Generation of Spatio-Temporally Controlled Targeted Somatic Mutations in the Mouse.

The generation of ligand-activated site-specific Cre recombinases has led to the development of cell type-specific temporally controlled targeted somatic mutagenesis in the mouse. We illustrate this technique using K14-Cre-ER(T2) transgenic mice that express the tamoxifen (tam)-activatable Cre-ER(T2) recombinase in epidermal basal keratinocytes to induce mutations in epidermal keratinocytes of adult mice. Our highly reproducible technique, based on induction of Cre-ER(T2) recombinase activity by tamoxifen administration at low doses (once daily 100-µg intraperitoneal injection for 5 days), has allowed the generation of site-directed somatic mutations of numerous genes in mouse epidermal keratinocytes, and several mouse models of human diseases. The present step-by-step protocol describes how to introduce temporally controlled targeted mutations in epidermal keratinocytes of adult mice. Curr. Protoc. Mouse Biol. 1:55-70. © 2011 by John Wiley & Sons, Inc.