title: Eimeria trichosuri: phylogenetic position of a marsupial coccidium, based on 18S rDNA sequences.
abstract: Phylogenetic analysis of the genus Eimeria suggests that parasite and host have coevolved over broad evolutionary timescales. Here we extend this analysis by determining the 18S rDNA gene sequence of the marsupial coccidium, Eimeria trichosuri, and assessing its phylogenetic position relative to Eimeria from birds, reptiles and placental mammals. This analysis placed E. trichosuri clones in a clade that diverged before the major clade comprising species from placental mammals. The position of E.trichosuri is consistent with host phylogeny where marsupials represent an ancient evolutionary line that predates the placental mammal line.
authors.affiliation: Department of Biological Sciences, Macquarie University, North Ryde, Sydney NSW 2109, Australia. mpower@els.mq.edu.au
authors.forename: M L
authors.initials: ML
authors.lastname: Power
authors.forename: C
authors.initials: C
authors.lastname: Richter
authors.forename: S
authors.initials: S
authors.lastname: Emery
authors.forename: J
authors.initials: J
authors.lastname: Hufschmid
authors.forename: M R
authors.initials: MR
authors.lastname: Gillings
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003048:Coccidiosis / Q000469:parasitology / Q000662:veterinary*; D004275:DNA, Ribosomal / Q000737:chemistry*; D004539:Eimeria / Q000145:classification* / Q000235:genetics / Q000648:ultrastructure; D005243:Feces / Q000469:parasitology; D008394:Marsupialia / Q000469:parasitology*; D008969:Molecular Sequence Data; D033661:Oocysts / Q000648:ultrastructure; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D016415:Sequence Alignment / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D014739:Victoria
chemical_list: D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S