Complete Mitochondrial (mtDNA) Genome Analysis of Economically Significant Fish in Bangladesh.

Complete mitochondrial DNA genome annotation of an ecologically and commercially important fish species was executed with next-generation sequencing (NGS) for nucleotide and phylogenetic analyses. The findings of this study showed that the mitochondrial genome contained 16,593 bp, including 13 protein-coding genes, 2 ribosomal RNA genes, 22 tRNA genes, and a D-loop region. The overall base composition was 32% adenine, 25% thiamine, 16% guanine, and 27% cytosine. This mitochondrial DNA exhibits an AT biasness, with 56% AT content in its genome. Significant fluctuations were identified in the AT and GC skew values of the gene, indicating that the selection and mutation forces acting on this gene might be different from those acting on other genes. The Ka/Ks ratios of most protein-coding genes were less than 1, indicating very strong natural selection pressure. Phylogenetic analysis of with and suggested a closer evolutionary relationship among these species, which might have shared a more recent common ancestor. It has been also found that the genera and are not monophyletic.