在真核生物中，异染色质的转录沉默不仅参与基因表达的调控，对于维持基因组的稳定性至关重要，而且能够经过DNA复制过程稳定传递。已有研究表明：DNA复制偶联的核小体组装在异染色质转录沉默的建立和维持过程中起着非常重要的作用，组蛋白分子伴侣是DNA复制偶联的核小体组装的关键因子。我们的前期工作表明：组蛋白分子伴侣FACT调控异染色质的转录沉默过程，然而其作用机制还是未知，这将是本项目的研究重点。本项目将通过染色质免疫共沉淀的方法分析FACT对异染色质区域Sir蛋白动态变化与组蛋白去乙酰化水平的影响，并进一步研究FACT与Sir蛋白的相互作用；利用微球菌核酸酶处理结合PCR检测分析FACT对核小体分布情况的影响；应用染色质构象捕获技术分析FACT对异染色质高级结构的影响。从异染色质形成的不同层次进行研究，以期阐明FACT参与异染色质转录沉默的作用机制，为理解表观遗传信息如何稳定传递提供理论依据。

In eukaryotes, heterochromatin silencing is crucial for not only the regulation of gene expression, but also the maintenance of genome stability. Previous studies has shown that DNA replication coupled nucleosome assembly plays an important role in the establishment and maintenance of heterochromatin silencing. Histone chaperones are key players during DNA replication coupled nucleosome assembly. Our previous work has indicated that histone chaperone FACT participates in the regulation of heterochromatin silencing. However, the mechanism underlying this process remains to be explored. In this study, we aim to investigate FACT’s role in heterochromatin silencing. Firstly, we plan to use the Chromatin immunoprecipitation (ChIP) assay to observe how FACT regulates Sir proteins recruitment and histone deacetylation during heterochromatin formation. And the interaction between FACT and Sir proteins will be further detected. Secondly, we will perform MNase digestion to analyze FACT’s effect on nucleosome dynamic. Lastly, we will employ chromosome conformation capture (3C) technology to analyze FACT’s role in the establishment of heterochromatin higher-order structure. Based on these research, we will clarify the mechanism by which FACT participates in heterochromatin silencing. It may provide clues for illuminating possible ways to ensure stable epigenetic inheritance.