Recently, David Liu won the Breakthrough Prize for inventing two tools for precise, small-scale genome editing (base editing and prime editing). However, in some cases, rather than correcting a mutation within a defective gene, it may be more practical to insert a fully functional copy of the gene. That’s the mission of evoCAST, the latest invention from the Broad Institute near Boston, a hub for next-generation CRISPR tools.

The system, developed by Liu in collaboration with Samuel Sternberg from Columbia University, was presented in Science and promises a major advance in the field of large DNA insertions.

This new approach is based on an enzyme complex that, in nature, enables the movement of mobile genetic elements known as transposons. A particular class of transposases has hijacked CRISPR to direct these insertions to specific genomic sites. The acronym CAST stands for “CRISPR-associated transposase,” while the prefix “evo” refers to the tool’s optimization through directed evolution.

Although the evoCAST platform is not yet ready for therapeutic use, it may one day prove valuable for treating diseases caused by a wide range of mutations within the same gene, such as cystic fibrosis or Stargardt disease. To learn more, we recommend this Nature news article.