FIG. 1.

Simultaneous induction of V(D)J recombination cleavage at both κ and λ gene loci. (A) Analysis of recombination signal ends at three gene loci, Vλ1/2, Jλ1, and Jκ1/2. DNA samples were isolated from ts-Ab-MLV transformants of s/+ and s/s cells that had been subjected to various culture conditions: 33°C (33), 39°C for 3 days (39), or 39°C for 2 days followed by 1 day at 33°C (39–33). Recombination signal ends cleaved at Vλ1, Jλ1, and Jκ gene loci (Vλ1-SE, Jλ1-SE, and Jκ-SE, respectively) were amplified by LMPCR and revealed by Southern blot analysis using Vλ1, Jλ1, and Jκ1 probes, respectively. Amplification of the actin gene was used as a control for the input DNA. (B) Semiquantitative analysis of Jκ signal ends (Jκ-SE). Serial dilutions of ligated DNA molecules were subjected to PCR for amplifying Jκ signal ends. 1, 2, and 3, undiluted, threefold diluted, and ninefold diluted input DNA, respectively.