Figure 12

Expression of Gli1 , Ptc , Olig2 , Islet1 , and Mash1 in the forebrain of control and mutant embryos at embryonic day (E)13.5. (A-D) In situ hybridisation for Gli1 (A, C) and Ptc (B, D) transcripts (dark staining) in control (A, B) and mutant (C, D) presented as greyscale images. Gli1 and Ptc are expressed at similarly low levels in the cerebral cortex (cc) of control embryos and mutant embryos. Both transcripts are expressed at similarly high levels in the thalamus (t) of control and mutant embryos. The ubiquitous pale staining is non-specific background. (E-J) Immunohistochemistry for Olig2 (E, H), Islet1 (F, I), and Mash1 (G, J) proteins (brown) in control (E-G) and mutant forebrain (H-J) at E13.5. In both control and mutant embryos, Olig2, Islet1, and Mash1 are strongly expressed in ventral telencephalic (vtel) domains but not in the cerebral cortex. All images to same scale, bar in (J) 200 μm.