The "inviviable off-target verification" VIVO system detects off-target mutations in CRISPR-Cas9 in organisms.

An efficient detection system for genome-wide genome off-targeting effects of CRISPR-Cas9 genome editing has been tested in mice, according to a team of European and American scientists, according to a genetic editing study published online Tuesday in the journal Nature.
the results of this research will facilitate the transformation of genome editing from research to clinical.
CRISPR-Cas9 genome editing technology, known as "gene shears", is considered to have great potential in the history of human medicine, but only when additional non-target (off-target) mutations are fully identified and eliminated can the technology be truly clinically applied.
so-called off-target mutation, which refers to the CRISPR-Cas9 complex attached to multiple points in the genome and cut the wrong DNA fragments.
systems that detect this mutation must be tested in vitro and throughout the organism.
, researchers at Massachusetts General Hospital and AstraZeneca in Sweden described a highly sensitive "verification of in vivo off-targets" system that detects off-target mutations in organisms called CRISPR-Cas9.
VIVO system sits on potential off-target sites in advance and confirms that any sites have changed in the genome.
team tested the accuracy of the system in mouse livers by designing a variety of guided RNAs (gRNAs) that target the Pcsk9 gene in mice, including mixed gRNAs (which can target multiple points) and more specific gRNAs.
results confirm that the VIVO system not only detects dozens of off-target mutations induced by mixed gRNA (including mutations with an incidence rate of only 0.13%), but that properly designed gRNAs do not result in any detectable off-target mutations.
researchers believe that the VIVO system sets important criteria for defining the off-target effects of genome editing in practical applications and confirms the importance of designing highly specific gRNAs.
Source: ScienceDaily.