[Objective]The mitochondrial genome structural characteristics and phylogenetic relationships of Dy-somma anguillare were investigated so as to provide theoretical basis for species identification and germplasm resource as-sessment of this fish.[Method]The complete mitogenome of D.anguillare was obtained by high-throughput sequencing technology in this study.The gene composition and structure characteristics were analyzed,based on the mitochondrial ge-nome sequence of related fish published by GenBank,the phylogenetic evolutionary tree was constructed using the maxi-mum likelihood method based on the sequence similarity of protein-coding genes(PCGs)to analyze the relationship and evolutionary status of the fish in Anguilliformes.[Result]The total length of mitochondrial genome of D.anguillare was 16690 bp,including 13 PCGs,22 tRNA genes,2 rRNA(12S rRNA and 16S rRNA)and 2 non-coding regions(D-loop and OL).The base composition showed obvious noticeable A/T preference and anti-G-bias.The content of AT in D-loop re-gion was the highest(65.56%).ATG was the most common start codon in PCGs.Six genes used incomplete codons T-and TA-as stop codons.Only tRNA-Ser(AGN)could not fold into the typical clover shape due to the absence of dihydroura-cil arm among the 22 tRNAs.The motif 5'-TGGCAGAGCCTGG-3'was identified in tRNA-Leu(UUR),which was highly similar to the binding site of mammalian mitochondrial transcription termination factor(mTERF).The secondary struc-tures of 12S rRNA and 16S rRNA were composed of multiple stem-loops,with the latter more complex than the former.Domain VI of 16S rRNA contained a conserved multibranched loop(CML)homologous to the prokaryotic 23S rRNA peptidyl transferase center(PTC).In D-loop region,extended termination sequence regions(ETAS),central conserved re-gions(CSB-F,CSB-E and CSB-D)and conserved sequence regions(CSB-1,CSB-2 and CSB-3)were identified.The phylogenetic tree constructed based on PCGs sequence similarity demonstrated that the D.anguillare was closely related to Simenchelys parasitica,Ilyophis brunneus and Synaphobranchus kaupii.[Conclusion]The mitogenomic structure of D.anguillare is similar to those of most bony fishes,the total length of the mitochondrial genome is between the range of An-guilliformes fishes,and the phylogenetic relationships supports to place D.anguillare in Synaphobranchidae,Dysomma.
关键词
前肛鳗/线粒体基因组/结构特征/系统发育分析
Key words
Dysomma anguillare/mitochondrial genome/structure and characteristics/phylogeny
维普
万方数据