Figure 5.
Loss of E74 causes non-cell autonomous c4da neuron pruning defects. (A–D) Dendrite pruning defects in a E74 mutant. (A) C4da neuron labeled by CD8::GFP expressed under ppk-GAL4 in heterozygous E74DL-1/+ animal at 16 h APF. (B) C4da neuron in E74DL-1/v4 mutant animal at 16 h APF. (C) Penetrance of dendrite severing defects (fraction of neurons with dendrites attached to soma) in samples A and B. N = 68, 39, *P < 0.05, two-tailed Fisher’s exact’s test. (D) Total length of unpruned dendrites in samples A and B. Values are mean ± SEM, ***P < 0.0005, Wilcoxon’s test. (E–H′) C4da neurons were labeled by CD8::GFP expression under the control of ppk-GAL4, and immunofluorescence of the pruning factors Sox14 and Mical was performed at 2 h APF. (E–F′) Sox14 expression in E74DL-1/+ heterozygous controls (E and E′) or in E74DL-1/v4 mutants (F and F′). (G–H′) Mical expression in E74DL-1/+ heterozygous controls (G and G′) or in E74DL-1/v4 mutants (H and H′). (I–M) Non-cell autonomous requirement for E74 during dendrite pruning. (I)E74 dsRNA was expressed in c4da neurons under ppk-GAL4, and dendrite pruning was assessed at 14 h APF. (J and K)Orco control dsRNA (J) or E74 dsRNA (K) were expressed ubiquitously under act5C-GAL4 in the presence of ppk-GAL80 to exclude c4da neurons, and dendrite pruning was assessed at 14 h APF. (L) Penetrance of dendrite severing defects in I–K. N = 32, 25, 21, **P < 0.005, ***P < 0.0005, two-tailed Fisher’s exact test. (M) Total length of unpruned dendrites in I–K. Values are mean ± SEM, ***P < 0.0005, Wilcoxon’s test.