title: ITS2 ribosomal RNA indicates Schistosoma hippopotami is a distinct species.
abstract: The internal transcribed spacer region of the ribosomal RNA, ITS2, was sequenced from a single specimen of S. hippopotami collected from a pulmonary artery of the hippopotamus, Hippopotamus amphibius in South Africa. The nucleotide sequence was aligned with those of S. mansoni, S. rodhaini, S. haematobium, S. intercalatum, S. curassoni, S. bovis and S. japonicum. Both maximum parsimony and genetic distance analyses were performed on these data sets. Using S. japonicum as outgroup to the African schistosomes, a single most-parasmonious tree was obtained of length 64 steps with a consistency index of 1-S. hippopotami was the sister-group to the remaining African species. This species has lateral-spined eggs and its basal position in the tree suggests that this condition is primitive and that terminal-spined eggs developed secondarily. Molecular data clearly show that S. hippopotami cannot be considered synonymous with S. mansoni. Assuming the hippopotamus is the normal host of S. hippopotami, phylogenetic analysis is consistent with an ancient association between schistosomes and ungulates.
authors.affiliation: Laboratoire de Biologie des Populations d'Altitude, CNRS URA 1946 Université J. Fourier, Grenoble, France.
authors.forename: L
authors.initials: L
authors.lastname: Després
authors.forename: F J
authors.initials: FJ
authors.lastname: Kruger
authors.forename: D
authors.initials: D
authors.lastname: Imbert-Establet
authors.forename: M L
authors.initials: ML
authors.lastname: Adamson
mesh_terms: D000818:Animals; D001188:Artiodactyla / Q000469:parasitology*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009865:Oocytes / Q000648:ultrastructure; D010802:Phylogeny; D018510:RNA, Helminth / Q000737:chemistry / Q000235:genetics*; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics*; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D012547:Schistosoma / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D018509:DNA, Helminth; D004275:DNA, Ribosomal; D018510:RNA, Helminth; D012335:RNA, Ribosomal; D012340:RNA, Ribosomal, 5.8S