Discovery and engineering of retrons for precise genome editing.

Highly efficient retron-based gene editors for mammalian cells and vertebrates achieve editing levels comparable to conventional methods using a genetically encoded cassette.

• Why it matters: Current gene editing tools face limitations in efficiency and delivery, especially in eukaryotic systems, highlighting the need for more versatile and precise approaches.
• What they did: The authors identified and engineered retron reverse transcriptases through bioinformatics and functional screening, improving editing efficiency and expanding target scope with Cas12a and Cas9 enzymes, and developed DNA-free delivery methods.
• The result: The engineered retron editors enable precise, versatile genome editing, including live-cell imaging with split GFP tags and DNA-free editing in cells and embryos, broadening potential applications.