Rooting the eukaryote tree by using a derived gene fusion.
Single-gene trees have failed to locate the root of the eukaryote tree because of systematic biases in sequence evolution. Structural genetic data should yield more reliable insights into deep phylogenetic relationships. We searched major protist groups for the presence or absence of a gene fusion in order to locate the root of the eukaryote tree. In striking contrast to previous molecular studies, we show that all eukaryote groups ancestrally with two cilia (bikonts) are evolutionarily derived. The root lies between bikonts and opisthokonts (animals, Fungi, Choanozoa). Amoebozoa either diverged even earlier or are sister of bikonts or (less likely) opisthokonts.
Stechmann
Alexandra
A
Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK. alexandra.stechmann@zoo.ox.ac.uk
Cavalier-Smith
Thomas
T
D000818:Animals; D005075:Biological Evolution; D016798:Ciliophora / Q000145:classification / Q000235:genetics; D056890:Eukaryota / Q000145:classification* / Q000235:genetics*; D005057:Eukaryotic Cells / Q000145:classification; D019143:Evolution, Molecular; D005658:Fungi / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics*; D010802:Phylogeny; D010944:Plants / Q000145:classification / Q000235:genetics; D011995:Recombination, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D013940:Thymidylate Synthase / Q000235:genetics*
D009097:Multienzyme Complexes; C056930:thymidylate synthase-dihydrofolate reductase; D013762:Tetrahydrofolate Dehydrogenase; D013940:Thymidylate Synthase