Symmetry-based classification of forces driving chromatin dynamics
Symmetry-based classification of forces driving chromatin dynamics
复制标题
基于对称性的染色质动力学驱动力分类
DOI：
10.1039/d2sm00840h
复制
发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Grosberg, Alexander Y.
中科院分区：
文献类型：
--
作者：
Eshghi, Iraj;Zidovska, Alexandra;Grosberg, Alexander Y.
染色质-细胞中DNA的功能形式-以聚合物的形式存在于细胞核内的核质液中。染色质和核质都受到局部生物过程产生的主动力的影响。这种活动导致非平衡现象，影响染色质的组织和动力学，但其背后的物理机制还远未被理解。在这里，我们扩大了以前开发的双流体模型的染色质和核质考虑三种类型的活动的形式的力偶极子-两个与两个力的偶极子作用在同一流体（无论是聚合物或核质）和第三，两个力推动染色质和溶剂在相反的方向。我们发现，后一种类型的结果在最重要的流量，占主导地位的最感兴趣的长度尺度。由于流体之间的摩擦和粘度，我们观察到紧急屏蔽长度尺度在这个系统的主动流。我们预测，不同的活动类型和它们的相对强度的存在下，可以推断从观察的动力学波动的染色质和核质的功率谱。
Chromatin – the functional form of DNA in the cell – exists in the form of a polymer immersed in a nucleoplasmic fluid inside the cell nucleus. Both chromatin and nucleoplasm are subject to active forces resulting from local biological processes. This activity leads to non-equilibrium phenomena, affecting chromatin organization and dynamics, yet the underlying physics is far from understood. Here, we expand upon a previously developed two-fluid model of chromatin and nucleoplasm by considering three types of activity in the form of force dipoles – two with both forces of the dipole acting on the same fluid (either polymer or nucleoplasm) and a third, with two forces pushing chromatin and solvent in opposite directions. We find that this latter type results in the most significant flows, dominating over most length scales of interest. Due to the friction between the fluids and their viscosity, we observe emergent screening length scales in the active flows of this system. We predict that the presence of different activity types and their relative strengths can be inferred from observing the power spectra of hydrodynamic fluctuations in the chromatin and the nucleoplasm.