The FGF effects on the neurogenesis of ES cells and the FGFR expressions in ES cells. (A) After treatment with FGF1, FGF2, FGF4, and FGF8b from day 1 to day 3 using the SFEB method, the numbers of 46C ES-derived Sox1-GFP+ cells were estimated by flow cytometry on day 6 (n = 3 for each panel). (B) On indicated days, FGFRs in 46C ES cells were analyzed by RT-PCR. (C) Expression of FGFRs and the GFP+ ES cells was analyzed by immunostaining on day 6 or day 2. Single GFP positive cells were indicated by arrow. Nuclei of all cells are revealed by DAPI staining in blue. Scale bar, 10 μm in C. *, p < 0.01, Anova test.