In Vivo Fate Analysis Reveals the Multipotent and Self-Renewal Features of Embryonic AspM Expressing Cells
Figure 6
The selective killing of E12.7/E13.2 AspM+ cells altered the forebrain cortical organization.
Panels A, G show low magnification of E18.5 coronal sections from a control –i.e. embryos lacking the Nestin-GFPflox-TK allele (A) and AspM-CreERT2/Nestin-GFPflox-TK (G) forebrains both treated with Tam and GCV (n = 3 for each group). Asterisks indicate the VZ/SVZ regions assayed for Tbr2 and TuJ1 detection. Control mice displayed a distinct layer of Tbr2+ BP cells that was clustered in the outer VZ (B). In contrast, double transgenic mice treated with GCV displayed a severe reduction of these cells (H). Double transgenic mice show a preserved cortical layer organization, although upper layers appeared thinner than normal. Coronal sections from control (C) and double transgenic (D) brains stained with Foxp2, which label deep layer neurons, show the preservation of deep cortical layer. Cells were count at three different levels along the anterior-posterior axes and the mean number of FoxP2+ cells (± S.D.) is plotted on panel E. Sections were also stained for Ctip2 (layer V) and Cux1 (layer II–IV) in control (I) and double transgenic (J) brains. Cell counts are provided in panels F and K, and show a significant reduction of upper cortical neurons in AspM-CreERT2/Nestin-GFPflox-TK mice. VS, ventricular surface, Iz intermediate zone, PS pial surface. * p<0.05, ** p<0.01, *** p<0.001, t-student. Scale bar 100 µm.