Fig. 2.

Cell division timing depends on Notch signalling. (A) N^sfGFP expression pattern at 12 h AP. H2B^mRFP labels nuclei. Scale bar: 50 µm. (A′) Higher magnification image of A. Scale bar: 5 µm. (B) False-coloured panel of N^sfGFP -expressing ECs. Asterisk indicates SOP. Primary (1) and secondary (2) neighbours are indicated by dashed boxes. Scale bar: 5 µm. (B′) Time series of nuclear ROIs for cells 1 and 2 until nuclear envelope breakdown (NEBD; indicated by black boxes), leading to transient depletion of signal. (C) N^sfGFP dynamics in ECs (n=29 each, N=3). (D) Rate of N^sfGFP increase for the data shown in C. (E) Maximum normalized N^sfGFP signal for the data shown in C. (F) Mean ratio of local SOP neighbourhood N^sfGFP signal (n=27 SOP, 133 each EC type; N=3). (G-I) neur-GAL4 expression of Delta^DN reduces Notch signalling in wild-type 1N (G) or 2N (H) cells (n=16, N=2) versus control (UAS-lifeActRuby, n=30, N=3) and delays cell division timing in Shotgun^GFP; neu-GAL4, UAS-GMCA>UAS-Delta^DN pupae (I) (N=3). (J) Cell division timing in Shotgun^GFP; pnrGAL4>UAS-Su(H) RNAi pupae relative to control (N=2). ECs, epithelial cells in regions lacking differentiating SOPs. Mean±s.e.m. for C,F,G,H; mean±s.d. for D,E,I,J. n.s., not significant; **P<0.01; ***P<0.0001 by unpaired, two-tailed, t-test as indicated compared with control of the same type (i.e. RNAi-1N to control-1N). (n)=number of cells.