Impaired T cell development in the thymi of Mib1 conditional KO mice. (A and B) Thymocytes from ∼8–10-wk-old littermate controls (left) and the mutant (right) mice indicated were stained for CD4 and CD8 (A) and CD19 and B220 gated on CD4−CD8− DN thymocytes (B) and were analyzed by flow cytometry. Percentages of each population are indicated in the quadrants. Numbers are mean ± SD from 10 independent experiments. (C) Thymocytes from the indicated mice were analyzed by flow cytometry for the expression of CD44 and CD25 gated on CD4−CD8− DN thymocytes. Percentages indicated are mean ± SD from five independent experiments. (D) Absolute cell numbers for total thymocytes and thymocyte subsets of the MMTV-Cre;Mib1+/f and MMTV-Cre;Mib1f/f mice were calculated and are shown as histograms. The error bars represent mean ± SD from five independent experiments. *, P < 0.01. (E and F) The Mx1-Cre;Mib1+/f and Mx1-Cre;Mib1f/f mice were injected i.p. four times at 2-d intervals with 300 μg pIpC. At ∼8–14 wk after the final injection, the thymocytes were analyzed by flow cytometry for the expression of CD4 and CD8 (D) and CD19 and B220 (E) gated on CD4−CD8− DN thymocytes. Percentages indicated are mean ± SD from five independent experiments.
