Fig. 5. Localization of fusion machinery in different mutant classes. Lateral views of stage 14 rp298-lacZ embryos stained with phalloidin to label F-actin (red) and an antibody against β-galactosidase to label FCs/myotubes (blue). Channels are shown separately and merged. Scale bar: 5 µm. (A-C'') Embryos stained with an antibody against Blow (green). (A) Class 1: sns^XB3 mutant. Blow no longer has a polarized localization (compare with Fig. 3F) and instead is distributed cortically in FCMs. (B) Class 2: loner^T1032 mutant. Blow localization overlaps with the actin focus (arrowhead, compare with Fig. 3F). (C) Class 3: kette^J4-48 mutant. Blow is polarized and distributed throughout large actin accumulations (arrowhead). (D-F'') Embryos stained with antibody against Rols to label FCs/myotubes (green). (D) kette^J4-48 mutant. (E) blow¹ mutant. (F) mbc^C1 mutant. Dotted lines indicate FC/myotube membranes and were drawn based on Rols localization. In each case, enlarged actin foci localize across both the myotube and FCM.