Fig. 4

Examples of segmental degeneration of Drosophila muscle fibers. A Three longitudinally sectioned IFM fibers stained for F-actin (green) and DNA (blue), demonstrating different degrees of degeneration: from no degeneration (fiber I) to complete degeneration (fiber III). Fiber II is partially degenerated, with a segment positive for both F-actin and DNA. Red autofluorescence is used to determine fiber-occupied areas. B A fragment of the TDT muscle from two different transverse sections stained for T-tubules (Dlg, red), F-actin (green), and DNA (blue). In section 1, no apparent fiber degeneration is evident; in section 2, a single degenerative fiber is present based on the loss of F-actin and DNA staining and significant perturbations in the Dlg staining pattern. Dashed lines outline degenerative fibers. Scale bars: 50 µm (all panels)