Figure 3.

Impaired generation of CD4 single-positive (SP) thymocytes expressing the MHC class II-restricted OT-II T-cell receptor (TCR) in the absence of extracellular signal-regulated kinase 3 (ERK3). CD4/CD8 FACS profiles (a) are shown for OT-II Erk3^+/+ and OT-II Erk3^−/− mice. The percentage of each gated population is indicated on the dot plot. A representative FACS profile out of six independent experiments is shown. Total thymocyte numbers (b), double-positive (DP) thymocytes, CD4⁺ CD8^lo thymocytes and CD4SP thymocytes frequencies (c) are shown for OT-II^+/+ and OT-II^−/− mice. The line represents the mean and the error bars are the standard error of the mean (SEM). Each dot represents one individual mouse. The statistical significance was determined with a Mann–Whitney U-test (*P < 0·05). The results of three independent experiments are shown.