Transcriptional module identification and network visualisation in the UPSC-Leaf microarrays. A Average linkage hierarchical clustering dendrogram of the UPSC-Leaf dataset. Five transcriptional modules were detected. Modules were assigned colours as indicated by the bar below the dendrogram. Rows and columns in the heat map represent genes in a symmetric fashion. Colour intensity represents connection strength between two genes from red (the strongest connection) to pale yellow (no connection). B Network visualisation based on pair-wise Pearson correlations. Nodes represent genes and are connected by edges where significant correlation between genes exists. Nodes are coloured based on the five modules detected in A. Edges are drawn for correlations > 0.7. Unconnected nodes are not plotted and nodes with only individual pair-wise connections that were not connected to the central network were removed.