Vienna Biocenter Core Facilities, Vienna Biocenter (VBC), Dr. Bohr Gasse 3, Vienna, Austria.
Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Vienna Biocenter (VBC), Dr. Bohr Gasse 3, 1030, Vienna, Austria.
Nat Commun. 2019 Nov 29;10(1):5454. doi: 10.1038/s41467-019-13403-y.
CRISPR-Cas9 is an efficient and versatile tool for genome engineering in many species. However, inducible CRISPR-Cas9 editing systems that regulate Cas9 activity or sgRNA expression often suffer from significant limitations, including reduced editing capacity, off-target effects, or leaky expression. Here, we develop a precisely controlled sgRNA expression cassette that can be combined with widely-used Cre systems, termed CRISPR-Switch (SgRNA With Induction/Termination by Cre Homologous recombination). Switch-ON facilitates controlled, rapid induction of sgRNA activity. In turn, Switch-OFF-mediated termination of editing improves generation of heterozygous genotypes and can limit off-target effects. Furthermore, we design sequential CRISPR-Switch-based editing of two loci in a strictly programmable manner and determined the order of mutagenic events that leads to development of glioblastoma in mice. Thus, CRISPR-Switch substantially increases the versatility of gene editing through precise and rapid switching ON or OFF sgRNA activity, as well as switching OVER to secondary sgRNAs.
CRISPR-Cas9 是一种在许多物种中进行基因组工程的高效、通用工具。然而,诱导型 CRISPR-Cas9 编辑系统在调节 Cas9 活性或 sgRNA 表达时常常受到显著限制,包括编辑能力降低、脱靶效应或漏表达。在这里,我们开发了一种精确控制的 sgRNA 表达盒,可以与广泛使用的 Cre 系统相结合,称为 CRISPR-Switch(通过 Cre 同源重组诱导/终止的 sgRNA)。Switch-ON 有利于 sgRNA 活性的受控、快速诱导。反过来,Switch-OFF 介导的编辑终止可以提高杂合基因型的产生,并限制脱靶效应。此外,我们以严格可编程的方式设计了基于 CRISPR-Switch 的两个基因座的顺序编辑,并确定了导致小鼠胶质母细胞瘤发生的突变事件的顺序。因此,CRISPR-Switch 通过精确和快速的 sgRNA 活性 ON 或 OFF 切换,以及切换到辅助 sgRNA,极大地增加了基因编辑的多功能性。