C57Bl6 mice were purchased from Janvier Labs. Cx3cr1EGFP/+ (Jung et al., 2000 (link)), Csf1r-Gal4VP16/UAS-ECFP (MacBlue; Ovchinnikov et al., 2008 (link)), and Ccr2−/− mice were intercrossed to generate MacBlue × Cx3cr1EGFP/+, MacBlue × Cx3cr1EGFP/+ × Ccr2−/− litermate mouse strains. These strains, and MMTV PyMT-P2A-mCherry-P2A-OVA (PyMT-ChOVA) mice (Engelhardt et al., 2012 (link)) were bred at Pitié-Salpêtrière animal facility. Csf1rMeriCreMer; Rosa26tdTomato-LSL (Qian et al., 2011 (link)) and Tnfrsf11aCre; Rosa26YFP-LSL (Maeda et al., 2012 (link)) were bred at the Memorial Sloan Kettering Research Animal Resource Center. For the labeling of the EMP lineage, pulse labeling was performed in Csf1rMeriCreMer; Rosa26tdTomato-LSL E8.5 embryos with 4-hydroxytamoxifen (OH-TAM, Sigma-Aldrich). Embryonic development was estimated considering the day of vaginal plug formation as 0.5 d after coitum. Cre recombination was induced by a single injection of 37.5 mg per kg (body weight) of OH-TAM into pregnant females. OH-TAM was supplemented with 18.75 mg per kg (body weight) progesterone (Sigma-Aldrich) to counteract the mixed estrogen agonist effects of tamoxifen, which can result in fetal abortions.
All mice were maintained under SPF conditions and used between 8 and 14 wk old except for PyMT-ChOVA that develop primary breast tumors and lung metastases at around 25 wk.
All mice were maintained under SPF conditions and used between 8 and 14 wk old except for PyMT-ChOVA that develop primary breast tumors and lung metastases at around 25 wk.
