Characterization and comparative analysis of the complete mitochondrial genome of Azygia hwangtsiyui Tsin, 1933 (Digenea), the first for a member of the family Azygiidae

Abstract

<jats:p><jats:italic>Azygia hwangtsiyui</jats:italic> (Trematoda, Azygiidae), a neglected parasite of predatory fishes, is little-known in terms of its molecular epidemiology, population ecology and phylogenetic study. In the present study, the complete mitochondrial genome of <jats:italic>A. hwangtsiyui</jats:italic> was sequenced and characterized: it is a 13,973 bp circular DNA molecule and encodes 36 genes (12 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes) as well as two non-coding regions. The A+T content of the <jats:italic>A. hwangtsiyui</jats:italic> mitogenome is 59.6% and displays a remarkable bias in nucleotide composition with a negative AT skew (–0.437) and a positive GC skew (0.408). Phylogenetic analysis based on concatenated amino acid sequences of twelve protein-coding genes reveals that <jats:italic>A. hwangtsiyui</jats:italic> is placed in a separate clade, suggesting that it has no close relationship with any other trematode family. This is the first characterization of the <jats:italic>A. hwangtsiyui</jats:italic> mitogenome, and the first reported mitogenome of the family Azygiidae. These novel datasets of the <jats:italic>A. hwangtsiyui</jats:italic> mt genome represent a meaningful resource for the development of mitochondrial markers for the identification, diagnostics, taxonomy, homology and phylogenetic relationships of trematodes.</jats:p>

Characterization of complete mitochondrial genome and ribosomal operon forCarassotrema koreanumPark, 1938 (Digenea: Haploporidae) by means of next-generation sequencing data

“…The paraphyly of the Xiphidiata, expressed by a considerable differentiation of the Dicrocoeliidae from other members of the suborder, was shown in phylogenetic studies of Digenea based on mitochondrial DNA sequence data (Locke et al ., 2018; Fu et al ., 2019b; Wu et al ., 2020; Atopkin et al ., 2021). However, most of the authors paid no attention to this paraphyly, noting only a stable differentiation of all digeneans into two clades, the Plagiorchiida and the Diplostomida.…”

“…In our opinion, there are still not enough complete mtDNA sequence data on trematodes to generate the final systematic and phylogenetic conclusions concerning Digenea in general and the Xiphidiata in particular. However, the paraphyly of this suborder has been demonstrated in the latest phylogenetic studies based on individual rDNA sequences of more than 1000 species from 106 families and on complete mitochondrial genome sequence data for more than 50 species (Locke et al ., 2018; Pérez-Ponce de León & Hernández-Mena, 2019; Fu et al ., 2019b; Wu et al ., 2020; Atopkin et al ., 2021), as well as in our present work, which was based on 59 species. Therefore, we believe that the Xiphidiata in its present state cannot be recognized as a valid and self-sufficient taxon.…”

“…The mitochondrial gene rearrangements in Digenea have been discussed in detail by Wu et al . (2020). In this study, we provided a new complete mtDNA sequence of C .…”

Complete mitochondrial genome sequence of Lepus yarkandensis Günther, 1875 (Lagomorpha, Leporidae): characterization and phylogenetic analysis

“…Characterized by small size, stable gene content, high evolutionary rate, relatively conserved gene arrangement, high information content, and maternal inheritance, animal mitogenomes are powerful tools used to investigate molecular evolution, phylogenetic relationships, and protective biology for many animals ( Yu et al 2017 ; Zhang et al 2018 ; Song et al 2019 ; Hu et al 2020 ; Wu et al 2020 ).…”

Taxonomic myths and phylogenetic realities in the systematics of the Opisthorchiidae (Trematoda)

“…Phylogenetic analyses based on ribosomal 18S and 28S rRNA gene sequence data and complete mitochondrial genome sequence data do not support the monophyly of the subfamily Opisthorchiinae (e.g. Dennis et al, 2019;Fu et al, 2019;Le et al, 2019;Ma et al, 2019;Na et al, 2016;Sokolov et al, 2021;Tatonova et al, 2020;Wu et al, 2020).…”