Beat-Va _L neurons undergo hormone-dependent, caspase-activated, Hox gene–mediated apoptosis. (A and B) Beat-Va neurons at wL3 (A) and HE (B) were genetically labeled with mCD8::GFP expressing UAS-LacZ (control). (C and D) Beat-Va neurons at HE expressing mCD8::GFP with EcR^DN (C) or UAS-P35 (D). Lime green circles indicate normal lateral cells before remodeling. Pink circles indicate the position of dead lateral cells. Blue circles indicate lateral cells surviving beyond the normal time point. Scale bars, 20 µm. (E) Quantification of the number of lateral cells at wL3, or HE in controls, or animals expressing EcR^DN or P35. Two-way ANOVA, Sidak multiple comparison test. N = number of animals. (F and G) Beat-Va neurons at (F) wL3 or (G) HE labeled with mCD8::GFP stained with Abdominal-B antibody (magenta). White dashed line denotes the boundary of the Abd-B expression. (H and I) Beat-Va neurons at wL3 (H) or HE (I) genetically labeled with mCD8::GFP crossed to UAS-LacZ as a control. Green circles indicate Beat-Va_L neurons. Magenta circles, the position of dead cells. (J) Expression of UAS-Abd-B^RNAi in Beat-Va neurons. Blue circles, cells that survive ectopically. (K) Expression of Abd-B in all lateral cells by HE leads to cell death. (L) Quantification of E–H. Two-way ANOVA, Sidak test for multiple comparisons. n = number of animals. (A–G) Scale bars are 20 µm in population images and 5 µm in the magnified view. (H–K) Scale bars are 20 µm. Colored data points correspond to the representative image shown in the figure. All error bars are SEM.