Impaired positive selection in γδ^– × hδTg mice. (A) Dot plots show CD4 and CD8 expression in thymocytes from WT and γδ^– × hδTg mice expressing transgenic HY (females), OT-I, or AND TCR. Numbers within dot plots indicate the percentage of CD8⁺ or CD4⁺ SP cells in the gated region. (B) Histograms depict transgenic TCR expression, assessed with anti-TCRVα or anti-TCRVβ antibodies, in DP and positively selected CD8⁺ (HY and OT-I) or CD4⁺ (AND) SP cells from WT (dotted line) and γδ^– × hδTg (solid line) mice. (C) Percentages (top panel) and absolute numbers (bottom panel) of CD8⁺ (HY and OT-I) or CD4⁺ (AND) SP thymocytes in TCR transgenic WT (□) and γδ^– × hδTg (▪) mice. Five to 8 mice per group were analyzed. Error bars indicate the mean plus or minus standard deviation.