CRISPR-Cas9 is a sophisticated tool in which Cas9/sgRNA complexes bind to the programmed target sequences and induce DNA double-strand breaks (DSBs) enabling highly efficient genome editing. Moreover, when nuclease-inactive Cas9 (dCas9) is employed, its specific DNA-binding activity provides a variety of derivative technologies such as transcriptional activation/repression, epigenome editing, and chromosome visualization. In these derivative technologies, particular effector molecules are fused with dCas9 or recruited to the target site. However, there had been room for improvement, because both genome editing and derivative technologies require not only the DNA-binding tools but also the additional components for their efficient and flexible outcomes. For genome editing, DSB repair molecules and knock-in donor templates need to act at the DSB sites. Derivative technologies also require their various effector domains to be gathered onto the target sites. Recently, many groups have developed and utilized inventive platforms to accumulate these additional components to the target sequence by modifying Cas9 protein and/or sgRNA. Here, we summarize the strategies of CRISPR-based effector accumulation and the improved methodologies using these creative platforms.

CRISPR-Cas9是一种复杂的工具，其中Cas9 / sgRNA复合物与编程的靶序列结合并诱导DNA双链断裂（DSB），从而实现高效的基因组编辑。此外，当使用无核酸酶的Cas9（dCas9）时，其特定的DNA结合活性可提供多种衍生技术，例如转录激活/抑制，表观基因组编辑和染色体可视化。在这些衍生技术中，特定的效应分子与dCas9融合或募集到靶位点。但是，存在改进的空间，因为基因组编辑和衍生技术不仅需要DNA结合工具，而且还需要其他组件来实现有效而灵活的结果。对于基因组编辑，DSB修复分子和敲入供体模板需要在DSB位置起作用。衍生技术还要求将其各种效应子域收集到目标位点上。最近，许多小组已经开发并利用本发明的平台通过修饰Cas9蛋白和/或sgRNA将这些额外的组分积累到靶序列上。在这里，我们总结了基于CRISPR的效应子积累策略以及使用这些创新平台的改进方法。