title: Nucleosomal organization of replication origins and meiotic recombination hotspots in fission yeast.
abstract: In Schizosaccharomyces pombe, DNA replication origins (ORIs) and meiotic recombination hotspots lack consensus sequences and show a bias towards mapping to large intergenic regions (IGRs). To explore whether this preference depended on underlying chromatin features, we have generated genome-wide nucleosome profiles during mitosis and meiosis. We have found that meiotic double-strand break sites (DSBs) colocalize with nucleosome-depleted regions (NDRs) and that large IGRs include clusters of NDRs that overlap with almost half of all DSBs. By contrast, ORIs do not colocalize with NDRs and they are regulated independently of DSBs. Physical relocation of NDRs at ectopic loci or modification of their genomic distribution during meiosis was paralleled by the generation of new DSB sites. Over 80% of all meiotic DSBs colocalize with NDRs that are also present during mitosis, indicating that the recombination pattern is largely dependent on constitutive properties of the genome and, to a lesser extent, on the transcriptional profile during meiosis. The organization of ORIs and of DSBs regions in S. pombe reveals similarities and differences relative to Saccharomyces cerevisiae.
authors: Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca, Spain.
authors: Elisa
authors: E
authors: de Castro
authors: Ignacio
authors: I
authors: Soriano
authors: Laura
authors: L
authors: Marín
authors: Rebeca
authors: R
authors: Serrano
authors: Luis
authors: L
authors: Quintales
authors: Francisco
authors: F
authors: Antequera
mesh_terms: D053903:DNA Breaks, Double-Stranded; D016681:Genome, Fungal; D008540:Meiosis; D009707:Nucleosomes / Q000378:metabolism*; D011995:Recombination, Genetic; D018741:Replication Origin; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D009707:Nucleosomes; D029702:Schizosaccharomyces pombe Proteins