A, Diagram of time-course experiment shown in B. B, Time-course experiment after synchronization of CyclinA2-enhanced green fluorescent protein (EGFP) mouse embryonic fibroblasts (MEFs). Cells were immunostained with antibodies to green fluorescent protein (GFP), Serine 28 phosphohistone 3 (S28pH3), and stained for 5-ethynyl-2′-deoxyuridine (EdU) and with DAPI. Scale bar: 100 μm. C, Fluorescence microscope images of CyclinA2-EGFP MEFs in mid G1 (a1–4), S (b1–4), metaphase (c1–4), and telophase (d1–4). Note cytosolic dispersion of CyclinA2-EGFP in metaphase (c2) and its disappearance in telophase (d2). Scale bar: 50 μm. D, Quantitative analysis of CyclinA2-EGFP or EdU-positive cells at each time point. E, Quantitative analysis of CyclinA2-EGFP/EdU double- or single-positive cells at each time point. F, Schematic diagram of CyclinA2-EGFP expression and EdU incorporation throughout cell cycle.