Figure 2

Small but significant buffering of duplicate genes against gene-KO/KD. In most organisms of our analysis, duplicates contribute significantly to survival against gene-KO/KD (P-value ≤ 0.05), although to only a small extent. Buffering is increased amongst genes of high expression levels (high CBI, black bars) compared to genes of lower expression levels (white bars). In highly expressed genes, duplicates contribute to survival by up to 23% (E. coli). Significant enrichment of duplicates amongst non-essential genes (hypergeometric distribution) and significant differences between genes of high and low expression (χ² test) are marked with *, **, and *** for P-value thresholds of 0.05, 0.01, and 0.001, respectively. For abbreviations see Figure 1.