Beat-Va _M neurons remodel when neuronal EcR signaling or expression is inhibited. (A and B) Surface rendering of control Beat-Va_M neuron driving UAS-LacZ using the MCFO technique at wL3 (A) and HE (B). Intact neurites, magenta; fragmented neurites, cyan. Boxed area is shown in high magnification below each image. (C and D) Beat-Va_M neuron expressing EcR^DN labeled with the MCFO technique at wL3 (C) and HE (D). (E) Quantification of Beat-Va_M branch point number at HE in EcR^DN background. (F) Quantification of Beat-Va_M total neurite length in EcR^DN background. (G and H) Beat-Va neurons genetically labeled with mCD8::GFP and expressing Cas9 under UAS control. gRNAs are expressed ubiquitously. Cell-specific knockout of control gRNAs at wL3 (G) and HE (H). (I and J) Targeting EcR with gRNAs in Beat_M neurons at wL3 (I) or at HE (J). Fine neurites, yellow arrow. Boxed areas are displayed in high magnification below each image. (K and L)usp gRNAs in Beat_M neurons at wL3 (K) or HE (L). Fine neurites, yellow arrow. (M and N) Expression of plum gRNAs in wL3 neurons (M) and HE (N). Fine neurites, yellow arrow. (O and P) Expression of Rpn6 gRNAs in wL3 neurons (O) and HE (P). Fine neurites, yellow arrow. (Q and R) Expression of UAS-WldS in wL3 neurons (Q) and HE (R) does not change Beat-Va_M neurite pruning. Comparisons with two-way ANOVA and Sidak test for multiple comparisons. (G–R) Scale bars are 20 µm. (A–D) Scale bars are 20 µm in single cell images and 5 µm in the magnified view. (E and F) Each data point represents one cell. For wL3 LacZ cells were imaged from seven animals, for HE LacZ cells were imaged from five animals, for wL3 EcRDN cells were imaged from eight animals, for HE EcRDN cells were imaged from five animals. (G–R) At least seven animals were examined per genotype and timepoint. Colored data points correspond to the representative image shown in the figure. All error bars are SEM.