University of Chicago scientists led by chemist Weixin Tang have created new CRISPR systems that are smaller and can easily slip into cells yet retain their potency. Tang's team hopes that these systems could someday pave the way toward improved therapies for diseases such as sickle cell disease, Huntington's disease, cystic fibrosis, and muscular dystrophy, among many others.
Tang and her lab started with the CRISPR-Cas12f system that was invented by others and was impressively small but did not always work very well once it got into cells. To boost the performance of CRISPR-Cas12f, they looked at the protein as they thought the system's flawed performance might be because its protein wasn't clamping onto the DNA inside the cell. The group experimented with different mutations and found five that, when combined, boosted the proteins' activity.
The team also looked at the RNA part of the system using cryogenic electron microscopy. They were able to reduce the RNA size by about a third, which according to the team is "a significant shortening." The team also found that it performs its functions just as well as the original, and was significantly more potent and precise when the final version was tested.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)