CPEB1 mRNA is expressed in the Xenopus embryonic retina. (A) RT-PCR shows that CPEB1 is expressed in stage 35/36 and stage 41 eyes and that the level of expression is higher at stage 41. (B, C) Wholemount in situ hybridization on stage 35/36 (B) and stage 41 (C) embryos shows that CPEB1 is weakly expressed in the eyes, as well as the nasal placode and brain, and in a segmented pattern in the dorsal spinal cord. The sense probe gives no signal. AS, antisense; np, nasal placode; S, sense; sc, spinal cord. (D) Section of stage 41 eye before (D) and after (D') laser capture microdissection of the retinal ganglion cell layer. Abbreviations: inl, inner nuclear layer; le, lens; onl, outer nuclear layer; rgc, retinal ganglion cell layer; rpe, retinal pigment epithelium. (E) RT-PCR on RNA from the retinal ganglion cell layer isolated by laser capture microdissection shows that CPEB1 is expressed in retinal ganglion cells. (F) CPEB2–4 are also expressed in embryonic eyes and brains by RT-PCR.