Figure 5.

Flanking MARs synergize with Eδ to stimulate V(D)J recombination. (A) Schematic representation of the Eδ wild-type and Eδ(MAR−) transgenic V(D)J recombination reporter substrates. X, XbaI; D, DraI; Bg, BglII; S, SmaI. (B) PCR strategy to detect transgene Vδ2 rearrangement events. (C) Thymocyte genomic DNA preparations from transgenic lines carrying an Eδ minilocus or an Eδ(MAR−) minilocus were amplified by PCR using the Cδ primer pair, the Vδ2–Jδ1 primer pair, or the Vδ2–Jδ3 primer pair. Southern blots were probed with radiolabeled Cδ or Vδ2 DNA fragments. Transgene copy numbers were determined by comparison of human Cδ and control murine Cα hybridization signals on Southern blots of EcoRI-digested tail DNA.