Figure 6

Notch acts in cap cells to maintain adult niche. (A) Adult expression of Notch RNAi was induced by temperature shift using Gal4-Gal80^ts system. Only Bab1-Gal4 expression produces significant decline of cap cell number in 15 day adults compared to WT (*** indicates p < 0.001, t-test of slope coefficients). (B) C587, Ptc-Gal4, Bab1-Gal4 and C306-Gal4 driven Notch RNAi cause loss of GSCs over time compared to WT (* indicates P < 0.05; *** P < 0.001, t-test of slope coefficients). Note flies expressing Notch RNAi with Ptc-Gal4 do not survive to 15 days. Data in B, C displayed as means ± SEM normalized to % of cap cell or GSC numbers on eclosion, n = 27–65. (C-E) Niches of 15 day old adults expressing Notch RNAi, marked with anti-Coracle (purple), anti-LaminC (green), and anti-Spectrin (also green). Arrow marks location of niche, arrowheads mark presence of GSCs. (C) En-Gal4 driven RNAi has no effect on niche or GSCs. (D) Bab1 driven RNAi reduces cap cell and GSC number, (E) C587-Gal4 driven RNAi reduces GSC numbers but does not affect cap cell number.