Figure 1. Overview of the genomic expression resopnses to MMS and ionizing radiation . The expression patterns of genes whose transcript levels changed more than two-fold in response to either MMS or ionizing radiation (IR) are shown. Hierarchical clustering was performed similar to that described in Materials and Methods, except that only genes that changed at least 2-fold on at least one microarray experiment were clustered. For clarity, the mock-irradiated timecourses that were used in the clustering analysis have been omitted from this display. The results of five timecourses are shown, as indicated by the legend at the top of the figure. In each timecourse, the columns in the figure represent samples taken at 5, 15, 30, 45, 60, 90, and 120 minutes after the MMS treatment in the wild-type and mec1 cells, at 30, 90, and 120 minutes after MMS treatment in dun1 cells, and at 5, 10, 20, 30, 45, 60, 90, and 120 minutes after ionizing radiation exposure in wild-type and mec1 cells. The fold changes in transcript abundance relative to the pretreament levels are represented by a color scale, as indicated by the key at the bottom of the figure.