Figure 2

Distribution of polymorphic HML-2 proviruses in breast cancer cases and controls. A. Comparative schematic representing the in silico-predicted sizes for HML-2 containing fragments following BsrI digestion and detected by the K-seq probe within the Hg19 genome build. Asterisks at left indicate the confirmed polymorphic proviruses, whose distribution coincides exactly between unblot banding patterns and PCR data. B. CPSII samples were sorted by case/control status (n = 25 each) and BsrI digested WGA-DNA from each group was separated by gel electrophoresis and probed with the ³²P-radiolabeled K-seq oligonucleotide. HML-2 junction fragments were visualized following exposure to film, and polymorphic insertions inferred by variable banding patterns among samples. C. Results from PCR analysis of known polymorphic proviruses for direct comparison of described polymorphic elements, where ‘+’ indicates the confirmed presence of the tested provirus. Novel polymorphic fragments whose identity could not be inferred by comparison to PCR analysis or in silico predictions, have been indicated with arrows at right. Asterisks (at right) are used to indicate the observed fragment sizes of polymorphic elements detected in ≤5% individuals screened here.