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.
Erwin
Jennifer A
JA
Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.
Lee
Jeannie T
JT
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