Forced expression of Drosha∆,E859K leads to neuronal overgrowth. DroshaR662X (A, C, E, G, and I) or WT (B, D, F, H, and J) OK107-Gal4, UAS-mCD8::GFP-labeled adult MB clones expressing UAS-DroshaWT (A and B), UAS-Drosha∆+E859K (C and D) UAS-Drosha∆ (E and F), UAS-DroshaE859K (G and H), or UAS-DroshaDN (I and J) and stained with anti-FasII antibody (magenta) and anti-Flag antibody (magenta; Insets in C, E, and I). Arrows point to mistargeted neurons. (Scale bar, 25 μm.)