Nicked DNA being repaired by DNA ligaseWIKIMEDIA, MEDCHETaking advantage of a deaminase enzyme that introduces a single nucleotide change to DNA, researchers have created a modified CRISPR/Cas9 tool that avoids the generation of a deleterious double-stranded break, minimizes the potential for the introduction of collateral mutations, and does not require the addition of a DNA template. The new method, described today (August 4) in Science, is the second reporting of such a precise gene-editing tool.
“These deaminases solve the biggest problems with most previous genome-editing methods, including TALENSs, zinc finger nucleases, and Cas9, which is that the desired edits are in competition with random insertions an deletions via non-homologous end-joining (NHEJ),” wrote Harvard University’s George Church whose lab has also developed a deaminase-based base-editing tool. The newly described system “also “reduces the toxicity caused by double stranded breaks,” he added.
“It is always encouraging and helpful for the field when another lab replicates a major finding,” said David Liu, a professor of chemical biology at Harvard University whose lab recently described a similar technique using a different deaminase enzyme. “The authors here were also able to demonstrate that this gene editing strategy works in cells.”
With the CRISPR/Cas9 system, researchers ...
