Red2Flpe-SCON: a versatile, multicolor strategy for generating mosaic conditional knockout mice

Abstract

Image-based lineage tracing enables tissue turnover kinetics and lineage potentials of different adult cell populations to be investigated. Previously, we reported a genetic mouse model system, Red2Onco, which ectopically expressed mutated oncogenes together with red fluorescent proteins (RFP). This system enabled the expansion kinetics and neighboring effects of oncogenic clones to be dissected. We now report Red2Flpe-SCON: a mosaic knockout system that uses multicolor reporters to label both mutant and wild-type cells. We develop the Red2Flpe mouse line for red clone-specific Flpe expression, as well as the FRT-based SCON (Short Conditional IntrON) method to facilitate tunable conditional mosaic knockouts in mice. We use the Red2Flpe-SCON method to study Sox2 mutant clonal analysis in the esophageal epithelium of adult mice which reveal that the stem cell gene, Sox2, is less essential for adult stem cell maintenance itself, but rather for stem cell proliferation and differentiation. © The Author(s) 2024.; Inducible genetic mosaics can provide information about cellular lineages that are otherwise difficult to obtain. Here the authors report a mosaic knockout system called Red2Flpe-SCON, which allows lineage tracing of wild-type and mutant cells using a multicolour fluorescent reporter in mice. © The Author(s) 2024.