Correction of a Genetic Disease in Mouse via Use of CRISPR-Cas9

TLDR

CRISPR‑Cas9 has been widely used to generate mutant alleles, but efficient correction of a genetic disease had not yet been reported. The study aimed to rescue a dominant cataract‑causing Crygc mutation in mice by co‑injecting Cas9 mRNA and a sgRNA targeting the mutant allele into zygotes. Correction was achieved via homology‑directed repair using either an exogenous oligonucleotide or the endogenous wild‑type allele, with minimal off‑target events. The corrected mice were fertile, transmitted the repaired allele to offspring, and demonstrated proof of principle for CRISPR‑Cas9–mediated disease correction.

Abstract

Highlights•A dominant cataract-causing mutation in the Crygc gene is corrected using CRISPR-Cas9•Genetic correction via HDR uses information from the endogenous WT allele•Genetic correction can also occur using information from an exogenous oligo•The rescued mice can transmit the corrected allele to their progenySummaryThe CRISPR-Cas9 system has been employed to generate mutant alleles in a range of different organisms. However, so far there have not been reports of use of this system for efficient correction of a genetic disease. Here we show that mice with a dominant mutation in Crygc gene that causes cataracts could be rescued by coinjection into zygotes of Cas9 mRNA and a single-guide RNA (sgRNA) targeting the mutant allele. Correction occurred via homology-directed repair (HDR) based on an exogenously supplied oligonucleotide or the endogenous WT allele, with only rare evidence of off-target modifications. The resulting mice were fertile and able to transmit the corrected allele to their progeny. Thus, our study provides proof of principle for use of the CRISPR-Cas9 system to correct genetic disease.Graphical abstract