Escape Artists of the X Chromosome.
Inactivation of one X chromosome in mammalian females achieves dosage compensation between XX females and XY males; however, over 15% of human X-linked genes continue to be expressed from the inactive X chromosome. New genomic methodologies have improved our identification and characterization of these escape genes, revealing the importance of DNA sequence, chromatin structure, and chromosome ultrastructure in regulating expression from an otherwise inactive chromosome. Study of these exceptions to the rule of silencing highlights the interconnectedness of chromatin and chromosome structure in X-chromosome inactivation (XCI). Recent advances also demonstrate the importance of these genes in sexually dimorphic disease risk, particularly cancer.
Department of Medical Genetics, Molecular Epigenetics Group, University of British Columbia, Vancouver, British Columbia, V6T 1Z3 Canada.
Bradley P
BP
Balaton
Department of Medical Genetics, Molecular Epigenetics Group, University of British Columbia, Vancouver, British Columbia, V6T 1Z3 Canada. Electronic address: carolyn.brown@ubc.ca.
Carolyn J
CJ
Brown
D000818:Animals; D002843:Chromatin / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics*; D019175:DNA Methylation / Q000235:genetics; D004303:Dosage Compensation, Genetic; D005260:Female; D006801:Humans; D008297:Male; D008322:Mammals; D049951:X Chromosome Inactivation / Q000235:genetics*
D002843:Chromatin
X chromosome; X-chromosome inactivation; allelic sequence analysis; dosage compensation; epigenetic silencing; sex chromosomes