Fig. 2

The mesoderm and neural ectoderm are Fgf sources required for postchordal neurocranial formation (A-E, A′-E′) 24 h post-fertilization confocal images of transplanted wildtype tissues into fgf3;fgf8 morpholino-injected hosts with and without DIC, respectively; (A′′-E′′) corresponding 4 days post-fertilization (dpf) neurocranial wholemounts with viscerocrania removed. Transplanted side of neurocrania is marked with a T, and control side with a C. (F and G) 4 dpf postchordal neurocrania of uninjected and fgf3;fgf8 morpholino injected,embryos respectively. Anterior is to the left. (A, A′ and A′′) Endoderm transplants, (B, B′ and B′′) otic placode transplants, (C, C′ and C′′) mesoderm only, (D, D′ and D′′) neural ectoderm only, and (E, E′ and E′′) mesoderm and neural ectoderm double-transplants. Endoderm and otic placode transplants fail to rescue the posterior neurocranium (compare A′′ and B′′ to F and G, n=0/12 for endoderm and n=0/9 for otic placode). Transplantation of mesoderm or neural ectoderm alone partially rescues the postchordal neurocranium (compare C′′ and D′′ to F and G, n=4/7 for mesoderm and n=8/16 for neural ectoderm). Transplantation of mesoderm and neural ectoderm together can fully rescue the postchordal neurocranium on the side of the embryo receiving the transplant (compare E′′ to F and G, n=4/12 for full rescue and n=4/12 for partial rescue). Quantification of partial or full rescue is shown in graph H. scale bars=100 µm in A-E and scale bar=20 µm in A′′.