Sequencing and characterization of the complete mitochondrial genome of Japanese Swellshark (Cephalloscyllium umbratile)

Sci Rep. 2017 Nov 10;7(1):15299. doi: 10.1038/s41598-017-15702-0.

Abstract

To further comprehend the genome features of Cephalloscyllium umbratile (Carcharhiniformes), an endangered species, the complete mitochondrial DNA (mtDNA) was firstly sequenced and annotated. The full-length mtDNA of C. umbratile was 16,697 bp and contained ribosomal RNA (rRNA) genes, 13 protein-coding genes (PCGs), 23 transfer RNA (tRNA) genes, and a major non-coding control region. Each PCG was initiated by an authoritative ATN codon, except for COX1 initiated by a GTG codon. Seven of 13 PCGs had a typical TAA termination codon, while others terminated with a single T or TA. Moreover, the relative synonymous codon usage of the 13 PCGs was consistent with that of other published Carcharhiniformes. All tRNA genes had typical clover-leaf secondary structures, except for tRNA-Ser (GCT), which lacked the dihydrouridine 'DHU' arm. Furthermore, the analysis of the average Ka/Ks in the 13 PCGs of three Carcharhiniformes species indicated a strong purifying selection within this group. In addition, phylogenetic analysis revealed that C. umbratile was closely related to Glyphis glyphis and Glyphis garricki. Our data supply a useful resource for further studies on genetic diversity and population structure of C. umbratile.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA, Mitochondrial / genetics*
  • Genome, Mitochondrial*
  • Phylogeny*
  • Sharks / genetics*

Substances

  • DNA, Mitochondrial