Fig. 4. fgf3 mutants fail to initiate the expression of early pituitary-specifying genes, whereas the hypothalamus develops normally. Probes used for in situ-hybridizations are indicated in the lower right corners. (A,C,E,G,I,K) wild-type siblings (wt). (B,D,F,H,J,L) fgf3 mutants (lia), with age of embryos indicated in the upper right corners. (A,B) Tailbud stage, animal views, dorsal to the right; embryos were genotyped after photography. (C-L) Lateral views on heads. Arrows in (C,E) indicate expression in anterior domain, arrowheads expression in lateral posterior domains of adenohypophyseal anlage [compare with Fig. 3M and Nica et al. (Nica et al., 2004)]. Arrowheads in (K) indicate the two adenohypophyseal pomc expression domains. anc, endorphin-synthesizing arcuate nuclei cells of hypothalamus; fe, facial ectoderm; adh, anterior-dorsal hypothalamus; i, isthmus; os, optic stalk; pvh, posterior-ventral hypothalamus.