Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution
<p>Abstract</p> <p>Background</p> <p>Nematodes are putatively the most species-rich animal phylum. They have various life styles and occur in a variety of habitats, ranging from free-living nematodes in aquatic or terrestrial environments to parasites of animals and pla...
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| Format: | Article |
| Language: | English |
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BMC
2009-08-01
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| Series: | BMC Evolutionary Biology |
| Online Access: | http://www.biomedcentral.com/1471-2148/9/212 |
| _version_ | 1818902436665884672 |
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| author | Sommer Ralf J Herrmann Matthias Mayer Werner E |
| author_facet | Sommer Ralf J Herrmann Matthias Mayer Werner E |
| author_sort | Sommer Ralf J |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Nematodes are putatively the most species-rich animal phylum. They have various life styles and occur in a variety of habitats, ranging from free-living nematodes in aquatic or terrestrial environments to parasites of animals and plants. The rhabditid nematode <it>Caenorhabditis elegans </it>is one of the most important model organisms in modern biology. <it>Pristionchus pacificus </it>of the family of the Diplogastridae has been developed as a satellite model for comparison to <it>C. elegans</it>. The Diplogastridae, a monophyletic clade within the rhabditid nematodes, are frequently associated with beetles. How this beetle-association evolved and whether beetle-nematode coevolution occurred is still elusive. As a prerequisite to answering this question a robust phylogeny of beetle-associated Diplogastridae is needed.</p> <p>Results</p> <p>Sequences for the nuclear small subunit ribosomal RNA and for 12 ribosomal protein encoding nucleotide sequences were collected for 14 diplogastrid taxa yielding a dataset of 5996 bp of concatenated aligned sequences. A molecular phylogeny of beetle-associated diplogastrid nematodes was established by various algorithms. Robust subclades could be demonstrated embedded in a phylogenetic tree topology with short internal branches, indicating rapid ancestral divergences. Comparison of the diplogastrid phylogeny to a comprehensive beetle phylogeny revealed no major congruence and thus no evidence for a long-term coevolution.</p> <p>Conclusion</p> <p>Reconstruction of the phylogenetic history of beetle-associated Diplogastridae yields four distinct subclades, whose deep phylogenetic divergence, as indicated by short internal branch lengths, shows evidence for evolution by successions of ancient rapid radiation events. The stem species of the Diplogastridae existed at the same time period when the major radiations of the beetles occurred. Comparison of nematode and beetle phylogenies provides, however, no evidence for long-term coevolution of diplogastrid nematodes and their beetle hosts. Instead, frequent host switching is observed. The molecular phylogeny of the Diplogastridae provides a framework for further examinations of the evolution of these associations, for the study of interactions within the ecosystems, and for investigations of diplogastrid genome evolution.</p> |
| first_indexed | 2024-12-19T20:35:37Z |
| format | Article |
| id | doaj.art-3e9becb928fc44e288df791b614a5e5d |
| institution | Directory Open Access Journal |
| issn | 1471-2148 |
| language | English |
| last_indexed | 2024-12-19T20:35:37Z |
| publishDate | 2009-08-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Evolutionary Biology |
| spelling | doaj.art-3e9becb928fc44e288df791b614a5e5d2022-12-21T20:06:33ZengBMCBMC Evolutionary Biology1471-21482009-08-019121210.1186/1471-2148-9-212Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolutionSommer Ralf JHerrmann MatthiasMayer Werner E<p>Abstract</p> <p>Background</p> <p>Nematodes are putatively the most species-rich animal phylum. They have various life styles and occur in a variety of habitats, ranging from free-living nematodes in aquatic or terrestrial environments to parasites of animals and plants. The rhabditid nematode <it>Caenorhabditis elegans </it>is one of the most important model organisms in modern biology. <it>Pristionchus pacificus </it>of the family of the Diplogastridae has been developed as a satellite model for comparison to <it>C. elegans</it>. The Diplogastridae, a monophyletic clade within the rhabditid nematodes, are frequently associated with beetles. How this beetle-association evolved and whether beetle-nematode coevolution occurred is still elusive. As a prerequisite to answering this question a robust phylogeny of beetle-associated Diplogastridae is needed.</p> <p>Results</p> <p>Sequences for the nuclear small subunit ribosomal RNA and for 12 ribosomal protein encoding nucleotide sequences were collected for 14 diplogastrid taxa yielding a dataset of 5996 bp of concatenated aligned sequences. A molecular phylogeny of beetle-associated diplogastrid nematodes was established by various algorithms. Robust subclades could be demonstrated embedded in a phylogenetic tree topology with short internal branches, indicating rapid ancestral divergences. Comparison of the diplogastrid phylogeny to a comprehensive beetle phylogeny revealed no major congruence and thus no evidence for a long-term coevolution.</p> <p>Conclusion</p> <p>Reconstruction of the phylogenetic history of beetle-associated Diplogastridae yields four distinct subclades, whose deep phylogenetic divergence, as indicated by short internal branch lengths, shows evidence for evolution by successions of ancient rapid radiation events. The stem species of the Diplogastridae existed at the same time period when the major radiations of the beetles occurred. Comparison of nematode and beetle phylogenies provides, however, no evidence for long-term coevolution of diplogastrid nematodes and their beetle hosts. Instead, frequent host switching is observed. The molecular phylogeny of the Diplogastridae provides a framework for further examinations of the evolution of these associations, for the study of interactions within the ecosystems, and for investigations of diplogastrid genome evolution.</p>http://www.biomedcentral.com/1471-2148/9/212 |
| spellingShingle | Sommer Ralf J Herrmann Matthias Mayer Werner E Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution BMC Evolutionary Biology |
| title | Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution |
| title_full | Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution |
| title_fullStr | Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution |
| title_full_unstemmed | Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution |
| title_short | Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution |
| title_sort | molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode beetle coevolution |
| url | http://www.biomedcentral.com/1471-2148/9/212 |
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