ИСТИНА

Metabarcoding studies of marine invertebrates have used various regions of nuclear small-(18S) and large-subunit (28S) rRNA genes, which allow accurate classification of novel sequencesand reliable amplification with conservative primers. However, this may underestimate speciesdiversity in a community under investigation due to their low nucleotide distances (if any) inclosely related species. To assess faunistic diversity at the species level, more variable genes areneeded. Widely used Folmer DNA barcoding region COI is not often suitable because of commonpseudogene amplification or pure primer match. We propose to use the ITS (internal transcribespacer of rRNA) region for metabarcoding of invertebrates in the Arctic seas. For some taxa theITS has been used quite often as a nuclear marker in recent years, in particular, for therepresentatives of Cnidaria. The use of this marker for the representatives of this group is rathersuccessful, but in many cases, its use is limited due to intragenomic polymorphism that associatedwith multicopy of this marker (and as a result it cannot be used in the Sanger sequencing).Amplicon sequencing by NGS with relatively long reads (such as offered by MiSeq chemistry)makes the application of this marker highly effective. We obtained sequences of ITS2 region formore than 300 species from different taxa using the Illumina Miseq technology. Thus, we havenow a representative Database and hope that we can use metabarcoding analysis for monitoringof Arctic marine ecosystems.