Research Paper Volume 7, Issue 5 pp 307—318

Figure 1. The pS/TQ signal increases with age and under the influence of oxidative stress in Drosophila intestinal stem cells (ISCs). (A) The age- and oxidative stress-induced increase in pS/TQ signals in Delta protein-positive (Dl⁺) small cells. (a–i) An age-related increase of pS/TQ signals in Dl⁺ small cells. The gut of 10- (a–c), 20- (d–f), and 45-day-old (g–i) wild-type flies was stained with anti-Dl (green) and anti-pS/TQ (red) antibodies and 4′,6-diamidino-2-phenylindole (DAPI; blue). (j–o) An oxidative stress-induced increase in pS/TQ signals in Dl⁺ small cells. The gut of 10-day-old 10 mM PQ-fed (j–l) and Catⁿ¹/+ (m–o) flies was labeled with anti-Dl (green) and anti-pS/TQ (red) antibodies and DAPI (blue). Red arrows indicate Dl⁺ small cells. c, f, i, l, and o are merged images. The original magnification is 400×. (B–C) The florescence value of pS/TQ signals in Dl⁺ small cells as a function of age and oxidative stress. The gut of 10-, 20-, and 45-day-old wild-type flies and 10-day-old Catⁿ¹/+ (B) and 10 mM PQ-fed (C) flies was labeled with anti-GFP (green) and anti-pS/TQ (red) antibodies and DAPI (blue). The fluorescence intensity of pS/TQ signals in the Dl⁺ cells was measured in the 5a and b regions of the posterior midgut. The variable n indicates the number of Dl⁺ cells. Fluorescence intensity of the cells, which are exactly in focus, was measured in approximately 10 to 14 midgut specimens; ***p < 0.0001, **p < 0.001. (D) An age- and oxidative stress-induced increase in pS/TQ signals in esg⁺ small cells. (a–i) The age-related increase in pS/TQ signals in esg⁺ small cells. The gut of 10- (a–c), 20- (d–f), and 45-day-old (g–i) esg>GFP flies was labeled with anti-GFP (green) and anti-pS/TQ (red) antibodies and DAPI (blue). (j–o) The oxidative stress-induced increase in pS/TQ signals in esg⁺ small cells. The gut of 10-day-old esg>GFP 10 mM PQ-fed (j–l) and esg>GFP+Catⁿ¹ (m–o) flies was labeled with anti-GFP (green) and anti-pS/TQ (red) antibodies and DAPI (blue). Red arrows indicate esg⁺ cells. c, f, i, l, and o are merged images. The original magnification is 400×. (E–F) The fluorescence values of pS/TQ signals in esg⁺ small cells as a function of age and oxidative stress. The gut of 10-, 20-, and 45-day-old esg>GFP and 10-day-old esg>GFP+Catⁿ¹ (E) and 10 mM PQ-fed (F) flies was labeled with anti-GFP (green) and anti-pS/TQ (red) antibodies and DAPI (blue). The fluorescence intensity of pS/TQ signals in esg⁺ cells was measured in the 5a and b regions of the posterior midgut. The variable n indicates the number of esg⁺ cells; ***p < 0.0001, **p < 0.001.