A stain upon the silence: genes escaping X inactivation.
X-chromosome inactivation is a remarkable epigenetic event in mammalian females that results in the transcriptional silencing of one of the pair of X chromosomes. However, not all X-linked genes are subject to inactivation, and in humans, the proportion of genes on the X chromosome that escapes inactivation is more than 15%. Here we examine the causes and consequences of failure to silence the entire X chromosome. We discuss the impact of the evolutionary history of the X (and Y) chromosome, and the bioinformatic approaches that promise to provide new insights into the genomic architecture of genes or regions that escape X-chromosome inactivation.
Brown
Carolyn J
CJ
Department of Medical Genetics, University of British Columbia, 6174 University Blvd, Vancouver, British Columbia, Canada V6T 1Z3. cbrown@interchange.ubc.ca
Greally
John M
JM
D000818:Animals; D004303:Dosage Compensation, Genetic; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006801:Humans; D051379:Mice; D014178:Translocation, Genetic; D014960:X Chromosome