Fig. 4. smoothened is expressed both maternally and zygotically. (A) Maternal smoothened mRNA present at four-cell stage. (B,C) smoothened mRNA present throughout the embryo at shield (B) and 60% epiboly (C). (D) smoothened expression was downregulated in the non-neural ectoderm at tailbud stage. (E,F) smoothened was expressed at higher levels in the head than the rest of the body at 18-somites (E) and 24 h (F). (G) By 2 d, smoothened expression in the head was confined to dorsal brain nuclei and jaw cartilages. (H,I) At 2 d, smoothened was also expressed in the pectoral fin of wild-type (H) and smub641 mutant (I) embryos. (A,B,D) Animal pole views. (B,D) Anterior is towards the top. (C,E-I) Side views, dorsal towards the top, anterior towards the left. Scale bar: 200 µm in A-E; 250 µm in F; 115 µm in G; 90 µm in H,I.
