Department of Fisheries, Wildlife, and Conservation Biology, Minnesota Aquatic Invasive Species Research Center, University of Minnesota , Twin Cities, Saint Paul, Minnesota 55108, United States.
Environ Sci Technol. 2016 Feb 16;50(4):1859-67. doi: 10.1021/acs.est.5b05672. Epub 2016 Jan 28.
Degradation of environmental DNA (eDNA) in aquatic habitats can affect the interpretation of eDNA data and the ability to detect aquatic organisms. The effect of temperature and trophic state on the decay of Common Carp (Cyprinus carpio) eDNA was evaluated using lake water microcosms and quantitative PCR for a Common Carp-specific genetic marker in two experiments. The first experiment tested the effect of temperature on Common Carp eDNA decay. Common Carp eDNA exhibited exponential decay that increased with temperature. The slowest decay rate was observed at 5 °C, with a T90 value (time to 90% reduction from initial concentration) of 6.6 days, as opposed to ∼1 day at higher temperatures. In a second experiment, decay was compared across waters from lakes of different trophic states. In this experiment, Common Carp eDNA exhibited biphasic exponential decay, characterized by rapid decay for 3-8 days followed by slow decay. Decay rate was slowest in dystrophic water and fastest in oligotrophic water, and decay rate was negatively correlated to dissolved organic carbon concentration. The overall rapid decay of eDNA and the effects of temperature and water quality should be considered in protocols for water sample storage and field sampling design.
环境 DNA（eDNA）在水生栖息地中的降解会影响对 eDNA 数据的解释和对水生生物的检测能力。本研究使用湖泊水微宇宙和定量 PCR 针对鲤鱼（Cyprinus carpio）的特异性遗传标记，在两个实验中评估了温度和营养状态对鲤鱼 eDNA 降解的影响。第一个实验测试了温度对鲤鱼 eDNA 降解的影响。鲤鱼 eDNA 表现出随温度升高而呈指数衰减的特征。在 5°C 时观察到最慢的衰减率，T90 值（从初始浓度降低 90%所需的时间）为 6.6 天，而在较高温度下约为 1 天。在第二个实验中，比较了来自不同营养状态湖泊的水样的降解情况。在这个实验中，鲤鱼 eDNA 表现出双相指数衰减，特征为 3-8 天的快速衰减，随后是缓慢衰减。在贫营养水中衰减速度最慢，在寡营养水中衰减速度最快，衰减速度与溶解有机碳浓度呈负相关。水样储存和野外采样设计方案中应考虑到 eDNA 的快速衰减以及温度和水质的影响。
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