The gene-editing tool that has revolutionized biology is becoming even more powerful.
CRISPR, as the system is known, allows scientists to target and snip a specific sequence of letters on a strand of DNA with unprecedented precision. That has opened up new possibilities for treating genetic diseases, helping plants adapt to global warming and even preventing mosquitoes from spreading malaria.
CRISPR is made up of two basic components. The first is a piece of RNA that locates a predetermined sequence of DNA in an organisms genome that scientists want to alter. The second is a type of protein called an enzyme that attaches itself to the target section of DNA and splices it.
Cas9 has been the workhorse enzyme because it executes a neat, blunt cut. But in the last few years, scientists have started to search for and find alternative CRISPR systems that cut with enzymes other than Cas9.