Physical and functional interactions among basic chromosome organizational features govern early steps of meiotic chiasma formation.
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.
Blat
Yuval
Y
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Protacio
Reine U
RU
Hunter
Neil
N
Kleckner
Nancy
N
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
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