COP1 cooperates with Trib1 to increase committed myeloid progenitors. (A) CMP (Lin⁻c-Kit⁺Sca-1⁻FcR^loCD34⁺), GMP (Lin⁻c-Kit⁺Sca-1⁻FcR^hiCD34⁺), and MEP (Lin⁻c-Kit⁺Sca-1⁻FcR^loCD34⁻) in GFP-positive BM cells shown in Figure 6E were analyzed. (B) Several months after BMT, the populations containing CMP/GMP/MEP (Lin*^negSca-1⁻Mac1⁻c-Kit⁺), committed myeloid progenitors (Lin*^negSca-1⁻Mac1⁺c-Kit⁺), and differentiated myeloid cells (Lin*^negSca-1⁻Mac1⁺c-Kit^lo/−) in GFP-positive BM cells were analyzed as in Figure 5B. (C) BM cells isolated from mice transplanted with Trib1 BM cells and Trib1+COP1 BM cells were cultured in medium containing mouse IL3 (2.5 ng/mL), mouse GM-CSF (5 ng/mL), human CSF-1 (2000 U/mL), human G-CSF (25 ng/mL), and human Epo (1 U/mL). Cells were enumerated on the second and fourth days. *BM cells cultured with no cytokines, CSF-1, G-CSF, and Epo. (D) Summary of the data for the fourth day in C. Results shown in A and B are representative of 5 independent experiments. Data presented in C and D are averages of 3 independent experiments shown as means ± SD.