Figure 5.

Nuclear proteins from IL-7Rα^−/− thymocytes binding to regions of the TCR-γ enhancer. Thymocyte cell suspensions were prepared from normal C57BL/6 embryos (day 15 of gestation), IL-7Rα^−/−, or Rag2^−/− mice. Nuclear extracts were prepared. Gel mobility shift assays were performed using labeled oligonucleotides from three sites in the enhancer region of the TCR-γ locus. To assess specificity of binding, unlabeled competitors were added in 10-fold excess to the labeled oligonucleotide (Specific denotes the same sequence used in the labeled probe; Non-specific is an unrelated sequence of the same size). Antibodies were added to determine whether the NFγ2-binding protein complex contained STAT5a or -b proteins.