Scientists have developed a new tool for precise genome editing using retron technology, which allows for efficient and targeted modification of genes in cells and vertebrates. By identifying highly active retron reverse transcriptases and rational designing improved editors, researchers have achieved levels comparable to conventional single-stranded oligodeoxynucleotide donors but from a genetically encoded cassette. This breakthrough has the potential to expand the scope of genome editing and enable DNA-free gene editing in cells and embryos.
The discovery and engineering of highly efficient retron-based gene editors for mammalian cells and vertebrates is reported here. Through bioinformatic analysis of metagenomic data and functional screening, researchers identified retron reverse transcriptases that are highly active in mammalian cells. Rational design further improved the editing efficiency to levels comparable with conventional single-stranded oligodeoxynucleotide donors but from a genetically encoded cassette.
Retron editors exhibit robust activity with Cas12a nuclease and Cas9 nickase, expanding the genomic target scope and bypassing the need for a DNA double-stranded break. Using a rationally engineered retron editor, researchers incorporated a split GFP epitope tag for live-cell imaging. Lastly, they developed an all-RNA delivery strategy to enable DNA-free gene editing in cells and vertebrate embryos.
This work establishes retron editors as a versatile and efficient tool for precise genome editing, with potential applications in disease modeling, therapy, and basic research.
Source: https://www.nature.com/articles/s41587-025-02879-3