SPECIES IDENTIFICATION WITHIN Mytilus GENUS - COMPARISON OF METHODS

Species identification (SI) in seafood has become increasingly important among consumers, due to consequences in food safety and sustainability. Nowadays, is mandatory to declare the common and scientific names in the label (EU Nº 1379 2013). DNA sequence analysis (SA) is reliable for SI in seafood; however, it can be performed by Direct Sequence Comparison (DSC), Forensically Informative Nucleotide Sequencing (FINS), Automatic Barcoding Gap Discovery (ABGD), Best Close Match (BCM) and the All Barcodes (AB) methods. These differ in the rigorousness to define how similar a barcode match needs to be before it can be identified. To compare SA methods, sequences of the Histone H1C gene from 61 mussels (9 Mytilus galloprovincialis and 52 M. chilensis determined by a 49 SNPs panel) were analyzed by DSC, ABGD, BCM and AB. These sequences with other 14 from GeneBank, were used for FINS analysis. The performance identifying the species was assessed by determining concordance (Cohen's Kappa statistics) between SI methods. FINS and ABGD were no able to separate the species. Concordance among the other methods ranged from κ=0 (slight agreement) between AB and DSC or BCM, to κ=0.72 (substantial agreement) between DSC and BCM. BCM showed the highest concordance with the 49 SNP panel (κ=0.67, substantial agreement). The SA method affects SI when the taxonomic resolution of the gene within the genus is low.ANID-FONDEF ID16I10013/20013, FONDECYT 1130302 and 1191765; Eurofins Genomics Europe Applied Genomics GmbH.