Clathrin recruits GTSE1 to the spindle. (A) Immunofluorescence images of U2OS cells stably expressing an RNAi-resistant GTSE1-GFP BAC transgene, stained with antibodies against GFP and α-tubulin. Cells were transfected with control (Ctrl) or CHC siRNA (66 h). All cells were concurrently transfected with GTSE1 siRNA to deplete endogenous GTSE1. (B) Quantification of the spindle recruitment of GTSE1-GFP in cells from A (n = 3 experiments, n ≥ 34 half-spindles from 17 cells per condition and experiment, one experiment presented as a box and whisker plot). (C) Immunofluorescence images of mESCs stained with antibodies against α-tubulin, CHC, and GTSE1, after indicated RNAi. (D) Immunofluorescence images of clonal U2OS cells stably expressing a CHC-GFP BAC transgene after indicated RNAi. Cells were stained for α-tubulin; the GFP signal is from the fluorescing protein. (E) Quantification of CHC-GFP on the spindle of cells from G (n = 3 experiments, n ≥ 44 half-spindles from 22 cells per condition and experiment, one experiment presented as a box and whisker plot). n.s., not significant. (F) Immunofluorescence images of U2OS and GTSE1^KO cells stained with antibodies against CHC, TACC3, and α-tubulin. (G) Immunofluorescence images of mESCs stained with antibodies against TACC3 and α-tubulin after indicated siRNA. Scale bars: 5 µm. P values from Wilcoxon test. Numeric data is shown in Table S1.