Figure 1.
Effects of FGFs on [3H]thymidine incorporation by embryonic hippocampal NPCs. (A) FGF-1, FGF-2, FGF-4 to FGF-7 (20 ng/ml each) were added to cells. Although FGF-1 showed some incorporation, FGF-2 and FGF-4 had the highest effects. The values for FGF-5 to -7 were not different from that of control (no FGF). (B) Dose-dependent effects of FGF-4 on NPCs showed a proliferative effect at or above 10 ng/ml. FGF-2 (20 ng/ml) was included as an internal control. (C) Additive effects of FGF-2, FGF-4, and FGF-5. Combination of FGF-2 and FGF-4 did not increase the thymidine incorporation by the cells. Combination of FGF-2 and FGF-5 showed the proliferative effects of FGF-2. (D) Sequence identity between FGFs in the 10-aa region. The common amino acids between all the FGFs are boxed (solid lines). The amino acids not common between FGF-2 and FGF-4 are boxed in broken lines. FGF-2–2 represents the sequence of second receptor binding site of FGF-2.