title: The complete mitochondrial genomes of Schistosoma haematobium and Schistosoma spindale and the evolutionary history of mitochondrial genome changes among parasitic flatworms.
abstract: Complete mitochondrial genome sequences for the schistosomes Schistosoma haematobium and Schistosoma. spindale have been characterized. S. haematobium is the causative agent of urinary schistosomiasis in humans and S. spindale uses ruminants as its definitive host; both are transmitted by freshwater snail intermediate hosts. Results confirm a major gene order rearrangement among schistosomes in all traditional Schistosoma species groups other than Schistosoma japonicum; i.e., species groups S. mansoni, S. haematobium, and S. indicum. These data lend support to the 'out of Asia' (East and Southeast Asia) hypothesis for Schistosoma. The gene order change involves translocation of atp6-nad2-trnA and a rearrangement of nad3-nad1 relative to other parasitic flatworm mt genomes so far sequenced. Gene order and tRNA secondary structure changes (loss and acquisition of the DHU and/or TPsiC arms of trnC, trnF, and trnR) between mitochondrial genomes of these and other (digenean and cestode) flatworms were inferred by character mapping onto a phylogeny estimated from nuclear small subunit rRNA gene sequences of these same species, in order to find additional rare genomic changes suitable as synapomorphies. Denser and wider taxon sampling of mt genomes across the Platyhelminthes will validate these putative characters.
authors.affiliation: Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK. T.Littlewood@nhm.ac.uk
authors.forename: D Timothy J
authors.initials: DT
authors.lastname: Littlewood
authors.forename: Anne E
authors.initials: AE
authors.lastname: Lockyer
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Webster
authors.forename: David A
authors.initials: DA
authors.lastname: Johnston
authors.forename: Thanh Hoa
authors.initials: TH
authors.lastname: Le
mesh_terms: D000818:Animals; D001482:Base Composition / Q000235:genetics; D001483:Base Sequence; D018387:Codon, Initiator / Q000235:genetics; D018388:Codon, Terminator / Q000235:genetics; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D019143:Evolution, Molecular; D023061:Gene Order; D017238:Genes, Helminth / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010986:Platyhelminths / Q000145:classification / Q000235:genetics*; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D012547:Schistosoma / Q000235:genetics*; D012548:Schistosoma haematobium / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D041201:Taenia solium / Q000235:genetics
chemical_list: D018387:Codon, Initiator; D018388:Codon, Terminator; D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D012335:RNA, Ribosomal; D012343:RNA, Transfer