Comparative mitochondrial genome brings insights to slight variation in gene proportion and large intergenic spacer and phylogenetic relationship of mudskipper species.

Abstract

Fish mitochondrial genome have been largely studied worldwide for evolutionary and other genetic purposes and the structure and gene organization are commonly conservative. However, several studies have demonstrated that this scenario may present variations in some taxa, showing differentiation on the gene rearrangement. In this study, the complete mitogenome of terrestrial fish Boleophthalmus dussumieri was generated and compared with other species of the Exudercidae fishes. The newly complete mitogenome generated is circular and 16,685 pb of length, and it contained 13 protein-coding genes (PCGs), two ribosomal RNA (rRNAs), 22 transfer RNA genes (tRNAs), and one control region (CR), with high conservative structure, like other Mudskippers. Most of the PCG showed similar codon usage bias. The gene length was found to be different specially for the CR, 12S rRNA gene and ND5 gene in some taxon. All the Boleophthalmus species showed a gene duplication in the CR, except for B. dussumieri. The phylogenetic analysis grouped all mudskippers species as a monophyletic group and the analysis positioned the Periophthalmus clade as the most basal in the terrestrial fishes. This finding provides basis and brings insights for gene variation, gene rearrangements and replications showing evidence for variety of mitochondrial structure diversity within mudskippers.

Insights into structural features and phylogenetic implications of the complete mitochondrial genome of Fasin rainbow fish (Melanotaenia fasinensis)

“…In addition, in this study showed that greater diversity in both location and intergenic nucleotide lengths compared to the overlaps. The same phenomenon has been observed in other teleost organisms [7,14,37,41,42].…”

“…The overlapping of nucleotides between adjacent genes is a common characteristic found in teleost mitogenomes, which aids in compacting the mitogenomes [30,36]. The overlapping regions between ND4L/ND4 and ATP8/ATP6 were identi ed as common features found in Melanotaenia species [6,21,[26][27][28][29] and other teleosts [37][38][39][40]. In addition, in this study showed that greater diversity in both location and intergenic nucleotide lengths compared to the overlaps.…”