Multispecies assessment of genetic differentation of aquatic insects in inttermittent river revealed by next-generation sequencing

We investigated gene flow of 15 aquatic insects (3 of Ephemeroptera species; 12 of Diptera, Chironomidae species) in Shigenobu River (Ehime, Japan) using Next-Generation DNA Sequencing (NGS) system. We collected aquatic insects from 10 sites. Mixed DNAs from each site were extracted from mushed community sample. Cytochrome Oxidase subunit I region in mitochondrial DNA were amplified by COI primer with DNA tag indicating each sampling site and were genotyped using GS FLX system. Comparison of pairwise Fsts between flagmented sited and between non-flagmented sited by intermittend interval showed that most spesies were not interrupted by intermittent interval other than Baetis sp. MK-2015d and Chironomus kiiensis. Although Chironomidae was predicted separated genetic structure and low gene flow because of their wing and body size, average pairwise Fst supported stronger dispersal than Ephemeroptera. Chironomidae might dispersal by wind passively and could use habitat outside of river such as rice field. The limitations of this study were power of DNA reading by NGS and DNA barcording to identify species name. Because several dominant species were not detected, ideal sample volume must be clarified. In addition, The current DNA database have less information about Japanese aquatic insects. Study species could be expanding by DNA information in the database increased.