title: Replication profile of Saccharomyces cerevisiae chromosome VI.
abstract: BACKGROUND
  An understanding of the replication programme at the genome level will require the identification and characterization of origins of replication through large, contiguous regions of DNA. As a step toward this goal, origin efficiencies and replication times were determined for 10 ARSs spanning most of the 270 kilobase (kb) chromosome VI of Saccharomyces cerevisiae.
  
  
  RESULTS
  Chromosome VI shows a wide variation in the percentage of cell cycles in which different replication origins are utilized. Most of the origins are activated in only a fraction of cells, suggesting that the pattern of origin usage on chromosome VI varies greatly within the cell population. The replication times of fragments containing chromosome VI origins show a temporal pattern that has been recognized on other chromosomes--the telomeres replicate late in S phase, while the central region of the chromosome replicates early.
  
  
  CONCLUSIONS
  As demonstrated here for chromosome VI, analysis of the direction of replication fork movement along a chromosome and determination of replication time by measuring a period of hemimethylation may provide an efficient means of surveying origin activity over large regions of the genome.
authors.affiliation: Genetics Department, University of Washington, Seattle 98195-7360, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Friedman
authors.forename: B J
authors.initials: BJ
authors.lastname: Brewer
authors.forename: W L
authors.initials: WL
authors.lastname: Fangman
mesh_terms: D002453:Cell Cycle / Q000235:genetics*; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D004261:DNA Replication; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D016681:Genome, Fungal; D008745:Methylation; D016133:Polymerase Chain Reaction; D018741:Replication Origin; D016196:S Phase / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development; D016615:Telomere / Q000235:genetics; D013997:Time Factors
chemical_list: D004271:DNA, Fungal