Characterization of the mitochondrial Huso huso genome with new aspects into its organization with presence of tandem repeat in the 12SrRNA and tRNA-Glu

Abstract

The sturgeon group is an economically important group in the world due to the production of caviar, and they are also a suitable old species for researching on the evolution of the mitochondrial genome. In H.huso sequencing, we identified a distinct genome organization relative to other species that has never been reported before. In this specie, the mitochondrial genome consisted of 13 genes encoding proteins, 22tRNA and 2rRNA, and two non-coding regions that followed other vertebrates. In addition, H.huso had an pseudo tRNA-Glu between ND6 and Cytb and also had a 52-nucleotide tandem repeat with two replications in the 12SrRNA. This duplication event is related to the slipped strand during replication, which can remain in the strand as a result of mispairing during replication. Furthermore, an 82 bp repeat sequence with three replications was observed in the D-loop control region, which is usually visible in different species. Regulatory elements are also visible in the control region of the mitochondrial genome that include termination sequences and conserved regulatory blocks. Genomic compounds showed the highest conservation in terms of rRNA and tRNA, while protein-encoded genes and non-encoded regions had the highest divergence. The mitochondrial genome was phylogenetically assayed using 13 protein-encoding genes.