Figure 4. GO enrichment clusters in nth-1;xpa-1. The transcriptional response in the double mutant nth-1;xpa-1 is dominated by genes involved in cell-cycle regulation (clusters I-III) and DNA repair (cluster IV). Cluster I (p < 0.003) and II (p < 0.01) contain genes that function in mitosis -related processes. Cluster III (p < 0.00001) reflect regulation of progression through meiosis. Genes involved in DNA repair and DNA damage checkpoint pathways in cluster IV (p < 0.02) are downregulated. Genes in red and blue are found to be upregulated and downregulated, respectively.