Extended Data Fig. 8: Resilience of cells transfected at different stages of the cell cycle.

A: Cell cycle progression was followed by FACS analysis at the indicated times after the BrdU pulse (t0) in JEFF lymphoblasts non-transfected (Nt) or transfected with the indicated siRNAs. Fractions of the cells in each phase of the cell cycle were quantified (percentages indicated in red polygons of each panel); unlabelled (G1, S, G2) and BrdU labelled (G1b, Sb, G2b). The nomenclature is the same for all panels. B: Nt cells that were in G1 at the time of BrdU pulse (G1) exit this phase, enter unlabelled in S-phase (S) and are back in G1 by 16 h with kinetics fully compatible with the known parameters of JEFF cell cycle (G1: 6 h; S: 8 h; G2M: 2 h). In striking contrast, cells transfected in G1 exit this phase and enter S-phase extremely slowly. By 24 h post-transfection, only a small fraction of them have progressed to S. C, D: Non-transfected cells that were G2M (G2/M) (C) or in S (Sb) (D) at the time of BrdU pulse progress as expected in the cycle. Cells transfected G2/M or in S-phase exited these phases with a 6-h delay. This delay is still visible when cells transfected in S-phase progress in G2M (labelled G2/M) and then in G1 (labelled G1). Experiments were done once.