title: Global organization of replication time zones of the mouse genome.
abstract: The division of genomes into distinct replication time zones has long been established. However, an in-depth understanding of their organization and their relationship to transcription is incomplete. Taking advantage of a novel synchronization method ("baby machine") and of genomic DNA microarrays, we have, for the first time, mapped replication times of the entire mouse genome at a high temporal resolution. Our data revealed that although most of the genome has a distinct time of replication either early, middle, or late S phase, a significant portion of the genome is replicated asynchronously. Analysis of the replication map revealed the genomic scale organization of the replication time zones. We found that the genomic regions between early and late replication time zones often consist of extremely large replicons. Analysis of the relationship between replication and transcription revealed that early replication is frequently correlated with the transcription potential of a gene and not necessarily with its actual transcriptional activity. These findings, along with the strong conservation found between replication timing in human and mouse genomes, emphasize the importance of replication timing in transcription regulation.
authors.affiliation: Department of Molecular Biology, Hebrew University Medical School Jerusalem 91120, Israel.
authors.forename: Shlomit
authors.initials: S
authors.lastname: Farkash-Amar
authors.forename: Doron
authors.initials: D
authors.lastname: Lipson
authors.forename: Andreas
authors.initials: A
authors.lastname: Polten
authors.forename: Alon
authors.initials: A
authors.lastname: Goren
authors.forename: Charles
authors.initials: C
authors.lastname: Helmstetter
authors.forename: Zohar
authors.initials: Z
authors.lastname: Yakhini
authors.forename: Itamar
authors.initials: I
authors.lastname: Simon
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D004261:DNA Replication; D042522:DNA Replication Timing; D016678:Genome; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D018741:Replication Origin; D014158:Transcription, Genetic