Characterization of fractionated OT-I DP thymocytes. (A) Representative flow cytometric analysis of WT (top panel) or OT-I (bottom panel) DP thymocytes. (B) Representative qPCR analysis of ZAP70 transcripts in total or fractionated OT-I DP thymocytes. Data depict transcript abundance relative to WT DP thymocytes. We tested 3 mice per group. *P < .05. (C) Representative flow cytometric analysis of ZAP70 intracellular staining performed on total or fractionated OT-I DP thymocytes. The isotype control is shown in black, total DPs in brown, DP1 in red, DP2 in green, and DP3 in blue. Numbers indicate the mean fluorescence intensity. Data shown are representative of 3 separate experiments. (D) Representative Western blot analysis of signaling molecules involved in positive selection. (E) Densitometry quantification of all Western blots performed. Six mice per group were tested.