Figure 3: Characterization of Sox21a tumours.

(a–d) AMG of 10-day-old Sox21a/+ (control, a,c) and Sox21a flies (b,d), carrying either esg>GFP (a,b) or Dl-lacZ and GBE>GFP (b,d). (e) A confocal section to show the basal–apical (bottom-up) organization of ISCs and EBs in Sox21a fly. (f) Quantification of tumour burden of Sox21a flies at the indicated age at 25 °C (n=30, 33, 42 and 50, respectively). (g–n) Superficial view (g–j, DAPI) and cross-sections (k–n, EBs in green, phalloidin in red) of intestines from Sox21a flies. Tumour grade is colour-coded from green (grade 0) to red (grade 3). Arrows indicate small clusters of progenitor cells (h). (o,p) Quantification of the number of ISCs (o) and EBs (p) in a 10, 000-μm² area from tumours of different grade (n=16, 10, 14 and 13, respectively in o; n=24, 17, 15 and 6, respectively in p). Error bars indicate s.e.m. (o,p). P values in f from χ²-test, and in o and p from Student’s t-test (*P<0.05; **P<0.01; ***P<0.001; NS, not significant). Each plot (f,o,p) is representative of three biological replicates. Each image shown in a–e and g–n represents 25 flies tested in one experiment and repeated three times.