Fig. 3.

Actin is required for centriole stability in mature ependymal cells. a F-actin (phalloidin, grey) and centrioles (FOP, red) in mature ependymal cells from explants treated with DMSO or 1 or 2 μM cytochalasin-D (CytoD) for 12 or 40 h showing concentration- and time-dependent actin impairment; cell borders and centriolar patches are outlined with dashed white and red lines, respectively. b Representative 200 ms kymographs of motile cilia in brain slices treated for 40 h with DMSO or 2 μM cytochalasin-D. The graph displays the ciliary beating frequency (Hz) that was not affected by the drug. Error bars represent the sem of n = 48 cells for DMSO- and CytoD-treated explants, from three independent experiments; P-values were determined with the Mann-Whitney test; ns, P > 0.05. c Representative images of Centrin2-GFP⁺ centriolar patches in mature ependymal cells treated with DMSO or 1 or 2μM cytochalasin-D for 12 to 40 h. d Representative quantification of the number of centrioles per cell in lateral wall explant at P15 with contralateral brain of the same animal treated with DMSO or cytochalasin-D at 1 μM for 40 h. Error bars represent the sem of n = 301 cells for DMSO- and n = 93 for CytoD-treated explants, from one representative animal out of 6; P-values were determined with the Mann–Whitney test; ***P ≤ 0.0001. e–f Fold change in centriole number relative to DMSO-treated contralateral brain in lateral ventricles treated with 1 or 2 μM cytochalasin-D for 6 up to 40 h. A time- (e) and dose- (f) dependent reduction in the number of centrioles was observed following actin depolymerisation; P-values were determined by one-way ANOVA followed by Dunn’s multiple comparison test. Error bars represent the sem of for the dose dependent experiments, n = 389, 388 and 940 cells for DMSO-, CytoD 1µM- and CytoD 2µM-treated explants, respectively, from at least three independent experiments. For the time-dependent experiments, n = 2852, 704, 587 and 889 cells for DMSO-, CytoD 6h-, CytoD 12h- and CytoD 40 h-treated explants from at least three independent experiments. *** P ≤ 0.0001. * DMSO vs. CytoD 6 h P = 0.0287. *CytoD 12 h vs. CytoD 40 h, P = 0.0484. Scale bars=5 μm