title: Mapping Polycomb-repressed domains in the bithorax complex using in vivo formaldehyde cross-linked chromatin.
abstract: The Polycomb group (Pc-G) proteins are responsible for keeping developmental regulators, like homeotic genes, stably and inheritably repressed during Drosophila development. Several similarities to a protein class involved in heterochromatin formation suggest that the Pc-G exerts its function at the higher order chromatin level. Here we have mapped the distribution of the Pc protein in the homeotic bithorax complex (BX-C) of Drosophila tissue culture cells. We have elaborated a method, based on the in vivo formaldehyde cross-linking technique, that allows a substantial enrichment for Pc-interacting sites by immunoprecipitation of the cross-linked chromatin with anti-Pc antibodies. We find that the Pc protein quantitatively covers large regulatory regions of repressed BX-C genes. Conversely, we find that the Abdominal-B gene is active in these cells and the region devoid of any bound Pc protein.
authors.affiliation: Zentrum für Molekulare Biologie, Universität Heidelberg, Federal Republic of Germany.
authors.forename: V
authors.initials: V
authors.lastname: Orlando
authors.forename: R
authors.initials: R
authors.lastname: Paro
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism* / Q000648:ultrastructure; D003001:Cloning, Molecular; D003432:Cross-Linking Reagents; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005557:Formaldehyde; D005801:Genes, Homeobox; D006570:Heterochromatin / Q000378:metabolism; D007301:Insect Hormones / Q000378:metabolism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D063150:Polycomb Repressive Complex 1; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping
chemical_list: D002843:Chromatin; D003432:Cross-Linking Reagents; D029721:Drosophila Proteins; D006570:Heterochromatin; D007301:Insect Hormones; D009838:Oligodeoxyribonucleotides; C066770:Pc protein, Drosophila; D011506:Proteins; D005557:Formaldehyde; D004247:DNA; D063150:Polycomb Repressive Complex 1