Suppression of <i>Foxp1</i> inhibits neuronal migration.

<p>(A), E14.5 mouse embryos electroporated with a GFP expression plasmid along with shRNA-Scr, <i>Foxp1</i> shRNA-a or shRNA-b together with pCMV-mFoxp1 were allowed to develop until E17.5. Coronal sections (14 μm) of E17.5 brains were immunostained with an antibody against GFP (green). Nuclei were stained with DAPI (blue). Short black lines indicate the borders between CP, IZ, SVZ/VZ. Scale bar, 50μm. (B), Statistical analysis of the percentages of GFP-positive cells in the indicated regions of the cerebral cortex as showed in (A). *p<0.05, ***p<0.001, one-way ANOVA. (C), E14.5 mice receiving mir30-ScrRNA or mir30-shRNA-b were examined at E17.5. Scale bar, 50μm. (C)-a and (C)-b, Representative images of migrating neurons (Green) stained with FOXP1 antibody (Red) showed FOXP1 expression in control neurons but not in mir30-shRNA-b expressing neurons. (D), Statistical analysis of the percentages of electroporated cells in the indicated regions of the cerebral cortex as showed in (C). ***p<0.001, Student’s <i>t</i>-test. (E), GFP-pCAGGS was coelectroporated with pX330 or pX330-gFoxp1 into E14.5 mouse brains. Sections were examined at E17.5. Scale bar, 50μm. Immunostaining for FOXP1 (Red) indicated a lack of FOXP1 expression in pX330-gFoxp1 transfected neurons (E-b). Vector pX330 transfected neurons expressed FOXP1 in the CP normally (E-a). (F), Quantitative analysis of the distribution of electroporated cells in cortical layers as showed in (E). **p<0.01 and ***p<0.001, Student’s <i>t</i>-test.