Figure 3.

Mef2-Gal4 knockdown of RBPs produces diverse myofibril and sarcomere phenotypes. (A) Graphical summary of confocal phenotypes from 35 hairpins targeting 17 RBP genes. Dots represent hairpins and are colored by flight (flightless, red; weak flier, orange) and lethality (blue shades) phenotype. Hairpins may appear in more than one morphological phenotype category. (B–I) Confocal Z-projections of IFM hemi-thoraxes showing myofiber phenotypes at 90 h APF (B–E) or in 1 d adult (F–I). Torn, detached or missing fibers are observed in severe examples (yellow arrow heads in D,E,G,H) and classified as “detached myofiber” in (A). Other myofibers are stretched (yellow arrows in (E,I)), likely reflecting hypercontraction. White dotted lines mark boundary of the thorax in (C,D,G) and (H). Scale bars = 100 μm. (J–AA) Confocal single-plane images showing myofibril and sarcomere structure at 90 h APF (J–O2) or in 1 d adult (P–AA). As compared to w¹¹¹⁸ control images (J,P), knockdown of RBPs can result in split or frayed myofibrils (K,L,N2,Q,R,V), actin blobs which are commonly known as zebra bodies (M,N,O,R,S,U–AA), thick or thin myofibrils (K,L,O2,Q,R,S,U,V,X), as well as sarcomeres that are disorganized, short (N1,N2,O2,Q,S,T,U) or degenerate (K,N,Q,V). Scale bars = 5 μm; phalloidin stained F-actin, white.