Cebpa/EYFP⁺ LSK and DN1/DN2 cells display retained early lymphoid potential, but Cebpa/EYFP⁺ DN1/DN2 cells are hampered in T-cell differentiation. (A) LSK and DN1/DN2 cells were cultured in FTOC for 3 weeks. Results show the mean ± SEM values of cell numbers obtained of the indicated LSK population of 3 independent experiments. (B) In a competitive FTOC assay, EYFP⁺ and EYFP⁻ LSK/DN1/DN2 cells were mixed as indicated (see annotation on the x-axis), and the percentage of EYFP⁺CD3ϵ⁺ was analyzed after 3 weeks of culture. Results show the mean percentage (± SEM) of 3 assays. (C) Analysis of CD4 and CD8 expression in cells obtained from FTOC assays after 3 weeks of culture. Although most cells derived from EYFP⁻ DN1/DN2 cell are double positive, the majority of EYFP⁺ DN1/DN2-derived cells are DN.