Powerful CRISPR system inserts whole gene into human DNA

A new genome-editing tool promises to insert entire genes, precisely and efficiently, into human DNA. The method uses a bacterial enzyme complex called a CRISPR-associated transposase (CAST), which can introduce full-length genes at targeted sites in a single step, without creating double-stranded breaks in DNA. Researchers used directed evolution — a process that harnesses the power of Darwinian natural selection in the lab — to produce an optimised version of the enzyme complex, called evoCAST, that showed a more than 400-fold improvement in efficiency over the non-evolved original.