利用动态力松弛探测染色体结构。

Probing chromosome structure with dynamic force relaxation.

作者信息

Poirier M G, Nemani A, Gupta P, Eroglu S, Marko J F

机构信息

Department of Physics, University of Illinois at Chicago, 60607-7059, USA.

出版信息

Phys Rev Lett. 2001 Jan 8;86(2):360-3. doi: 10.1103/PhysRevLett.86.360.

DOI:10.1103/PhysRevLett.86.360

PMID:11177831

Abstract

We report measurements of the dynamics of force relaxation in single mitotic chromosomes, following step strains applied with micropipettes of force constant approximately 1 nN/microm. The force relaxes exponentially after an elongation (l/l(0)) to less than 3x native length, with a relaxation time approximately 2 sec. This relaxation time corresponds to an effective viscosity approximately 10(5) times that of water. We experimentally rule out solvent flow into the chromosome as the mechanism for the relaxation time. Instead, the relaxation can be explained in terms of the disentanglement dynamics of approximately 80 kb chromatin loop domains.

摘要

我们报告了在单条有丝分裂染色体中力松弛动力学的测量结果，这些测量是在使用力常数约为1 nN/μm的微量移液器施加阶跃应变之后进行的。在伸长至小于天然长度的3倍（l/l(0)）后，力呈指数松弛，松弛时间约为2秒。该松弛时间对应的有效粘度约为水的10^5倍。我们通过实验排除了溶剂流入染色体作为松弛时间的机制。相反，这种松弛可以用大约80 kb染色质环结构域的解缠结动力学来解释。