Equality of the sexes: mammalian dosage compensation.
X chromosome inactivation achieves dosage equivalence for most X-linked genes between the two X chromosomes in females and the single X chromosome in males. In this article the evidence for random inactivation of an X chromosome is reviewed, along with the exceptions that result in nonrandom inactivation. Another exception to X chromosome inactivation is the presence of genes that escape inactivation and are expressed from both the active and inactive X chromosomes. The phenotypic consequences of such expression from the inactive X chromosome are discussed. The major players in the process of inactivation are presented. Initiation of inactivation requires the functional RNA, XIST, and the subsequent stable inactivation of the X chromosome relies upon the recruitment of many other factors, the majority of which are generally associated with heterochromatin.
Brown
C J
CJ
Department of Medical Genetics, University of British Columbia, Vancouver, Canada.
D000818:Animals; D019175:DNA Methylation; D004261:DNA Replication; D004303:Dosage Compensation, Genetic; D006570:Heterochromatin / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*
D006570:Heterochromatin; D006657:Histones; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors; C077885:XIST non-coding RNA