Fig. 5. Bmps are required for roof plate development and induction of c1 and RLS cells in vitro. (A-E) Isolation and culturing of e8.5 mid-hindbrain dorsal (d) neural fold explants. Addition of noggin and follistatin (N+F) decreased induction of Lmx1a (B-D) and Gdf7, as measured by RT-PCR (E). (D) Quantification of numbers of Lmx1a⁺ cells in dorsal explants cultured with and without Bmp inhibitors. (F-N) Examples of wild-type E8.75-E9.0 intermediate neural tube explants (int) at the level of r1, cultured with and without chick r1 roof plate (r.p.). Addition of noggin and follistatin (N+F) reduces induction of c1 and RLS cells. Intermediate explants and roof plate are labeled and demarked by the broken line. (J,N) Quantification of numbers of Math1⁺ (J) and Lhx2/9⁺ (N) cells appeared in wild-type intermediate explants. Blue, intermediate explants cultured alone (int). Red, intermediate explants cultured with chick roof plate (int+rp). Green, intermediate explants cultured with chick roof plate together with noggin and follistatin (int+rp+N+F). ^* indicates P<0.01. Bars indicate s.e.m.