Figure 5.

Lack of Shh signaling in the zebrafish cerebellum. In lateral view, neither Shha (a), Shhb (b), nor Ptc1 (c) are expressed in the cerebellum at 3 d development or at any stage through to 8 d (data not shown). In transverse section, Shha (d) is expressed at the ventral midline (vml) of the hindbrain. Ptc1 (e) is expressed in both the ventral midline and surrounding ventral tissue but not in the cerebellum (cb). Dorsal view at 8 d shows Gdf7 (f) expressed in the valvulus (va). Double in situ hybridization (g) shows that Gdf7 (blue) and Atoh1a (red) domains abut. In the CNS, Gdf6a (h) and Atoh1c (i) are expressed in the same spatial domain comprising the upper rhombic lib (url) and cerebellar midline. They are also coexpressed within a subset of anterior lateral line neuromasts (arrows).