Fig. 6. Dll1 deletion in a large number of NPCs in the developing mouse telencephalon induces premature neurogenesis. The Dll1 gene was ablated in the majority of NPCs by crossing Dll1 floxed with nestin-Cre mice. (A-Z) Immunoreactivity was compared between Dll1-intact mice (control, these mice were littermates of Dll1 conditional KO mice of genotype Dll1^flox/flox or Dll1^flox/wt without Cre) (A,C,E,E',G,I,K,M,O,Q,S,U,W,Y) and Dll1 conditional KO (cKO) mice (genotype was Dll1^flox/flox with nestin-Cre) (B,D,F,F',H,J,L,N,P,R,T,V,X,Z). Brain sections from each mouse at E11.5 (A-H,E',F',K,L,O,P,S,T,W,X) or E13.5 (I,J,M,N,Q,R,U,V,Y,Z) were immunostained with anti-Dll1 (A-D), anti-active Notch1 (actN1) (E-F'), anti-β III-tubulin (TuJ1) (G-J), anti-Sox2 (K-N), anti-BrdU (O-R), anti-phosphorylated histone H3 (pH3) (S-V) or anti-Tbr2 (W-Z). TO-PRO-3 was used for nuclear staining (E',F',O-Z). Dorsal side is up in all panels. NCX, neocortex; GE, ganglionic eminence. Scale bars: 100 µm.