Phylogenetic illustration of species and higher taxa for which data are available concerning Pao-like elements. Species for which genomes have been sequenced and are available for whole genome BLAST searches in GenBank are enclosed in ovals. These genomes were tBLASTn searched using a deduced amino acid sequence from Sinbad (from the Cys-His Box through the protease domain) as the search sequence. Genomes with sequences significantly similar (E ≤ 0.001) to Sinbad are identified by a green "+" symbol, and those negative for Sinbad-like sequences with a red "-" symbol. Other species, with not yet fully sequenced genomes, shown to include Pao-like sequences (through EST searches or other means) are shown in smaller font and unenclosed, and are also marked with a green "+". This diagram is based on a tree of life style diagram in Pennisi  and reflects broad relationships between taxonomic groups only. It is not a phylogram – stem lengths do not represent phylogenetic distances.
Copeland et al. BMC Evolutionary Biology 2005 5:20 doi:10.1186/1471-2148-5-20