Figure 2

FGF and LIF stimulate separate populations of colony forming neural stem cells at distinct times in anterior neurectoderm development. (A) Clonal cell cultures derived from ex vivo cultured tissue dissected at either 7.5 or 8.5 dpc and maintained in serum-free media in the absence of growth factors, or in the presence of either LIF or FGF2 + heparin (H). The number of colonies derived after 14 days in vitro was quantified (n = 3; 4 wells/n; asterisks denote statistical significance from stage specific control, P < 0.05) (B) Quantification of FGF responsive colonies in the presence of FGF2, FGF8b or FGF4 and compared to Wnt3a (three separate experiments; n = 2 to 3 embryos for each treatment group; four replicates per culture condition per treatment in each experiment; asterisks denote statistical significance from FGF2 + H control, P < 0.05). (C) Anterior neural plate cultures derived from embryos injected with either PBS or FGF8b at 7.0 dpc and cultured until 8.5 dpc. The number of FGF responsive colonies was quantified after 14 days in vitro (four separate experiments; n = 2 to 3 embryos for each treatment group; four replicates per culture condition per treatment in each experiment; asterisks denote a statistical significance from PBS injection control, P < 0.05). S.d., standard deviation.