title: Evolution of the mouse polyubiquitin-C gene.
abstract: The polymeric ubiquitin (poly-u) genes are composed of tandem 228-bp repeats with no spacer sequences between individual monomer units. Ubiquitin is one of the most conserved proteins known to date, and the individual units within a number of poly-u genes are significantly more similar to each other than would be expected if each unit evolved independently. It has been proposed that the rather striking similarity among poly-u monomers in some lineages is caused by a series of homogenization events. Here we report the sequences of the polyubiquitin-C (Ubc) genes in two mouse strains. Analysis of these sequences, as well as those of the previously reported Chinese hamster and rat poly-u genes, supports the assertion that the homogenization of the ubiquitin-C gene in rodents is due to unequal crossing-over events. The sequence divergence of noncoding DNA was used to estimate the frequency of unequal crossing-over events (6.3 x 10(-5) events per generation) in the Ubc gene, as well as to provide evidence of apparent selection in the poly-u gene.
authors.affiliation: Department of Biology, Georgia State University, 24 Peachtree Center Avenue, Atlanta, GA 30303, USA. bioaap@panther.gsu.edu
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Perelygin
authors.forename: Fyodor A
authors.initials: FA
authors.lastname: Kondrashov
authors.forename: Igor B
authors.initials: IB
authors.lastname: Rogozin
authors.forename: Margo A
authors.initials: MA
authors.lastname: Brinton
mesh_terms: D000818:Animals; D001483:Base Sequence; D006224:Cricetinae; D003434:Crossing Over, Genetic; D004247:DNA; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D051381:Rats; D011995:Recombination, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D025822:Ubiquitin C / Q000235:genetics*
chemical_list: D025822:Ubiquitin C; D004247:DNA