Editing compact gene segments TALEN is more efficient than CRISPR

Schematic diagram of gene editing.

Using single-molecule imaging tools, the researchers observed that the editing tool TALEN is up to five times more efficient than CRISPR-Cas9 at editing relatively tightly coiled regions of genes like heterochromatin.

Heterochromatin is a tightly assembled structure within DNA. Diseases such as fragile X syndrome, sickle cell anemia and beta-thalassemia have been linked to defects in heterochromatin.

Huimin Zhao, a professor of chemical and biomolecular engineering at the University of Illinois at Urbana-Champaign, who led the study, said the research shows the need to expand the selection of gene editing tools to target genes. The study shows the need to expand the selection of gene editing tools to target different parts of the genome.

“CRISPR is an innovation in genetic engineering and a very powerful tool, but it also has limitations,” Zhao said. Hui-Min Zhao said.

CRISPR is a bacterial molecule that detects invading viruses and then allows biological enzymes, such as Cas-9, to shear at specific locations in the genome. talen also scans DNA to find and target specific genes. both CRISPR and talen can be designed to target specific genes for use in treating diseases, improving crop characteristics, and more.

Hui-Min Zhao’s group uses single-molecule fluoroscopy to directly observe the two gene editing tools at work in living mammalian cells. The fluoroscopic markers give researchers a way to measure the Time it takes for the two tools to edit genes.

“We found that CRISPR performed better at loosely coiled locations within the genome, while TALEN performed better in heterochromatin regions.” Hui-Min Zhao said, “We also found that TALEN cut and modified DNA more efficiently than CRISPR.” In several experiments they conducted, TALEN was up to five times more efficient than CRISPR.

Zhao Hui-min said the study shows that researchers need to select the most appropriate editing tools to use for different segments of the genome.

The study was recently published in the journal Nature Communications.