Figure 9.

Assessment of proviral integration and TCR-β gene rearrangements. (a) As in Figure 3c, Southern blot analysis of tumors from transplanted animals demonstrates the presence of provirus. A human TEL probe that did not cross-hybridize with the endogenous murine TEL was used as a virus-specific probe. Neomycin vectors yield a 5-kb band (filled arrowhead), and GFP-containing vectors yield a 4-kb band (open arrowhead). (b) Genomic DNA isolated from F2, F7, and F8 mediastinal tumors subjected to Southern blot analysis using a TCR-β probe. Rearrangement of the TCR-β locus in each case proves the T-cell identity of these tumors. Clonality is demonstrated by the presence of 2 unique TCR-β alleles per case and is seen in the majority of tumors. The tumor from mouse 13.17 shows 4 bands, suggesting a biclonal tumor in this case. Contamination of tumor samples with stromal cells results in the presence of the unrearranged germline band (arrowhead).