Tamoxifen-Induced Cre Recombination in Mouse Salivary Glands

All animal experiments and procedures were performed in accordance with the State University of New York at Buffalo (University at Buffalo) Institutional Animal Care and Use Committee (IACUC) regulations. All procedures were approved by University at Buffalo IACUC. C57BL/6J (Stock No. 000664), Rosa26-tdTomato (B6.Cg-Gt(ROSA)26Sor^{tm14(CAG-tdTomato)Hze}/J; Stock No. 007914), and UBC^CreERT2 (B6.Cg-Ndor1^{Tg(UBC-cre/ERT2)1Ejb}/1J; Stock No. 007001) mice were purchased from The Jackson Laboratory (Bar Harbor, Maine). Acta2^CreERT2 mice were provided from Pierre Chambon and ΔNp63-floxed (ΔNp63^fl/fl) mice were provided by Elsa Flores and have been described previously [26 (link), 31 (link)]. All mice were maintained on a C57BL/6J background. To induce Cre-loxP recombination for knockout studies and lineage tracing analysis, the inactive form of tamoxifen (TAM; Sigma-Aldrich, T-5648) was dissolved in corn oil, and 2 mg of TAM was intraperitoneally (IP) injected to 8-week adult mice twice as previously described [11 (link)]. Animals were euthanized by CO₂ inhalation and the salivary glands were further dissected at specific time points of interest. Sample sizes were determined according to the standard protocols in the field. No criteria was set for excluding mice and no blinding to group allocation was performed.