Research progress in microbial gene editing based on retrons

Abstract:

A retron, a bacterial genetic element mainly composed of a non-coding RNA and a reverse transcriptase, is involved in the anti-phage defense system. Since retrons can produce multi-copy single-stranded DNAs, combining retrons with proteins of homologous recombination or CRISPR/Cas has achieved efficient and accurate gene editing in bacteria and yeast, without relying on the direct introduction of exogenous DNAs. The optimized retron system can be applied in multiple fields such as mutant library construction, molecular recorder, and continuous evolution of proteins. This review introduces the structures and molecular mechanisms of retrons, summarizes the application of retron-based gene editing in bacteria and fungi, and analyzes the advantages and limitations of this technology. Finally, the future development of gene editing based on retrons is prospected.