title: Evolutionary relationships in Trypanosoma cruzi: molecular phylogenetics supports the existence of a new major lineage of strains.
abstract: For the purpose of investigating the evolutionary relationships among strains of the human parasite Trypanosoma cruzi, we have determined the nucleotide sequence, in 16 T. cruzi stocks, of a DNA fragment having approximately 1030 nucleotides in length. Phylogenetic analyses show the presence of at least three major groups of T. cruzi strains, a result that contradicts previous phylogenetic inferences based on polymorphism data. We also performed an analysis of the relative extent of nucleotide divergence among T. cruzi strains compared to the divergence between Leishmania species, using the gene encoding pteridine reductase. The results presented in this work show that the divergence among the most distant T. cruzi strains is at least as high as the divergence between two different species complexes of Leishmania, those containing L. major and L. mexicana.
authors.affiliation: Depto. de Bioquímica, Fac. de Medicina, Montevideo, Uruguay.
authors.forename: C
authors.initials: C
authors.lastname: Robello
authors.forename: F
authors.initials: F
authors.lastname: Gamarro
authors.forename: S
authors.initials: S
authors.lastname: Castanys
authors.forename: F
authors.initials: F
authors.lastname: Alvarez-Valin
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000818:Animals; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000145:classification / Q000235:genetics*
chemical_list: D018528:ATP-Binding Cassette Transporters; D016054:DNA, Protozoan; D015800:Protozoan Proteins; C115577:Tcp17 protein, Trypanosoma cruzi; C102792:Tcpgp2 protein, Trypanosoma cruzi