(A–Q): expression of bmp-antagonists nog2, chrd, fsta and grem2b in the ANP at 11 and 12 hpf. (A–D): ISH for nog2. (A,B): 11 hpf; (C,D): 12 hpf. (E–H): ISH for chrd. (E,F): 11 hpf; (G,H): 12 hpf. (I–M): ISH for fsta. (I,K): 11 hpf; (L,M): 12 hpf. (N–Q): ISH for grem2b. (N,O): 11 hpf; (P,Q): 12 hpf. (A,C,E,G,I,L,N,P): dorsal view. (B,D,F,H,K,M,O,Q): lateral view. Scalebars indicate 200 µm. (R): summary of experimental procedure. (S–Bb): Embryos were heat shocked at 8.5 hpf and observed at 24 hpf or 48 hpf, resp. (S,T): bright-field image of wildtype at 48 hpf. (U,V): bmp4-induced larva at 48 hpf. (S,U): dorsal view. (T,V): lateral view. Scalebars indicate 250 µm. (W,X): transversal confocal sections of larvae with rx2:GFP at 24 hpf. injection of LY-tdTomato mRNA in zygote. (W): wildtype. (X): bmp4-induced, scalebars indicate 50 µm. (Y–Bb): ISH for rx2 at 24 hpf. (Y,Z): wildtype. (Aa,Bb): bmp4-induced. (Y,Aa): dorsal view; (Z,Bb): lateral view. Scalebars indicate 250 µm.