Phylogeny of calcareous sponges
Zusammenfassung der Projektergebnisse
Calcareous sponges (Class Calcarea) are one of the three recent classes of phylum Porifera. They play an important role for our understanding of early metazoan evolution because they are probably more closely related to eumetazoa (‘Coelenterata’ + Bilateria) than to the other main sponge taxa Demospongiae and Hexactinellida. However, supraspecific relationships within Calcarea remained largely unresolved as a high degree of morphological homoplasy did not yet allow a well-supported phylogenetic classification. With a primarily molecular approach we provided additional insight in the phylogenetic relationships of this class of sponges, especially for the subclass Calcinea. The phylogeny of Calcarea inferred from complete 18S and nearly complete 28S rRNA data suggests that several higher taxa are not monophyletic (Order Leucosolenida, Order Clathrinida, Order Lithonida, Family Grantiidae, Family Heteropiidae, Family Jenkinidae, Family Sycettidae; Family Clathrinidae, Family Leucaltidae; Genus Sycettusa, Genus Sycon, Genus Ute, Genus Grantia, Genus Clathrina, Genus Leucetta). Clearly many of the diagnostic characters in Calcarean taxonomy are in need for reevaluation. We could show that DNA analyses could provide a valuable independent source of information that taxonomist cannot afford to neglect when revising this Class of sponges. The genotyping approach developed in this project allows to screen larger collections relatively quickly, and allows rapid identification of specimens belonging to the same species. In the future, when more comparative sequence data has become available and a well-supported phylogenetic system of Calcarea has been established, even DNA-based species identification might be possible. We are optimistic that a well-supported phylogenetic system of Calcarea can be established when an extended taxon sampling has been achieved, which then supports new hypotheses of the evolution of morphological traits. Biomarker analyses revealed that Calcarean fatty acid patterns significantly differ from those of the Demospongiae and Hexactinellida, thus supporting the distinction of Calcarea from Silicea, and independently corroborating molecular data. Calcarean sterol patterns clearly differ from those found in Hexactinellida, whereas partial overlap occurred with some Demospongiae. The small intraspecific variability observed for both, fatty acids and sterols, indicates that the inventories found are characteristic traits of the species studied. However, when transposing the biomarker data into a presence-absence matrix, no intraclass phylogenetic resolution within Calcarea was gained. At the same time, the uniformity of biomarker patterns across both subclasses implies that the main lipid characteristics of Calcarea had been established before the separation of Calcinea and Calcaronea.
Projektbezogene Publikationen (Auswahl)
- 2006. CO1 phylogenies in diploblasts and the ´Barcoding of Life´ - are we sequencing a suboptimal partition? Molecular Ecology Notes 6: 550–553
Erpenbeck, D., Hooper, J.N.A., Wörheide, G.
- 2006. Non-monophyly of most supraspecific taxa of calcareous sponges (Porifera, Calcarea) revealed by increased taxon sampling and partitioned Bayesian analysis of ribosomal DNA. Molecular Phylogenetics and Evolution, 40:830-843
Dohrmann M, Voigt O, Erpenbeck D, Wörheide G.
- 2006. The fatty acids of calcareous sponges (Calcarea, Porifera). Chemistry and Physics of Lipids, 143 (1-2), 29-37
Schreiber A, Wörheide G, Thiel V.
- 2007. Mitochondrial diversity of early-branching metazoa is revealed by the complete mt genome of a haplosclerid demosponge. Molecular Biology and Evolution, 24(1)
Erpenbeck D, Voigt O, Adamski M, Adamska M, Hooper JN, Wörheide G, Degnan BM
- Oral presentation at the 7th International Sponge Symposium (7th-13th May 2006). New insights into the Phylogeny and Evolution of Calcareous Sponges
Voigt O, Dohrmann M, Wülfing E, Erpenbeck D, Wörheide G
- 2007. Analysis of evolutionary, biogeographical and taxonomic patterns of nucleotide composition in demosponge rRNA. Journal of the Marine Biological Society of the United Kingdom. 87: 1607-1614
Erpenbeck D, Cleary DFR, Voigt O, Nichols SA, Degnan BM, Hooper JNA, Wörheide G
- 2007. DNA taxonomy of sponges – progress and perspectives. Journal of the Marine Biological Association of the United Kingdom 87: 1629-1633
Wörheide, G., Erpenbeck, D.
- 2007. Low genetic structuring among Pericharax heteroraphis (Porifera: Calcarea) populations from the Great Barrier Reef (Australia), revealed by analysis of rDNA and nuclear intron sequences. Coral Reefs 26: 807-816
Bentlage, B., Wörheide, G.
- 2007. On the molecular phylogeny of sponges (Porifera). In: Zhang, Z.-Q., and Shear, W.A. (Eds.), Linnaeus Tercentenary: Progress in Invertebrate Taxonomy. Zootaxa 1668. Magnolia Press, pp. 107-126
Erpenbeck, D, Wörheide, G.
- 2007. Phylogenetic Analyses Under Secondary Structure-Specific Substitution Models Outperform Traditional Approaches: Case Studies with Diploblast LSU. Journal of Molecular Evolution, 64:543-557
Erpenbeck D, Nichols SA, Voigt O, Dohrmann M, Degnan BM, Hooper JN, Wörheide G
- 2007. Structure and composition of calcareous sponge spicules: A review and comparison to structurally related biominerals. Micron 39: 209-228
Sethmann, I., Wörheide, G.
- 2007. Towards a DNA taxonomy of Carribean demosponges: a gene tree reconstructed from partial mitochondrial CO1 gene sequences supports previous rDNA phylogenies and provides a new perspective on the systematics of Demospongiae. Journal of the Marine Biological Society of the United Kingdom 87: 1563-1570
Erpenbeck, D., Duran, S., Rützler, K., Paul, V., Hooper, J.N.A., Wörheide, G.
- 2008. Molecular evolution of rDNA in early diverging Metazoa: First comparative analysis and phylogenetic application of complete SSU rRNA secondary structures in Porifera. BMC Evolutionary Biology, 8(69). (Open access. "Highly accessed")
Voigt O., Erpenbeck D., Wörheide G.
- Oral presentation at the Evolution 2008 conference (University of Minnesota, Minneapolis, USA) (20-24 Juni 2008). The phylogeny of sponges. Dohrmann
M., Voigt, O., Erpenbeck, D., Pick, K., Wörheide, G.
- Poster presentation at the Systematics 2008 conference (7th-11th April 2008). Phylogeny of Calcareous Sponges: Resolving relationships of morphological highly problematic taxa
Voigt O, Wülfing E, Wörheide G
