针对DNA复制起点的研究在原生动物类群中的缺乏，且一些基于基因组层面的DNA复制起点鉴定方法还存在缺陷这两大问题。本项目提出以模式原生动物嗜热四膜虫为研究对象、以高通量测序和生物信息学技术为主要手段、通过检测组蛋白3第27号赖氨酸单甲基化（H3K27me1）缺陷型细胞中的单链DNA，从而实现对嗜热四膜虫中DNA复制起点的鉴定及其特征分析。项目的实施不仅将填补相关领域的研究空白并增进对真核生物DNA复制起点及其特征的认识，而且将开辟在真核生物中鉴定DNA复制起点的又一新方法，对进行类似研究具有重要的指导意义。

Study of DNA replication origins identification is absent in protozoa, and there are some disadvantages of the genome-wide DNA replication origin identification methods. Focusing on these questions, this project will identify the DNA replication origins in model protozoa Tetrahymena thermophila, and analyze their characters by detecting the ssDNA in H3K27me1 deficient cells using high-throughput sequencing techniques and bioinformatics methods. The implementation of this project will not only fill the gap in related field and enhance the understanding of eukaryotic DNA replication origins and their characteristics,but also establish a new genome-wide DNA replication origin identification method and give a important reference to similar studies.