Multiple full-length variants of the Mitochondrial COI DNA Barcode Region are prevalent in North European Sawflies

DNA barcoding, the use of standard DNA fragment for species identification, has emerged as a major field of biodiversity research. The effectiveness of these approaches rests on the premise that much less variation exists within species than between them. While exceptions occur, this has been demonstrated in many animal taxa where the COI gene is effective in species discrimination. Sawflies are an exception to this pattern because DNA barcodes often fail to distinguish congeneric species. Using high-throughput single-molecule DNA sequencing to recover COI sequences from thousands of sawflies, we found that single individuals often possess multiple, seemingly functional, full-length DNA barcodes – a phenomenon not documented at similar prevalence in any animal taxon. While the evolutionary causes of multiple variants require further investigation, our observation is remarkable as it violates the one-barcode-one-specimen assumption. The presence of multiple variants of barcodes within in..., , # Multiple full-length variants of the Mitochondrial COI DNA Barcode Region are prevalent in North European Sawflies

Dataset DOI: [10.5061/dryad.r4xgxd2rz](10.5061/dryad.r4xgxd2rz)

## Description of the data and file structure

Reference sawfly COI sequences in fastA format

### Files and variables

#### File: DatasetS3.fas

**Description:** Reference sawfly COI protein sequences in fastA used for re-identification of PacBio reads.

#### File: DatasetS2.fas

**Description:** Reference sawfly COI sequences in fastA format used for re-identification of PacBio reads. 

#### File: DatasetS4.fas

**Description:** Sawfly specimens with intraindividual COI variants (fastA alignment used to build the tree in Fig. S1) after the most stringent filtering steps (sequences supported by at least three reads, with minimum of two differences between the intraindividual variants, no contaminations, no variants identifiable as NUMTs, no chimeras).
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