title: The long and the short of it: RNA-directed chromatin asymmetry in mammalian X-chromosome inactivation.
abstract: Mammalian X-chromosome inactivation is controlled by a multilayered silencing pathway involving both short and long non-coding RNAs, which differentially recruit the epigenetic machinery to establish chromatin asymmetries. In response to developmentally regulated small RNAs, dicer, a key effector of RNA interference, locally silences Xist on the active X-chromosome and establishes the heterochromatin conformation along the silent X-chromosome. The 1.6 kb RepA RNA initiates silencing by targeting the PRC2 polycomb complex to the inactive X-chromosome. In addition, the nuclear microenvironment is implicated in the initiation and maintenance of X-chromosome asymmetries. Here we review new findings involving these various RNA species in terms of understanding Xist gene regulation and the establishment of X-chromosome inactivation.
authors.affiliation: Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden. kanduri.chandrasekhar@genpat.uu.se
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Kanduri
authors.forename: Joanne
authors.initials: J
authors.lastname: Whitehead
authors.forename: Faizaan
authors.initials: F
authors.lastname: Mohammad
mesh_terms: D000818:Animals; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008957:Models, Genetic; D009690:Nucleic Acid Conformation; D012313:RNA / Q000235:genetics* / Q000378:metabolism*; D049951:X Chromosome Inactivation / Q000235:genetics*
chemical_list: D002843:Chromatin; D012313:RNA