A. CG1674 expression was knocked down in flight muscles using three different Gal4 drivers, and two different UAS-CG1674 RNAi lines. Flight ability of Control and knockdown female flies is shown. Note that control flies (first three columns) predominantly fly upwards in the assay, whereas all of the knockdown lines showed strongly reduced flight, with the majority of the flies unable to fly at all (null category). B. Jumping ability of control (columns 1, 2 and 3) and CG1674 knockdown (columns 4 and 5) females. a and b refer to statistically different categories, showing that control animals (category a) did not differ from each other in jumping ability, but did differ significantly from the jumping ability of knockdown animals (category b). Jumping ability of knockdowns did not differ significantly from each other. C. Horizontal sections of y w control and CG1674 knockdown females stained for accumulation of F-actin (red) in flight (F) and jump (J) muscles. F-actin-rich deposits were only observed in the knockdown animals. Additionally, the morphology of the jump muscles was abnormal in the knockdown animals. Bar, 250μm. D. Myofibril organization in control y w flight muscles of pharate adults, stained for accumulation of F-actin (green), alpha-actinin to label the Z-discs (red), and DAPI to label nuclei (blue). Bar, 5μm. D. Phenotypes of knockdown myofibrils, stained as in B. Note the large actin-rich structures observed in all experimental conditions, that also accumulate alpha-actinin (arrows). Bar, 5μm.