title: Evidence for DNA modification in the maintenance of X-chromosome inactivation of adult mouse tissues.
abstract: The role of DNA modification in the maintenance of mammalian X-chromosome inactivation was investigated by using the technique of DNA transformation in mammalian cells. The ability of inactive X-chromosome DNA from adult mouse tissues to act in transformation for the X-linked hypoxanthine phosphoribosyltransferase gene (Hprt) could be ascertained by utilizing a recently discovered electrophoretic variant form of the hypoxanthine phosphoribosyltransferase enzyme and a previously available X:autosome translocation. Our findings indicate that inactive X-chromosome DNA from several tissues of adult female mice is strikingly inefficient, in comparison to active X-chromosome DNA, in eliciting genetic transformation for hypoxanthine phosphoribosyltransferase. These results provide in vivo evidence that is consistent with DNA modification playing an important role in the maintenance of X-chromosome inactivation.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000502:physiology; D004247:DNA / Q000235:genetics*; D005260:Female; D005796:Genes; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D007525:Isoelectric Focusing; D008297:Male; D051379:Mice; D010641:Phenotype; D012730:Sex Chromosomes / Q000502:physiology*; D014178:Translocation, Genetic; D014960:X Chromosome / Q000502:physiology*
chemical_list: D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase