Structural characteristics of the control region of the Beaufortia kweichowensis mitochondrial genome

In present study, we identified the structural characteristics of the Beaufortia kweichowensis mtDNA control region using the next-generation sequencing method. Result showed that the control region could be further divided into three parts, including the extended termination associated sequence domain (ETAS), the central conserved domains (CSB-F, CSB-E, CSB-D) and the conserved sequence block domains (CSB-1, CSB-2, CSB-3), and their conserved sequences were identified. Additionally, we found the ETAS domain could be folded and form a 25 bp loop, which are usually considered to play an important role in mtDNA transcript termination. Finally, we reconstructed the phylogenetic relationship among the family of Balitoridae based on the nucleotide sequence of the control region, result showed that the Balitoridae can be divided into two clades, one clade is Gastromyzoninae and the other is Homalopterinae, and the B. kweichowensis was grouped into clade Gastromyzoninae and shared a close relationship with B. szechuanensis.