Cytogenetic and biochemical investigations on fibroblast cultures and clones with one and two active X chromosomes of a 69,XXY triploidy.
Bromodeoxyuridine replication patterns showed that fibroblasts from a 69,XXY triploidy carried either one or two early replicating X chromosomes. The activity of alpha-galactosidase A measured in single cells fell into two classes with a ratio of 1:2. Dilute plating produced clones of both types with the activity of alpha-galactosidase A corresponding to the number of active X chromosomes. To our knowledge, this is the first report on clones of a triploidy with different numbers of active X chromosomes, and on a gene-dosage effect of an X-linked gene using triploid cells with one active X as control.
D002455:Cell Division; D002478:Cells, Cultured; D002999:Clone Cells / Q000166:cytology; D004303:Dosage Compensation, Genetic; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D005696:Galactosidases / Q000235:genetics*; D006801:Humans; D066298:In Vitro Techniques; D007231:Infant, Newborn; D007713:Klinefelter Syndrome / Q000235:genetics*; D008297:Male; D011123:Polyploidy; D014960:X Chromosome; D000519:alpha-Galactosidase / Q000235:genetics*
D005696:Galactosidases; D000519:alpha-Galactosidase