Thorny-headed worms

Phylogenetic analyses of endoparasitic Acanthocephala based on mitochondrial genomes suggest secondary loss of sensory organs.

Publication Type:Journal Article
Year of Publication:2013
Authors:M. Weber, Wey-Fabrizius, A. R., Podsiadlowski, L., Witek, A., Schill, R. O., Sugár, L., Herlyn, H., Hankeln, T.
Journal:Mol Phylogenet Evol
Date Published:2013 Jan
Keywords:Acanthocephala, Animals, Bayes Theorem, Biological Evolution, DNA, Mitochondrial, Gene Order, Genome, Mitochondrial, Likelihood Functions, Phylogeny, Sense Organs, Sequence Analysis, DNA

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 question comprising all major subgroups of Acanthocephala. Alongside with publicly available mt genome data of four additional syndermatans as well as 18 other lophotrochozoan (spiralian) taxa and one outgroup representative, the derived protein-coding sequences were used for Maximum Likelihood as well as Bayesian phylogenetic analyses. We achieved entirely congruent results, whereupon monophyletic Archiacanthocephala represent the sister taxon of a clade comprising Eoacanthocephala and monophyletic Palaeacanthocephala (Echinorhynchida). This topology suggests the secondary loss of lateral sensory organs (sensory pores) within Palaeacanthocephala and is further in line with the emergence of apical sensory organs in the stem lineage of Archiacanthocephala.

Alternate Journal:Mol. Phylogenet. Evol.
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith