title: Totipotency in the absence of CAF-I: unhindered choices when the chaperone is out.
abstract: Embryonal totipotent cells can produce both embryonic and extraembryonic tissues and can generate whole organisms. In mice this level of genome plasticity is preserved in the 2-cell embryos, but is absent in embryonic cells from later stages of development. Recently it has been demonstrated that totipotent-like cells spontaneously appear in embryonic stem cell cultures and that the depletion of the histone chaperone Chromatin Assembly Factor I (CAF-I) increases the abundance of 2cell-like cells. On the other hand, earlier studies have demonstrated that CAF-I is necessary for epigenetic conversions at the telomeres of S. cerevisiae. This commentary proposes that the absence of CAF-I confers totipotency of embryonic cells and that its activation triggers chromatin changes that reset the epigenome toward cell differentiation.
authors.affiliation: a Department of Molecular and Cellular Biology ; University of Guelph ; Guelph , Ontario , Canada.
authors.forename: Krassimir
authors.initials: K
authors.lastname: Yankulov
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism; D056504:Chromatin Assembly Factor-1 / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D044127:Epigenesis, Genetic; D051379:Mice; D018832:Molecular Chaperones / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D016615:Telomere / Q000378:metabolism; D039901:Totipotent Stem Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D002843:Chromatin; D056504:Chromatin Assembly Factor-1; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins
keywords: chromatin; chromatin Assembly Factor I; embryonic stem cells; epigenetic conversions; totipotent cells