Fig. 9. Temporal sensitivity to cyclopamine. Embryos were treated with 6.0 µg/ml cyclopamine beginning at the indicated times and allowed to develop in the presence of cyclopamine until 60 hpf when they were scored for DRG phenotypes. The X-axis indicates somite level; 1 is the most rostral somite, 33 is the most caudal somite, and the Y-axis shows the percentage of embryos with `normal DRG'. DRG were scored in at least 20 embryos for each treatment.