Reassessment of the mitochondrial 12S-rRNA gene for DNA barcoding of museum specimens of shelled marine gastropods from Japan

Abstract

DNA barcoding is an effective and powerful tool for taxonomic identification and thus very useful for biodiversity monitoring. This study investigated the usefulness of the mitochondrial 12S-rRNA gene for the DNA barcoding of shelled marine gastropods. To do so, we determined partial 12S-rRNA sequences of 75 vouchered museum specimens from 69 species of shelled gastropods from Japan. The specimens have been identified morphologically, and natural history data catalog. Sequence analyses through BLAST searches, maximum likelihood phylogenetic analysis, and species delimitation analysis suggested that the 12S-rRNA gene is helpful for barcoding shelled marine gastropods. They thus could be helpful to complement barcoding studies using other markers such as COI. The analyses successfully confirmed all samples’ identity at higher taxonomy (subfamily and above), but much less so at the species level. Our result thus also underlines the lingering problem of DNA barcoding: The lack of comprehensive reference databases of sequences. However, since we provided sequences of properly curated, vouchered museum specimens in this study, our result reported here has thus also helped to give taxonomically reliable reference sequences for biodiversity monitoring and identifications of shelled gastropods which include many important fisheries species.