title: Reactivation of the paternal X chromosome in early mouse embryos.
abstract: It is generally accepted that paternally imprinted X inactivation occurs exclusively in extraembryonic lineages of mouse embryos, whereas cells of the embryo proper, derived from the inner cell mass (ICM), undergo only random X inactivation. Here we show that imprinted X inactivation, in fact, occurs in all cells of early embryos and that the paternal X is then selectively reactivated in cells allocated to the ICM. This contrasts with more differentiated cell types where X inactivation is highly stable and generally irreversible. Our observations illustrate that an important component of genome plasticity in early development is the capacity to reverse heritable gene silencing decisions.
authors.affiliation: X inactivation group, MRC Clinical Sciences Centre, ICSM, Hammersmith Hospital, London, W12 0NN, UK.
authors.forename: Winifred
authors.initials: W
authors.lastname: Mak
authors.forename: Tatyana B
authors.initials: TB
authors.lastname: Nesterova
authors.forename: Mariana
authors.initials: M
authors.lastname: de Napoles
authors.forename: Ruth
authors.initials: R
authors.lastname: Appanah
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamanaka
authors.forename: Arie P
authors.initials: AP
authors.lastname: Otte
authors.forename: Neil
authors.initials: N
authors.lastname: Brockdorff
mesh_terms: D000107:Acetylation; D000818:Animals; D001755:Blastocyst / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D033481:Chromosomes, Mammalian / Q000502:physiology; D004303:Dosage Compensation, Genetic; D004622:Embryo, Mammalian / Q000502:physiology*; D005314:Embryonic and Fetal Development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting; D006657:Histones / Q000378:metabolism; D008297:Male; D008745:Methylation; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009028:Morula / Q000502:physiology; D063151:Polycomb Repressive Complex 2; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014960:X Chromosome / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; C491488:EED protein, human; C107275:Eed protein, mouse; D006657:Histones; D011506:Proteins; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D012097:Repressor Proteins; C120423:Smc1l1 protein, mouse; C077885:XIST non-coding RNA; D063151:Polycomb Repressive Complex 2