X chromosome inactivation and the Xist gene.
X chromosome inactivation in mammals was first described over 30 years ago. The biological problem is how to achieve gene dosage equivalence between XX females and XY males; the solution is to genetically silence one whole X chromosome in each cell of the early developing female embryo. The molecular mechanism by which this is achieved, however, remains a mystery. Recently, through the discovery of the Xist gene, it appears that we may be on the brink of learning how this unique phenomenon is mediated. Here, I discuss the developmental regulation of X inactivation and the candidacy of Xist as the X chromosome inactivation centre, with particular reference to its possible role in the initiation, spread and maintenance of X inactivation.
Rastan
S
S
MRC Clinical Research Centre, Harrow, UK.
D000818:Animals; D002874:Chromosome Mapping; D004303:Dosage Compensation, Genetic; D005260:Female; D006801:Humans; D008297:Male; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors / Q000235:genetics*; D014960:X Chromosome
D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors; C077885:XIST non-coding RNA