MN1-TEL causes aggressive myeloproliferative disease when coexpressed with IL-3 in vivo. (A) Retroviral transduction of MN1-TEL⁺ BM cells. BM cells were harvested from 6- to 8-week-old MN1-TEL/Mx1-Cre mice 2 weeks after the last injection with pI-pC (MN1-TEL⁺) or phosphate-buffered saline (PBS; MN1-TEL^-). Sorted Lin^- cells were transduced with pSRα–IL-3–IRES–YFP (IL-3) or pSRα-IRES-YFP (vector) retroviral vectors. Transduction efficiency was examined by FCM. A representative result of MN1-TEL⁺ cells transduced with IL-3 virus is shown. Uninfected WT BM cells were used as a negative control. Quadrants were determined using uninfected WT cells and GFP or YFP single-positive cells. (B) Survival analysis. Retrovirus transduced cells were transplanted into lethally irradiated syngeneic recipient mice (n = 10 in each group). Survival curves were generated according to the Kaplan-Meier method using StatView version 5.0 software (SAS Institute Inc, Cary, NC).