Figure 2.

 Broken SE intermediates 3′ of Dβ2 and 5′ of Jβ2.6 are only moderately reduced in Eβ^−/− versus wild-type and δ^−/− Eβ^−/− vs. ε^−/− mice. Genomic DNA purified from the thymuses of four individual Eβ^−/− mice (Eβ^−/− thy1–4), four individual δ^−/− Eβ^−/− mice, an ε^−/− mouse, and a wild-type mouse (WT mouse 2), and genomic DNA derived from the kidney of an δ^−/− Eβ^−/− mouse was linker ligated as diagrammed in Fig. 1A. Linker-ligated wild-type or ε^−/− thymus DNA was diluted serially 1 : 3 into linker-ligated δ^−/− Eβ^−/− kidney DNA to keep the DNA concentration constant and subjected to LM-PCR with primers specific for the detection of DSBs at the RSS 3′ of Dβ2 (3′ of Dβ2 SEs) or 5′ of Jβ2.6 (5′ of Jβ2.6 SEs), as indicated. Undiluted linker-ligated Eβ^−/− or δ^−/− Eβ^−/− thymus DNAs were amplified in parallel. Eβ^−/− thymus DNAs are the same as those used in the experiments shown in Fig. 1B and C. (A) Results of the wild-type thymus DNA titration versus Eβ^−/− thymus DNA. (B) Results of the ε^−/− thymus DNA titrations vs. the δ^−/− Eβ^−/− thymus DNA.