Stabilization of β-catenin induces a DP to SP developmental block. (A) The kinetics of developing CD4Cre-Ctnnb^Δex3 thymocytes were investigated by BrdU incorporation studies. Analysis of the BrdU content in the indicated subsets was done after electronic gating on subsets defined by expression of CD4, CD8, and TCRβ. Histograms are representative of BrdU incorporation at day 9 of treatment. Bars indicate gates for BrdU⁺ or BrdU⁻ cells and the numbers above the bars indicate percentages of labeled or unlabeled cells in each subset. (B) Turnover of CD4⁺CD8⁺ (DP) and production rate of mature single-positive (CD4 SP and CD8 SP) thymocytes. Mature thymocytes are defined as TCRβ hi and either CD4⁺CD8⁻ or CD4⁻CD8⁺. The percentages of labeled cells of control and CD4Cre-Ctnnb^Δex3 mice are shown. Two to 4 control and CD4Cre-Ctnnb^Δex3 mice were in each time point.