Characterization and phylogenetic analysis of the cytochrome oxidase subunit I gene of mitochondrial genome from Takifugu fasciatus

The Takifugu fasciatus mitochondrial cytochrome oxidase I gene(COI) and its associated tRNA genes were sequenced by PCR.The open reading frame of COI gene contains 1 546 bp nucleotides,encoding a putative protein of 515 amimo acid residues.The pattern of codon usage of the COI gene is less biased toward A+T.The COI gene of T.fasciatus shows a high degree of homology with that from the other 14 fish species recorded in the GenBank and it has 97.6% homology with Takifugu rubripes,76.5% with Masturus lanceolatus and 75.4% with Mola mola.The phylogenetic trees show that the relationships based on the homology is consistent with the morphological and taxonomic results.Predicted secondary structures of the tRNA genes suggest that they have the classical cloverleaf structures.