Fig. 1
From: The breaking and making of healthy adult human skeletal muscle in vivo
Cross-sectional profiles of regenerating fibres. Three serial frozen cross sections of a biopsy obtained from regenerating vastus lateralis skeletal muscle 7 days after injury induced by electrical stimulation-elicited eccentric contractions (right). Three serial cross sections from the control (uninjured) leg of the same individual are shown (left) for comparison. The sections have been stained with alpha-sarcoglycan, beta-dystroglycan or dystrophin to label the sarcolemma, along with a basement membrane protein (laminin or collagen IV) and a myogenic marker (desmin or neonatal/embryonic myosin; MHCn/e). Each column of images contains single channel and combined images for each staining. In the injured muscle, dystrophin staining is completely absent in several fibres, while the basement membrane (laminin) is preserved. MHCn/e staining is evident in some small dystrophin-negative fibres. A similar pattern is evident from the alpha-sarcoglycan and beta-dystroglycan staining, with negative fibres, together with desmin+ cells, contained within a preserved basement membrane (collagen IV). Asterisk indicates some of the necrotic fibres. Note the different profiles of the injured fibres, such as varying fibre size, and infiltrating cells either confined to the fibre periphery or dispersed throughout the fibre. Scale bar, 100 μm