d, Seckel organoids electroporated with constructs expressing GFP alone (i), GFP with CC5-GFP and (ii) GFP with CPAP-GFP (iii). Middle panel shows staining with anti-GFP antibodies (red) to show the transfected area. Note the presence of increased Pax6-positive (magenta) NPCs in CC5 and CPAP electroporated tissues compared to GFP control. Likewise, there is a larger neural epithelium with multiple RGs (arrowheads). Bar diagrams at right shows rescue effects of CPAP and CC5 electroporation compared with GFP alone (iv) lower TUJ1/Pax6 ratio (**p<0.01 and ***p<0.001 respectively) (v) smaller lumen diameter (**p<0.01) and (vi) shorter cilia length (**p<0.01 and ***p<0.001 respectively). Error bars are s. e. m. One-way ANOVA followed by Dunnett's multiple comparisons test. n = 3 organoids with 225 cells for GFP, 537 cells for CPAP and 569 for CC5. At least 10 ventricles from 3 independent organoids were used to measure the CPAP diameter. t test. Error bars are s.e.m. Scale bar 20 μm.e, Rescue effect of CC5 and CPAPelectroporation on cleavage planes of phospho-vimentin-positive RGs in Seckel organoids. Compared to GFP control, electroporation of CC5 or GFP increases the proportion of horizontally orientated SeckelRGs (for CC5 ***p<0.001) and decreases the portion of obliquely (for CC5 *p<0.05) or vertically oriented SeckelGFP (for CPAP and CC5 **p<0.01). Error bars are s.e.m. Two-way ANOVA followed by Tukey's multiple comparisons test. n = 4 organoids. 100 cells for GFP control, 112 cells for CPAP and 99 cells for CC5. 