测到了日本大鲵的eDNA，在这些地点我们也通过手工捕捉观察到了它们。此外，在两个我们无法用手工捕捉方法观察到个体的地点，我们也检测到了eDNA。而且，我们发现两个水采样区域（溪流表面和石头下）的eDNA浓度和检测率没有显著差异，尽管石头下水中的eDNA浓度比表面的变化更大。因此，我们得出结论，通过使用从水面采集的样本，eDNA方法可用于确定栖息在源头水系中的大型生物的分布。
