Fig. 3. Somatic Jak/Stat signalling is essential to prevent GSC differentiation in Drosophila. (A) yw hs-flp122; FRT82 Stat92E⁰⁶³⁴⁶/FRT82B ubi-GFP germarium dissected 25 days AE. It was double stained with anti-Hts (red) and anti-GFP (green) to document that Stat92E loss-of-function in the germline does not affect stem cell maintenance. (B) w; UASt-dome^CYT/+; bab1-Gal4/+ germarium grown at 25°C and dissected 25 days AE. The staining with anti-Hts shows that the two GSCs present in the niche possess an anchorless spectrosome. (C-E') FRT101 hop²/FRT101 ubi-GFP; bab1-Gal4 UASt-flp germaria stained with anti-Hts (red), anti-GFP (green) and the DNA dye Hoechst (white) to label hop² mutant CpCs. (C,C') GSC in contact with both mutant and wild-type CpCs showing a normal spectrosome. (D,D') GSCs in contact with mutant CpCs displaying anchorless spectrosomes. (E,E') Mutant CpCs in direct contact with a differentiating 8-cell cyst. Asterisks, GSCs; yellow and red dashed lines, CpCs; white dashed line, germline cyst. Scale bars: 10 µm.