Venn diagram showing the distribution and relationship among clusters of orthologous groups for haloarchaea (HOGs), prokaryotes (COGs), and eukaryotes (KOGs). Accessory HOGs (aHOGs) and core HOGs (cHOGs) (black outline) were associated with COGs and KOGs (drawn to scale). cHOGs not associated with COGs or KOGs were termed truly unique cHOGs (tucHOGs) or nearly unique cHOGs (nucHOGs). COGs and associated KOGs with no associated HOG are illustrated for comparison.
Capes et al. BMC Genomics 2012 13:39 doi:10.1186/1471-2164-13-39