Fig. 4
From: Fusion of myofibre branches is a physiological feature of healthy human skeletal muscle regeneration
Transmission electron microscopy images of cross-sections of regenerating human muscle, 30 days post injury, in two subjects (one subject A–F, second subject in G–H). A shows a small fibre surrounded by larger myofibres (20-μm scale bar). B–F (scale bar 10 μm (B), 5 μm (C), 5 μm (D), 2 μm (E), 1 μm (F)) show magnified images of A. G A myofibre branch (*) closely associated with a parent myofibre (scale bar 10 μm), with evidence of membrane fusion, further magnified in H (scale bar 2 μm). The arrows point to membrane-associated electron-dense plaques, indicative of membranes in the phase of fusing. In all images, Z is z-disc, cap is capillary, m is myofibre, mn is myonucleus and mf is myofilament