Department of Life Sciences, Imperial College London, Ascot, UK.
Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil.
Mol Ecol Resour. 2024 Jul;24(5):e13961. doi: 10.1111/1755-0998.13961. Epub 2024 Apr 22.
Over the past few years, insects have been used as samplers of vertebrate diversity by assessing the ingested-derived DNA (iDNA), and dung beetles have been shown to be a good mammal sampler given their broad feeding preference, wide distribution and easy sampling. Here, we tested and optimized the use of iDNA from dung beetles to assess the mammal community by evaluating if some biological and methodological aspects affect the use of dung beetles as mammal species samplers. We collected 403 dung beetles from 60 pitfall traps. iDNA from each dung beetle was sequenced by metabarcoding using two mini-barcodes (12SrRNA and 16SrRNA). We assessed whether dung beetles with different traits related to feeding, nesting and body size differed in the number of mammal species found in their iDNA. We also tested differences among four killing solutions in preserving the iDNA and compared the effectiveness of each mini barcode to recover mammals. We identified a total of 50 mammal OTUs (operational taxonomic unit), including terrestrial and arboreal species from 10 different orders. We found that at least one mammal-matching sequence was obtained from 70% of the dung beetle specimens. The number of mammal OTUs obtained did not vary with dung beetle traits as well as between the killing solutions. The 16SrRNA mini-barcode recovered a higher number of mammal OTUs than 12SrRNA, although both sets were partly non-overlapping. Thus, the complete mammal diversity may not be achieved by using only one of them. This study refines the methodology for routine assessment of tropical mammal communities via dung beetle 'samplers' and its universal applicability independently of the species traits of local beetle communities.
在过去的几年中，人们通过评估摄入衍生的 DNA（iDNA），利用昆虫作为脊椎动物多样性的采样器，而蜣螂因其广泛的摄食偏好、广泛的分布范围和易于采样，已被证明是一种很好的哺乳动物采样器。在这里，我们通过评估一些生物和方法学方面是否会影响蜣螂作为哺乳动物物种采样器的使用，来测试和优化利用蜣螂的 iDNA 来评估哺乳动物群落。我们从 60 个陷阱中收集了 403 只蜣螂。使用两个微型条形码（12SrRNA 和 16SrRNA）对每只蜣螂的 iDNA 进行 metabarcoding 测序。我们评估了与摄食、筑巢和体型相关的不同特征的蜣螂，它们的 iDNA 中发现的哺乳动物物种数量是否存在差异。我们还测试了四种不同的致死溶液在保存 iDNA 方面的差异，并比较了每个微型条形码对恢复哺乳动物的有效性。我们总共鉴定了 50 个哺乳动物 OTUs（分类操作单元），包括来自 10 个不同目科的陆生和树栖物种。我们发现，至少有 70%的蜣螂标本中获得了与哺乳动物匹配的序列。获得的哺乳动物 OTUs 数量与蜣螂特征以及致死溶液之间均无差异。16SrRNA 微型条形码比 12SrRNA 恢复了更多的哺乳动物 OTUs，尽管两者都有部分重叠。因此，仅使用其中一个可能无法获得完整的哺乳动物多样性。这项研究改进了通过蜣螂“采样器”对热带哺乳动物群落进行常规评估的方法，并且其普遍适用性与当地甲虫群落的物种特征无关。
