研究人员报道了一种利用活体细胞核内的可控磁力主动操纵基因组位点的方法。研究人员观察到，在接近皮牛顿的力的作用下，在几分钟内出现了超过微米的粘弹性位移，这与Rouse聚合物模型是一致的。这些结果突出了染色质的流动性，而周围材料的贡献不大，从而揭示了交联和拓扑效应的次要作用，并对间期染色质是一种凝胶状材料的观点提出挑战。这项技术为未来从染色体力学到基因组功能等领域的研究开辟了途径。
据悉，人们对组织细胞核内基因组的物理原理的理解受到了限制，因为缺乏工具来直接对体内的间期染色体施加和测量力并探测其物质性质。
附：英文原文
Title: Live-cell micromanipulation of a genomic locus reveals interphase chromatin mechanics
Author: Veer I. P. Keizer, Simon Grosse-Holz, Maxime Woringer, Laura Zambon, Koceila Aizel, Maud Bongaerts, Fanny Delille, Lorena Kolar-Znika, Vittore F. Scolari, Sebastian Hoffmann, Edward J. Banigan, Leonid A. Mirny, Maxime Dahan, Daniele Fachinetti, Antoine Coulon
Issue&Volume: 2022-07-29
Abstract: Our understanding of the physical principles organizing the genome in the nucleus is limited by the lack of tools to directly exert and measure forces on interphase chromosomes in vivo and probe their material nature. Here, we introduce an approach to actively manipulate a genomic locus using controlled magnetic forces inside the nucleus of a living human cell. We observed viscoelastic displacements over micrometers within minutes in response to near-piconewton forces, which are consistent with a Rouse polymer model. Our results highlight the fluidity of chromatin, with a moderate contribution of the surrounding material, revealing minor roles for cross-links and topological effects and challenging the view that interphase chromatin is a gel-like material. Our technology opens avenues for future research in areas from chromosome mechanics to genome functions.
DOI: abi9810
Source: https://www.science.org/doi/10.1126/science.abi9810