Characterization of the complete mitochondrial genome of the cloacal tapeworm Cloacotaenia megalops (Cestoda: Hymenolepididae)

Abstract

BackgroundThe cloacal tapeworm Cloacotaenia megalops (Hymenolepididae) is one of the most common cestode parasites of domestic and wild ducks worldwide. However, limited information is available regarding its epidemiology, biology, genetics and systematics. This study provides characterisation of the complete mitochondrial (mt) genome of C. megalops.MethodsThe complete mt genome of C. megalops was obtained by long PCR, sequenced and annotated.ResultsThe length of the entire mt genome of C. megalops is 13,887 bp; it contains 12 protein-coding, 2 ribosomal RNA and 22 transfer RNA genes, but lacks an atp8 gene. The mt gene arrangement of C. megalops is identical to that observed in Anoplocephala magna and A. perfoliata (Anoplocephalidae), Dipylidium caninum (Dipylidiidae) and Hymenolepis diminuta (Hymenolepididae), but differs from that reported in taeniids owing to the position shift between the tRNA (L1) and tRNA (S2) genes. The phylogenetic position of C. megalops was inferred using Maximum likelihood and Bayesian inference methods based on the concatenated amino acid data for 12 protein-coding genes. Phylogenetic trees showed that C. megalops is sister to Anoplocephala spp. (Anoplocephalidae) + Pseudanoplocephala crawfordi + Hymenolepis spp. (Hymenolepididae) indicating that the family Hymenolepididae is paraphyletic.ConclusionsThe complete mt genome of C. megalops is sequenced. Phylogenetic analyses provided an insight into the phylogenetic relationships among the families Anoplocephalidae, Hymenolepididae, Dipylidiidae and Taeniidae. This novel genomic information also provides the opportunity to develop useful genetic markers for studying the molecular epidemiology, biology, genetics and systematics of C. megalops.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1782-0) contains supplementary material, which is available to authorized users.

Long-read sequencing reveals a 4.4 kb tandem repeat region in the mitogenome of Echinococcus granulosus (sensu stricto) genotype G1

“…Parts of this region appear to be capable of folding into secondary stem-loop structures (see Fig. 1), which, as suggested previously [37, 42, 44, 55], could be associated with mt genome replication in cestodes. This hypothesis warrants testing.…”

“…[40–46]) are known to harbour non-coding regions of varying sizes, which may contain repeat elements. Two NCRs (66–875 bp) [47] appear to be characteristic of cestodes, in which repetitive elements are relatively common [47–55]. In E. granulosus genotype G1, the two NCRs are located between two tRNAs upstream of the nad 5 gene (NR1) and between nad 5 and tRNA-Gly (NR2), and have both been estimated at < 200 bp [16, 21].…”

Heteroplasmic mitochondrial genomes of a Raillietina tapeworm in wild Pangolin

“…In 12 PCGs of Raillietina mt1 and mt2, ATG was used as an initiation codon, whereas TAG and TAA were used as termination codons, as in Raillietina tetragona , Cloacotaenia megalops , and Hymenolepis nana [ 10 , 22 , 23 ]. The mt1 and mt2 of Raillietina sp.…”

Phylogeny of hymenolepidids (Cestoda: Cyclophyllidea) from mammals: sequences of 18S rRNA and COI genes confirm major clades revealed by the 28S rRNA analyses

“…An analysis using Basic Local Alignment Search Tool (BLAST analysis, see ) was applied for comparison and possible identification with sequences available in GenBank for the family Hymenolepididae. For phylogenetic analyses, we used published sequences of 18S rRNA gene (table 2) and COI gene (table 3) from several previous studies (Littlewood & Olson, 2001; Olson et al ., 2001, 2003; Littlewood et al ., 2008; Guo, 2016; Nkouawa et al ., 2016; Zhao et al ., 2016; Pistone et al ., 2017; Dimitrova et al ., 2019). GenBank sequences with less than 90% length coverage compared to our dataset were excluded.…”

“…The newly obtained 12 18S rRNA sequences and 12 COI sequences (table 1) were manually edited and then aligned using MEGA software, version 7.0 (Kumar et al, 2016) and Olson et al, 2001Olson et al, , 2003Littlewood et al, 2008;Guo, 2016;Nkouawa et al, 2016;Zhao et al, 2016;Pistone et al, 2017;Dimitrova et al, 2019). GenBank sequences with less than 90% a The identification of this sample from the Korean Peninsula requires further confirmation by morphological and molecular studies, since the original description of Hymenolepis hibernia is from Apodemus sylvaticus from Northern Ireland (Montgomery et al, 1987).…”