title: A role for non-coding Tsix transcription in partitioning chromatin domains within the mouse X-inactivation centre.
abstract: BACKGROUND
  Delimiting distinct chromatin domains is essential for temporal and spatial regulation of gene expression. Within the X-inactivation centre region (Xic), the Xist locus, which triggers X-inactivation, is juxtaposed to a large domain of H3K27 trimethylation (H3K27me3).
  
  
  RESULTS
  We describe here that developmentally regulated transcription of Tsix, a crucial non-coding antisense to Xist, is required to block the spreading of the H3K27me3 domain to the adjacent H3K4me2-rich Xist region. Analyses of a series of distinct Tsix mutations suggest that the underlying mechanism involves the RNA Polymerase II accumulating at the Tsix 3'-end. Furthermore, we report additional unexpected long-range effects of Tsix on the distal sub-region of the Xic, involved in Xic-Xic trans-interactions.
  
  
  CONCLUSIONS
  These data point toward a role for transcription of non-coding RNAs as a developmental strategy for the establishment of functionally distinct domains within the mammalian genome.
authors.affiliation: Unité de Génétique Moléculaire Murine, URA 2578, Institut Pasteur 75724, Paris Cedex 15, France.
authors.forename: Pablo
authors.initials: P
authors.lastname: Navarro
authors.affiliation: CEA/Institut de Génomique/Centre National de Génotypage, 2 rue Gaston Crémieux, 91057, Evry Cedex, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Chantalat
authors.affiliation: CEA/Institut de Génomique/Centre National de Génotypage, 2 rue Gaston Crémieux, 91057, Evry Cedex, France.
authors.forename: Mario
authors.initials: M
authors.lastname: Foglio
authors.affiliation: Unité de Génétique Moléculaire Murine, URA 2578, Institut Pasteur 75724, Paris Cedex 15, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Chureau
authors.affiliation: Unité de Génétique Moléculaire Murine, URA 2578, Institut Pasteur 75724, Paris Cedex 15, France.|Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Vigneau
authors.affiliation: Unité de Génétique Moléculaire Murine, URA 2578, Institut Pasteur 75724, Paris Cedex 15, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Clerc
authors.affiliation: Unité de Génétique Moléculaire Murine, URA 2578, Institut Pasteur 75724, Paris Cedex 15, France.
authors.forename: Philip
authors.initials: P
authors.lastname: Avner
authors.affiliation: Unité de Génétique Moléculaire Murine, URA 2578, Institut Pasteur 75724, Paris Cedex 15, France.|UMR 7216 Epigenetics and Cell Fate, Université Paris-Diderot Paris 7, CNRS, 35 rue Hélène Brion 75205 Paris Cedex 13, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Rougeulle