The mitochondrial genome of Onchocerca volvulus: Sequence, structure and phylogenetic analysis

Mapping the presence of Wolbachia pipientis on the phylogeny of filarial nematodes: evidence for symbiont loss during evolution

“…The obtained 12S rDNA sequences were aligned using the sequencer aligner tool available in the Ribo- (Keddie et al, 1998) and with those generated by Casiraghi et al (2001b). This alignment was straightforward, with a very limited number of gaps.…”

Phylogeny of the Ascaridoidea (Nematoda: Ascaridida) Based on Three Genes and Morphology: Hypotheses of Structural and Sequence Evolution

“…Like other nematode mtDNA sequences (Thomas and Wilson, 1991;Okimoto et al, 1992;Hyman and Azevedo, 1996;Hugall et al, 1997;Blouin et al, 1998;Keddie et al, 1998), cox2 is extremely AϩT rich in ascaridoids. The value for thirdposition base compositional bias of ascaridoid cox2 is the same as for Caenorhabditis species (Thomas and Wilson, 1991), which is only slightly less biased than Drosophila yakuba (Clary and Wolstenholme, 1985).…”

“…The position 104 replacement (valine) in H. fortalezae was unexpected based on conservation in other organisms; however, functional studies in yeast show that replacements of the conserved glycine with other small uncharged residues (such as valine) does not compromise subunit II function (Overholtzer et al, 1996). The conservative replacement at position 113 in the aromatic sequence (phenylalanine for tyrosine) was found in all Ascaridida; in C. elegans and O. volvulus the tyrosine is conserved (Okimoto et al, 1992;Keddie et al, 1998). Another highly conserved region in other organisms is the DV(hydrophobic amino acid)H sequence (Müller et al, 1988); ascaridoids have retained the aspartic acid (D) at position 161 (providing a negative charge for cytochrome c binding), followed by the invariant valine, an isoleucine, and the invariant histidine, which is 1 of 2 involved in copper A (Cu A ) binding.…”

“…Nematodes sequenced to date have the glycine, but the other 2 residues are characterized by nonconservative replacements. The Ascaridida and C. elegans (Okimoto et al, 1992) have the sequence SG (hydrophobic amino acid), whereas O. volvulus has NGI (Keddie et al, 1998). A region near the C-terminus of COII proteins contains the other critical ligands to Cu A and a second charged amino acid involved in cytochrome c binding.…”

Molecular and ultrastructure characterization of two nematodes(Thelandros scleratus and Physalopteroides dactyluris)based on ribosomal and mitochondrial DNA sequences

“…However, less attention has been paid to the mitochondrial DNA (mt DNA). Mitochondrial gene analysis has been used successfully in studies regarding identifi cation and phylogenetic relationships in some nematode groups (Blouin et al, 1997;Keddie et al, 1998;Hoberg et al, 1999;Denver et al, 2000;Blouin, 2002;Lavrov & Brown, 2001;Liu et al, 2013). The cytochrome c-oxidase subunit1 (Cox 1) gene has been successfully used to resolve the phylogenies of closely allied species in most animal phyla including nematodes (Kumazawa & Nishida, 1993;Hebert et al, 2003;Prosser et al, 2013).…”