title: Inhibition of condensation in the late-replicating X chromosome induced by 5-azadeoxycytidine in human lymphocyte cultures.
abstract: The cytidine analogue 5-azadeoxycytidine (5-azadC) induces a very distinct inhibition of condensation in the genetically inactive, late-replicating X chromosome (XL) when applied to human lymphocyte cultures. One of the two X chromosomes in cytogenetically normal female cells becomes dramatically longer than its homologous partner. The highest rate of metaphases with an undercondensed XL chromosome is achieved when 5-aza-dC is added at a final concentration of 10(-5) M 2 h before cell harvesting. The interactions between 5-aza-dC and chromosomal DNA as well as the factors involved in X chromosome inactivation are discussed.
mesh_terms: D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002478:Cells, Cultured; D004261:DNA Replication / Q000187:drug effects*; D000077209:Decitabine; D004303:Dosage Compensation, Genetic; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000648:ultrastructure; D008677:Metaphase; D014960:X Chromosome
chemical_list: D000077209:Decitabine; D001374:Azacitidine