Fig. 6. Targeted presynaptic dFMRP rescues dfmr1-null NMJ cytoskeletal defects. (A) Representative images of NMJs from wandering third instar Drosophila larvae probed for HRP and Futsch. GS animals were constitutively fed either EtOH vehicle or RU486 at 2 µg/mL. Note the increased number of Futsch loops present throughout the dfmr1-null synaptic terminals. (B) Quantification of Futsch loops. In wandering third instar larvae, constitutive treatment with RU486 partially rescues the cytoskeletal alteration of the null mutant. n=11-13 animals for each condition. (C) Quantification of Futsch loops after either early or late 12-hour treatment with RU486 (taken at 108 hours AEL). Age-matched control and dfmr1-nulls are presented. n=10-15 animals for each condition. Bars indicate mean±s.e.m. Dashed red line highlights control level quantifications. ^*P<0.05, ^**P<0.01, ^***P<0.001.