FIG 4.
The ICR and cHS4 insertions into the IgH locus specifically impair VH-to-DJH recombination. (A) A scheme of the IgH locus indicating the relative position of the primers used in PCR. (B) Genomic DNAs were prepared from sorted ICR pro-B cells with the indicated genotypes and were subjected to a semiquantitative PCR to amplify D-JH and VH-DJH rearrangements. The PCR was performed on serial 3-fold dilutions. A PCR of the HS4 enhancer from the 3′ regulatory region was used for normalization of the DNA input (n = 3). (C) Genomic DNAs were prepared from sorted cHS4 pro-B cells and assayed as described in the legend to panel B (n = 3).