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The phylogenetic relationships between bivoltine and polyvoltine silkworm B. mori strains were examined sequencing~520-bp of mitochondrial gene cytochrome c oxidase I (mtCOI). Multiple alignments of the sequences ascertained the probability of Transition/Transversion substitutions. The percentage of A+T content was higher than that of C+G region. Maximum likelihood (ML) analysis clustered four strains into two major groups and accurately segregated them according to their voltinism inheritance. The open reading frames of the gene were found exhibited the strain-specificity indicating their geographical origin. The protein coding sequence identified which commenced with 4-bp TTAG putative initiator codon. The outcome suggested the mtCOI gene has not only crucial task in learning the evolutionary evidences but it can also be characterized as a bar-coding marker for revealing voltinism’s expression and genetic variation in the silkworm, discriminating their genotype based on COI gene nucleotide versatilities. The study was fruitful as we noticed prominent intra-specific versatility among B. mori species, indicating presence of allele/s regulating diapause development-linked to COI gene. We conclude with an insight into potential utility of DNA bar-coding technique for ecological classification and taxonomic investigation of insect’s biodiversity.
Keywords: DNA bar-coding, Mitochondrial cytochrome c oxidase I gene, voltinism’s expression, genetic variation