Figure 4. Separation of insertion sites in the Warts KK RNAi line reveals potential for false-negative screening results and shows the power of KK RNAi lines if the 40D integration is removed.

(a–c) Wings of control flies (a) and F₁ flies carrying en-Gal4 crossed to VDRC line 106174 (wts) with double insertion (b) or single insertion at 30B (c). Flies were reared at 18 °C. (d–h) Adult eye phenotypes of F₁ flies carrying GMR-Gal4 crossed to VDRC genetic background (d), and wts RNAi lines Bloomington TRiP 27662 (e), NIG 12072R-1 (f), VDRC GD line 9928 (g) and VDRC KK line 106174, insertion at 30B only (h).