Scientists just cracked the code to editing entire chromosomes flawlessly

Chinese scientists developed Programmable Chromosome Engineering (PCE) systems for precise, large-scale DNA editing. They improved the Cre-Lox system by creating asymmetric Lox sites, engineering efficient recombinase variants, and developing a scarless editing strategy. This allows for targeted integration of DNA fragments up to 18.8 kb, replacement of 5-kb sequences, chromosomal inversions spanning 12 Mb, deletions of 4 Mb, and whole-chromosome translocations. They demonstrated the technology's potential by creating herbicide-resistant rice with a 315-kb inversion.