New phylogenomic data support the monophyly of Lophophorata and an Ectoproct-Phoronid clade and indicate that Polyzoa and Kryptrochozoa are caused by systematic bias

BMC Evolutionary Biology

Research Article

Iris Bruchhaus¹  Ingo Ebersberger²  Thomas Hankeln³  Alexander Witek³  Achim Meyer⁴  Bernhard Lieb⁴  Maximilian P Nesnidal⁵  Bernhard Hausdorf⁵  Martin Helmkampf⁶  Torsten H Struck⁷ 

[1] Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str 74, D-20359, Hamburg, Germany;Department for Applied Bioinformatics, Institute for Cell Biology and Neuroscience, Goethe University, Max-von-Laue-Str 13, D-60438, Frankfurt, Germany;Institute of Molecular Genetics, Biosafety Research and Consulting, Johannes Gutenberg University, J-J Becherweg 32, D-55099, Mainz, Germany;Institute of Zoology, Johannes Gutenberg University, J-J Becher-Weg 7, D-55128, Mainz, Germany;Zoological Museum, University of Hamburg, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany;Zoological Museum, University of Hamburg, Martin-Luther-King-Platz 3, D-20146, Hamburg, Germany;School of Life Sciences, Arizona State University, 427 East Tyler Mall, 85287, Tempe, AZ, USA;Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, D-53113, Bonn, Germany;

关键词: Bryozoa;    Brachiopoda;    Brachiozoa;    Ectoprocta;    Lophophorata;    Phoronida;    Polyzoa;    Kryptrochozoa;    Compositional bias;   

DOI  :  10.1186/1471-2148-13-253

 received in 2013-09-09, accepted in 2013-11-07,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundWithin the complex metazoan phylogeny, the relationships of the three lophophorate lineages, ectoprocts, brachiopods and phoronids, are particularly elusive. To shed further light on this issue, we present phylogenomic analyses of 196 genes from 58 bilaterian taxa, paying particular attention to the influence of compositional heterogeneity.ResultsThe phylogenetic analyses strongly support the monophyly of Lophophorata and a sister-group relationship between Ectoprocta and Phoronida. Our results contrast previous findings based on rDNA sequences and phylogenomic datasets which supported monophyletic Polyzoa (= Bryozoa sensu lato) including Ectoprocta, Entoprocta and Cycliophora, Brachiozoa including Brachiopoda and Phoronida as well as Kryptrochozoa including Brachiopoda, Phoronida and Nemertea, thus rendering Lophophorata polyphyletic. Our attempts to identify the causes for the conflicting results revealed that Polyzoa, Brachiozoa and Kryptrochozoa are supported by character subsets with deviating amino acid compositions, whereas there is no indication for compositional heterogeneity in the character subsets supporting the monophyly of Lophophorata.ConclusionOur results indicate that the support for Polyzoa, Brachiozoa and Kryptrochozoa gathered so far is likely an artifact caused by compositional bias. The monophyly of Lophophorata implies that the horseshoe-shaped mesosomal lophophore, the tentacular feeding apparatus of ectoprocts, phoronids and brachiopods is, indeed, a synapomorphy of the lophophorate lineages. The same may apply to radial cleavage. However, among phoronids also spiral cleavage is known. This suggests that the cleavage pattern is highly plastic and has changed several times within lophophorates. The sister group relationship of ectoprocts and phoronids is in accordance with the interpretation of the eversion of a ventral invagination at the beginning of metamorphosis as a common derived feature of these taxa.

【 授权许可】

Unknown   
© Nesnidal et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.