BSCs selected from average clustering with SGD classification showing an overview of enriched gene classes. Average methods cluster tree with the 50 top BSC clusters obtained with SGD classes are presented for comparison with fig. 2. Clusters are linked to table 4 [additional file 1] by the ordinal numbers in the data file. Three coloured cluster groups are the same as in figure 2 and they are shown in detail in table 2 (SGD/GO classes). Notice that although the clusters are placed differently than in fig. 2, similar functional classes are often associated to the same cluster tree branches. The tree is analyzed more in detail in the text. The figure is shown also as a postscript file for separate zooming and printing in figure 9 [see additional file 5].