Extended Data Fig. 9. Effects of the sexual identity of adult ISCs on the susceptibility to genetically induced tumours.

a, The number of mitoses in Apc-ras mutant midguts is larger than that of control clones in both sexes, but it is higher and dependent on Sxl in females. b, The size of Delta (Dl, the N ligand) null mutant (Dl^RevF10) MARCM clones is larger than that of control clones in both sexes, but female mutant clones are larger than male mutant clones. The graph shows quantifications of the number of cells within each clone 15 days after clone induction by heat shock, and the confocal images show representative clones (labelled in green with GFP) for each genotype. c, In tra “female” mutant flies (tra^KO and tra^KO/Df(3L)^st-j7) reduced N signalling in intestinal progenitors fails to induce the hyperplasia (quantified by the number of pH3 cells) normally observed in control females. d, Following 15 days of adult-specific downregulation of Notch (N) in intestinal progenitors, hyperplasia (quantified by the number of pH3-positive cells and also shown in representative images) is observed in female, but not male midguts. Adult-specific and cell-autonomous reversal of ISC/EB female identity – achieved by esg^TS-driven downregulation of Sxl – fully prevents the hyperplasia induced by Notch downregulation in females, but has no effects on males. Confocal images show intestinal progenitor coverage of representative midgut portions for each genotype (DNA: DAPI, in blue; ISC/EB marker: GFP, in green). e, pH3 quantifications show a comparable effect for an independent RNAi transgene against Sxl. f, Adult-specific downregulation of Notch (N) signalling by ectopic expression of the downstream N signalling antagonist Hairless (H)³⁸ leads to hyperplasia (quantified by the number of pH3-positive cells and also shown in representative images) in female, but not male midguts. Adult-specific and cell-autonomous reversal of ISC/EB female identity – achieved by esg^TS-driven downregulation of Sxl – fully prevents the hyperplasia induced by H overexpression in females, but has no effects on males. Confocal images show intestinal progenitor coverage of representative midgut portions for each genotype (DNA: DAPI, in blue; ISC/EB marker: GFP, in green). g, The number of pH3-positive cells 15 days after N downregulation in adult intestinal progenitors of double null mutant flies lacking dsx and fru^M (dsx^Δ,Df(3R)^Exel6179/dsx¹, fru^P1.LexA) is comparable to that of controls in both males and female flies. Like control flies, it is significantly higher in female flies. Virgin flies were used in all these experiments. n denotes the number of guts (a, c, d, e, f, g), or clones (b) that were analysed for each genotype. Results combined from at least two independent experiments. See Supplementary Information for full genotypes.