Fig. 2: SNV and INDEL signatures in RT-induced mammary tumours.
From: Mutational signatures in tumours induced by high and low energy radiation in Trp53 deficient mice
a De novo SNV signature extraction using NMF identified three distinct point mutation signatures, referenced to here and in the text as “A”, “B” and “C”. N = 21. b Deconvolution of the mutation signatures into known Cosmic signatures found in human tumours. Samples are denoted by radiation quality, tumour pathology and Trp53 genotype. DelP (Brown) = P53 Delta Proline (Trp53ΔP); Het = P53 Heterozygous (White), Sarcoma (Brown), Carcinoma (White), Gamma (Brown) and Fe (White). The red blocks represent the contribution of the signature 18 “ROS” to total mutations in each sample, and these are relatively enriched in tumours induced by gamma radiation compared to 56Fe ions (P < 0.032). Pale blue denotes contribution from variants not explained by known Cosmic signatures. N = 21. c Relative contribution of each insertion/deletion mutation type in the three INDEL signatures identified in the mammary tumour samples. See Supplementary Fig. 2 for a breakdown of all categories of INDEL types. “Del_B” = 1 bp deletion, “Ins_B” = 1 bp insertion, where “C” or “T” describes whether cytosine or thymidine was deleted at that position, “MH” = microhomology domain and “REP” = >1 bp deletion or insertion at repeats. N = 21. d Relationship between INDEL signatures and SNV signatures. Hierarchical clustering of both INDEL signatures and SNV signatures demonstrates an enrichment of de novo INDEL signature A (left) and SNV signature 18 (ROS, right) in samples induced by exposure to gamma radiation compared to those induced by 56Fe ions (P < 0.032). N = 21.
