Fig. 6. Overexpression of Shh in utero leads to expansion of CP and SVZ/VZ. pCIG-Shh expression vector was electroporated into the dorsal pallium in utero at E12.5. At E18.5, EGFP was detected mostly in CP on the electroporated side (A). Note that the dorsal pallium was expanded in a planar direction on the electroporated side (brackets in B). Ki67-positive proliferating cells in SVZ/VZ were greatly increased so that SVZ/VZ was almost twice the thickness as on the control side (bracket in C,C'). In situ hybridization on coronal sections of E18.5 dorsal pallium with Wnt7b (D,D') and Tbr1 probes (E,E'). On the electroporated side, the non-expression regions in SVZ/VZ were expanded compared with the control side (bracket in D-E'). TBR2-positive progenitors were greatly increased in the SVZ on the electroporated side (F,F') and their distribution was disturbed (arrows in F'). Scale bar: 100 µm in B; 50 µm in C-F'.