Fig. 9. CHR2-induced neuronal activation drives dFMRP-dependent pruning. (A) Single-cell MARCM clones expressing channelrhodopsin-2 (CHR2) in control or in dfmr1-null backgrounds, from animals grown on food containing all-trans retinal (ATR) or ethanol (ETOH vehicle). Post-eclosion animals (<12 hours AE) were stimulated with 470 nm light at 1 Hz pulses for 6 hours. Scale bar: 10 µm. (B,C) Quantified total axon branch number (B) and <5 µm branch number (C) of CHR2-expressing MARCM clones after stimulation. Horizontal bars are the mean for each data set. ^*0.01<P<0.05.