biostudies-literatureKhan AGNIBIB NIH HHSU.S. Department of Health & Human Services | NIH | National Institute of Biomedical Imaging and Bioengineering (NIBIB)National Science Foundation (NSF)NIGMS NIH HHSU.S. Department of Health & Human Services | NIH | National Institute of Biomedical Imaging and BioengineeringNational Science Foundation914-922https://www.ebi.ac.uk/biostudies/studies/S-EPMC11911249biostudies-literatureUnknown43(6)Retrons are bacterial immune systems that use reverse-transcribed DNA (RT-DNA) to detect phage infection. They are also deployed for genome editing, where they are modified so that the RT-DNA encodes an editing donor. Retrons are common in bacterial genomes, and thousands of unique retrons have been predicted bioinformatically. However, few have been characterized experimentally. We add to the corpus of experimentally studied retrons, finding 62 empirically determined, natural RT-DNAs that are not predictable from the retron sequence alone. We synthesize >100 previously untested retrons to identify the natural sequence of RT-DNA they produce, quantify their RT-DNA production and test the relative efficacy of editing using retron-derived donors to edit bacterial, phage and human genomes. WeNature biotechnologyAn experimental census of retrons for DNA production and genome editing.PMC11911249R21EB031393R21 EB031393MCB 2137692DP2 GM1409171DP2GM140917Shipman SLFang RFKhan AGCrawford KDRojas-Montero MGonzalez-Delgado ALopez SCfalseAn experimental census of retrons for DNA production and genome editing.Retrons are bacterial immune systems that use reverse-transcribed DNA (RT-DNA) to detect phage infection. They are also deployed for genome editing, where they are modified so that the RT-DNA encodes an editing donor. Retrons are common in bacterial genomes, and thousands of unique retrons have been predicted bioinformatically. However, few have been characterized experimentally. We add to the corpus of experimentally studied retrons, finding 62 empirically determined, natural RT-DNAs that are not predictable from the retron sequence alone. We synthesize >100 previously untested retrons to identify the natural sequence of RT-DNA they produce, quantify their RT-DNA production and test the relative efficacy of editing using retron-derived donors to edit bacterial, phage and human genomes. We2025-01-01T00:00:00Z2025 Jun2026-06-10T05:05:32.179Z2026-06-10T03:07:33.477ZS-EPMC119112493928952910.1038/s41587-024-02384-z