Relative presence of DSBs across the genome. Analyses based on the 5,610 DSB events delimited by 500 bp or less described in . The relative presence is measured as the ratio of the number of DSBs observed within each category to the number expected based on a random distribution of DSBs across the genome. Conservatively, we classified genes as showing no active transcription when FPKM < 0.001 and groups of genes with low-, medium- and high-transcription represent levels of target potential associated with transcription (FPKM x transcript length); 33, 46 and 21% of active genes belong to the low-, medium- and high- transcription groups, respectively. Probabilities (shown above each bar) associated with the relative presence of DSBs were obtained based on 10,000 independent replicates of the 5,610 DSBs randomly distributed across the genome.