title: X chromosome dosage compensation: how mammals keep the balance.
abstract: The development of genetic sex determination and cytologically distinct sex chromosomes leads to the potential problem of gene dosage imbalances between autosomes and sex chromosomes and also between males and females. To circumvent these imbalances, mammals have developed an elaborate system of dosage compensation that includes both upregulation and repression of the X chromosome. Recent advances have provided insights into the evolutionary history of how both the imprinted and random forms of X chromosome inactivation have come about. Furthermore, our understanding of the epigenetic switch at the X-inactivation center and the molecular aspects of chromosome-wide silencing has greatly improved recently. Here, we review various facets of the ever-expanding field of mammalian dosage compensation and discuss its evolutionary, developmental, and mechanistic components.
authors: Howard Hughes Medical Institute, Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. payer@molbio.mgh.harvard.edu
authors: Bernhard
authors: B
authors: Payer
authors: Jeannie T
authors: JT
authors: Lee
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D004303:Dosage Compensation, Genetic; D044127:Epigenesis, Genetic; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D007448:Invertebrates / Q000235:genetics; D008297:Male; D008322:Mammals / Q000235:genetics*; D008957:Models, Genetic; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics; D019849:Sex Determination Processes; D014960:X Chromosome / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics
chemical_list: D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; C077885:XIST non-coding RNA