Infrared laser ablation at the growing tip of terminal cells. (A and B) Terminal cell expressing CD4::mIFP and Utr::GFP under btl-gal4. (A) Cell immediately before laser cut. The white box marks the laser-ablated region. (B) Long-term recovery, z-projections. (C–F) Terminal cells expressing Utr::GFP under btl-gal4.(C and D) Cell with normal, ventrally guided tube. (E and F) Cell with a bifurcated tube. C and E are single z-plane images of cells immediately before laser cuts; black boxes mark the laser-ablated regions. D and F are z-projections of the recovery. See also Video 4. (G) Quantification of the recoil as determined by PIV. As control, we analyzed PIV in two successive time points before laser cuts. Box plots represent median, interquartile range (IQR), and IQR*1.5 below and above the IQR. Number of cells analyzed: cells with ventrally guided tube, n = 7; cells with a bifurcated tube, n = 5. Significance was assessed using t test. Ventral is down.