Fig. 4.

Muscle differentiation of ALS-iPSC-MyoD lines.

(A) Diagram of the differentiation protocol. HUESM: iPSC differentiation medium; GM: myoblast growth medium; DM: myoblast differentiation medium. Red line: time in doxycycline (Dox). Time points of medium change are indicated above. (B) Immunostaining for the muscle markers (green): MYOD (left panels), Myogenin (middle panels) or MYH1 (right panels), in differentiated WT I-MyoD cells or in iPSC-FUS^R514S/WT-MyoD, iPSC-FUS^R521C/WT-MyoD and iPSC-TDP-43^A382T/A382T-MyoD differentiated ALS mutant cells. Nuclei are counterstained with DAPI. Scale bar for all panels: 50 μm. (C) Quantification of the fraction of MYH1-positive cells in control and ALS differentiated cells. Histogram bars represent averages ± S.E.M. (30 fields and at least 1000 nuclei counted per line) and n.s. indicates that the differences between mutant lines and the WT I control are not statistically significant (p > 0.1; Student's t-test).