Figure 5

Evolution of the dynactin complex with respect to the species evolution. A). The tree represents the most widely accepted phylogenetic tree of the eukaryotes. However, especially the grouping of taxa that emerged close to the origin of the eukaryotes remains highly debated. Therefore, alternative branchings are also indicated in the tree. The phylogeny of the supposed supergroup Excavata is the least understood because only a few species of this branch have been completely sequenced so far. While the grouping of the Heterolobosea, Trichomonada, and Euglenozoa into the Excavata is found in most analyses, the grouping of the Diplomonadida as separate phylum or as part of the Excavata is still debated (arrow 1 [84]). According to most of the recent phylogenetic analyses, the Alveolata, Rhizaria, and Stramenopiles form the superfamily SAR [85, 86]. The placement of the Haptophyceae and Cryptophyta to the SAR is still highly debated. Although several analyses are in favour of this grouping (arrow 2; [87–89]) most analyses are in contrast [85, 86, 90–92]. At each leaf of the tree one representative species of the branch is printed. Branch lengths are arbitrary. The tree illustrates the presence and absence of each subunit of the dynactin complex in the corresponding species under the hypothesis of five eukaryotic supergroups and the position of the LECA as indicated. Alternative eukaryotic roots are indicated by coloured arrows. Coloured boxes show gene duplications and white boxes show gene loss events of dynactin subunits. The presence (green box) or absence (white box) of the cytoplasmic dynein heavy chain gene DHC1 is indicated for those species that do not have dynactin or miss most of the subunits. B) A possible tree of some major branches of the eukaryotes is shown together with the subunits encoded by the respective taxa. The tree is based on the most parsimonious way the branches could have diverged based on the assumption that during this evolution subunits have only been gained and not lost.