EpoR-tdTomato-Cre–mediated cleavage in erythroid cells. FL (A) and BM (B) erythroblasts. Left panels: representative plots of FSC-A vs CD44 of Ter119⁺ cells. Erythroblasts were gated. Right panels: expression of EpoR-tdTomato or R26R-EYFP in erythroblasts of different mouse strains as indicated. FL (C) and BM (D) progenitors. Left panels: representative plots of c-Kit vs CD71 of 7AAD^–Linages^–CD16^–CD32^–CD41^–CD34^–Sca1^– cells revealing 3 populations of the c-Kit⁺ cells. Right panels: expression of EpoR-tdTomato or R26R-EYFP in each erythroid progenitor population of different mouse strains as indicated. N = 3. FSC-A, forward scatter area.