title: Selection and dynamics of embryonic stem cell integration into early mouse embryos.
abstract: The process by which pluripotent cells incorporate into host embryos is of interest to investigate cell potency and cell fate decisions. Previous studies suggest that only a minority of the embryonic stem cell (ESC) inoculum contributes to the adult chimaera. How incoming cells are chosen for integration or elimination remains unclear. By comparing a heterogeneous mix of undifferentiated and differentiating ESCs (serum/LIF) with more homogeneous undifferentiated culture (2i/LIF), we examine the role of cellular heterogeneity in this process. Time-lapse ex vivo imaging revealed a drastic elimination of serum/LIF ESCs during early development in comparison with 2i/LIF ESCs. Using a fluorescent reporter for naive pluripotency (Rex1-GFP), we established that the acutely eliminated serum/LIF ESCs had started to differentiate. The rejected cells were apparently killed by apoptosis. We conclude that a selection process exists by which unwanted differentiating cells are eliminated from the embryo. However, occasional Rex1(-) cells were able to integrate. Upregulation of Rex1 occurred in a proportion of these cells, reflecting the potential of the embryonic environment to expedite diversion from differentiation priming to enhance the developing embryonic epiblast.
authors.affiliation: Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 4BG, UK.
authors.forename: Stoyana
authors.initials: S
authors.lastname: Alexandrova
authors.affiliation: Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.
authors.forename: Tuzer
authors.initials: T
authors.lastname: Kalkan
authors.affiliation: Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Humphreys
authors.affiliation: Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Riddell
authors.affiliation: Division of Stem Cells and Cancer, Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer Feld 280, Heidelberg 69120, Germany Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Im Neuenheimer Feld 280, Heidelberg 69120, Germany.
authors.forename: Roberta
authors.initials: R
authors.lastname: Scognamiglio
authors.affiliation: Division of Stem Cells and Cancer, Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer Feld 280, Heidelberg 69120, Germany Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Im Neuenheimer Feld 280, Heidelberg 69120, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Trumpp
authors.affiliation: Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 4BG, UK jn270@cam.ac.uk.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nichols
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001755:Blastocyst / Q000166:cytology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D002678:Chimera / Q000235:genetics / Q000254:growth & development*; D004624:Embryo Transfer; D047108:Embryonic Development / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000166:cytology*; D051379:Mice; D008810:Mice, Inbred C57BL; D039904:Pluripotent Stem Cells / Q000166:cytology*; D059008:Time-Lapse Imaging; D014157:Transcription Factors / Q000378:metabolism
chemical_list: C513672:Zfp42 protein, mouse; D014157:Transcription Factors
keywords: Chimaera; Embryonic stem cell; Live imaging; Mouse blastocyst; Pluripotency