Figure 4.

Clonality of lymphoid tumors in Blk(Y495F) transgenic mice. (A) Analysis of TCR-β rearrangements. Genomic DNA was extracted from thymus (T), spleen (S), lymph node (LN), or liver (Li) of transgenic mice (lanes 1–13) or nontransgenic littermates (lanes 14–16). The following individual transgenic mice were assayed: Blk(Y495F)-6 founder (lanes 1–3); Blk(Y495F)-6.15 (lanes 4 and 5); the Blk(Y495F)-16 founder (lanes 6–8); Blk(Y495F)-16.32 (lane 9); Blk(Y495F)-16.34 (lanes 10 and 11); Blk(Y495F)-60 founder (lanes 12 and 13). DNA was digested with BglII and assayed for rearrangement by Southern hybridization using a probe derived from the Jβ-Cβ1 intron. (B) Analysis of Ig heavy chain rearrangements. Genomic DNA was extracted from lymphoid organs of Blk(Y495F)-15.4 (lanes 3, 4, 10, and 11), Blk(Y495F)-15.15 (lanes 5–7 and 12–14), or nontransgenic littermates (lanes 1, 2, 8, and 9). DJ_H and V_HDJ_H rearrangements were amplified by PCR as described in ref. 28; products were fractionated by agarose gel electrophoresis and detected with ethidium bromide. Lanes 1–7, assays for DJ_H rearrangements; lanes 8–14, assays for V_HDJ_H rearrangements. The sizes of DNA standards, in bp, are indicated at left. (C) Analysis of junctional heterogeneity in Ig heavy chain rearrangements. DJ_H3- and V_HDJ_H3-containing PCR fragments from Blk(Y495F)-15.15 (lanes 2–4 and 6–8) or normal mice (lanes 1 and 5) were purified from an agarose gel and reamplified by using a radiolabeled J3 primer and D or V_H primers as described (28). Products were fractionated by electrophoresis through a 5% polyacrylamide-urea gel and detected using a PhosphorImager. Sizes of DNA standards, in bp, are indicated at right.