Cdc73 is important for Notch-dependent T-cell development. (A-H) Representative images of thymuses (A); absolute thymocyte counts (B); representative flow cytometric profiles of DN subsets (C); and absolute numbers of DN3a (D), DN3b (E), DN3 icTCRβ⁻ (F), DN3 icTCRβ⁺ (G), and DN4 (H) subsets in LckCre control and LckCre Cdc73^f/f(Cdc73^Δ/Δ) mice. (I-O) Representative flow cytometric profiles of CD4/CD8 subsets (I); %DN (J); %DP (K); and absolute numbers of immature single-positive (ISP) (L), DP (M), CD4 single-positive (SP) (N), and CD8 SP (O) thymic subsets in LckCre control and Cdc73^Δ/Δ mice. DN3a = Lineage⁻CD44⁻CD25⁺FSC^loCD27⁻; DN3b = Lineage⁻CD44⁻CD25⁺FSC^hiCD27⁺; DN4 = Lineage⁻CD44⁻CD25⁻; ISP = CD8⁺TCRb⁻; DP = CD4⁺CD8⁺; CD4 SP = CD4⁺TCRb⁺; And CD8 SP = CD8⁺TCRb⁺. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001. (P-R) Relative expression of Cdc73 (P), Hes1 (Q), and Myc (R) in sorted thymic subsets from LckCre mice (green) and Cdc73^Δ/Δ mice (orange). FSC, forward scatter; icTCR, intracellular T-cell receptor; ns, not significant.