0000000000323533
AUTHOR
Alexander Witek
showing 6 related works from this author
Phylogenetic analyses of endoparasitic Acanthocephala based on mitochondrial genomes suggest secondary loss of sensory organs
2012
The metazoan taxon Syndermata (Monogononta, Bdelloidea, Seisonidea, Acanthocephala) comprises species with vastly different lifestyles. The focus of this study is on the phylogeny within the syndermatan subtaxon Acanthocephala (thorny-headed worms, obligate endoparasites). In order to investigate the controversially discussed phylogenetic relationships of acanthocephalan subtaxa we have sequenced the mitochondrial (mt) genomes of Echinorhynchus truttae (Palaeacanthocephala), Paratenuisentis ambiguus (Eoacanthocephala), Macracanthorhynchus hirudinaceus (Archiacanthocephala), and Philodina citrina (Bdelloidea). In doing so, we present the largest molecular phylogenetic dataset so far for this…
Support for the monophyletic origin of Gnathifera from phylogenomics
2009
The monophyletic origin of Spiralia within the metazoan tree of life is supported by many large-scale phylogenomic data. While there is now substantial molecular evidence for Lophotrochozoa being a monophyletic taxon within Spiralia, the phylogenetic affiliations of many other spiralian phyla remain unclear. Here we focus on the question of a monophyletic taxon Gnathifera, which was originally characterized by jaw morphology as comprising the taxa Rotifera, Acanthocephala and Gnathostomulida. Based on a large-scale molecular sequence dataset of 11,146 amino acid residues, we reconstructed phylogenetic trees of spiralian phyla using maximum-likelihood and Bayesian approaches. We obtain the f…
EST based phylogenomics of Syndermata questions monophyly of Eurotatoria
2008
Abstract Background The metazoan taxon Syndermata comprising Rotifera (in the classical sense of Monogononta+Bdelloidea+Seisonidea) and Acanthocephala has raised several hypotheses connected to the phylogeny of these animal groups and the included subtaxa. While the monophyletic origin of Syndermata and Acanthocephala is well established based on morphological and molecular data, the phylogenetic position of Syndermata within Spiralia, the monophyletic origin of Monogononta, Bdelloidea, and Seisonidea and the acanthocephalan sister group are still a matter of debate. The comparison of the alternative hypotheses suggests that testing the phylogenetic validity of Eurotatoria (Monogononta+Bdel…
Selecting ribosomal protein genes for invertebrate phylogenetic inferences: how many genes to resolve the Mollusca?
2010
Summary 1. Multi-gene analyses are currently the gold standard in phylogenetics, despite limited taxon sampling. To facilitate broad taxon representation on an economically tolerable level, we optimize the gene selection for future PCR-based sampling strategies. 2. Highly expressed ribosomal proteins (RP) were sampled chiefly for molluscs, the second largest metazoan phylum with largely unknown internal relationships. Thirty-two new sequences for Lepidochitona cinerea (Polyplacophora) were integrated into a data-matrix of 79 RP genes, comprising 16 mollusc species (five classes). The resulting maximum likelihood tree was used to evaluate each single-gene tree according to its topological fi…
Spiralian phylogenomics supports the resurrection of Bryozoa comprising Ectoprocta and Entoprocta.
2007
Phylogenetic analyses based on 79 ribosomal proteins of 38 metazoans, partly derived from 6 new expressed sequence tag projects for Ectoprocta, Entoprocta, Sipuncula, Annelida, and Acanthocephala, indicate the monophyly of Bryozoa comprising Ectoprocta and Entoprocta, 2 taxa that have been separated for more than a century based on seemingly profound morphological differences. Our results also show that bryozoans are more closely related to Neotrochozoa, including molluscs and annelids, than to Syndermata, the latter comprising Rotifera and Acanthocephala. Furthermore, we find evidence for the position of Sipuncula within Annelida. These findings suggest that classical developmental and mor…
Transcriptome data reveal syndermatan relationships and suggest the evolution of endoparasitism in acanthocephala via an epizoic stage
2014
The taxon Syndermata comprises the biologically interesting wheel animals ("Rotifera": Bdelloidea + Monogononta + Seisonidea) and thorny-headed worms (Acanthocephala), and is central for testing superordinate phylogenetic hypotheses (Platyzoa, Gnathifera) in the metazoan tree of life. Recent analyses of syndermatan phylogeny suggested paraphyly of Eurotatoria (free-living bdelloids and monogononts) with respect to endoparasitic acanthocephalans. Data of epizoic seisonids, however, were absent, which may have affected the branching order within the syndermatan clade. Moreover, the position of Seisonidea within Syndermata should help in understanding the evolution of acanthocephalan endoparas…