The complete mitochondrial genome of Gastrothylax crumenifer (Gastrothylacidae, Trematoda) and comparative analyses with selected trematodes

Abstract

In the present study, we sequenced and analyzed the mitochondrial (mt) genome of Gastrothylax crumenifer and compared it with other selected trematodes. The full mt genome of G. crumenifer was amplified, sequenced, assembled, analyzed and then subjected to phylogenetic analysis. The complete mt genome of G. crumenifer is 14,801 bp in length and contains two rRNA genes, two non-coding regions (LNR and SNR), 12 protein-coding genes, and 22 transfer RNA genes. The gene organization of the G. crumenifer mt genome is the same as that of other trematodes, except for Schistosoma haematobium and Schistosoma spindale. All the genes are transcribed in the same direction and rich in "A + T", which is in accordance with other trematodes, such as Fasciola hepatica, Paramphistomum cervi, and Fischoederius elongatus. Phylogenetic analysis using concatenated amino acid sequences of the 12 protein-coding genes showed that G. crumenifer is closely related to F. elongatus. The availability of mt genome sequence of G. crumenifer can provide useful DNA markers for studying the molecular epidemiology and population genetics of this parasite and other paramphistomes.

Characterization of the complete mitochondrial genomes of Diplodiscus japonicus and Diplodiscus mehari (Trematoda: Diplodiscidae): Comparison with the members of the superfamily Paramphistomoidea and phylogenetic implication

“…There were only one NCR in both D. japonicus and D. mehari , which were similar to D. nigromaculati (MW698822). However, this was different from other trematodes in superfamily Paramphistomoidea, such as F. cobboldi , O. streptocoelium , G. crumenifer , P. cervi , P. leydeni and F. elongatus , which had two NCRs ( Yan et al, 2013 ; Ma et al, 2015 ; Yang et al, 2016 ; Zhao et al, 2017 ; Han et al, 2020 ). In Paramphistomoidea trematodes, the longest overall NCR length was G. crumenifer (813 bp) and the shortest overall NCR length was O. streptocoelium (310 bp).…”

“…Individual gene lengths vary from 56 bp to 74 bp ( Table 1 ). The lengths of D. japonicus and D. mehari tRNA were similar with to those of P. cervi (59–72 bp), P. leydeni (59–73 bp), G. crumenifer (59–72 bp), and O. streptocoelium (59–72 bp) ( Yan et al, 2013 ; Ma et al, 2015 ; Yang et al, 2016 ; Zhao et al, 2017 ), which suggested that tRNA gene size has changed quite slowly during trematode evolutionary divergence. All tRNA sequences could be folded into the typical cloverleaf structure, except trn S1, which lacked the dihydrouridine (DHU) arm in both Diplodiscus mitogenomes ( Fig.…”

Characterization of the Complete Mitochondrial Genome of Fischoederius elongatus Derived from Cows in Shanghai, China

“…Among the 12 protein genes of the present F. elongatus isolate, ATG (5/12) and GTG (5/12) were the most common start codons and TAA (9/12) was the predominant stop codon (Table 1). In current results herein, the 3′-end of genes of nd1, nd3, nd4, nd5, dn6, atp6, cox3, and cox1 was found immediately adjacent to a downstream tRNA gene (Table 1), which was in parallel arrangement with F. elongatus Tianmen isolates of Gastrothylax crumenifer and Paramphistomum cervi [3,13,14].…”

“…e present sequence of the mt genome has been submitted to the GenBank with the Accession number: MN537973. e circular mt genome of F. elongatus contains 12 protein-coding genes (cox1-3, nad1-6, nad4L, atp6, and cytb), 22 transfer RNA genes, and two ribosomal RNA genes (l-rRNA and s-rRNA) (Figure 1, Table 1); however, it lacks atp8, which is in line with F. elongatus of the Tianmen isolate and mt genomes of other trematodes, such as Gastrothylax crumenifer and Paramphistomum cervi [3,13,14]. e protein-coding genes of current F. elongatus isolates were transcribed in the same direction, and those genes were assembled in line of cox3, cytb, nd4L, nd4, atp6, nd2, nd1, nd3, cox1, l-rRNA, s-rRNA, cox2, nad6, and nad5 which was in accordance with previously reported results [3,13,14] (Figure 1; Table 1).…”

“…However, until now, it is still unclear whether this bias of codon usage contributes to parasite mt systems or not [18]. A total of 21 tRNA gene sequences (61-71 bp) and 2 noncoding regions (NCR) (l-RNA and s-RNA) were found in the F. elongatus mt genome (Figure 1, Table 1) depicting one undetected tRNA gene in the current isolate, as other trematodes contain 22 tRNA gene sequences [3,13,14]. e L-RNA and s-RNA were found to be located between cox1 and cox2 and separated by tRNA-r. ough NCR have been commonly reported in trematodes, however, still scarce information were available regarding the function of these special sequences [19].…”