A comparison of thymic cellularity and T-cell subset distribution between Sl/Sl^17H and controlSl/+ mice. (A) Thymocytes were harvested and counted as described in Materials and Methods. At least 5 mice from each group were examined. Data shown are the mean ± SEM. *P < .05. Thymocytes from mutant and control mice were harvested and analyzed by flow cytometry for the expression of (B) CD4 and CD8, (C) CD4 and CD3, and (D) CD8 and CD3 antigens. The percentage of various T-cell subsets are indicated.