Fig. 1.

Conditional deletion of Tak1 in mouse thymocytes. (A) Strategies for the generation and deletion of floxed Tak1 alleles. (B) Southern blotting of genomic DNA after digestion with NheI. (C) PCR of genomic DNA isolated from the tails or thymocytes of the mice, as indicated. (D) Western blotting of whole-cell lysates from splenocytes, thymocytes, and lymph node T cells. Lysates from 1.6 × 10⁶ cells were loaded on each lane. In lane 6, lymph node T cells for Lck-Cre/Tak1^flox/flox were pooled from three mice. The expression of TAK1 and loss of expression of Cre in these cells likely resulted from the selective expansion of TAK1-expressing cells that escaped from Cre-mediated excision.