Complete Mitochondrial Genome and Phylogenetic Position of Chirolophis wui (Perciformes: Stichaeidae)

Abstract

The complete mitochondrial genome of Chirolophis wui (Wang and Wang, 1935) was sequenced using the Illumina platform. The genome sequence is 16,522 bp in length with 54% A+T content and contains 13 protein coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and 1 control region (D-loop). The H-strand contains 28 genes (12 PCGs, 14 tRNAs, and 2 rRNAs), whereas the L-strand accommodates 9 genes (ND6 and 8 tRNAs). The nucleotide composition of the mitochondrial genome of C. wui is AT-biased, accounting for 54.0%, with an AT skew value of −0.0556 and a GC skew value of −0.2043. The majority of PCGs utilized the start codon, ATG, while only one gene, COI, utilized the alternative start codon, GTG. Of the 13 PCGs, 6 genes used the termination codon (TAA or TGA), whereas 7 genes used the incomplete termination codon (T or TA). Among the 22 tRNA genes, the tRNA-Leu and tRNA-Ser were found in duplicates. A phylogenetic tree was constructed using 10 complete mitochondrial genome sequences and indicated that C. wui has a very close relationship with C. japonicus and other species in the family Stichaeidae, with a high supporting bootstrap value. This study can provide valuable information for future evolutionary studies on C. wui and Stichaeidae.