Figure 3. Trib2 is preferentially expressed in hematopoietic progenitors of the erythroid lineage.

(A) Semi-quantitative RT-PCR analysis for differential expression of mRNA of the Trib2 gene and key regulatory transcription factors in various hematopoietic stem and progenitor cells. Bone marrow mononuclear cells were isolated from a femur of wild-type mice, and 5 × 10⁷ cells were subjected to FACS. See Supplementary Figure S3A for in-depth descriptions of LKS⁺, CMP, GMP and MEP. (B) Q-PCR of Trib2 mRNA in MEPs and four developmental stages of erythroblasts in bone marrow. Total bone marrow cells were isolated and purified with antibodies for CD71 and Ter119. See Supplementary Figure S3B for definitions of R1, R2, R3 and R4, n = 4. (C,D) Semi-quantitative RT-PCR analysis for differential expression of Trib2 in B220⁺ and Gr1⁺ CD11b⁺ cells in bone marrow (C), and for B220⁺, CD4⁺ and CD8⁺ cells in peripheral blood (D). LKS⁺, Lin⁻ c-kit⁺ ScaI⁺ cell; CMP, common myeloid progenitor; GMP, granulocyte/macrophage progenitor; MEP, megakaryocyte/erythrocyte progenitor; R1, proerythroblast; R2, basophilic erythroblast; R3, polychromatic erythroblast; R4, orthochromatic erythroblast.