New twists in X-chromosome inactivation.
Dosage compensation, the mechanism by which organisms equalize the relative gene expression of dimorphic sex chromosomes, requires action of a diverse range of epigenetic mechanisms. The mammalian form, 'named X-chromosome inactivation' (XCI), involves silencing of one X chromosome in the female cell and regulation by genes that make noncoding RNAs (ncRNA). With large-scale genomic and transcriptome studies pointing to a crucial role for noncoding elements in organizing the epigenome, XCI emerges as a major paradigm and a focus of active research worldwide. With more surprising twists, recent advances point to the significance of RNA-directed chromatin change, chromosomal trans-interactions, nuclear organization, and evolutionary change. These findings have impacted our understanding of general gene regulation and are discussed herein.
Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.
Jennifer A
JA
Erwin
Jeannie T
JT
Lee
D000818:Animals; D042002:Chromatin Assembly and Disassembly / Q000235:genetics*; D041321:Chromosomes, Human, X / Q000235:genetics*; D004303:Dosage Compensation, Genetic / Q000235:genetics*; D044127:Epigenesis, Genetic / Q000235:genetics; D019143:Evolution, Molecular; D020868:Gene Silencing / Q000502:physiology; D006801:Humans; D022661:RNA, Untranslated / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*; D049951:X Chromosome Inactivation / Q000235:genetics*
D022661:RNA, Untranslated; D012097:Repressor Proteins