The Complete Mitochondrial Genome of Bangana dero (Cyprinidae: labeoninae) and its Relationship with Other Labeonin Fishes

Bangana dero is a cyprinid fish species that is classified under the subfamily Labeoninae. It occurs in the streams of China, India and Nepal near the foot of the Himalayan range. B. dero's whole mitochondrial genome has been sequenced and annotated. In this work, the tRNAs, protein-coding genes have been characterized and analyzed the phylogenetic relation of this fish with other cyprinid species.

Nanopore sequencing was utilized to determine the entire mitochondrial genome of B. dero. Utilizing NEBNext Ultra DNA Library Prep Kit, end-repair was performed on the isolated DNA using the. Barcoding adapter ligation (BCA) and cleaned. Sequencing was done. All the long read bases were trimmed based on lowest base quality score, Q<9. Barcode and adapters sequences were also trimmed using a porechop programme and the statistical graph illustrations were generated and genome assembly was done using Canu1.5.

The mitogenome is 16613 bp and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, as well as a non-coding region. The nucleotide makeup is A=32.5%, T=25.21%, C=26.51% and G=15.77%, G + C = 42.28% and A+T=57.71%. The clover-leaf secondary structure was found in all tRNAs except tRNA-Ser2, which has no dihydrouridine arm. For 12 out of 13 protein-coding genes, the initiation codon was ATG, but COI used GTG. Methionine and tryptophan are unique among amino acids as they are each encoded by a single codon. Origin of light chain replication (OL) could fold into a hairpin secondary structure and carried a sequence 5'-GGCGG-3' in its stem. A long intergenic spacer of 46 bp was observed between tRNA-Leu1 and ND1. In the phylogenetic study, B. dero clustered closely with the Bangana species (AP013327) and Labeo boggut (NC_029450), a grouping supported by a bootstrap value of 100. This is the first study on the entire mitochondrial DNA analysis of B. dero.