Figure 2.

Genome-wide tallies of aflatoxin gene duplicates, correlations among gene duplicates and inferred gene modules. A. The histogram plot shows the total number of putative aflatoxin gene cluster duplicates on y-axis across five Aspergillus genomes. The gene order in the histogram follows the order of genes in the A. flavus cluster (see cluster schematic below histogram). B. Hierarchical cluster dendrogram showing the correlations among gene duplicates in Figure 2A. Correlations are based on a dissimilarity measure of (1-r²) in which correlation values are assigned "distance" values ranging from 0.0 (completely correlated, r² = 1) to 1.0 (completely uncorrelated, r² = 0). The y-axis represents the height or distance between the gene groups divided at that point. The dendrogram shows seven putative gene modules listed from left to right as: aflX/aflY, aflJ/aflR/aflS, aflC/aflW, aflA/aflB, aflF/aflE, aflT/aflQ and aflG/aflL that are highly correlated (0.80 <r² < 1) across the five Aspergillus genomes. We consider aflR/aflS/aflJ as correlated since only aflH separates aflR/aflS from aflJ. These correlated pairs are the inferred gene modules, color coded in Figure 3.