Characterization of the mitochondrial COI gene of eighteen species of skipper butterflies (Lepidoptera: Hesperiidae) from Bangladesh

Abstract

Hesperiid butterflies are cryptic due to sexual dimorphism, mimicry, and camouflage, thus identification by morphology is problematic. DNA barcoding through the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene has already been proven as a successful tool for species identification. The present study generated sequences of 18 species of Hesperiids for the COI gene, which showed 92.64% to 100% similarity to those in GenBank of NCBI. These sequences were submitted to GenBank and received unique accession numbers. The COI gene showed a 568 bp fragment that included 210 variable sites and 148 parsimony informative sites. The average nucleotide composition was 39.80% thymine (T), 16.61% cytosine (C), 29.82% adenine (A), and 13.75% guanine (G), showing an A+T bias and accounting for 69.62%. Nucleotide divergences among the 18 species ranged from 0.08 to 0.18%. The Maximum Likelihood (ML) tree showed four clades (A, B, C, and D), and all species arose from a common ancestor. In addition, the analysis showed that Hesperiidae butterflies of Bangladesh come under one cluster, indicating that these butterflies are genetically similar and regionally differeniated. Nontheless, this study contributes to DNA-based species identification, ecology, and the development of an appropriate conservation strategy.