Fig. 3.

Thymic subpopulations and cell surface TCR expression in ATM-deficient TCR transgenic mice. Thymocytes from female ATM WT or KO mice expressing the H-Y TCR transgene were stained with anti-CD4, anti-CD8, and anti-TCRβ antibodies and analyzed by flow cytometry. (a) CD4 and CD8 expression by ATM WT (Left) and KO (Right) thymocytes. (b) Percentages of DN, DP, and SP thymocytes in female ATM WT or KO mice expressing the H-Y TCR transgene. (c) Cell surface expression of TCRβ on DP, CD4 SP, and CD8 SP thymocytes. Overall TCRβ expression is similar on ATM WT and KO DP and SP thymocytes. (d) Clonotype (T3.70)^lo CD4 SP thymocytes, which express endogenous TCRα, are reduced in ATM KO mice.