Figure 4.

Phenotypic abnormalities in the neural derivatives of the mutant isogenic iPSCs: (A) The neural-rosette formation assay. Immunofluorescence staining for MAP2, a marker of neurons, and ZO-1, a marker of luminal rosettes. The results were reproduced in three independent experiments. Scale bar: 100 µm; (B) Mean area of neural rosettes; * p < 0.05, *** p < 0.001; (C) Increased sensitivity of mutant MSN (medium spiny neuron) progenitors to BDNF (brain-derived neurotrophic factor) withdrawal. Cell death was assessed by immunofluorescence staining with antibodies against activated caspase 3 after the removal of BDNF (n = 3, values for biological replicates are presented as mean ± standard error of the mean). * p < 0.05, ** p < 0.01, *** p < 0.001: a comparison between the cell lines after BDNF depletion; $ p < 0.05, $$ p < 0.01, $$$ p < 0.001: a comparison of one cell line before and after the BDNF depletion; (D) An immunofluorescence assay of neurons for the presence of mutant huntingtin aggregates. Scale bar: 50 µm.