title: Sequence instability in the long terminal repeats of avian spleen necrosis virus and reticuloendotheliosis virus.
abstract: Sequence divergence between the 3' long terminal repeats (LTR) of avian reticuloendotheliosis virus (REV), deletion variant proviral clone 2-20-4, and spleen necrosis virus (SNV)-proviral clones 14-44, 60, and 70-was found to involve two classes of base substitutions: low-frequency interspersed and high-frequency clustered substitutions. Clones 2-20-4 and 14-44 have diverged 4.4% owing to low-frequency substitutions. In contrast, two high-frequency substitution segments have diverged by 30% and 29%, respectively. Clustered substitutions appear to be located either within or next to tandem repeats, suggesting their introduction concomitant with sequence deletions and duplications commonly associated with such repeats. A new 19-bp tandem repeat is found in clone 2-20-4. Its sequence could have evolved from the 26-bp repeats found in the SNV clones.
authors.affiliation: Institute of Human Genetics, University of Minnesota, St. Paul 55108.
authors.forename: G
authors.initials: G
authors.lastname: Notani
authors.forename: W
authors.initials: W
authors.lastname: Sauerbier
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D005814:Genes, Viral; D014644:Genetic Variation; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D001356:Reticuloendotheliosis virus / Q000235:genetics*; D012190:Retroviridae / Q000235:genetics*