Fig. 5. Expression of Bmp4, noggin and Egfr genes in isolated mouse E12.5 dorsal spinal cord cultures following FGF2 treatment in the presence or absence of cyclopamine (1 µM). BMP4 expression is evident in both primary and FGF2-treated cultures. Noggin expression is downregulated upon FGF2 treatment, in contrast to the induction of EGFR.