Sequence variability of COI in Sigmodontine rodents highlights the taxonomic bottleneck

Abstract

Sigmodontinae is a high diverse rodent subfamily with difficult taxonomic identification, which plays a relevant role in environmental impact assessment and public health. We evaluated cytochrome c oxidase subunit I (COX-I) sequence variability in order to investigate the existence of ‘barcoding gap’ and to assess its phylogenetic potential in evolutionary studies. We generated 130 sequences from 21 species sampled. Also, we added 58 sequences available in Genbank. Preliminary analysis revealed some field misidentifications. Thus, we reclassified them in order to include in the further analysis. The mean distance was 14.7% overall, 15.2% among genera, and 2.4% among species. The ‘barcoding gap’ was found and an unexpected phylogenetic signal was recovered. Although it proved to be a useful tool that can enhance the discovery of biodiversity, the barcoding approach must be also supported by taxonomy and museum collections.