Cas9/Nickase-induced allelic conversion by homologous chromosome-templated repair in Drosophila somatic cells

• DOI: 10.1126/sciadv.abo0721
• Publication Date: 2022-07-01T17:55:26Z
• Authors: Sitara Roy; Sara Sanz Juste; Marketta Sneider; Ankush Auradkar; Carissa Klanseck; Zhiqian Li; Alison Henrique F...; Victor Lopez del Amo; Ethan Bier; Annabel Guichard
• Keywords: Homology directed repair; Gene conversion

Repair of double-strand breaks (DSBs) in somatic cells is primarily accomplished by error-prone nonhomologous end joining and less frequently precise homology-directed repair preferentially using the sister chromatid as a template. Here, Drosophila system performs efficient both DSBs single-strand (SSBs) intact sequences from homologous chromosome process we refer to chromosome-templated (HTR). Unexpectedly, HTR-mediated allelic conversion at white locus was more (40 65%) response SSBs induced Cas9-derived nickases D10A or H840A than fully active Cas9 (20 30%). phenotypes elicited Nickase versus differ developmental timing (late early stages, respectively) production undesired mutagenic events (rare frequent). Nickase-mediated HTR represents an unanticipated mechanism for correction, with far-reaching potential applications field gene editing.