The technique, described in a paper published in Cell on April 9, is reversible unlike traditional CRISPR, and the introduced changes can even be passed down to future lines of cells. This nondestructive gene-editing protein acts as a simple off switch for genes, recreating the benefits of the widely used CRISPR-Cas9 system without damaging cells' genetic material.
The researchers created a tiny protein machine to build an epigenetic editor that could imitate natural DNA methylation, which is an epigenetic mechanism that occurs by the addition of a methyl (CH3) group to DNA. The machine, guided by small RNAs, can turn methyl groups onto specific spots on the strand. The methylated genes are then "silenced," or turned off,
When the researchers silenced a gene in the stem cells and induced them to turn into neurons, it was seen that the gene remained silenced in 90 percent of the cells. This reveals that cells retain a memory of epigenetic modifications made by the CRISPRoff system.