Fig. 1

Variability of dystrophin protein expression, as shown by IF after PMO injection. a Representative images of C57BL/10 (WT) and b PMO-treated mdx tibialis anterior sections stained for dystrophin. The WT control shows uniform IF staining for dystrophin. Insert at ×40 shows expected staining pattern for dystrophin-positive fibers. b PMO-treated mdx tibialis anterior shows a mosaic staining pattern and clustering of positive fibers. The yellow line represents the border between the tibialis anterior and EDL. Quantification was performed on the entire area of the muscle section. c Representative images of mouse mdx-6 showing variability between the muscles of the same animal. Images were selected to show positive fiber clustering and do not represent total area quantification. d IF quantification of diaphragm, gastrocnemius, heart, quadriceps, tibialis anterior, and triceps for all mice (n = 6). e Geographic variability observed within the highly rescued triceps from mouse mdx-1. All tissues were sectioned (10-μm thick), stained, and probed with goat anti-rabbit IgG Alexa 594 antibody. Dystrophin-positive fibers were normalized to the area of the muscle section and the WT percentage of positive fibers. Original magnification for a, b, e = ×20; scale bar, 500 μm; for c = ×40; scale bar, 100 μm