Tighe Andrew J, Overby Sarah, Thurman Kiera, Gandola Robert, Fulanda Bernerd, Byrne John, Carlsson Jens
Area 52 Research Group School of Biology and Environmental Science/Earth Institute University College Dublin Dublin Ireland.
Fish Health Unit Marine Institute Oranmore Ireland.
Ecol Evol. 2020 Mar 6;10(7):3330-3337. doi: 10.1002/ece3.6115. eCollection 2020 Apr.
Swabbing scat has proved to be an effective noninvasive method to collect DNA from mammals in the field. Previously, this method has relied on preservative liquids or freezing to preserve the DNA collected on swabs. In this study, we determine the effectiveness of using silica to simply dry the swab in field as an alternative way to prevent DNA degredation. Four species were included in the study; reticulated giraffe, impala, fringe-eared oryx, and lion. Swabs were taken at multiple time points for giraffe and impala scat samples, with the lion and oryx sampled opportunistically. Mitochondrial DNA was successfully amplified and sequenced from scat swabs from all species; however, effectiveness varied between species, with 81.8% amplification success rate from swabs taken from impala scat compared to 25% amplification success rate in giraffe. This variation in success rate was overcome by taking multiple swabs, thus increasing the probability of a successful amplification. The true merit of this method is in its simplicity and cheapness; no preservative liquids were required to be brought into the field, at no stage in the 2 weeks of field sampling were samples frozen, and no commercial kits were used for DNA extraction.
事实证明，擦拭粪便样本是在野外从哺乳动物身上收集DNA的一种有效的非侵入性方法。此前，这种方法依赖于保存液或冷冻来保存拭子上收集到的DNA。在本研究中，我们确定了在野外使用硅胶简单干燥拭子作为防止DNA降解的替代方法的有效性。该研究涵盖了四个物种：网纹长颈鹿、黑斑羚、细纹斑马和狮子。长颈鹿和黑斑羚粪便样本在多个时间点采集拭子，狮子和细纹斑马则是机会性采样。所有物种的粪便拭子中均成功扩增并测序出线粒体DNA；然而，不同物种之间的有效性有所差异，从黑斑羚粪便拭子中获得的扩增成功率为81.8%，而长颈鹿的扩增成功率为25%。通过采集多个拭子克服了成功率的这种差异，从而提高了成功扩增的概率。这种方法的真正优点在于其简单性和低成本；无需携带保存液到野外，在为期两周的野外采样过程中任何阶段都无需冷冻样本，并且DNA提取未使用商业试剂盒。
