Andrew J. Roger
Wanda Danilchuk
Marlena Dlutek
Dayana Salas
Joran Martijn
Gregory Seaton
Dandan Zhao
Shelby Williams
Tengteng Zhang
Kelsey Williamson
Former Roger Lab Members
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Sebastian Hess, Post Doctoral Fellow
To access Sebastian's web page, click here
During my doctoral studies in Cologne (Germany), I investigated the structure, life histories and evolution of diverse, poorly known protists that feed specifically on freshwater microalgae. Besides my studies about vampyrellid amoebae (Vampyrellida, Rhizaria), I discovered and characterised the Viridiraptoridae, a family of cercozoan amoeboflagellates, which perforate algal cells to feed on protoplast material. I came to Halifax as a postdoctoral research fellow to study the molecular mechanisms involved in this complex feeding behaviour, in particular cell wall degrading enzymes and actin-binding proteins. These proteins will be explored in the species Orciraptor agilis (Viridiraptoridae) during different life history stages using a comparative transcriptomic approach and a selection of biochemical methods. For this project, I work together with Andrew Roger (Department of Biochemistry and Molecular Biology) and Alastair Simpson (Department of Biology).
Other interests include:
structure, evolution and systematics of vampyrellid amoebae (Vampyrellida, Cercozoa)
cytoskeleton architecture and ultrastructure of protists
endosymbiotic bacteria (e.g. Rickettsiales) in protists
Research papers:
Hess S. (2017). Hunting for agile prey: trophic specialisation in leptophryid amoebae (Vampyrellida, Rhizaria) revealed by two novel predators of planktonic algae. FEMS Microbiology Ecology 93(9): 1-12.
Hess S. (2017) Description of Hyalodiscus flabellus sp. nov. (Vampyrellida, Rhizaria) and identification of its bacterial endosymbiont, "Candidatus Megaira polyxenophila" (Rickettsiales, Alphaproteobacteria). Protist 168(1): 109-133.
Bush A. & Hess S. (2017). The cytoskeleton architecture of algivorous protoplast feeders (Viridiraptoridae, Rhizaria) indicates actin–guided perforation of prey cell walls. Protist 168(1): 12-31.
Hess S., Suthaus A., Melkonian M. (2016). “Candidatus Finniella” (Rickettsiales, Alphaproteobacteria), novel endosymbionts of viridiraptorid amoeboflagellates (Cercozoa, Rhizaria). Applied and Environmental Microbiology. 82: 659-670. doi:10.1128/AEM.02680-15.
Hess S. (2015). Algivorous freshwater protists of the phylum Cercozoa (Rhizaria) – structure, life histories and evolution. Dissertation University of Cologne, Verlag Dr. Hut, München, ISBN 9783843921688.
Hess S. & Melkonian M. (2014). Ultrastructure of the algivorous amoeboflagellate Viridiraptor invadens (Glissomonadida, Cercozoa).Protist 165(5): 605-635.
Hess S. & Melkonian M. (2013). The mystery of clade X: Orciraptor gen. nov. and Viridiraptor gen. nov. are highly specialised, algivorous amoeboflagellates (Glissomonadida, Cercozoa). Protist 164(5): 706-747.
Hess S., Sausen N., Melkonian M. (2013). Shedding light on vampires: the phylogeny of vampyrellid amoebae revisited. PloS one, 7(2): e31165.
Foissner W., Hess S., Al-Rasheid K. (2009). Two vicariant Semispathidium species from tropical Africa and central Europe: S. fraterculum nov. spec. and S. pulchrum nov. spec. (Ciliophora, Haptorida). European Journal of Protistology 46(1): 61-73.
Hess S., Frahm J.-P., Theisen I. (2005).Evidence of zoophagy in a second liverwort species, Pleurozia purpurea. The Bryologist 108(2): 212-218.
You can reach Sebastian at:
Work Phone: (+1) 902-494-2881
Fax: (+1) 902-494-1355
E-mail: shess{at}dal{dot}ca
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