Eukaryotic genomes are highly ordered through various mechanisms, including topologically associating domain (TAD) organization. We employed an in situ Hi-C approach to follow the 3D organization of the fission yeast genome during the cell cycle. We demonstrate that during mitosis, large domains of 300 kb–1 Mb are formed by condensin. This mitotic domain organization does not suddenly dissolve, but gradually diminishes until the next mitosis. By contrast, small domains of 30–40 kb that are formed by cohesin are relatively stable across the cell cycle. Condensin and cohesin mediate long- and short-range contacts, respectively, by bridging their binding sites, thereby forming the large and small domains. These domains are inversely regulated during the cell cycle but assemble independently. Our study describes the chromosomal oscillation between the formation and decay phases of the large and small domains, and we predict that the condensin-mediated domains serve as chromosomal compaction units.

中文翻译：

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细胞周期中裂变酵母基因组的结构改变

真核基因组通过各种机制（包括拓扑关联域（TAD）组织）高度有序。我们在原地雇用了Hi-C方法在细胞周期中遵循裂变酵母基因组的3D组织。我们证明，在有丝分裂过程中，凝集素形成了300 kb–1 Mb的大区域。该有丝分裂域组织不会突然溶解，但会逐渐减少，直到下一次有丝分裂为止。相比之下，粘着蛋白形成的30–40 kb的小区域在整个细胞周期中相对稳定。缩合蛋白和粘着蛋白通过桥接它们的结合位点分别介导长距离和短距离接触，从而形成大和小结构域。这些域在细胞周期中被反向调节，但独立组装。我们的研究描述了大域和小域的形成阶段和衰变阶段之间的染色体振荡，并且我们预测凝集素介导的域可作为染色体紧缩单位。