Cytoplasmic polyadenylation is required for growth cone collapse. (A) Typical examples of collapsed and non-collapsed growth cones. (B) Cordycepin (200 μM; 3'deoxyadenosine; Cordy), but not adenosine (Adeno), blocks Sema3A-induced growth cone collapse. (C) Cordycepin does not affect lysophosphatidic acid (LPA)-induced growth cone collapse. (D, E) Similar results are obtained as in (B, C) if axons are severed from their cell bodies. (F, G) Anti-puromycin western blots on stage 35/36 retinal cultures incubated for 15 minutes with 2 μM puromycin and 50 μM LnLL (F) or 0.5 μM puromycin (G), ± 2 μg/ml Sema3A-Fc, ± 40 μM anisomycin (aniso), ± 200 μM cordycepin or adenosine. Cordycepin slightly reduces, but does not abolish, Sema3A-induced translation (G); see text for details. The two separate sections in (F) are from the same blot with the same film exposure and contrast settings. (H) Cordycepin does not block basal translation in A6 fibroblasts, while cycloheximide (CHX) does. Numbers in bars indicate number of growth cones counted. *p < 0.05, **p < 0.01, ***p < 0.001. Error bars represent standard error of the mean.