The team of scientists behind the Crispr-cas9 gene-editing tool have found a way to mimic a tactic used by viruses to improve their original breakthrough. It is hoped that the discovery will prove to be the next major step forward in improving the efficiency of how DNA is doctored.

The advancement comes from the discovery of a molecular machine used by viruses to trick bacteria into helping, rather than hindering their spread. The Crispr-cas9 gene-editing tool is able to identify a particular strand of DNA, snip it out and replace it. The technique has revolutionised genetic engineering by drastically reducing its cost and the amount of time and effort required and is considered one of the most important genetic breakthroughs of the century.

Crispr itself was created using the blueprint for a weapon bacteria have evolved to fight viruses. When attacked by viruses, the bacteria respond by targeting their DNA and chopping it up, disabling the pathogens.

However, some viruses have upped the ante in their arms race with bacteria by learning how to ‘hijack’ bacteria, which are then tricked into attacking rival viruses with Crispr. The protein machine the viruses use to achieve this, discovered the team from Berkeley who in 2012 created Crispr, is more efficient than that used by the bacteria. It is more compact and efficient.

Research recently published by the team in the Science journal details how the team have mimicked the viral protein machine in the same way they once did with the less efficient bacterial version. Laboratories involved in gene-editing should now be able to improve their own systems by recreating the same protein builder used by the viruses.

The virus-encoded protein produced by the new machine is around half the size of that used by Crispr-cas9, says Jennifer Doudna, who is one of the most renowned scientists behind the original tool. That, she says, is significant as it will make it a lot easier to deliver into cells.

One key question not addressed by the research published in Science, is if the new CasΦ system is as accurate as larger CRISPR-Cas systems. However, even if it is not, it is likely to have a role in gene-editing scenarios that necessitate a slightly lower level of precision.