title: A fine-structure map of spontaneous mitotic crossovers in the yeast Saccharomyces cerevisiae.
abstract: Homologous recombination is an important mechanism for the repair of DNA damage in mitotically dividing cells. Mitotic crossovers between homologues with heterozygous alleles can produce two homozygous daughter cells (loss of heterozygosity), whereas crossovers between repeated genes on non-homologous chromosomes can result in translocations. Using a genetic system that allows selection of daughter cells that contain the reciprocal products of mitotic crossing over, we mapped crossovers and gene conversion events at a resolution of about 4 kb in a 120-kb region of chromosome V of Saccharomyces cerevisiae. The gene conversion tracts associated with mitotic crossovers are much longer (averaging about 12 kb) than the conversion tracts associated with meiotic recombination and are non-randomly distributed along the chromosome. In addition, about 40% of the conversion events have patterns of marker segregation that are most simply explained as reflecting the repair of a chromosome that was broken in G1 of the cell cycle.
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors.forename: Phoebe S
authors.initials: PS
authors.lastname: Lee
authors.forename: Patricia W
authors.initials: PW
authors.lastname: Greenwell
authors.forename: Margaret
authors.initials: M
authors.lastname: Dominska
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Gawel
authors.forename: Monica
authors.initials: M
authors.lastname: Hamilton
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Petes
mesh_terms: D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D004260:DNA Repair / Q000235:genetics; D016193:G1 Phase; D008938:Mitosis / Q000235:genetics*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*