Fig. 6. Expression patterns of Shh signalling molecules in the Pax6 mutant hindbrain. Adjacent sections of E12.5 wild-type (A-F) and Pax6 mutant (G-L) hindbrains at r7 level. In the Pax6 mutant hindbrain, Shh expression in the floor plate is no different from the wild-type (A,G). (B-F) In the wild type, Ptc1 is expressed in all ventral progenitor cells with a ventral-to-dorsal gradient, and is especially strong in the SM progenitor domain (bracket in C). Ventral limits of Gli1 and Gli2 expression domains are adjacent to the dorsal limit of Nkx2.2 domain (black arrowhead in B,D,E). The expression is missing in the BM progenitor cells expressing Nkx2.2, while it is detected at a high level in the SM progenitor cells (bracket in D,E). The dorsal limits of Gli1 and Gli2 expression domains correspond to that of Dbx1 domain (red arrowhead in D-F). (H-L) In the Pax6 mutant, strong Ptc1 expression in the ventral region was not seen. Gli1 and Gli2 was expressed in the region between dorsal limits of Nkx2.2 and Dbx1 (green and red arrowheads, respectively, in Fig. 6H,J-L).
