Fig. 6.

Insulin signaling within cap cells controls GSC maintenance via E-cadherin. (A) Total cap cell numbers in control mosaic germaria (C1) and in germaria without (C2) or with (dinr³³⁹) cap cell clones from dinr³³⁹ mosaics. The average cap cell number is not statistically different among genotypes. (B) Significant decrease in GSC number in germaria carrying dinr³³⁹ cap cells. The number of germaria analyzed is shown above each bar. **P < 0.01. Heterozygous (C) and dinr³³⁹/dinr^E19 mutant (D) germaria labeled with 1B1 (green, fusome), LamC (green, cap cell nuclear envelopes), and E-cadherin (red). Dashed outlines indicate GSCs. (Scale bar, 5 μm.) (E) DILPs integrate age and diet effects on GSC maintenance. DILPs control niche size via Notch (N) signaling in the niche [potentially via Delta (Dl)] and cap cell–GSC association via E-cadherin (EC). Dark green, terminal filament; light green, cap cells; red, GSC.