Fig. 2. Cell proliferation, apoptosis and differentiation in the Shh^N/- telencephalon. (A-F) TUNEL analysis of sections from E11.5 wild-type (A-C) and Shh^N/- (D-F) mouse embryos at the level of ventral (A,D), dorsal (B,E) and dorsal midline (C,F). (G) Bar chart showing that there are more apoptotic cells in ventral and dorsal regions of the Shh^N/- telencephalon (D,E, arrows). The number of apoptotic cells in the dorsal midline is comparable between Shh^N/- and control (C,F, arrowheads). (H-M) Coronal sections of E11.5 control (H-J) and Shh^N/- (K-M) telencephalon labeled with BrdU antibody. (N) Bar chart showing that there is a statistically significant increase in the percentage of BrdU-positive cells in ventral (v), dorsal (d) and dorsal midline (dm) of Shh^N/- telencephalic neuroepithelium as compared with controls. (O-X) Immunofluorescence of E11.5 control (O-S) and Shh^N/- (T-X) telencephalic sections labeled with Tuj (O-Q,T-V) and Isl1 (R,S,W,X) antibodies to highlight neuronal differentiation. Note that differentiation in the ventral region is visibly reduced in Shh^N/- neuroepithelium (compare O,R,S with T,W,X). v, Mash1⁺ ventral region; d, Pax6⁺ dorsal region; dm, dorsal midline.