Fig. 2

cyc mutant embryos are responsive to, but not rescued by, inhibition of PKA. cyc mutants injected with RNA encoding dnPKA–GFP fusion protein have dnPKA–GFP-containing cells in a fairly even but mosaic distribution (data not shown), as also seen in a wildtype background. (A) pax2 RNA in a 14-hpf cyc mutant embryo (dorsal view). (B) pax2 RNA in a 14-hpf cyc mutant embryo which was injected with dnPKA RNA (dorsal view). Although pax2 is expressed throughout the optic vesicle, the anterior– ventral fused morphology of the optic vesicle characteristic of cyc mutants is evident (arrows, and compare to Figs. 1C and 1D). (C) F-spondin RNA in a 30-hpf cyc mutant embryo (lateral view). F-spondin is absent from the ventral CNS (compare to Fig. 1E). The anterior F-spondin expression is in the lens and is also seen in wild-type embryos at this stage (data not shown). (D) F-spondin RNA in a 30-hpf cyc mutant embryo which was injected with dnPKA RNA (lateral view). Ectopic F-spondin is present in a pattern similar to that induced by dnPKA in wild-type embryos (compare to Fig. 1F). The cells in which F-spondin has been induced do not exhibit the characteristic morphology of the floor plate. Key: l, lens; ov, optic vesicle.