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Fig 3 -

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posted on 2023-05-25, 17:45 authored by Gaurav Bajpai, Samuel Safran

(a) Simulation snapshots are shown for different volume fractions of chromosome, ϕ. For ϕ = 0.001, corresponding to large confinement volume (shown in grey) with a weak attraction strength (ϵ = 0.25), (which is below the value where collapse is observed) the chains are separated. For ϕ = 0.2, the chromosomes begin to mix until each chromosome approximately occupies the entire confinement volume. For ϕ = 0.6, the smaller volume restricts the motions of the highly condensed chains. (b) The mixing index, represented by α, increases over time according to a power law, with the exponent β. This holds true for moderate volume fractions (0.01 ≤ ϕ ≤ 0.5). However, at very small volume fractions (ϕ = 0.001), the mixing exponent is β ≈ 0, indicating diffusion of chains. At larger volume fractions (ϕ = 0.6), the motion of chains is restricted due to small confinement volume, resulting in two exponents: β1 and β2. Right panel of (b) The exponent first increases and then decreases as the chain volume fraction is increased. These power laws suggest that the mixing dynamics is slow for very large and very small volume fractions (small and large confinement volumes, respectively). (c) Contact maps obtained from the simulations, calculated by averaging the last 500 frames, are shown for the different volume fractions, ϕ. (d) The single-chain contact probability (Pc(s)) is plotted with different colored points for different volume fractions of the chains, ϕ. The line corresponding to each color indicates a power-law relationship. The right panel of (d) is the scaling exponent γ as a function of chromosome volume fraction ϕ for persistence lengths lp = 1 (gray color) and lp = 5 (black color).