Extended Data Fig. 5: Chromosomes cluster in the presence of a mitotic spindle after flavopiridol-mediated induction of mitotic exit.
From: Chromosome clustering by Ki-67 excludes cytoplasm during nuclear assembly
Live-cell microscopy of wild-type HeLa cells stably expressing H2B–mCherry synchronized to metaphase by MG132 treatment. a, Upper panel: negative control treated with dimethyl sulfoxide (DMSO) solvent, lower panel: mitotic exit induced through acute flavopiridol addition at t = 0 min. Chromosome arms extend out of the metaphase plate before flavopiridol addition, but densely cluster on the metaphase plate 8 min after flavopiridol addition. b, Quantification of chromosome convex hull area of 24 control and 25 flavopiridol treated cells, as in a. c, Top, acute mitotic spindle depolymerization by addition of nocodazole at t = 2 min leads to chromosome movement out of the metaphase plate; bottom, mitotic exit was induced by flavopiridol (0 min), briefly before nocodazole-mediated spindle disassembly (2 min), preventing movement of chromosomes out of the metaphase plate. d, Chromosome convex hull area measurements of 27 nocodazole and 23 flavopiridol and nocodazole treated cells, as shown in c. Values normalized to average of all frames before first drug treatment. Showing single z-slices, lines and shaded areas indicate mean ± s.d., dashed vertical lines indicate drug addition, scale bars, 10 μm.
