Remini Loucif, Segers Midas, Parmeggiani Andrea, Carlon Enrico
Laboratoire Charles Coulomb (L2C), Univ Montpellier, CNRS, Montpellier, France.
Soft Matter and Biophysics, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium.
J Chem Phys. 2025 Feb 7;162(5). doi: 10.1063/5.0236067.
We analyze multiplexed fluorescence in situ hybridization (m-FISH) data for human and mouse cell lines. The m-FISH technique uses fluorescently-labeled single-stranded probes which hybridize to specific chromosomal regions, thereby allowing the measurement of the spatial positions of up to ∼100 tagged sites for several thousands of interphase chromosomes. Our analysis focuses on a wide range of different cell lines and two distinct organisms and provides a unified picture of chromatin structure for scales ranging from 5 kb (kilobases) up to 2 Mb (megabases), thus covering a genomic region of almost three orders of magnitude. Confirming recent analysis [Remini et al., Phys. Rev. E 109, 024408 (2024)], we show that there are two characteristic arrangements of chromatin referred to as phase α (crumpled globule) and phase β (looped domain) and discuss the physical properties of these phases. We show that a simple heterogeneous random walk model captures the main behavior observed in experiments and brings considerable insights into chromosomal structure.
我们分析了人类和小鼠细胞系的多重荧光原位杂交（m-FISH）数据。m-FISH技术使用荧光标记的单链探针，这些探针与特定的染色体区域杂交，从而能够测量数千个间期染色体上多达约100个标记位点的空间位置。我们的分析聚焦于广泛的不同细胞系和两种不同的生物体，并提供了一个从5千碱基（kb）到2兆碱基（Mb）范围内染色质结构的统一图景，从而覆盖了近三个数量级的基因组区域。证实了最近的分析[雷米尼等人，《物理评论E》109, 024408 (2024)]，我们表明染色质存在两种特征性排列，分别称为α相（皱缩球体）和β相（环状结构域），并讨论了这些相的物理性质。我们表明，一个简单的非均匀随机游走模型捕捉到了实验中观察到的主要行为，并为染色体结构带来了相当多的见解。
