Department of Genetics, School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Mishima 411-8540, Japan.
Cell Architecture Laboratory, Department of Chromosome Science, National Institute of Genetics, Mishima 411-8540, Japan.
Phys Rev Lett. 2022 Apr 29;128(17):178101. doi: 10.1103/PhysRevLett.128.178101.
During early embryogenesis of the nematode, Caenorhabditis elegans, the chromatin motion markedly decreases. Despite its biological implications, the underlying mechanism for this transition was unclear. By combining theory and experiment, we analyze the mean-square displacement (MSD) of the chromatin loci, and demonstrate that MSD-vs-time relationships in various nuclei collapse into a single master curve by normalizing them with the mesh size and the corresponding time scale. This enables us to identify the onset of the entangled dynamics with the size of tube diameter of chromatin polymer in the C. elegans embryo. Our dynamical scaling analysis predicts the transition between unentangled and entangled dynamics of chromatin polymers, the quantitative formula for MSD as a function of nuclear size and timescale, and provides testable hypotheses on chromatin mobility in other cell types and species.
在秀丽隐杆线虫的早期胚胎发生过程中，染色质运动显著减少。尽管这具有生物学意义，但这种转变的潜在机制尚不清楚。通过理论和实验的结合，我们分析了染色质位点点的均方位移（MSD），并证明通过用网格大小和相应的时间尺度对它们进行归一化，可以将各种核中的 MSD-vs-时间关系压缩到单个主曲线上。这使我们能够通过线虫胚胎中染色质聚合物的管直径大小来识别纠缠动力学的开始。我们的动力尺度分析预测了染色质聚合物的未纠缠和纠缠动力学之间的转变，MSD 作为核大小和时间尺度函数的定量公式，并为其他细胞类型和物种中的染色质流动性提供了可测试的假设。
