Figure 2.

Myoblasts from FSHD-muscle biopsies die when efficiently differentiated to myotubes. (A) Drawing of photo arrangement shown in (B) showing a cytopathic lesion represented as a white circle. The microscope was programmed to take pictures (shown as blue squares) spanning the lesion. (B) Immunofluorescent microscopy of a 49 images spanning a 4 × 5 mm lesion from an FSHD myotube culture differentiated in medium supplemented with KOSR for 48 h. Green = MHC. (C) Numbered fields from (B) shown at increased magnification to demonstrate that nuclei adjacent to the lesion (Inset #2) are DUX4(+), whereas nuclei outside of the lesion are DUX4(−) (Inset #1). Red = antibody to C-terminus of DUX4. Green = antibody to MHC. Scale Bar = 50 μm.