Fig. 8. Fgf8 and chordin interact genetically. (A-D) Expansion of the ventral mesoderm (arrowheads) in embryos injected with chordin morpholino (mo-chd) (C) is enhanced by co-injection of mo-fgf8 (D) when compared with injection of mo-fgf alone (B) or with wild type (A). (E-H) Injection of mo-fgf8 causes a reduction of head size in chordino (din) mutant embryos. mo-fgf8 injection leads to loss of the cerebellum (arrowheads). (I-L) ace/fgf8 mutation enhances the expansion of the ventral hematopoietic mesoderm induced by mo-chd injection. (I,K) Loss of en3 expression (arrowheads) identifies ace homozygous mutants (K). (J,L) Expression of hemoglobin (hem) (arrows) after injection of mo-chd in heterozygous ace^+/– embryo (J) and in homozygous ace^–/– mutant (L). (M,N) Injection of mo-fgf8 does not affect cyp26a expression (N) compared with wild type (M). (O,P) The reduction of neural cyp26a expression caused by mo-chd (O) is further enhanced by co-injection of mo-fgf8 (P). (Q,R) Injection of mo-fgf8 does not affect drl expression (R) compared with wild type (Q). (S,T) The dorsal expansion of the expression of ventral mesodermal marker draculin (drl) caused by mo-chd (S) is further enhanced by co-injection of mo-fgf8 (T). Arrowheads in S,T indicate the dorsal limit of the drl expression domain. (A-E,G,I-L) Lateral views, anterior towards the left. (F,H) Frontal views, dorsal towards the top. (M-P) Dorsal views, anterior upwards. (Q-T) Optical sections through the margin, dorsal towards the right. (A-L) 30 hpf, (M-T) 75% epiboly.