title: Understanding the X chromosome inactivation cycle in mice: a comprehensive view provided by nuclear transfer.
abstract: During mouse development, imprinted X chromosome inactivation (XCI) is observed in preimplantation embryos and is inherited to the placental lineage, whereas random XCI is initiated in the embryonic proper. Xist RNA, which triggers XCI, is expressed ectopically in cloned embryos produced by somatic cell nuclear transfer (SCNT). To understand these mechanisms, we undertook a large-scale nuclear transfer study using different donor cells throughout the life cycle. The Xist expression patterns in the reconstructed embryos suggested that the nature of imprinted XCI is the maternal Xist-repressing imprint established at the last stage of oogenesis. Contrary to the prevailing model, this maternal imprint is erased in both the embryonic and extraembryonic lineages. The lack of the Xist-repressing imprint in the postimplantation somatic cells clearly explains how the SCNT embryos undergo ectopic Xist expression. Our data provide a comprehensive view of the XCI cycle in mice, which is essential information for future investigations of XCI mechanisms.
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan; Medical Research Institute; Tokyo Medical and Dental University; Tokyo, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Oikawa
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan; Graduate School of Life and Environmental Science; University of Tsukuba; Tsukuba, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Inoue
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan.
authors.forename: Hirosuke
authors.initials: H
authors.lastname: Shiura
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Matoba
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan; Graduate School of Life and Environmental Science; University of Tsukuba; Tsukuba, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kamimura
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Hirose
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Mekada
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshiki
authors.affiliation: Department of Animal Resource Sciences/Veterinary Medical Sciences; University of Tokyo; Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan; Graduate School of Life and Environmental Science; University of Tsukuba; Tsukuba, Japan.
authors.forename: Kuniya
authors.initials: K
authors.lastname: Abe
authors.affiliation: Medical Research Institute; Tokyo Medical and Dental University; Tokyo, Japan.
authors.forename: Fumitoshi
authors.initials: F
authors.lastname: Ishino
authors.affiliation: RIKEN BioResource Center; Tsukuba, Japan; Graduate School of Life and Environmental Science; University of Tsukuba; Tsukuba, Japan; Center for Disease Biology and Integrative Medicine; University of Tokyo; Tokyo, Japan.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Ogura
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D047108:Embryonic Development; D005260:Female; D018392:Genomic Imprinting; D008297:Male; D051379:Mice; D053652:Nuclear Transfer Techniques; D062085:RNA, Long Noncoding / Q000235:genetics*; D049951:X Chromosome Inactivation / Q000502:physiology*
chemical_list: D062085:RNA, Long Noncoding; C077885:XIST non-coding RNA
keywords: X chromosome inactivation; embryo; mouse; nuclear transfer