Fig. 3. Ectopic expression of DMyb promotes increased S phase in imaginal discs. Dissected wing (A,B), haltere (C,D) and leg (E,F) imaginal discs from wandering third instar larvae were labeled for DNA synthesis by BrdU incorporation (white dots). S-phase cells were similarly distributed in the anterior and posterior compartments of a control en-Gal4/+ disc (A,C,E). By contrast, higher levels of BrdU incorporation were observed in the posterior compartment of each disc when en-Gal4 was used to drive expression of either UAS-DMyb (B,F) or UAS-DMyb (D) in posterior compartments. White lines indicate compartment boundaries, posterior towards the right. Scale bars: in A 0.05 mm for A,B; in C, 0.05 mm for C-F shown at same magnifications.