Sox7-enforced expression blocks hematopoietic differentiation. (A) Pictures of colonies from day 5 iSox7 EB cells noninduced (−dox) or induced (+dox) with doxycycline at 1 μg/mL in semisolid clonogenic replating assay for hematopoietic progenitors 5 days after replating (×4 magnification). (B) Colony counts from day 5 iSox7 EB cells replated with or without doxycycline (+dox, −dox) in clonogenic assay for hematopoietic progenitors. (C) Representative pictures of blastic colonies obtained in clonogenic replating assay with doxycycline (×40 magnification). (D) Individual colonies grown without or with doxycycline tested for the expression of the indicated genes by real-time PCR. (E) Flow cytometric analysis for the indicated cell surface markers of pooled colonies grown for 5 days in semisolid clonogenic replating for hematopoietic progenitors without or with doxycycline. (F) May-Grünwald Giemsa and O-dianidisine staining of cells derived from sorted hematopoietic precursors grown for 6 days in liquid cultures with or without doxycycline (black arrows indicate primitive erythrocytes; green arrows, macrophages; and red arrows, blast cells). All data are representative of at least 3 independent experiments.