Researchers have developed another efficient version of the CRISPR tool
Dubbed as ‘INTEGRATE’, the upgraded version introduces a gentle DNA editing technique
While the recent successful human trials based on CRISPR have infused new hope in the treatment of genetic diseases using this revolutionary medical tool, medical researchers continue to improve the techniques involved in the associated gene-editing process. One such improvement was introduced in CRISPR 2.0 using the prime editing technique.
The traditional CRISPR tool works by identifying a defective gene causing a certain disease, then using the CRISPR tool like a pair of DNA scissors to cut this defected gene & replacing it with a healthy gene strand. Critics of this process point out that this cut and paste of genes is pretty invasive and can cause unintended results sometimes. Therefore, the researchers have been working on a more benign version of the solution.
The prime editing technique is one such attempt. More recently, researchers at Columbia University have developed another version of the CRISPR tool which accomplishes the same process but in a gentler way. This new approach is highlighted in the new system devised by the team, which is called INTEGRATE (Insertion of Transposable Elements by Guide RNA-Assisted Targeting).
The new tool is based on a “jumping gene” found in Vibrio cholerae bacteria which was discovered by the researchers earlier this year. It is called as such since the gene had the capability of jumping around the genome and inserting itself into different places without the cutting of the DNA strand. In essence, the process starts off as the CRISPR tool but has a different ending.
“These new images, a wonderful collaboration with Israel Fernández’s lab, explain the biology with incredible molecular detail and will help us improve the system by guiding protein engineering efforts.”
~ Sam Sternberg, Lead Researcher
The tool employed a Nobel Prize-winning technique called cryo-electron microscopy — a process whereby a sample of the gene-editing complex is flash-frozen in liquid nitrogen and then bombarded with electrons, basically slowing things down at sub-microscopic stage to get a clear picture with the fine resolution images that are captured with the electron microscope.
The team determined that INTEGRATE used the same scanning mechanism as the traditional CRISPR tool, which cuts both strands of the target DNA to repair the defected genes, but this process can often produce unintended gene-edits on top of performing poorly when it comes to inserting large genetic payloads in a precise fashion.
The INTEGRATE tool, on the other hand, is much more efficient & accurate. It uses the guide RNA to scan the cell, looking for a matching DNA sequence. Once found, it threads its own genes through TniQ “transposition” proteins, then employing other enzymes to help change the DNA. The new tool would enable scientists to perform gene-editing in other cell types like neurons where CRISPR has been comparatively less successful.
Complete Research is published in Journal Nature.