title: The complete mitochondrial genome sequence of Oncicola luehei (Acanthocephala: Archiacanthocephala) and its phylogenetic position within Syndermata.
abstract: In the present study, we determined the complete mitochondrial genome sequence of Oncicola luehei (14,281bp), the first archiacanthocephalan representative and the second complete sequence from the phylum Acanthocephala. The complete genome contains 36 genes including 12 protein coding genes, 22 transfer RNA (tRNA) genes and 2 ribosomal RNA genes (rrnL and rrnS) as reported for other syndermatan species. All genes are encoded on the same strand. The overall nucleotide composition of O. luehei mtDNA is 37.7% T, 29.6% G, 22.5% A, and 10.2% C. The overall A+T content (60.2%) is much lower, compared to other syndermatan species reported so far, due to the high frequency (18.3%) of valine encoded by GTN in its protein-coding genes. Results from phylogenetic analyses of amino acid sequences for 10 protein-coding genes from 41 representatives of major metazoan groups including O. luehei supported monophyly of the phylum Acanthocephala and of the clade Syndermata (Acanthocephala+Rotifera), and the paraphyly of the clade Eurotatoria (classes Bdelloidea+Monogononta from phylum Rotifera). Considering the position of the acanthocephalan species within Syndermata, it is inferred that obligatory parasitism characteristic of acanthocephalans was acquired after the common ancestor of acanthocephalans diverged from its sister group, Bdelloidea. Additional comparison of complete mtDNA sequences from unsampled acanthocephalan lineages, especially classes Polyacanthocephala and Eoacanthocephala, is required to test if mtDNA provides reliable information for the evolutionary relationships and pattern of life history diversification found in the syndermatan groups.
authors.affiliation: Graduate Program in Cell Biology and Genetics and Department of Parasitology, College of Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Mohiuddin
authors.initials: M
authors.lastname: Gazi
authors.forename: Tahera
authors.initials: T
authors.lastname: Sultana
authors.forename: Gi-Sik
authors.initials: GS
authors.lastname: Min
authors.forename: Yung Chul
authors.initials: YC
authors.lastname: Park
authors.forename: Martín
authors.initials: M
authors.lastname: García-Varela
authors.forename: Steven A
authors.initials: SA
authors.lastname: Nadler
authors.forename: Joong-Ki
authors.initials: JK
authors.lastname: Park
mesh_terms: D000049:Acanthocephala / Q000145:classification* / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D005260:Female; D023061:Gene Order; D054629:Genome, Mitochondrial / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal