The complete mitochondrial genomes of Gobiobotia meridionalis (Cypriniformes: Cyprinidae)

Abstract In this study, we sequenced the complete mitogenome of Gobiobotia meridionalis (Chen et Tsao, 1982). The genome is 16,609 base pair (bp) in length, encoding 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and 1 non-coding control region (D-loop). The nucleotide composition is A: 30.34%, T: 26.88%, G: 16.49%, and C: 26.29% (AT content: 55.22%). The complete mitogenome of G. meridionalis provides essential and important DNA molecular data for the genetic diversity conservation of this species.

Gobiobotia meridionalis (Chen et Tsao, 1982), is a small-sized bottom-dwelling fish endemic to China, mainly distributed in Zhujiang basin, the tributaries of the middle Yangtze River, the Yuanjiang River, and the lower reach of the Lancang River (Chen 1998). It is easy to distinguish G. meridionalis from other species of genus Gobiobotia, for absence of the basal process of the pelvic fin bone (He 1997). Here, we first determined the complete mitochondrial genome of G. meridionalis and reconstructed the phylogenetic relationship with other Gobiobotinae species. It may shed light on some genetic background of G. meridionalis, and could provide essential and important DNA molecular data for the genetic diversity conservation of this species.
The specimen of G. meridionalis used in this study were obtained from the Fuhe River (116 14 0 10 00 E, 26 33 0 03 00 N), Jiangxi, China. Muscles were immediately fixed in 95% ethanol until it was picked out for DNA extraction. Some specimen of G. meridionalis was deposited in Nanchang Normal University (maqindoris@163.com) under the Voucher number NCNU20200828032.
Total genomic DNA was extracted from muscle samples of G.
The complete mitogenome of G. meridionalis was a circular DNA of 16,609 bp in length (GenBank with the accession number of MW442088) and contained 13 PCGs (cyt b, ATP6, ATP8, COX1-3, ND1-6, and ND4L), 22 tRNA genes, 2 rRNA genes (12S and 16S rRNA), and 1 control region (CR or D-Loop). It played similar patterns in gene arrangements, codon use, and gene overlaps, which have been reported in other Gobioninae mitogenomes (Hwang et al. 2013;Li et al. 2018). Eight tRNA genes (Ala, Asn, Cys, Gln, Glu, Tyr, Ser, and Pro) and NADH dehydrogenase subunit 6 (ND6) are encoded on the light strand (L-strand), the other 29 genes are encoded on the heavy strand (H-strand). The nucleotide composition is A: 30.34%, T: 26.88%, G: 16.49%, and C: 26.29% (AT content: 55.22%). Almost all 13 PCGs for G. meridionalis share the regular initiation codon ATG except COI gene with GTG. There are three different patterns of termination codons: nine PCGs (terminated with the stop codons TAA or TAG, while three PCGs (cyt b, COX2, COX3, and ND4) use incomplete stop codon (TA-or T-).

Disclosure statement
No potential conflict of interest was reported by the author(s).