Figure 5. G1 phase progression in human ES cells is independent of exogenous FGF2.
(A) Experimental design. (B) Mitotically synchronized WA09/H9 cells were generated in standard hES medium (Medium 1) on a feeder layer of inactivated mouse embryo fibroblasts (MEFs) by mitotic inhibition using nocodazole for 16 h. Cells were then released from mitotic block and allowed to reenter the cell cycle in the presence of fresh complete DMEM/F12 medium (Medium 1) (first row), the same medium but without bFGF/FGF2 (Medium 2) (second row), or incomplete DMEM/F12 medium (Media 3) (third row). Cell cycle progression was examined at the indicated hourly time points after release (columns) by monitoring BrdU incorporation (scale bar = 200 μm).