Fig. 5. E2f1 destruction is replication-dependent. (A-E) Stage 11 embryos were pulse-labeled with BrdU for 5 minutes, and stained for E2f1 (green), BrdU incorporation (red) and phospho-tyrosine (cyan). (A) stg^7B/stg^7B. (B) dup^a1/dup^a1. (C) dup^a3/dup^a3. (D) dap⁴⁴⁵⁴/dap⁴⁴⁵⁴; arrow indicates epithelial cells expressing low levels of E2f1. (E) UAS dap/arm-Gal4 VP16. (F) Stage 11 Df(1)biD3/Df(1)biD3 fzr-mutant embryos were pulse-labeled with BrdU for 15 minutes, and stained for E2f1 (green) and BrdU incorporation (red); arrow indicates epithelial cells expressing low levels of E2f1 similar to dap mutants. Scale bars: 50 µm.