Wnt3a promotes disorganization of RG and IP distribution. Characterization of E18.5 brains electroporated at E13.5 by immunolabeling for progenitor markers. A–P, Immunolabeling for Pax6, Tbr2, and the active cell cycle marker Ki67 to show the distribution and cell cycle state of progenitors. C, D, K, L, Arrows indicate examples of scattered progenitors, and arrowheads indicate examples of progenitors in rosette formations. Higher-magnification pictures in E–H and M–P correspond to boxed areas in A–D and I–L and illustrate colocalization of Ki67 with Pax6 and Tbr2. cp, Cortical plate; ht, heterotopias; hc, hippocampus. Scale bars: A, 200 μm; E, 100 μm.