Selected phenotypes of Tbr2
cKO cortex (right panels) compared with normal controls (left panels). (A) On E14.5, non‐surface mitoses (red) are increased in Tbr2
cKO cortex, and occur ectopically in the IZ and CP. The IPs express Pax6 and Insm1 at higher levels than normal, especially outside the VZ. (B) In postnatal Tbr2
cKO cortex, layers 2–4 (blue) are thinner than normal, and layer 5 (green) is thicker than normal. Layer 6 is near normal size. (C) Area patterning is caudalized (yellow) with decreased rostral identity (blue) in Tbr2
cKO cortex. The cortex also has a slightly reduced surface area, and the olfactory bulb (OB) is very small.