Extended Data Fig. 6: Additional characterization of chromosomal viscoelasticity.
From: Ion-mediated condensation controls the mechanics of mitotic chromosomes
(A) Relative change of the linear stiffness as a function of the relative change in critical force for histone depleted chromosomes. Filled symbols compare chromosomes before and after histone-depletion, open symbols compare chromosomes before histone-depletion with chromosomes during histone-depletion (while in 1 M salt buffer) (N = 10 chromosomes). The data does not follow a simple scaling relation since the contour length changes drastically during histone depletion. (B) Box plot of the elastic stiffness in the absence and presence of polyamines or PEG. Chromosomes showed strong stiffening from 0.12 ± 0.02 pN/nm to 0.42 ± 0.08 pN/nm (p = 0.02, two-sided t-test for related samples, N=6 chromosomes) for polyamines and from 0.16 ± 0.04 pN/nm to 0.48 ± 0.1 pN/nm (p=0.003, N = 10 chromosomes) for PEG. The box plot marks the quartiles of the distribution, the whiskers show the whole distribution, and the center line marks the median.
