Figure 3.

Overexpression of STAT5A(1*6) in CB CD34⁺ cells induces erythroid differentiation. CB CD34⁺ cells were transduced with MiGR1 or STAT5A(1*6) as described in Fig. 1 and grown in cocultures on MS5. Cultures were weekly demidepopulated, nonadherent cells were counted and used for cytospins (A), CFC assays (B), or CFU-E assays (C), as described in Materials and Methods. Week 0 represents transduced cells before plating on MS5 stroma. The arrows in A indicate the following: 1, proerythroblasts; 2, basophilic erythroblasts; 3, polychromatic and orthochromatic erythroblasts; and 4, erythrocytes.