Fig. 5. pitx3 is required for pituitary placode formation, whereas dlx3b and dlx4b control pituitary placode size. Wild-type (A-C) and morpholino (MO)-injected (D-L) embryos labeled with probes for lim3 (A,D,G,J), nkx2.2 (B,E,H,K) and pomc (C,F,I,L). (D-F) Injection of pitx3 morpholinos (n=94) leads to loss of pituitary placode (20/94 embryos) or severe reduction in pituitary cell number (D, inset; n=69/94). (G-I) Injection of dlx3b and dlx4b morpholinos (n=103) leads to enlarged pituitary placodes and increased pituitary cell numbers (n=78/103), arrowheads in B,E,H. (J-L) Injection of pitx3, dlx3b and dlx4b morpholinos (n=83) leads to loss of pituitary placode (42/83 embryos) or severe reduction in pituitary cell number (n=25/83). (A,C,D,F,G,I,J,L) Frontal views, dorsal towards the top; (B,E,H,K) side views, anterior towards the left. Scale bars: 100 µm in A-L; 25 µm in D, inset.