Dataset Information

CRISPR-Switch regulates sgRNA activity by Cre recombination for sequential editing of two loci.

ABSTRACT: 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.

SUBMITTER: Chylinski K

PROVIDER: S-EPMC6884486 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

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CRISPR-Switch regulates sgRNA activity by Cre recombination for sequential editing of two loci.

Chylinski Krzysztof K Hubmann Maria M Hanna Ruth E RE Yanchus Connor C Michlits Georg G Uijttewaal Esther C H ECH Doench John J Schramek Daniel D Elling Ulrich U

Nature communications 20191129 1

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 recombin ...[more]

PMID: 31784531

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Project description:BACKGROUND:The CRISPR/Cas (clustered regularly interspaced short palindromic repeat and CRISPR-associated nucleases) based technologies have revolutionized genome engineering. While their use for prokaryotic genome editing is expanding, some limitations remain such as possible off-target effects and design constraints. These are compounded when performing systematic genome editing at distinct loci or when targeting repeated sequences (e.g. multicopy genes or mobile genetic elements). To overcome these limitations, we designed an approach using the same sgRNA and CRISPR-Cas9 system to independently perform gene editing at different loci. RESULTS:We developed a two-step procedure based on the introduction by homologous recombination of 'bait' DNA at the vicinity of a gene copy of interest before inducing CRISPR-Cas9 activity. The introduction of a genetic tool encoding a CRISPR-Cas9 complex targeting this 'bait' DNA induces a double strand break near the copy of interest. Its repair by homologous recombination can lead either to reversion or gene copy-specific editing. The relative frequencies of these events are linked to the impact of gene editing on cell fitness. In our study, we used this technology to successfully delete the native copies of two xenogeneic silencers lsr2 paralogs in Streptomyces ambofaciens. We observed that one of these paralogs is a candidate-essential gene since its native locus can be deleted only in the presence of an extra copy. CONCLUSION:By targeting 'bait' DNA, we designed a 'generic' CRISPR-Cas9 toolkit that can be used to edit different loci. The differential action of this CRISPR-Cas9 system is exclusively based on the specific recombination between regions surrounding the gene copy of interest. This approach is suitable to edit multicopy genes. One such particular example corresponds to the mutagenesis of candidate-essential genes that requires the presence of an extra copy of the gene before gene disruption. This opens new insights to explore gene essentiality in bacteria and to limit off-target effects during systematic CRISPR-Cas9 based approaches.

Dataset Information

CRISPR-Switch regulates sgRNA activity by Cre recombination for sequential editing of two loci.

Publications

CRISPR-Switch regulates sgRNA activity by Cre recombination for sequential editing of two loci.

Similar Datasets

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