Illustration of the results from the OrthoMCL analysis with five genomes. Each strain has its own colour and an indication of the total number of protein-coding genes indicated in parenthesis next to the strain name. The number in the middle is the number of ortholog groups shared by all five strains. The number of singletons (i.e. genes for which no orthologous gene was found) is indicated for each strain, with the number in parenthesis indicating the total number of strain-specific genes (singletons defined by OrthoMCL together with the genes from ortholog groups consisting of multiple genes from one strain only).