Abstract:
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.
摘要:
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。以前,使用圆形染色体构象捕获(4‰)方法对细胞群体,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失。4C方法作为所有连接介导的方法能够检测核中染色质环之间相当紧密的相互作用。为了独立地确认单细胞中接触的形成和频率,我们使用FISH方法。这里,我们显示在单个细胞中的DUX基因在所有测试的HEK293T细胞中形成稳定的接触。在热休克期间,DUX4基因可逆地远离细胞核1-3μm。我们得出结论,核仁形成的染色体间接触很强,动态,和可逆的,提供差异化状态的启动和维持。