Fig. 6. Mib2 localisation and functional analysis in Drosophila adult muscle. (A-A''') Mib2 (green) accumulates at the Z band (Kettin staining, blue) of myofibrils and to lesser an extent in the M band (absence of actin). (B-D') Electron micrographs of longitudinal sections of IFM from 3-day-old wild-type (B,B'), 1-day-old (C,C') and 3-day-old (D,D') 1151-GAL4/UAS-RNAi-mib2 adults. IFMs of 1151-GAL4/UAS-RNAi-mib2 young adults show poorly defined M bands and irregular Z disks (C'), compared with the wild type (B'). Three-day-old 1151-GAL4/UAS-RNAi-mib2 IFMs lack sarcomeres and display remains of dense material that probably corresponds to distorted and split Z bands (D', arrow and arrowhead, respectively). (E-G) Co-immunoprecipitation experiments showing a physical interaction between Mib2 and nonmuscle myosin. Protein extracts from sqh-GFP thoraces were immunoprecipitated with anti-Mib2 (E), anti-GFP (F) or anti-nonmuscle Mhc (G) antibodies, followed by immunoblotting with anti-GFP (E) or anti-Mib2 (F,G). Note the presence of bands of 47 kDa corresponding to Sqh-GFP (arrowhead in E) and 115 kDa corresponding to Mib2 (arrowheads in F,G) in the experimental and their absence in the control P lanes. In E, the weak bands detected in P lanes correspond to immunoglobulins. Input, immunoprecipitation reaction samples; P, immunoprecipitated pellets; S, supernatants. Scale bars: 0.5 µm in B; 0.1 µm in B'.