title: Localization of the X inactivation centre on the human X chromosome in Xq13.
abstract: X-chromosome inactivation results in the strictly cis-limited inactivation of many but not all genes on one of the two X chromosomes during early development in somatic cells of mammalian females. One feature of virtually all models of X inactivation is the existence of an X-inactivation centre (XIC) required in cis for inactivation to occur. This concept predicts that all structurally abnormal X chromosomes capable of being inactivated have in common a defineable region of the X chromosome. Here we report an analysis of several such rearranged human X chromosomes and define a minimal region of overlap. The results are consistent with models invoking a single XIC and provide a molecular foothold for cloning and analysing the XIC region. One of the markers that defines this region is the XIST gene, which is expressed specifically from inactive, but not active, X chromosomes. The localization of the XIST gene to the XIC region on the human X chromosome implicates XIST in some aspect of X inactivation.
authors.affiliation: Department of Genetics, Stanford University School of Medicine, California 94305.
authors.forename: C J
authors.initials: CJ
authors.lastname: Brown
authors.forename: R G
authors.initials: RG
authors.lastname: Lafreniere
authors.forename: V E
authors.initials: VE
authors.lastname: Powers
authors.forename: G
authors.initials: G
authors.lastname: Sebastio
authors.forename: A
authors.initials: A
authors.lastname: Ballabio
authors.forename: A L
authors.initials: AL
authors.lastname: Pettigrew
authors.forename: D H
authors.initials: DH
authors.lastname: Ledbetter
authors.forename: E
authors.initials: E
authors.lastname: Levy
authors.forename: I W
authors.initials: IW
authors.lastname: Craig
authors.forename: H F
authors.initials: HF
authors.lastname: Willard
mesh_terms: D002874:Chromosome Mapping; D004303:Dosage Compensation, Genetic; D015321:Gene Rearrangement; D006801:Humans; D014960:X Chromosome / Q000648:ultrastructure*