(a) Effect of FGF-2 on colony area in mouse bone marrow cultures from Fgf2^+/+ and Fgf2^–/– mice. Cells were plated at a density of 1 million cells per well in αMEM containing penicillin/streptomycin and 10% heat inactivated FCS in the absence or presence of FGF-2 (10 nM). On day 3, media were changed and cells were cultured in differentiation media (αMEM, 10 nM dexamethasone, 10% FCS, 8 mM β-glycerophosphate, 50 μg/mL ascorbic acid) for an additional 11 days. ^ASignificantly different from control cultures; P < 0.05. ^BSignificantly different from Fgf2^+/+; P < 0.05. (b) Comparison of the ability to form ALP colonies and mineralized nodules as determined by von Kossa staining in mouse bone marrow cultures from Fgf2^+/+ and Fgf2^–/– mice. Cells were plated at a density of 20 million cells per well in αMEM containing penicillin/streptomycin and 10% heat inactivated FCS. On day 3, media were changed and cells were cultured in differentiation media (αMEM, 10 nM dexamethasone, 10% FCS, 8 mM β-glycerophosphate, 50 μg/mL ascorbic acid) for the indicated times.