Figure 4. Effects of E2f1/Dp overexpression on cell cycle progression during wing imaginal disc culture.

Imaginal discs were dissected from larvae with single copies of the transgenes en-GAL4, UAS-E2f1, UAS-Dp, and tub-GAL80^ts. These larvae were either grown constantly at 23°C (A, B; - E2f1/Dp overexpression) or at 29°C for the final 18 hours before disc dissection (C, D; + E2f1/Dp overexpression). Dissected wing imaginal discs were labeled with EdU (EdU), anti-PH3 (PH3) and a DNA stain (DNA) either immediately (0 h) or after 7 hours of cultivation at 25°C (7 h). Complete imaginal discs (A, C; scale bar  = 50 µm) and high magnification views of the central pouch region (B, D; scale bar  = 20 µm) are shown with dashed lines indicating the boundary between anterior and posterior compartment, in which en-GAL4 driven UAS transgene expression occurs at 29°C.