Chromatin state switching in a polymer model with mark-conformation coupling

Kyosuke Adachi; Kyogo Kawaguchi

doi:10.1103/physreve.100.060401

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arXiv · 1907.10533

Chromatin state switching in a polymer model with mark-conformation coupling

Kyosuke Adachi·Kyogo Kawaguchi

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Abstract

We investigate the phase transition properties of the polymer-Potts model, a chain composed of monomers with magnetic degrees of freedom, with the motivation to study the conformation and mark switching dynamics of chromatin. By the mean-field approximation, we find that the phase transition between the swollen-disordered state and the compact-ordered state is discrete; it is first-order as in the long-range Potts model, but with a significantly larger jump in magnetization (i.e., mark coherence) upon the ordering transition. The results imply how small changes in epigenetic writer concentrations can lead to a macroscopic switching of the chromatin state, suggesting a simple mechanism of discrete switching observed, for instance, in cell differentiation.

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Kyosuke Adachi, Kyogo Kawaguchi. 2019-12-11. Chromatin state switching in a polymer model with mark-conformation coupling. https://doi.org/10.1103/physreve.100.060401

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