Fig. 3

DUX4c overexpression induces abnormal clusters of myonuclei and misdistribution of β-catenin. a FSHD and healthy primary myoblasts were transfected with the empty pCIneo or pCIneo-DUX4c expression vector, and differentiation was induced 24 h later. Immunofluorescence detection with antibodies against β-catenin (green) or DUX4c (red) was performed at day 3. Nuclei were labeled with DAPI. Scale bar: 20 μm. b Representative field from each culture (white light). Scale bar: 50 μm. c The nuclei per cluster were counted in each culture (10 fields per culture) and are presented as the mean ± SD. The proportion of nuclei present per cluster is shown in grayscale. Nuclear clusters with more than 16 nuclei were seldom found in healthy myotubes; the mean is therefore close to zero. ***p < 0.001