title: Physical and functional interactions among basic chromosome organizational features govern early steps of meiotic chiasma formation.
abstract: Analysis of meiotic recombination by functional genomic approaches reveals prominent spatial and functional interactions among diverse organizational determinants. Recombination occurs between chromatin loop sequences; however, these sequences are spatially tethered to underlying chromosome axes via their recombinosomes. Meiotic chromosomal protein, Red1, localizes to chromosome axes; however, Red1 loading is modulated by R/G-bands isochores and thus by bulk chromatin state. Recombination is also modulated by isochore determinants: R-bands differentially favor double-strand break (DSB) formation but disfavor subsequent loading of meiotic RecA homolog, Dmc1. Red1 promotes DSB formation in both R- and G-bands and then promotes Dmc1 loading, specifically counteracting disfavoring R-band effects. These complexities are discussed in the context of chiasma formation as a series of coordinated local changes at the DNA and chromosome-axis levels.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Blat
authors.forename: Reine U
authors.initials: RU
authors.lastname: Protacio
authors.forename: Neil
authors.initials: N
authors.lastname: Hunter
authors.forename: Nancy
authors.initials: N
authors.lastname: Kleckner
mesh_terms: D018797:Cell Cycle Proteins; D002843:Chromatin / Q000648:ultrastructure; D002875:Chromosomes / Q000648:ultrastructure*; D004247:DNA / Q000648:ultrastructure; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000378:metabolism; D000939:Epitopes; D005656:Fungal Proteins; D017343:Genes, Plant; D008540:Meiosis; D008938:Mitosis; D008954:Models, Biological; D009693:Nucleic Acid Hybridization; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D011995:Recombination, Genetic; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; C513033:DMC1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D000939:Epitopes; D005656:Fungal Proteins; C086673:RED1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA