Figure 5.

Axonal Phenotypes Caused by MT Destabilization in R406W Mutant Neurons

(A and B) Immunostaining of iPSC-derived neurons with MAP2, tau, and DAPI 30 days after dissociation (A). Arrowheads indicate neurons with tau on MAP2⁺ area. Scale bars, 10 μm. The percentage of tau on the dendrites was significantly increased in the mutant neurons when compared with the control neurons (B) (n = 3 independent experiments, ^∗p < 0.05; one-way ANOVA followed by Tukey's test).

(C) Immunostaining of iPSC-derived neurons with MAP2, βIII-tubulin, and tau. Scale bars, 20 μm.

(D and E) Representative immunofluorescence pictures of βIII-tubulin⁺ axons with (lower) or without (upper) Epothilone D (EpoD) treatment (D). Scale bars, 10 μm. There was a significantly greater number of puncta in the mutant neurons compared with control neurons, which was rescued with EpoD treatment (E) (n = 3 independent experiments). ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001 when comparing control with R406W mutants; one-way ANOVA followed by Tukey's test. ^#p < 0.05, ^###p < 0.001 when comparing mock with EpoD; Student's t test.

Error bars indicate mean ± SEM. See also Figure S5.