Figure 4

Targets of AKT activity are expressed in dividing radial glia during cortical development. Immunohistofluorescence staining of cortical sections at embryonic day 12.5 reveals AKT activity as assessed by targets of AKT phospho-β-catenin [S552] and phosphor-GSK3β [S9] in the ventricular zone (VZ). (A) Phospho-beta-catenin-Ser 552 (pseudocolored red) is expressed in dividing radial glial cortical precursors identified by the expression of phosphorylated vimentin 4A4 (P-vim, pseudocolored green) located at the apical (lumenal) surface of the VZ. (B) Phospho-GSK3beta-Ser 9 (pseudocolored red) is expressed in dividing radial glial cortical precursors expressing phosphorylated vimentin 4A4 (P-vim, pseudocolored green) at the apical ventricular surface. Scale bar = 20 µm. 74.3±5.9% (1 SEM) of P-Vim expressing cells were also expressing P-β-catenin (n = 3 brains), and 82.5±3.6% (1 SEM) of P-Vim-expressing cells were also P-GSK3β positive (n = 3 brains).