Loss of Cavin-1 in muscle is associated with large vacuoles and a dilated T-tubule system. (A and B) Ruthenium red labeling of WT muscle fibers highlighting the muscle fiber surface, T tubules (inset in A represents enlargement of boxed area) and caveolar rosettes (inset in B represents enlargement of boxed area). (C–E) Ruthenium red labeling of cavin-1^−/− muscle fibers across the surface and within T tubules (arrows, C and D) and large vacuoles (arrows, E). Bars: (A and B, main images) 2 µm; (A and B, insets) 200 nm; (C–E) 1 µm.