Fig. 7

Loss of has2 in Fgf knockdown embryos contributes to the postchordal neurocranial loss phenotype. (A-D, A′-D′) Images of 10 h post-fertilization, and (E-F) 24 h post-fertilization embryos labeled with has2 riboprobe. Dorsal view and anterior to the left in all images. (G-J) Wholemounted zebrafish neurocrania with the viscerocrania removed at 5 days post fertilization. Anterior is to the left. (A′-D′) Magnified areas of region outlined in (A-D). (A and A′) Uninjected wildtype, (B and B′) fgf8a mutants, and (C and C′) fgf3 morpholino-injected wildtype display normal expression of has2, however, (D and D′) fgf3 morpholino-injected fgf8a mutants exhibit loss of expression of has2 in the presumptive postchordal neurocrania (D and D′). (E) At 24 hpf, some has2 expression remains along the notochord, however, (F) expression is lost in fgf8a;fgf3 double mutant embryos. Arrowheads denote end of the notochord. (G) Control morpholino-injected wildtype and (H) fgf8a mutants, as well as (I) has2 morpholino-injected wildtypes retain the postchordal neurocranium. However, (J) has2 morpholino-injected fgf8a mutants have a substantial loss of the postchordal neurocranium (arrowheads). n=notochord. scale bar=50 µm in A, 10 µm in A′ and E, and 20 µm in G.