Figure 3. DISC1 variants negatively impact neural progenitor proliferation and differentiation in vivo.

(A) DISC1 variants differentially rescue DISC1 shRNA-mediated inhibition of progenitor proliferation. Left, images of E16 embryonic mouse brain sections stained for Brdu and GFP after electroporation at E13 with the indicated constructs. Arrowheads indicate double positive cells (GFP+Brdu+). The scale bar represents 25 μm. Right, graph displaying quantification of the percentage of electroporated cells that were double positive for BrdU and GFP. *p<0.05, NS=not significant. Error bars represent mean ± standard error of the mean (SEM). (B) DISC1 variants have different abilities to rescue increased cell cycle exit due to DISC1 loss of function. Expression of DISC1 variants leads to increased premature cell cycle exit. E13 mouse brains were electroporated with constructs expressing DISC1 variants, BrdU (100 mg/kg) was administered at E15 and analyzed 24 hours later at E16. Left, confocal images of brain sections stained for GFP, Ki67 and BrdU. Arrowheads indicate GFP+BrdU+Ki67+ cells while arrows indicate GFP+BrdU+Ki67–cells. Right, graph showing quantification of the cell cycle exit index (n=3, ^#,*p<0.05, ns=not significant, mean ± SEM). The scale bar represents 25 μm. (C) DISC1 variants display different abilities to cause premature neural differentiation. Left, confocal images of E16 brain sections stained for Tuj1 after electroporation. Right, quantification of the percentage of GFP-Tuj1 double positive cells relative to total GFP positive cells is shown as a bar graph. (n=3 for each experiment, *p<0.05, ns=not significant, mean ± SEM). The scale bar represents 25 μm. See also Figure S2.