Representative dorsal longitudinal muscles (DLMs) from wild type Canton S (A–D), Mhc1/CyO; Mef2GAL4/UAS-Mhcwt (E–H), Mhc1/CyO; Mef2GAL4/UAS-MhcR672H (I–L), Mhc1/CyO; Mef2-GAL4/UAS-MhcR672C (M–P) and Mhc1/CyO; Mef2GAL4/UAS-MhcT178I (Q–T), 20 days post-eclosion, labeled by immunofluorescence for Kettin marking the Z-disc (red), and Actin labeling the thin filament (green). The boxed regions in the merge images C, G, K, O and S are magnified and shown in D, H, L, P and T respectively. All images are from a single, representative Z-plane from one of the replicates. Scale bar in S is 5 μm and T is 1 μm.