Genes expressed differentially in white mycelia and mycelia with primordia A. Hierarchical clustering illustrating groups of 192 M. perniciosa genes coordinately expressed at the moment of fruiting versus white mycelium stage by macrorray assay. The column W represents samples of white mycelium stages and P the primordium stage. For each gene, the medium mRNA levels represented by red or green, indicating up-regulation or down-regulation, respectively. The legend indicates the corresponding values of intensity. Two groups are formed: A = higher gene expression in 'white' mycelium and B = higher expression in mycelium with 'primordia'. On the right are examples of genes evaluated in each group.