Fig. 5. Floorplate differentiation fails in mol^-/- but not in smu^-/- embryos. Lateral (A-I) and dorsal (J-O) views of the trunk floorplate in 36 hpf (A-I) and 24 hpf (J-O) wild-type, mol^-/- and smu^-/- embryos. (A-O) Expression of floorplate differentiation markers col2a1, min1, min2, arx and ctgf is similar in wild-type and smu^-/- embryos but expression is severely reduced or absent in the mol^-/- embryos (despite the presence of floorplate cells, arrowhead in B). Although floorplate expression is retained, the somitic expression of arx and ctgf is lost in the smu^-/- mutants (L,O). fp, floorplate; hy, hypochord; nc, notochord.