title: Dynamic single-cell imaging of direct reprogramming reveals an early specifying event.
abstract: The study of induced pluripotency often relies on experimental approaches that average measurements across a large population of cells, the majority of which do not become pluripotent. Here we used high-resolution, time-lapse imaging to trace the reprogramming process over 2 weeks from single mouse embryonic fibroblasts (MEFs) to pluripotency factor-positive colonies. This enabled us to calculate a normalized cell-of-origin reprogramming efficiency that takes into account only the initial MEFs that respond to form reprogrammed colonies rather than the larger number of final colonies. Furthermore, this retrospective analysis revealed that successfully reprogramming cells undergo a rapid shift in their proliferative rate that coincides with a reduction in cellular area. This event occurs as early as the first cell division and with similar kinetics in all cells that form induced pluripotent stem (iPS) cell colonies. These data contribute to the theoretical modeling of reprogramming and suggest that certain parts of the reprogramming process follow defined rather than stochastic steps.
authors.affiliation: Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.
authors.forename: Zachary D
authors.initials: ZD
authors.lastname: Smith
authors.forename: Iftach
authors.initials: I
authors.lastname: Nachman
authors.forename: Aviv
authors.initials: A
authors.lastname: Regev
authors.forename: Alexander
authors.initials: A
authors.lastname: Meissner
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D065150:Cellular Reprogramming / Q000502:physiology*; D053595:Embryonic Stem Cells; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D055785:Gene Knockdown Techniques; D007150:Immunohistochemistry; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods*; D008954:Models, Biological; D010781:Photography / Q000379:methods*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53