Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Moscow, Russia.
Dokl Biochem Biophys. 2024 Aug;517(1):259-263. doi: 10.1134/S1607672924700935. Epub 2024 Jul 13.
Nucleoli form interchromosomal contacts with genes controlling differentiation and carcinogenesis. DUX4 genes specify transcription factor possessing two homeodomains. Previously, using Circular Chromosome Conformation Capture (4С) approach on population of cells, it was demonstrated that DUX4 gene clusters form frequent contacts with nucleoli. It was found also that these contacts are almost completely abolished after heat shock treatment. 4C approach as all ligation-mediated methods is capable to detect rather close interactions between chromatin loops in nuclei. In order to independently confirm the formation and the frequency of the contacts in single cells we used FISH approach. Here, we show that DUX genes in single cells form stable contacts in all tested HEK293T cells. During heat shock, DUX4 genes reversibly move 1-3 µm away from the nuclei. We conclude that interchromosomal contacts formed by nucleoli are strong, dynamic, and reversible, providing both the initiation and maintenance of a differentiated state.
核仁与控制分化和癌变的基因形成染色体间接触。DUX4 基因指定具有两个同源结构域的转录因子。先前，在细胞群体中使用环形染色体构象捕获（4C）方法，证明 DUX4 基因簇与核仁形成频繁接触。还发现这些接触在热休克处理后几乎完全消除。4C 方法与所有连接介导的方法一样，能够检测细胞核中染色质环之间的相当接近的相互作用。为了在单细胞中独立确认接触的形成和频率，我们使用了 FISH 方法。在这里，我们表明，在所有测试的 HEK293T 细胞中，DUX 基因在单细胞中形成稳定的接触。在热休克期间，DUX4 基因可逆地从核中移动 1-3 µm。我们得出结论，核仁形成的染色体间接触是强大的、动态的和可逆的，为分化状态的启动和维持提供了条件。
