Figure 2

Southern blotting analysis. (A) and (B) Tumor DNA was analyzed by Southern blot hybridization using probes detecting germline (g.l.) and rearranged configurations (arrowhead) of the Igκ locus (A), IgH locus (B) and the TCRβ chain (data not shown). DNA from spleen from un-injected NMRI mice was included as control (c) and tumors with rearrangements are indicated in bold (lane 4 in (A): tumor ID 99-115, lane 6 in (B): 01-340, and lane 8 in (B): 99-34). (C) List of all tumors with detected rearrangements in any of the analyzed loci. (D) Evaluation of integration site clonality by Southern blotting analysis. Tumor DNA was analyzed by Southern blot hybridization using an ecotropic envelope-specific probe, the position of which is indicated. The blot exemplifies an analysis of DNA from seven tumors harboring integration in Cd74 (lanes marked by numbers), DNA from spleen of un-infected NMRI mice (lane denoted C), and DNA from spleen of un-infected BALB/c mice (lane denoted B). The lane denoted M contains the marker. BALB/c DNA contains one copy of an endogenous ecotropic MLV (which upon Nco I digestion and hybridization with this probe yields a band of app. 7 kb), thus serving as a positive control for the envelope probe, whereas NMRI was included as a negative control as it does not harbor endogenous ecotropic MLVs. LTR denotes the long terminal repeats of integrated proviruses.