Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
Nature
2011 Feb 10;4707333:255-8. doi: 10.1038/nature09676.
Show Gene links
Show Anatomy links
Acoelomorph flatworms are deuterostomes related to Xenoturbella.
Philippe H
,
Brinkmann H
,
Copley RR
,
Moroz LL
,
Nakano H
,
Poustka AJ
,
Wallberg A
,
Peterson KJ
,
Telford MJ
.
???displayArticle.abstract???
Xenoturbellida and Acoelomorpha are marine worms with contentious ancestry. Both were originally associated with the flatworms (Platyhelminthes), but molecular data have revised their phylogenetic positions, generally linking Xenoturbellida to the deuterostomes and positioning the Acoelomorpha as the most basally branching bilaterian group(s). Recent phylogenomic data suggested that Xenoturbellida and Acoelomorpha are sister taxa and together constitute an early branch of Bilateria. Here we assemble three independent data sets-mitochondrial genes, a phylogenomic data set of 38,330 amino-acid positions and new microRNA (miRNA) complements-and show that the position of Acoelomorpha is strongly affected by a long-branch attraction (LBA) artefact. When we minimize LBA we find consistent support for a position of both acoelomorphs and Xenoturbella within the deuterostomes. The most likely phylogeny links Xenoturbella and Acoelomorpha in a clade we call Xenacoelomorpha. The Xenacoelomorpha is the sister group of the Ambulacraria (hemichordates and echinoderms). We show that analyses of miRNA complements have been affected by character loss in the acoels and that both groups possess one miRNA and the gene Rsb66 otherwise specific to deuterostomes. In addition, Xenoturbella shares one miRNA with the ambulacrarians, and two with the acoels. This phylogeny makes sense of the shared characteristics of Xenoturbellida and Acoelomorpha, such as ciliary ultrastructure and diffuse nervous system, and implies the loss of various deuterostome characters in the Xenacoelomorpha including coelomic cavities, through gut and gill slits.
Abascal,
TranslatorX: multiple alignment of nucleotide sequences guided by amino acid translations.
2010, Pubmed
Abascal,
TranslatorX: multiple alignment of nucleotide sequences guided by amino acid translations.
2010,
Pubmed
Baguñà,
Back in time: a new systematic proposal for the Bilateria.
2008,
Pubmed
Birney,
GeneWise and Genomewise.
2004,
Pubmed
Blanquart,
A site- and time-heterogeneous model of amino acid replacement.
2008,
Pubmed
Bourlat,
Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida.
2006,
Pubmed
,
Echinobase
Bourlat,
Xenoturbella is a deuterostome that eats molluscs.
2003,
Pubmed
Bourlat,
The mitochondrial genome structure of Xenoturbella bocki (phylum Xenoturbellida) is ancestral within the deuterostomes.
2009,
Pubmed
Castresana,
Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis.
2000,
Pubmed
Dunn,
Broad phylogenomic sampling improves resolution of the animal tree of life.
2008,
Pubmed
Egger,
To be or not to be a flatworm: the acoel controversy.
2009,
Pubmed
Felsenstein,
CONFIDENCE LIMITS ON PHYLOGENIES: AN APPROACH USING THE BOOTSTRAP.
1985,
Pubmed
Hejnol,
Assessing the root of bilaterian animals with scalable phylogenomic methods.
2009,
Pubmed
Hejnol,
Acoel development supports a simple planula-like urbilaterian.
2008,
Pubmed
Hrdy,
Trichomonas hydrogenosomes contain the NADH dehydrogenase module of mitochondrial complex I.
2004,
Pubmed
Huang,
CAP3: A DNA sequence assembly program.
1999,
Pubmed
Jeanmougin,
Multiple sequence alignment with Clustal X.
1998,
Pubmed
Lartillot,
Improvement of molecular phylogenetic inference and the phylogeny of Bilateria.
2008,
Pubmed
Lartillot,
A Bayesian mixture model for across-site heterogeneities in the amino-acid replacement process.
2004,
Pubmed
Lartillot,
PhyloBayes 3: a Bayesian software package for phylogenetic reconstruction and molecular dating.
2009,
Pubmed
Lartillot,
Suppression of long-branch attraction artefacts in the animal phylogeny using a site-heterogeneous model.
2007,
Pubmed
Nielsen,
After all: Xenoturbella is an acoelomorph!
2010,
Pubmed
Papillon,
Identification of chaetognaths as protostomes is supported by the analysis of their mitochondrial genome.
2004,
Pubmed
Philippe,
Acoel flatworms are not platyhelminthes: evidence from phylogenomics.
2007,
Pubmed
Philippe,
Phylogenomics revives traditional views on deep animal relationships.
2009,
Pubmed
Philippe,
MUST, a computer package of Management Utilities for Sequences and Trees.
1993,
Pubmed
Rodríguez-Ezpeleta,
Detecting and overcoming systematic errors in genome-scale phylogenies.
2007,
Pubmed
Roure,
SCaFoS: a tool for selection, concatenation and fusion of sequences for phylogenomics.
2007,
Pubmed
Roure,
Site-specific time heterogeneity of the substitution process and its impact on phylogenetic inference.
2011,
Pubmed
Ruiz-Trillo,
Acoel flatworms: earliest extant bilaterian Metazoans, not members of Platyhelminthes.
1999,
Pubmed
Ruiz-Trillo,
A phylogenetic analysis of myosin heavy chain type II sequences corroborates that Acoela and Nemertodermatida are basal bilaterians.
2002,
Pubmed
Ruiz-Trillo,
Mitochondrial genome data support the basal position of Acoelomorpha and the polyphyly of the Platyhelminthes.
2004,
Pubmed
Schmidt,
TREE-PUZZLE: maximum likelihood phylogenetic analysis using quartets and parallel computing.
2002,
Pubmed
Sempere,
The phylogenetic distribution of metazoan microRNAs: insights into evolutionary complexity and constraint.
2006,
Pubmed
Sempere,
Phylogenetic distribution of microRNAs supports the basal position of acoel flatworms and the polyphyly of Platyhelminthes.
2007,
Pubmed
Stamatakis,
RAxML-VI-HPC: maximum likelihood-based phylogenetic analyses with thousands of taxa and mixed models.
2006,
Pubmed
Telford,
Combined large and small subunit ribosomal RNA phylogenies support a basal position of the acoelomorph flatworms.
2003,
Pubmed
Telford,
Xenoturbellida: the fourth deuterostome phylum and the diet of worms.
2008,
Pubmed
,
Echinobase
Wheeler,
The deep evolution of metazoan microRNAs.
2009,
Pubmed
