title: The gastrula transition reorganizes replication-origin selection in Caenorhabditis elegans.
abstract: Although some features underlying replication-origin activation in metazoan cells have been determined, little is known about their regulation during metazoan development. Using the nascent-strand purification method, here we identified replication origins throughout Caenorhabditis elegans embryonic development and found that the origin repertoire is thoroughly reorganized after gastrulation onset. During the pluripotent embryonic stages (pregastrula), potential cruciform structures and open chromatin are determining factors that establish replication origins. The observed enrichment of replication origins in transcription factor-binding sites and their presence in promoters of highly transcribed genes, particularly operons, suggest that transcriptional activity contributes to replication initiation before gastrulation. After the gastrula transition, when embryonic differentiation programs are set, new origins are selected at enhancers, close to CpG-island-like sequences, and at noncoding genes. Our findings suggest that origin selection coordinates replication initiation with transcriptional programs during metazoan development.
authors.affiliation: Institute of Human Genetics, CNRS, Montpellier, France.
authors.forename: Marta
authors.initials: M
authors.lastname: Rodríguez-Martínez
authors.affiliation: Institute of Human Genetics, CNRS, Montpellier, France.
authors.forename: Natalia
authors.initials: N
authors.lastname: Pinzón
authors.affiliation: Agropolymer Engineering and Emerging Technologies, University of Montpellier, Montpellier, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Ghommidh
authors.affiliation: Institute of Human Genetics, CNRS, Montpellier, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Beyne
authors.affiliation: Institute of Human Genetics, CNRS, Montpellier, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Seitz
authors.affiliation: Institute of Human Genetics, CNRS, Montpellier, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Cayrou
authors.affiliation: Institute of Human Genetics, CNRS, Montpellier, France.
authors.forename: Marcel
authors.initials: M
authors.lastname: Méchali
mesh_terms: D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D002875:Chromosomes / Q000378:metabolism; D018899:CpG Islands / Q000235:genetics; D004261:DNA Replication / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005775:Gastrula / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D055029:Inverted Repeat Sequences / Q000235:genetics; D009876:Operon / Q000235:genetics; D018741:Replication Origin / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D006657:Histones