Effect of Roquin loss in thymic epithelial cells. (A) Growth curve of nude mice transplanted with fetal thymic epithelium as indicated. Means ± SD for recipients of six wild-type and six Rc3h1^−/− thymi are shown. (B) Rc3h1^+/+ and Rc3h1^−/− thymic epithelium–derived thymus lobes on kidneys of C57BL/6 nude mice 10 wk after transplantation. Bar chart shows absolute numbers of thymocytes. Bars, 500 µm. (C) Proportions of thymocyte subsets. DN, (CD4/CD8) double negative; DP, double positive; SP, single positive; T_reg cells, CD4⁺FoxP3⁺. (D) Usage of individual Vα (left) and Vβ (right) chains in the TCR on CD4 T cells in mice of the indicated genotypes. (B–D) Columns and error bars represent means ± SD of five to six mice per group. **, P < 0.001; Student’s t test.