Fig. 3

Colonic adenomas resulting from inducible loss of adenomatous polyposis coli (Apc) in leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1)+/− stem cells have a distinct pattern of somatic mutations dominated by C:G>A:T transversion point mutations. The somatic signature of mutations of the adenomas are plotted as rows; there were nine adenomas from three mice. Each adenoma was found to contain a nearly identical pattern of somatic mutations based on motifs and background sequence context. The somatic signature is characterized by an abundance of C to A transversion point mutations, which are caused by defects in repairing DNA adducts of guanine and are frequently observed in cancer associated with tobacco tar and Helicobacter pylori infections