Kaunisto Kari M, Roslin Tomas, Sääksjärvi Ilari E, Vesterinen Eero J
Zoological Museum Biodiversity Unit University of Turku Turku Finland.
Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden.
Ecol Evol. 2017 Sep 14;7(20):8588-8598. doi: 10.1002/ece3.3404. eCollection 2017 Oct.
Recent advances in molecular techniques allow us to resolve the diet of unstudied taxa. Odonates are potentially important top-down regulators of many insects. Yet, to date, our knowledge of odonate prey use is based mainly on limited observations of odonates catching or eating their prey. In this study, we examine the potential use of metabarcoding in establishing the diet of three adult odonate species (, and ) at a site in southwestern Finland. To this purpose, we compared three different methods for extracting DNA from fecal samples: the Macherey-Nagel Nucleospin XS kit, a traditional salt extraction, and the Zymo Research Fecal Microprep kit. From these extracts, we amplified group-specific mitochondrial markers (COI and 16S rRNA) from altogether 72 odonate individuals, and compared them to comprehensive reference libraries. The three odonate species show major overlap in diet, with no significant differences between individuals of different size and/or gender, reflecting opportunistic foraging of adult odonates. Of a total of 41 different prey species detected, the most frequently consumed ones were Diptera, with additional records of six other orders. Based on our data, the best DNA extraction method is the traditional salt extraction, as it provides the most information on prey content while also being the most economical. To our knowledge, this is the first study to resolve the species-level diet of adult odonates. Armed with the appropriate methodological caveats, we are ready to examine the ecological role of odonates in both terrestrial and aquatic food webs, and in transferring subsidies between these two realms.
分子技术的最新进展使我们能够解析未被研究的分类群的食性。蜻蜓目昆虫可能是许多昆虫重要的自上而下的调控者。然而，迄今为止，我们对蜻蜓目昆虫猎物利用的了解主要基于对蜻蜓目昆虫捕捉或进食猎物的有限观察。在本研究中，我们考察了在芬兰西南部某一地点使用宏条形码技术确定三种成年蜻蜓目物种（、和）食性的可能性。为此，我们比较了从粪便样本中提取DNA的三种不同方法：Macherey-Nagel Nucleospin XS试剂盒、传统盐提取法和Zymo Research粪便微量制备试剂盒。从这些提取物中，我们对总共72只蜻蜓目个体的特定群体线粒体标记（COI和16S rRNA）进行了扩增，并将它们与全面的参考文库进行比较。这三种蜻蜓目物种在食性上有很大重叠，不同大小和/或性别的个体之间没有显著差异，这反映了成年蜻蜓目昆虫的机会主义觅食行为。在总共检测到的41种不同猎物物种中，最常被消耗的是双翅目，另外还有其他六个目的记录。根据我们的数据，最好的DNA提取方法是传统盐提取法，因为它能提供关于猎物含量的最多信息，同时也是最经济的方法。据我们所知，这是第一项解析成年蜻蜓目昆虫物种水平食性的研究。在具备适当的方法学注意事项的情况下，我们准备研究蜻蜓目昆虫在陆地和水生食物网中的生态作用，以及在这两个领域之间转移补贴方面的作用。
