Inducible Genetic Manipulation in Mice

Housing of mice and in vivo experiments were performed in compliance with the European Communities Council Directive of 24, November 1986 (86/609/EEC) and national and institutional guidelines. Animal care and experimental procedures were approved by the Animal Care Committee of the Institute of Molecular Genetics (ref. 58/2017). Apc^cKO/cKO mice [41 (link)] were obtained from the Mouse Repository (National Cancer Institute, Frederick, MD, USA); Villin-CreERT2 mice [42 (link)] were kindly provided by Sylvie Robine (Institut Curie, Centre de Recherche, Paris, France); Apc^+/Min (C57BL/6J-ApcMin/J) [43 (link)], Ki67-RFP (Mki67tm1.1Cle/J) [44 (link)], Lgr5-EGFP-IRES-CreERT2 (B6.129P2-Lgr5tm1(cre/ERT2)Cle/J) [45 (link)], and Rosa26-tdTomato (B6;129S6-Gt(ROSA)26Sortm14(CAG-tdTomato)Hze/J) [46 (link)] mice were purchased from the Jackson Laboratory (Bar Harbor, ME, USA). The animals were kept under specific pathogen-free conditions. To induce Cre-mediated gene recombination, mice were gavaged with 1 mg tamoxifen (Merck). tamoxifen was dissolved in ethanol (100 mg/mL) and combined (1:9) with mineral oil (Merck) before administration. Mice were sacrificed by cervical dislocation at various time points after administration of a single dose (100 µL) of the tamoxifen/oil solution.