Analysis of Eyfp expression in primary and secondary recipients. (A) Overview of the experimental strategy: bone marrow of tamoxifen treated (5 mg day 1, 2 mg days 2-5) HSC-SCL-Cre-ER^T;R26R-EYFP mice (n = 2) was transplanted (day 8) into lethally irradiated congenic recipients (Ly5.1/CD45.1). After 6 months primary recipient bone marrow was transplanted into secondary recipients (Ly5.1/CD45.1). Peripheral blood was analyzed 6 months after the primary and 4 months after secondary transplants. The proportion of EYFP-positive cells was determined within donor-derived peripheral blood granulocytes (Gr-1^highCD45.2⁺), B cells (B220⁺CD45.2⁺), and T cells (CD3⁺CD45.2⁺). Representative plots are shown, and the indicated percentages represent means of 2 to 4 recipient mice. Dashed lines represent negative controls.