This project is being carried out through a Strategic Award from the Wellcome Trust to Steve Jackson, Mike Stratton, Peter Campbell, Serena Nik-Zainal and others. This grant is to fund work aimed at identifying “mutational signatures” arising through cells being defective in DNA repair and other cellular factors, and/or through cellular exposure to various DNA damaging agents. The samples that are here being provided here are derived from the yeast Saccharomyces cerevisiae, and represent wild-type strains plus various gene knock-out strains that have or have not been propagated over several months to acquire mutations. The samples are to be subject to whole-genome sequencing. Ensuing sequence data will be subject to bioinformatic analyses to identify mutation signatures and their underlying causes.