Abstract:
Executive Summary
The featherback chital or clown knifefish (Chitala chitala) is categorized as an endangered
species in Bangladesh whereas, in global context, the fish is considered as near threatened
species. The study aimed to characterize the mitochondrial genome sequencing of Chitala
chitala and to explore phylogenetic history. Featherback chital fish specimens were collected
from the Netrokona district of Bangladesh for investigating mitogenome sequencing during
February 2021 to June 2022. The genomic DNA was extracted from the fish tissue using the
DNeasy® Blood and Tissue Kit according to the manufacturer’s manual. After confirming
the species by DNA barcoding technology, the mitochondrial DNA was extracted with
mitochondrial DNA isolation kit. The next generation sequencing (NGS) was performed
using the Illumina MiSeq platform. The process of NGS was performed from South Korea.
The MiSeq raw reads were assembled using the Geneious® Prime 2020.0.3 software to
construct a complete mitogenome of C. chitala. The circular gene map of C. chitala was
drawn by OGDRAW software and the phylogenetic tree was constructed by MEGA7
program. The complete mitochondrial genome was 16248 bp in size. The mitogenome
formed a circular double-stranded DNA molecule containing a total of 37 mitochondrial
genes (13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes) with
two non-coding regions, an origin of light strand replication (OL) and a displacement loop
(D-loop), similar structure with other fishes of Teleostei. The phylogenetic tree demonstrated
its close relationship with osteoglossiform fishes. The complete mitogenome of Chitala
chitala (GenBank accession number: ON764424) showed 92.87 % identity to another
species, Chitala ornata (AP008923.1), followed by 91.42 % identity with Chitala lopis
(AP008922.1). Sequence of the complete mitochondrial genome of C. chitala would be an
essential resource for studying population genetic structure and conservation management of
the endangered fish species.
