Fig. 9: Weakened interaction between F-actin and microtubules precedes mitotic failures.
From: Elevated temperature fatally disrupts nuclear divisions in the early Drosophila embryo
A Schematic depicts dramatic reorganisation of F-actin, microtubules, and chromatin as the nuclei transition from prophase to late metaphase (left). The images are then manually annotated (center) to facilitate automated quantitative analysis of F-actin caps and microtubule spindles (right). B–E F-actin cap and microtubule spindle dynamics during mitosis. Montages from representative control nuclear divisions (B, C) and mitotic failures (D, E) from embryos developing at 25 °C (B, D) and 29 °C (C, E), during mitosis 13. Left panels show montage of UtrABD- and Jupiter-GFP signal: dashed contour, manually outlined F-actin cap; white dots, manually marked spindle poles. Right panels show montage of corresponding Histone-RFP signal: dashed green line, long axis of F-actin cap; solid cyan line, spindle position; insets, time till end of metaphase. F–K Quantifications showing F-actin cap size (F) and aspect ratio (G) at metaphase, microtubule spindle length at metaphase (H), spindle extension rate (I) and cumulative rotation (J) during mitosis, and the angle mismatch between spindle axis and cap long axis (K) at metaphase. n = 27 (25 °C control division), 27 (29 °C control division), 10 (25 °C mitotic failure), 15 (29 °C mitotic failure) nuclei, pooled from N = 9 (25 °C) and 9 (29 °C) embryos. Scale bars, 5 µm. F–K show scatters with median, with whiskers showing 95% CI. Non-parametric Kruskal–Wallis test with Dunn’s uncorrected test for multiple comparisons: *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001; non-significant comparisons are not shown. Source data and exact p-values for plots are available in the Source Data file.
