Fig. 7. Constitutive presynaptic dFMRP does not rescue dfmr1-null FM1-43 function defect. (A) Representative images of wandering third instar Drosophila larval NMJs loaded with FM1-43 and then subsequently unloaded with high [K⁺] depolarizing saline. Note the elevated relative fluorescence retained in control versus dfmr1-null and GS mutants. Insets show representative synaptic boutons at higher magnification. (B) Quantification of the FM1-43 unload:load fluorescence intensity ratio. Sample sizes: n=8 each control and dfmr1-null; n=13 GS+E; n=6 GS+R0.5; and n=9 GS+R2. (C) Quantification of average fluorescence intensity per bouton in loaded and unloaded conditions. Sample sizes: n=5 for each control, dfmr1-null, GS+E, GS+R0.5 and GS+R2. Bars indicate mean±s.e.m. ^*P<0.05, ^**P<0.01.