Abstract: Described herein are compositions and methods that provide precise editing of cells, including mammalian cells and human cells. The compositions and methods utilize retrons as repair donors, retron reverse transcriptases to make those retron repair donors, retron-encoded guide RNAs, and CRISPR nucleases.

Abstract: Described herein are retrons that are engineered to have binding sites for transcription factors, as well as compositions, systems, and methods for obtaining and using such engineered retrons.

Abstract: Engineered retrons, modified to enhance production of multicopy single-stranded DNA (msDNA), are provided. In addition, vector systems encoding such engineered retrons and methods of using engineered retrons and vector systems encoding them in various applications such as CRISPR/Cas-mediated genome editing, recombineering, cellular barcoding, and molecular recording are also disclosed.

Abstract: Engineered retrons, modified to enhance production of multicopy single-stranded DNA (msDNA), are provided. In addition, vector systems encoding such engineered retrons and methods of using engineered retrons and vector systems encoding them in various applications such as CRISPR/Cas-mediated genome editing, recombineering, cellular barcoding, and molecular recording are also disclosed.

Abstract: Methods and compositions for introducing an exogenous mitochondrion harvested from a donor cell into a recipient cell are provided. Also provided are methods and compositions for producing a modified mitochondrion and treating mitochondrial disease in an individual with the mitochondrial disease. Further provided are modified mitochondria, genetically modified mitochondria, genetically modified cells, isolated compositions and pharmaceutical compositions for practicing the subject methods.