title: Specification of a DNA replication origin by a transcription complex.
abstract: In early Xenopus development, transcription is repressed and DNA replication initiates at non-specific sites. Here, we show that a site-specific DNA replication origin can be induced in this context by the assembly of a transcription domain. Deletion of the promoter element abolishes site-specific initiation, and its relocalization to an ectopic site induces a new origin of replication. This process does not require active transcription, and specification of the origin occurs mainly through a decrease in non-specific initiation at sites distant from the promoter. Finally, chromatin immunoprecipitation experiments suggest that site-specific acetylation of histones favours the selection of the active DNA replication origin. We propose that the specification of active DNA replication origins occurs by secondary epigenetic events and that the programming of chromatin for transcription during development contributes to this selection in higher eukaryotes.
authors.affiliation: Institute of Human Genetics, CNRS, Genome Dynamics and Development, 141 rue de la Cardonille, 34396 Montpellier Cedex 5, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Danis
authors.forename: Konstantin
authors.initials: K
authors.lastname: Brodolin
authors.forename: Sophie
authors.initials: S
authors.lastname: Menut
authors.forename: Domenico
authors.initials: D
authors.lastname: Maiorano
authors.forename: Claire
authors.initials: C
authors.lastname: Girard-Reydet
authors.forename: Marcel
authors.initials: M
authors.lastname: Méchali
mesh_terms: D000107:Acetylation; D000818:Animals; D002843:Chromatin / Q000378:metabolism; D004261:DNA Replication; D005260:Female; D006657:Histones / Q000378:metabolism; D009154:Mutation; D010063:Ovum; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D018741:Replication Origin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014981:Xenopus
chemical_list: D002843:Chromatin; D006657:Histones