A new gene editing tool enables recording of linear cuts over time

Researchers from the University of Illinois at Chicago have discovered a new gene editing technique that allows programming of sequences – or edits – over time.

CRISPR is a gene editing tool that allows scientists to modify the DNA sequences in cells and sometimes insert a sequence or genes you want. CRISPR uses an enzyme called Cas9 that acts like scissors to make precise cuts at a desired location in the DNA. Once a cut is made, the ways in which cells repair DNA breakdown can have the effect of altering or differentiating the DNA sequence.

The gene editing capabilities in the CRISPR system were described in the early 2010s. In just a few years, scientists became easily identified by directing CRISPR to target almost any DNA sequence in a cell or to target many different sites in a cell in a single test.

“One advantage of the CRISPR-based editing systems right now is that all the edits or cuts are made all at once. There is no way in management until they happen in a sequential way, one after the other, “Bradley said at UIC. Merrill, associate professor of biochemistry and molecular genetics at the College of Medicine and lead author of the paper.

Merrill and colleagues ’new process involves the use of specific molecules called RNA guides that restore the Cas9 enzyme inside the cell and determine the exact DNA sequence at which Cas9 is involved. cut. Their specially engineered RNA guide is called “proGuides” and the molecules allow programmed sequential editing of DNA using Cas9.

Their findings are published in the journal Cell molecular.

While proGuide is still at prototype stage, Merrill and colleagues plan to develop their concept and hope that researchers can use this method soon.

“The ability to pre-record Cas9 activity at multiple sites includes a new tool for biological analysis and genetic engineering,” Merrill said. “The time factor is an essential part of human development and also disease progression, but the conventional methods for the genetic analysis of these processes do not work effectively with the time element. Our system allows gene editing in a pre-programmed manner, allowing researchers to better study time-sensitive processes such as how cancer develops from a number of gene mutations and how the order in which these mutations occur may affect the disease. “


University of Illinois at Chicago

Magazine Reference:

Clarke, R., et al. (2020) Continued implementation of Guidance RNAs to enable CRISPR-Cas9 Activities. Cell molecular. doi.org/10.1016/j.molcel.2020.12.003.