title: Translocation of the nucleolus organizer region to the human X chromosome.
abstract: We report the unique finding of a satellited X chromosome in a woman with Turner syndrome and a mosaic karyotype 45,X/46,X,mar(X)(sat,QFQ55),var(21)(sat,QFQ55). In PHA-stimulated lymphocytes and in lymphoblast culture, the satellited X chromosome was consistently late replicating. The translocated nucleolus organizer region (NOR) genes in the stalk of the satellite, however, remained transcriptionally active, and an unusual, late-replicating band was seen at the distal end of Xp. Analysis of fibroblast clones containing the satellited X chromosome suggests that the mar(X) is relatively stable.
mesh_terms: D000328:Adult; D004261:DNA Replication; D004275:DNA, Ribosomal / Q000235:genetics; D004303:Dosage Compensation, Genetic; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D009697:Nucleolus Organizer Region; D012335:RNA, Ribosomal / Q000235:genetics; D012729:Sex Chromosome Aberrations / Q000235:genetics*; D014178:Translocation, Genetic; D014960:X Chromosome
chemical_list: D004275:DNA, Ribosomal; D012335:RNA, Ribosomal