Fig. 4
Fig. 4 Floorplate develops in mol-/- embryos independently of Hh activity. Lateral views (A,B), dorsal views (C-H) and transverse sections (I-R) of wild-type (A,C,E,G,I,K,M,O,Q) and mol-/- (B,D,F,H,J,L,N,P,R) embryos with (A,B,D,G,H) and without (C,E,F,I-R) cyclopamine treatment. (A,B) Both the wild-type and the mol-/- embryo treated with cyclopamine have cuboidally shaped floorplate cells (arrowhead) at 20 hpf. (C,D) Clutches of embryos from parents heterozygous for the moltv53a mutation. Treatment with cyclopamine between the 4-hour and 2-somite stages did not appear to affect expression of twhh in either wild-type or mol-/- mutants. (E-H) Wild-type and mol-/- embryos showing patchy ntn1 expression after treatment with cyclopamine. (I-R) Transverse sections through the spinal cord of wild-type and mol-/- embryos showing changes in floorplate expression of various genes in the mutants. cpm, cyclopamine.