Skip Navigation



MBE Advance Access published online on September 18, 2006
Molecular Biology and Evolution, doi:10.1093/molbev/msl120
This Article
Right arrow Advance Access manuscript (PDF) Freely available
Right arrow Supplementary Material
Right arrow All Versions of this Article:
23/12/2455    most recent
msl120v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Kim, E.
Right arrow Articles by Graham, L. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kim, E.
Right arrow Articles by Graham, L. E.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org
Accepted September 12, 2006

Research Article

Evolutionary Relationships of Apusomonads Inferred from Taxon-rich Analyses of Six Nuclear-encoded Genes

Eunsoo Kim 1 *, Alastair G. B. Simpson 2, and Linda E. Graham 1

1 Department of Botany, University of Wisconsin-Madison, 132 Birge Hall, 430 Lincoln Dr., Madison, WI 53706, USA
2 Department of Biology, Dalhousie University, Halifax. N.S., B3H 4J1, Canada

* To whom correspondence should be addressed.
Eunsoo Kim, E-mail: eunsookim{at}wisc.edu


  Abstract

The phylogenetic relationships of the biflagellate protist group Apusomonadidae have been unclear despite the availability of some molecular data. We analyzed sequences from six nuclear encoded genes--SSU rRNA, LSU rRNA, {alpha}-tubulin, {beta}-tubulin, actin, and Hsp90--to infer the phylogenetic position of Apusomonas proboscidea Aléxéieff 1924. To increase the taxon richness of the study, we also obtained new sequences from representatives of several other major eukaryotic groups: Chrysochromulina sp. NIES 1333 (Haptophyta), Cyanophora paradoxa (Glaucophyta), Goniomonas truncata (Cryptophyceae), Leucocryptos marina (Kathablepharidae), Mesostigma viride (Streptophyta, Viridiplantae), Peridinium limbatum (Alveolata), Pterosperma cristatum (Prasinophytae, Viridiplantae), Synura sphagnicola (Stramenopiles), and Thaumatomonas sp. (Rhizaria). In most individual gene phylogenies, Apusomonas branched close to either of two related taxa - Opisthokonta (including animals, fungi, and choanoflagellates) or Amoebozoa. Combined analyses of all four protein-coding genes, or all six studied genes strongly supported the hypothesis that Apusomonadidae is closely related to Opisthokonta (or to all other eukaryotic groups except Opisthokonta, depending the position of the eukaryotic root). Alternative hypotheses were rejected in AU tests at the 5% level. However, the strong phylogenetic signal supporting a specific affiliation between Apusomonadidae and Opisthokonta largely originated from the {alpha}-tubulin data. If {alpha}-tubulin is not considered, topologies in which Apusomonadidae are sister to Opisthokonta or are sister to Amoebozoa were more or less equally supported. One current model for deep eukaryotic evolution holds that eukaryotes are divided into primary ‘unikont’ and ‘bikont’ clades and are descended from a ‘uniflagellate’ common ancestor. Together with other information, our data suggest instead that ‘unikonts’ (=Opisthokonta and Amoebozoa) are not strictly monophyletic and are descended from biflagellate ancestors.

Keywords: Apusomonas; Apusomonadidae; Opisthokonta; Amoebozoa; protists; evolution.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.