(Yicai) Aug. 7 -- Chinese researchers have developed two advanced DNA editing tools that could lead to breakthroughs in crop breeding and new treatments for cancer and genetic diseases.

A team led by Gao Caixia at the Institute of Genetics and Developmental Biology under the Chinese Academy of Sciences created the tools to enable large-scale chromosomal rearrangements in both plant and human cells, according to a recent paper published in Cell, a US-based journal.

The scientists successfully engineered a 315-kilobase DNA rearrangement that enabled rice plants to survive herbicide treatment without damage. They also achieved a much larger 12-megabase inversion at sites associated with human diseases.

While genome editing has made major strides in recent years, challenges remain in achieving precise, large-scale modifications in complex organisms. Existing tools often suffer from inefficiency, limited editing range, and the presence of "scars" -- unwanted DNA fragments left behind after editing, the paper said.

To overcome these obstacles, the team enhanced the existing Cre-Lox system, a genetic engineering platform developed in the 1980s. They built a high-throughput engineering platform and introduced a novel approach by targeting asymmetric Lox sites instead of the traditional symmetrical sequences. This significantly improved editing precision and reduced the risk of unintended genetic changes, lowering DNA reversal by a factor of 10.

The researchers also used an artificial intelligence-informed model to create AiCErec, a recombinase engineering method that boosts the DNA recombination performance of the Cre recombinase enzyme by 3.5 times.

To address the issue of post-editing scars, the team developed Re-pegRNA, a cleanup technique using specially designed pegRNAs to remove residual sequences after DNA recombination.

This pioneering research not only addresses long-standing limitations of the Cre-Lox system but also paves the way for more precise genome engineering in a variety of organisms, the team concluded.

Editor: Emmi Laine