Schematic of a myofiber, depicting the inter Z-disc distance and Z-disc width (A). Quantification of the inter Z-disc distance 5 (B) and 20 (D) days post-eclosion, and Z-disc width 5 (C) and 20 (E) days post-eclosion respectively in DLMs of wild type Canton S, Mhc1/CyO; Mef2GAL4/UAS-Mhcwt, Mhc1/CyO; Mef2GAL4/UAS-MhcR672H, Mhc1/CyO; Mef2GAL4/UAS-MhcR672C and Mhc1/CyO; Mef2GAL4/UAS-MhcT178I flies. The inter Z-disc distance (F) and Z-disc width (G) at 5 days post-eclosion compared to 20 days post-eclosion for each genotype. The graphical data is presented as mean ± standard error of the mean using a minimum of 5 replicates.