Phenotypic analysis of lymphocytes in PLN. Lymphocytes from PLN were counted and stained with FITC-conjugated H57-597 (anti-Cβ TCR) and biotinylated MEL-14 (anti–L-selectin) MoAb followed by phycoerythrin-conjugated streptavidin and analyzed in a FACScan (Becton Dickinson). (A) Total 10,000 cells of PLN from MSM-+/+ or DDD/1-plt/plt were analyzed and percentage was indicated at the corner of each quadrant.plt/plt was characteristically distinguished by small content of T cells, especially of L-selectin⁺TCR⁺cells (15.0%) compared with those of +/+ (73.0%). (B) PLN cell number and the percentage of L-selectin⁺TCR⁺ cells in PLN lymphocytes of individual mouse in MSM-+/+, DDD-plt/plt, F₁, and BC progeny were assessed and represented with a dot. BC was pool of 101 (DDD/1-plt/plt × F₁)BC and 89 (F₁ × DDD/1-plt/plt)BC. plt/pltwas distinguished by paucity of PLN cell number (less than 1 × 10⁷) and small content of L-selectin⁺TCR⁺ cells (less than 31%). The percentage of L-selectin⁺TCR⁺ cells of wild-type (+/+ or plt/+) were more than 32%. Some mice (□ or ▧) in BC were decided their phenotype by the T-cell distribution in the spleen in immunohistochemical analysis as shown in Fig 1i, k. Wild-type or plt/plt were indicated with black or white, respectively. One exceptional mouse (▴) in BC showed 26% L-selectin⁺TCR⁺ cells in PLN, but this was classified as a heterozygote based on large number of PLN cells and the quite similar distribution of T cells in spleen to that in+/+. The number of wild-type versus that of plt/pltis indicated at the upper corner of each group.