Pax6+ cells start to detach during early corticogenesis with PC defects observed earlier in the Eml1 cKO mouse model. (A) Representative images of immunolabelling for Pax6 in WT and Eml1 cKO embryonic brain coronal sections from E12.5 to E15.5. (B and C) Quantifications of Pax6+ cell counts per region of interest (ROI of 200 µm width) and C proportion of detached Pax6+ cells above the VZ, expressed as mean ± SEM. (D) Quantifications of cortical wall thickness (CW), ventricular zone thickness (VZ), and the ratio of VZ/CW in percentage, represented as mean ± SEM. Analyses performed at least on three individuals from two different litters and two sections per individual for each genotype and age. (E) Representative images of immunolabeling for Arl13b at the ventricular surface at E12.5 for WT and Eml1 cKO. (F and G) Quantification of cilia mean size and number at E12.5, expressed as mean ± SEM. (H–J) Similar analyses performed at E15.5 with five individuals per genotype and age, analyzed from three different litters. Test and significance: Two-way ANOVA, Sidak’s multiple comparison (Pax6 analyses, CW and VZ thickness [data distribution was assumed to be normal but this was not formally tested]), Mann-Whitney (Arl13b analyses). P value <0.05 *, <0.01 **, <0.001 ***, <0.0001 ****. Scale bars (equivalent for WT and cKO): 30 µm in A, 20 µm in E and 10 µm in H.