Mechanistic insights into chromosome-wide silencing in X inactivation
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In mammals, one of the two X chromosomes in female cells is transcriptionally silenced for dosage compensation between the sexes. Chromosome-wide silencing is initiated by the non-coding Xist RNA that accumulates within the inactive X chromosome territory and triggers gene repression and chromatin modifications. Epigenetic changes of the inactive X chromosome in a developmentally regulated manner result in stable gene repression in female somatic cells. X inactivation is a model for understanding the formation of facultative heterochromatin in mammalian development and represents a paradigm for RNA mediated regulation of gene expression. In this review, we summarize the present knowledge of the mechanism of chromosome-wide silencing and give an outlook on future directions.
KeywordsGene Silence Mouse Embryonic Stem Cell Chromatin Modification Gene Repression Chromosome Territory
We thank members of the laboratory for critical discussion and comments. AK is supported by a Medical Research Council studentship. AW is supported by a Wellcome Trust Senior Research Fellowship (grant reference 087530/Z/08/A).
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