Cul4B and β-catenin accumulated in the same NPCs in vivo in mouse and human brains. A. Using the nestin-GFP mice, the subventricular zone (SVZ) and subgranular zone (SGZ) NPCs were identified by immunostaining with the mouse anti-GFP antibody. Cul4B-positive NPCs strongly expressed β-catenin. x20 objective; scale bar, 15 μm. B. Cul4B-expressing NPCs had the mitotic epitope as shown by the MPM-2 antibody-staining. x40 objective; scale bar, 5 μm. C. In normal human brains, Cul4B-positive cells accumulated β-catenin in both SGZ and SVZ, but cyclin E was only increased in SGZ in Cul4B-positive cells. D. TUNEL staining showed that Cul4B-positive cells did not have fragmented DNA although some other cells did have. x20 objective in C and D; Blue, DAPI counterstain; scale bar, 10 μm. SGZs are labeled with a bracket and a more compact layer of granule cells are visible for orientation. V, ventricle.