Figure 4.

Conditional dfmr1 rescue/removal shows restricted critical period requirement. Gal80ts repressive paradigm for conditionally dfmr1 rescue (A) and knockdown (B) during critical period development for both excitatory input mPN2 and inhibitory output MBON-11 neurons. Animals raised at 18°C permissive temperature (Gal80 active, Gal4 inactive, red) until pupal day 4 (P4), then shifted to 29°C restrictive temperature (Gal80 inactive, Gal4 active, green) until 1 day post-eclosion (1 dpe). (C–F) K⁺ depolarization-induced Ca²⁺ transient GCamp5G fluorescence changes for genetic controls (grey line), constitutively active rescue/RNAi (black line), and conditional Gal80ts rescue/RNAi (red line). AL-mPN2 dfmr1 critical period rescue (dfmr1 control n=15, constitutive rescue n=22, conditional rescue n=25) (C) and RNAi knockdown (WT control n=16, constitutive RNAi n=16, conditional RNAi n=14) (D) shows restricted temporal FMRP requirement. Parallel, MBON-11 critical period rescue (dfmr1 control n=21, constitutive rescue n=23, conditional rescue n=17) (E) and removal (WT control n=15, constitutive RNAi n=21, conditional RNAi n=10) (F) of dfmr1 shows similar results. Each plot represents the change of average fluorescence intensity over time (mean±SEM), and includes an inset peak intensity histogram (minimum, median, maximum and quartiles). Significance determined by one-way ANOVA and indicated as ***p<0.001 or not significant (n.s.).