Med1 and Med12 are dynamically recruited to the IgH locus during CSR. (A–C) Med1 and Med12 ChIP-qPCR experiments performed on chromatin prepared from 107 splenic resting B cells (A) or cells stimulated with LPS + IL-4 (B) or LPS alone (C) for 72 h. qPCR was performed at the indicated locations (see Table S3 for primers). Results are expressed as the mean of the percentage input (+SD) from three independent biological replicate experiments. Statistical significance from WT results versus Cγ2a (two-tailed Student's t test) is indicated. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001. White bars represent ChIP performed on WT samples; black bars represent ChIP performed on Med1-deficient samples. See Table S1 for full statistical analysis. (D and E) Nuclear extracts (D) from CH12 cells and whole-cell extracts (E) prepared from WT splenic B cells stimulated with LPS + IL-4 for 72 h were immunoprecipitated and blotted with antibodies specific for Med1 and Med12. Input represents 1% of material used. Theoretical molecular masses in kilodaltons are indicated. Data are representative of two independent experiments.
