title: Open and closed domains in the mouse genome are configured as 10-nm chromatin fibres.
abstract: The mammalian genome is compacted to fit within the confines of the cell nucleus. DNA is wrapped around nucleosomes, forming the classic "beads-on-a-string" 10-nm chromatin fibre. Ten-nanometre chromatin fibres are thought to condense into 30-nm fibres. This structural reorganization is widely assumed to correspond to transitions between active and repressed chromatin, thereby representing a chief regulatory event. Here, by combining electron spectroscopic imaging with tomography, three-dimensional images are generated, revealing that both open and closed chromatin domains in mouse somatic cells comprise 10-nm fibres. These findings indicate that the 30-nm chromatin model does not reflect the true regulatory structure in vivo.
authors.affiliation: Program in Genetics and Genome Biology, Hospital for Sick Children, Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Eden
authors.initials: E
authors.lastname: Fussner
authors.forename: Mike
authors.initials: M
authors.lastname: Strauss
authors.forename: Ugljesa
authors.initials: U
authors.lastname: Djuric
authors.forename: Ren
authors.initials: R
authors.lastname: Li
authors.forename: Kashif
authors.initials: K
authors.lastname: Ahmed
authors.forename: Michael
authors.initials: M
authors.lastname: Hart
authors.forename: James
authors.initials: J
authors.lastname: Ellis
authors.forename: David P
authors.initials: DP
authors.lastname: Bazett-Jones
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000737:chemistry; D004447:Echinodermata; D055032:Electron Microscope Tomography; D016678:Genome; D006657:Histones / Q000737:chemistry; D051379:Mice; D046032:Microscopy, Energy-Filtering Transmission Electron; D008958:Models, Molecular; D008968:Molecular Conformation; D009707:Nucleosomes / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D006657:Histones; D009707:Nucleosomes; D004247:DNA