Evolution of the WASP family proteins in algae and plants. Schematic representation of the phylogenetic tree of the sequenced algae and plant species. Branch lengths are arbitrary. The WAVE and WASH protein inventories of the species have been plotted to the tree with WASH and WAVE families and classes given in colour-coded boxes. Loss of the ARP2/3 complex and WASP family proteins in certain lineages or species is indicated by white boxes. Volvox carteri and Chlamydomonas reinhardtii contain the ARP2/3 complex and are thus expected to contain an actin nucleation promoting protein although none of the WASP family members could be identified. The red "F" indicates that only a fragment of the WASH protein in Sorghum and Oryza is available. The genome assemblies of these species are of high quality and do not contain any gaps downstream of the WASH fragments. Because the found N-terminal fragments are highly similar to the respective regions of the WASH homologs of Picea, Selaginella, and Physcomitrella but homologous sequence to the rest of the WASH proteins could not be identified in the genome sequences these WASH proteins are most probably pseudogenes in the process of being disbanded.