Fig. 6. Pitx3 is required for pitx3 expression at bud stage, and Dlx3b and Dlx4b restrict pituitary pre-placode size during mid-somitogenesis. (A-I) Control and morpholino injected embryos, labeled with pitx3 probe at bud stage (tb, A-C), 18-somite stage (D-F) and prim-5 stage (24 h; G-I). (B,E,H) pitx3 morpholino injection leads to reduced pitx3 expression in placodal field (B; n=23/30), in pituitary pre-placode (E; n=33/46) and in pituitary placode (H; n=43/68). (C,F,I) Injection of dlx3b and dlx4b morpholinos leads to reduction of pitx3 expression in prospective lens precursors (arrowheads in C; n=29/38), and an expansion of the pituitary pre-placode (F, white bar; n=23/30) and pituitary placode size (I; n=32/40; arrowheads: ectopic pitx3 expression). (A-C) Dorsal view, ventral towards the top. (D-I) Frontal view, dorsal towards the top. Scale bar: 100 µm.