. A 7d intestine Dronc heterozygous (+/-) intestine in which intestinal stem cells express GFP under the regulation of Dl-Gal4. All of the experiments described in the figure were performed in Oxford medium following an experimental regime that protects the epithelial integrity (flies transferred every two days into vials with fresh food). DAPI (blue) labels the DNA in the entire Figure. Genotype: w1118; ;delta-Gal4 UAS-GFP TubG80ts UAS-Histone-RFP DroncKO/+ (recombinant chromosome made for this study; the parental line delta-Gal4 UAS-GFP TubG80ts UAS-Histone-RFP was obtained from Maria Dominguez) B. A 7d intestine in which the Intestinal Stem Cells have become Dronc homozygous mutant (-/-) upon expressing UAS-Flp under the regulation of Dl-Gal4. Dl-expressing cells are labelled with UASGFP (green); there are no morphological differences between A and B. Genotype: w1118; ;delta-Gal4 UAS-GFP TubG80ts UAS-Histone-RFP DroncKO / UAS-Flippase (BL8209) FRT Dronc-GFP-APEX FRT suntag-HA-Cherry C. Relative number of GFP+ Delta-expressing cells normalised to DAPI; there is no significant increase in intestinal stem cell number between heterozygous and homozygous Dronc mutant conditions (ns; P = 0.9231) (Quantifications were made using N ≥ 2 biological replicates; unpaired two-tailed t test, +/- n = 22, -/- n = 13). Error bars represent Standard Deviation of the Mean. Genotypes: