Fig. 2

Mild replication stress stabilizes microtubules. a Representative images of cold- treated RPE1 centrin1-GFP cells stained with α-tubulin antibodies (green) and DAPI (blue). Cells were categorized into Class 1, 2 or 3 depending on the integrity of the mitotic spindle. All scale bars in Figure = 10 μm. b Mean percentages of class 1, class 2 and class 3 RPE1 centrin1-GFP cells; N = 4 examining in NT = 159 and Aph = 170 metaphases; p < 0.0001 in chi-square test. c Representative time-lapse images of metaphasic RPE1 centrin1-GFP cells stained with SiR-tubulin and treated with a nocodazole pulse at t = 0 after indicated treatments. d Quantification of the spindle intensity over time after a nocodazole pulse, as shown in (c), in metaphase RPE1 centrin1-GFP cells; N = 33 metaphases for siCTR and 31 for siMCAK/Kif2a. *p < 0.05; **p < 0.01; ***p < 0.001 in a repeated measurement Anova test. e Representative time-lapse images of metaphasic RPE1 centrin1-GFP cells stained with SiR-tubulin and treated with a nocodazole pulse at t = 0 after indicated treatments. f Quantification of the spindle signal as in (d); N = 32 for NT and 31 for Aph. *p < 0.05; **p < 0.01; ***p < 0.001 in a repeated measurement Anova test. g Representative time-lapse images of metaphasic MCF10A cells, stained with SiR-tubulin and treated with a nocodazole pulse at t = 0 after indicated treatments. h Quantification of the spindle signal as in (d) and (f); N = 49 metaphases/condition. *p < 0.05; **p < 0.01; ***p < 0.001 in a repeated measurement Anova test. i Mean percentage of RPE1 cells containing CENP-A-negative and CENP-A-positive micronuclei, treated with 10 ng/µl Nocodazole, 400 nM Aphidicolin or both combined. N = 3 examining Noc = 3125, Aph = 2421 and Aph/Noc = 2397 interphase cells, error bars indicate sem. CENP-A positive MN: Noc vs. Aph p = 0.1539; Aph vs Aph/Noc p = 0.0029 in unpaired t-test. Source data are provided as a Source Data file