X-chromosome inactivation: lessons from transgenic mice.
X-chromosome inactivation (XCI) is the process by which mammals perform dosage compensation of X-linked gene products between XY males and XX females, resulting in the transcriptional silencing of all but one X chromosome per diploid cell. XCI involves counting the X chromosomes in a cell, randomly choosing those to be inactivated, spreading the inactivation signal in cis throughout the chromosome, and maintaining the inactive state of those X chromosomes during cell divisions thereafter. How the cell performs all these tasks is a fascinating problem and, together with epigenetic inheritance, a basic cellular mechanism that remains to be fully understood. In this review, we describe recent experiments aimed at understanding the first events of XCI and propose a model for initiation of XCI.
Pereira
L V
LV
Depto. Biologia, Instituto de Biociências, Universidade de Sao Paulo, Sao Paulo, Brazil. lpereira@usp.br
Vasques
L R
LR
D000818:Animals; D004303:Dosage Compensation, Genetic; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*
D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014157:Transcription Factors; C077885:XIST non-coding RNA