Characterization of the complete mitochondrial genomes of Coronocyclus labiatus and Cylicodontophorus bicoronatus: Comparison with Strongylidae species and phylogenetic implication.

摘要: Coronocyclus labiatus and Cylicodontophorus bicoronatus are two significant horse parasitic nematodes which classified into subfamily Cyathostominae, family Strongylidae, however, the classification of these has been controversial for more than a century. Mitochondrial (mt) genomes considered valuable sources parasite taxonomy, population genetics, systematics studies. In present study, mt Co. Cd. (type species) were determined subsequently compared with those from closely related species by phylogenetic analysis based on concatenated datasets amino acid sequences predicted protein-coding genes. The complete circular 13,827 bp 13,753 in size, respectively. Both consisted total 12 genes, 22 transfer RNA ribosomal genes non-coding regions. All protein coding transcribed same direction, gene order both belonged to arrangement type 3 (GA3). There 19 intergenic spacers 1 35 one overlap 4 genome labiatus, 1-29 size but no bicoronatus. A + T content 75.87 % 75.16 %, Similar genones other Strongylidae published GenBank, they also exhibited strong bias not only nucleotide composition codon usage. Comparative analyses sequence showed that had higher identities Cylicostephanus goldi (90.3 86.9 respectively), followed Cyathostomum (89.9∼90.0 %; 86.4 %), Phylogenetic using 26 Strongyloidea revealed was species, formed distinct branch Cyathostominae closer Triodontophorus Poteriostomum imparidentatum. We concluded might be represent genus comparative analyses. availability provides new useful genetic markers further studies nematodes.