title: Genetic variability and phylogeny of the 5' long terminal repeat from Brazilian bovine leukemia virus.
abstract: We conducted a phylogenetic analysis of 22 strains of bovine leukemia virus obtained by polymerase chain reaction to amplify a 582-base pair fragment of the transcriptional regulatory region 5' long terminal repeat (LTR). Twenty-two samples of proviral DNA from peripheral blood mononuclear cells containing bovine leukemia virus from naturally infected bovine from 4 distinct geographic regions in Brazil were investigated. The products obtained by polymerase chain reaction were subjected to direct sequencing and sequence alignment. Fragments of 422 nucleotides were obtained, located between positions -118 and +303 base pairs of the 5'LTR. These fragments corresponded to 80% of the LTR region and included 56% of sub-region U3, 100% of R, and 82.5% of U5. Phylogenetic analysis of these sequences showed a high conservation degree in the 5'LTR region, with 5 well defined groups. However, a hotspot occurrence in the R-U5 region was also observed, which contained 40% of all nucleotide variability observed.
authors.affiliation: Laboratório de Retroviroses, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: C
authors.initials: C
authors.lastname: Hirsch
authors.affiliation: Laboratório de Biologia Molecular, Laboratório Nacional Agropecuário, Pedro Leopoldo, MG, Brasil.
authors.forename: M F
authors.initials: MF
authors.lastname: Camargos
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: E F
authors.initials: EF
authors.lastname: Barbosa-Stancioli
authors.affiliation: Laboratório de Biologia Molecular, Laboratório Nacional Agropecuário, Pedro Leopoldo, MG, Brasil.
authors.forename: A A
authors.initials: AA
authors.lastname: Fonseca Júnior
authors.affiliation: Laboratório de Retroviroses, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: D S
authors.initials: DS
authors.lastname: Rajão
authors.affiliation: Laboratório de Retroviroses, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: M B
authors.initials: MB
authors.lastname: Heinemann
authors.affiliation: Laboratório de Retroviroses, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil jenner@ufmg.br.
authors.forename: J K P
authors.initials: JK
authors.lastname: Reis
authors.affiliation: Laboratório de Retroviroses, Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: R C
authors.initials: RC
authors.lastname: Leite
mesh_terms: D000818:Animals; D001483:Base Sequence; D001938:Brazil; D002417:Cattle; D004279:DNA, Viral / Q000235:genetics; D014644:Genetic Variation; D001909:Leukemia Virus, Bovine / Q000235:genetics*; D010802:Phylogeny; D020079:Terminal Repeat Sequences / Q000235:genetics*
chemical_list: D004279:DNA, Viral