Sustained expression of activated Notch1 impairs CD34^hi thymic lymphoid precursors from progressing into the DP stage. (A) Absolute numbers of CD4⁺CD8⁺ (DP) and CD3^-CD4^-CD8^- (TN) cells derived from ICN-transduced (▪) or mock-transduced (○) CD34^hi thymic lymphoid progenitors at the indicated time points in FTOCs. Numbers were normalized to 2 × 10³ GFP⁺ transduced cells/lobe. (B) Percentages of TN, CD4 ISP, DP, and TCRγδ⁺ cells derived from ICN1- (ICN1) or mock-transduced (GFP) progenitors at the indicated time points in FTOC. (C) Flow cytometry analysis of CD4 versus CD8 expression on GFP⁺ progenies derived from ICN1-transduced (ICN1) or mock-transduced (GFP) progenitors after 14 and 30 days in FTOC. (D) Expression of CD4 or CD8 versus TCRγδ on ICN1-transduced progenitors after 30 days in FTOCs. Results are representative of 4 independent experiments.