title: Expression of common fragile sites on the X chromosome corresponds with active gene regions.
abstract: The expression of common chromosomal fragile sites on human chromosomes has been proposed to be a cytogenetic expression of gene activity. Distinctive patterns of expression of two common fragile sites on the human X chromosome were observed in females. The fragile site at Xp22.31, located in a band region that contains genes which escape X inactivation, was expressed on both X chromosomes. By contrast, the fragile site at Xq22.1, in a region assumed to be subject to X inactivation, was expressed almost exclusively on one X, the active X chromosome. These findings provide evidence that common fragile site expression only occurs in regions with active genes.
authors.affiliation: Department of Human Genetics, Medical College of Virginia, Virginia Commonwealth University, Richmond.
authors.forename: M J
authors.initials: MJ
authors.lastname: Austin
mesh_terms: D016590:Aphidicolin; D002874:Chromosome Mapping; D004261:DNA Replication; D004224:Diterpenes / Q000008:administration & dosage; D004303:Dosage Compensation, Genetic; D005260:Female; D005600:Fragile X Syndrome / Q000503:physiopathology*; D015870:Gene Expression; D005796:Genes; D006801:Humans; D008297:Male; D014427:Twins; D014960:X Chromosome / Q000502:physiology*
chemical_list: D004224:Diterpenes; D016590:Aphidicolin