Fig. 6. Expression of Tag1 in the cortex and the distribution of GFP⁺ neurons. Coronal sections of an E13.5 (A) or E15.5 (B) mouse cortex were immunostained for Tag1 (red). Only a small fraction of GFP⁺ cells migrate in the region where Tag1 immunoreactivity can be observed. (C) High-magnification view of the area shown by a rectangle in B. Arrows indicate radially oriented Tag1⁺ fibers. Note while the fibers are strictly oriented radially (see Fig. 6A also) in the cortical plate, only a fraction of GFP⁺ neurons are. Scale bar: 50 µm.