MIT and UCSF Researchers Create On and Off Switch for CRISPR

CRISPR has just got better with the latest gene editing technology called CRISPRoff. Researchers from the Massachusetts Institute of Technology and the University of California, San Francisco (UCSF) described the new reversible CRISPR method in the Cell journal.

Since its discovery, CRISPR-Cas9 has revolutionized genetic engineering by enabling researchers to make targeted modifications in the DNA. However, CRISPR-Cas9 involved cutting DNA strands, which can lead to permanent changes in the genetic material. With CRISPRoff, researchers can regulate gene expression with high specificity without changing the DNA of the organism. Such modifications, which are called "epigenetic gene silencing" become effective through methylation, which involves adding chemical tags to specific locations in the DNA. When tagged, the DNA portion becomes unreachable to RNA polymerase, which reads the genetic data in the DNA into mRNA transcripts that serve as blueprints for proteins.

The researchers developed a tiny protein machine that can tack methyl groups onto certain locations on the DNA strand. The methylated genes become silenced or switched off, thus the name CRISPRoff. Since the DNA strand is not changed, the researchers can reverse the silencing effect with the use of enzymes that remove methyl groups, a technique they dubbed as CRISPRon.

Read the press release in SciTech Daily and the research article in Cell for more information.