Low levels of stabilized β-catenin induce reprograming of NS cells through spontaneous cell fusion. (A): Quantification of FACS analysis (% total double-labeled cells) and representative growth plates with quantification of reprograming efficiency (fold-increase in colony number) of the cocultured cells (mean ± SEM; n = 3), for wild-type ESCs (E14), ES-β-catenin clones (E1, α-8, C2) with NS-Oct4-puro cells (mean ± SEM; n = 3). (B): 1 × 104 sorted cell fusion hybrids between wild-type ESCs, ES-β-catenin clones (E1, α-8, C2) with NS-Oct4-puro cells were plated and apoptosis was evaluated using Cell Death Detection Elisa kits 48 hours after sorting (mean ± SEM; n = 3). Fold changes were calculated with respect to wild-type ESC × neural stem cell hybrids. Abbreviations: ES, embryonic stem; FACS, fluorescence activated cell sorting; FITC, fluorescein isothiocyanate.