Reduced numbers of lymph node αβ T cells but not γδT cells in FU-Lck^tg mice. (A) FACS dot plots showing proportions of αβ and γδ T cells in lymph nodes from 7-week-old WT, Lck^−/−, Lck^tg/Lck^−/−, and FU-Lck^tg/Lck^−/− mice. Values within dot plots represent the percentage of lymphocyte-gated αβ and γδTCR-positive cells. (B) Distribution of CD4⁺ and CD8⁺ T cells in lymph nodes. Values represent proportions of αβTCR⁺ cells within CD4⁺ and CD8⁺ gates. Histograms showing CD44 expression on gated lymph node αβTCR⁺CD4⁺ T cells (C) or CD8⁺ T cells (D) from WT, Lck^−/−, Lck^tg/Lck^−/−, and FU-Lck^tg/Lck^−/− mice. Values in histograms represent percentages of cells falling within the illustrated CD44 “high” gate. In all cases, data are representative of at least 11 mice of each genotype.