Figure 6. RAG1 association with DJ_H rearranged Igh alleles.

(a) Schematic of the germline Igh locus in Bcl2-Tg RAG1/D708A-Tg (D345) pro-B cells²⁰ and the DJ_H junctions in the D345-derivatives 3E and 1C6 cells are shown (not to scale) along with the positions of amplicons analyzed by real-time PCR. 3E cells have a DSP2.2-J_H2 junction and 1C6 cells have a DFL16.1-J_H1 junction. The second allele in these cells is in germline configuration. (b, c) ChIP assays were performed with a RAG1-specific antibody in D345 (dark blue bars), 3E (b; light blue bars) and 1C6 (c; pink bars) cells. The numbers within the parentheses indicate positions in kb 5′ (−) or 3′ (+) of the indicated gene segment. Amplicons for J_H4 and β-globin served as positive and negative controls for RAG1 binding. All amplicons were assayed in duplicate by quantitative real-time PCR and IP/Input_corr was calculated as before²⁰. Data show the average of 2 or 3 independent ChIP experiments; error bars represent standard deviation between experiments. ND stands for `not determined'.