Fig. 5. Effects of Mib2 mis-expression in FCMs and its requirement in FMs to eliminate Lmd from myotubes. In all embryos, the lateral-ventral region is shown and anterior is to the left. (A) Mef2GAL4; 2xUAS-mib2, (B) snsGAL4; 2xUAS-mib2 and (C) Mef2GAL4; 2xUAS-mib2-C935S-C1020S Drosophila embryos. (A',B',C') Higher magnification views of corresponding embryos. Note the presence in A' and B' (but not in C') of thin (mono/bi-nucleated) myotubes (anti-myosin staining). (D-F) Mef2GAL4; 2xUAS-mib2 embryos. (D) Duf (green) and Rols (red) co-localise to the membrane of mini-myotubes (arrowheads) induced by overexpression of Mib2-FL. (E,F) Overexpression promotes death (activated-Caspase 3 expression, red) of FCMs (Kettin labelling, green) starting at stage 12 (E) and most prevalent at stage 14 (F). Mini-myotubes did not express activated-Caspase 3 (arrowhead in F). (G,H) Late stage 13 yw and mib2¹ embryos, respectively, stained with anti-Connectin (red) and anti-Lmd (green). (I) Schematic representation of late stage 13 Connectin-expressing precursors. (J,K) Stage 16 mib2¹/CyO and mib2¹ embryos stained with anti-Tm (red) and anti-Lmd (green). Lmd is not detected in early precursors (G) or late myotubes (J) of wild-type embryos, but it is not eliminated in mib2¹ embryos (H,K).