Data from: Influence of killing method on Lepidoptera DNA barcode recovery

The global DNA barcoding initiative has revolutionized the field of biodiversity research. Such large-scale sequencing projects require the collection of large numbers of specimens, which need to be killed and preserved in a way that is both DNA-friendly and which will keep voucher specimens in good condition for later study. Factors such as time since collection, correct storage (exposure to free water and heat) and DNA extraction protocol are known to play a role in the success of downstream molecular applications. Limited data are available on the most efficient, DNA-friendly protocol for killing. In this study, we evaluate the quality of DNA barcode (cytochrome oxidase I) sequences amplified from DNA extracted from specimens collected using three different killing methods (ethyl acetate, cyanide and freezing). Previous studies have suggested that chemicals, such as ethyl acetate and formaldehyde, degraded DNA and as such may not be appropriate for the collection of insects for DNA-based research. All Lepidoptera collected produced DNA barcodes of good quality, and our study found no clear difference in nucleotide signal strength, probability of incorrect base calling and phylogenetic utility among the three different treatment groups. Our findings suggest that ethyl acetate, cyanide and freezing can all be used to collect specimens for DNA analysis.

全球DNA条形码（DNA barcoding）倡议彻底革新了生物多样性研究领域。此类大规模测序项目需采集大量标本，这些标本需以既符合DNA友好型要求，又能使凭证标本（voucher specimen）维持良好状态以供后续研究的方式进行处死与保存。已知采集后的存放时长、正确的储存方式（避免暴露于游离水与高温环境）以及DNA提取方案（DNA extraction protocol），均会对下游分子应用的成败产生影响。目前关于高效且符合DNA友好型要求的处死方案的相关数据仍较为有限。本研究针对采用三种不同处死方式（乙酸乙酯、氰化物与冷冻法）采集的标本所提取的DNA，评估了其扩增得到的DNA条形码（DNA barcode，细胞色素氧化酶I，cytochrome oxidase I）序列的质量。既往研究表明，乙酸乙酯、甲醛等化学试剂会降解DNA，因此可能不适用于以DNA研究为目的的昆虫标本采集。所有采集到的鳞翅目（Lepidoptera）标本均可获得高质量的DNA条形码序列，且本研究发现，三种处理组之间的核苷酸信号强度、碱基误判概率以及系统发育适用性均无显著差异。本研究结果显示，乙酸乙酯、氰化物处理以及冷冻法均可用于采集用于DNA分析的标本。