A CRISPR on-off switch for genes controls expression without altering DNA - The Science Board

April 12, 2021 -- A new gene silencing tool allows scientists to switch genes on and off without altering genetic sequences.

The tool, described in a paper published in Cell on April 9, uses a modified CRISPR-Cas9 system to introduce reversible epigenetic changes that control gene expression.

To get around this difficulty, Weissman and his colleagues attempted to find a way to control gene expression without altering the genetic sequence.

Gene expression is controlled naturally in the cell through epigenetic changes, such as adding methyl groups to the DNA strands.

Another tool called CRISPRon, a fusion protein including transcriptional activator domains, can reverse the process and switch the genes back on.

"The big story here is we now have a simple tool that can silence the vast majority of genes," said Weissman.

It's a great tool for controlling gene expression.".

"I think our tool really allows us to begin to study the mechanism of heritability, especially epigenetic heritability, which is a huge question in the biomedical sciences," said first author James Nuñez, PhD, a postdoctoral researcher in Weissman's lab?

It could also potentially be used to increase the expression of some genes by silencing the antisense RNA transcripts that inhibit those genes