CD8⁺ T cells from antigen-expressing H-Y TCR transgenic mice possess an activated/memory phenotype. (A) The dot plots depict the CD4 and CD8 profile of thymocytes from H-2^b H-Y female, H-2^b H-Y male, and H-2^b/d H-Y male TCR transgenic mice. The bar graph depicts the mean number of double-positive (DP), double-negative (DN), and CD4 and CD8 single-positive (SP) cells recovered from these mice with the error bars representing one standard deviation. (B) The expression of CD8 and the H-Y TCRα by lymph node cells from the mice in panel A. The histograms depict the expression of the indicated cell surface markers by gated H-Y TCR⁺ CD8⁺ T cells.