Figure 2.

Deletion of caspase 8 in the T-cell lineage. (A) Southern blot performed on BamHI-digested genomic DNA extracted from tcasp8^−/− mice shows a specific and complete deletion of exons 3 and 4 of caspase 8 in thymocytes in comparison to tail extracted DNA. (Lane 1) Wild-type tail DNA. (Lane 2) casp8^fl3-4/wt; LckCre tail DNA. (Lane 3) casp8^fl3-4/wt; LckCre thymocyte DNA. (Lane 4) tcasp8^−/− tail DNA. (Lane 5) tcasp8^−/− thymocyte DNA. (B) The casp8^Δ3-4 nucleotide sequence contained several termination codons that disrupted the open reading frame of caspase 8 shortly beyond exon 2. (C) Western blot performed on thymocyte cell extracts derived from control and tcasp8^−/− mice confirmed the absence of caspase 8 protein in thymocytes. (D) Representative dot blots showing similar thymocyte populations in tcasp8^−/− and control mice. (E) Mean total thymocyte numbers in tcasp8^−/− and control mice (n = 17, p = 0.601).