title: Expansions and contractions of the genetic map relative to the physical map of yeast chromosome III.
abstract: To examine the relationship between genetic and physical chromosome maps, we constructed a diploid strain of the yeast Saccharomyces cerevisiae heterozygous for 12 restriction site mutations within a 23-kilobase (5-centimorgan) interval of chromosome III. Crossovers were not uniformly distributed along the chromosome, one interval containing significantly more and one interval significantly fewer crossovers than expected. One-third of these crossovers occurred within 6 kilobases of the centromere. Approximately half of the exchanges were associated with gene conversion events. The minimum length of gene conversion tracts varied from 4 base pairs to more than 12 kilobases, and these tracts were nonuniformly distributed along the chromosome. We conclude that the chromosomal sequence or structure has a dramatic effect on meiotic recombination.
authors.affiliation: Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637.
authors.forename: L S
authors.initials: LS
authors.lastname: Symington
authors.forename: T D
authors.initials: TD
authors.lastname: Petes
mesh_terms: D002874:Chromosome Mapping; D002875:Chromosomes / Q000502:physiology; D004262:DNA Restriction Enzymes; D005800:Genes, Fungal; D005838:Genotype; D010957:Plasmids; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D004262:DNA Restriction Enzymes