Researchers have managed to unlock a new CRISPR system that targets RNA, rather than DNA.

CRISPR – or clustered regularly interspaced short palindromic repeats – is a relatively new genome editing tool which could transform the field of biology. It allows scientists to edit genomes with unprecedented precision, efficiency and flexibility.

And this latest discovery, by researchers from the Broad Institute of MIT and Harvard, Massachusetts Institute of Technology (MIT), the National Institutes of Health (NIH), Rutgers University – New Brunswick and the Skolkovo Institute of Science and Technology, has the potential to open up a powerful avenue in cellular manipulation.

While DNA editing makes permanent changes to the genome of a cell, this CRISPR-based RNA targeting approach may allow researchers to make temporary changes that can be adjusted with greater functionality than any existing methods.

The findings – which have been published in Science – report the identification and functional characterisation of C2c2, an enzyme capable of targeting and degrading RNA.

C2c2, the first naturally-occurring CRISPR system targeting RNA, helps protect bacteria against viral infection. It can be programmed to split particular RNA sequences in bacterial cells, which would make it an important addition to the field of molecular biology.

The ability to specifically target RNA – which helps carry out genomic instructions – presents an option to precisely manipulate RNA in a high-throughput manner, and edit gene function more broadly. This is particularly exciting as it has the potential to accelerate progress to understand, treat and prevent disease.

“C2c2 opens the door to an entirely new frontier of powerful CRISPR tools,” explained Feng Zhang, senior author and member of the Broad Institute. “There are an immense number of possibilities for C2c2 and we are excited to develop it into a platform for life science research and medicine.”

Eugene Koonin, senior author and leader of the evolutionary genomic group at the NIH, added: “The study of C2c2 uncovers a fundamentally novel biological mechanism that bacteria seem to use in their defense against viruses. Application of this strategy could be quite striking.”

The most common technique for carrying out gene knockdown is currently small interfering RNA (siRNA). But according to the researchers, RNA editing methods using C2c2 could enable greater specificity and hold the potential for a wider range of applications.

The team was able to precisely target and remove specific RNA sequences using C2c2, which suggests that it could represent an alternative approach to siRNA, offering researchers adjustable gene knockdown capability.

Reiterating the importance of the finding for medical and genetic research, co-first author Omar Abudayyeh concluded: “C2c2’s greatest impact may be made on our understanding of the role of RNA in disease and cellular function.”