Dr. Gianna Dirren
phone: +41 (0)44 63 49214
fax: +41 (0)44 63 41225 Research InterestsEducation Fellowships and Awards List of Publications | |
[ print version ] |
I have been fascinated by the world of aquatic microorganisms since my first look through a microscope. My research is focussed on eukaryotic microorganisms, in particular on pelagic ciliates. Thereby, a special emphasis lies on the ecophysiology of ciliates: what they feed on, which are their main predators, when and why they bloom during the season, and finally how these protists will react on environmental changes (e.g., lake warming). To answer these questions, ciliates need to be identified and quantified in their natural environments at a high temporal and spatial resolution. Apart from the morphological approach, which is by microscopy, we investigate the diversity of ciliates in Lake Zurich also by molecular tools like high-throughput sequencing (HTS). By using a combination of both approaches, we intend to receive a holistic picture of ciliates, aquatic microorganisms in general, and their interactions in the pelagic realm of Lake Zurich.
DGP 2019, Poster |
38th Meeting of the German Society for Protozoology (Wien, Austria, 2019) Poster presentation: "Seasonality of planktonic freshwater ciliates: are analyses based on V9 regions of the 18S rRNA gene correlated with morphospecies counts?" |
DGP 2018, Poster |
37th Meeting of the German Society for Protozoology (Koeln, Germany, 2018) Poster presentation: "Morphological and Molecular Based Analyses of Planktonic Ciliates in Lake Zurich" |
SAME 2017, Talk |
15th SAME, Symposium of Aquatic Microbial Ecology (Zagreb, Croatia, 2017) Oral presentation: "The green Tetrahymena utriculariae n. sp. (Ciliophora, Oligohymenophorea) with its endosymbiotic algae (Micractinium sp.), living in traps of a carnivorous aquatic plant" |
FBFW 2017, Poster |
5th Meeting of Fresh Blood for Fresh Water (Česk? Budĕjovice, Czech Republic, 2017) Poster presentation: "The green Tetrahymena utriculariae n. sp. (Ciliophora, Oligohymenophorea) with its endosymbiotic algae (Micractinium sp.), living in traps of a carnivorous aquatic plant" |
DGP 2017, Poster |
36th Meeting of the German Society for Protozoology (Meissen, Germany, 2017) Poster presentation: "The green Tetrahymena utriculariae n. sp. (Ciliophora, Oligohymenophorea) with its endosymbiotic algae (Micractinium sp.), living in traps of a carnivorous aquatic plant" |
DGP 2016, Poster |
35th Meeting of the German Society for Protozoology (Saignelegier, Switzerland, 2016) Poster presentation: "When a lake stops mixing: the fatal effects of lake warming on the protistan community" |
ECOP 2015, Poster |
7th European Congress of Protistology ECOP in partnership with ISOP (Sevilla, Spain, 2015) Poster presentation: "When a lake stops mixing: the fatal effects of lake warming on the protistan community" |
2019 - present | University of Zurich, Postdoc at the Limnological Station |
2015 - 2019 | University of Zurich, PhD in Ecology at the Limnological Station, supervised by Prof. Thomas Posch Title: "Ciliates in Freshwater Ecosystems: Insights from Morphological and Molecular Approaches" |
2014 - 2015 | University of Zurich, Master in Microbiology at the Limnological Station, supervised by Prof. Thomas Posch Title: "Morphological and molecular based analyses of planktonic ciliates in Lake Zurich" |
2009 - 2014 | University of Zurich, Bachelor of Science in Biology |
2017 | Poster prize (first place) at the conference of the German Society for Protozoology, Meissen (Germany) |
2017 | Poster prize (first place) at the conference of Fresh Blood for Fresh Water, Česk? Budĕjovice (Czech Republic) |
2016 | Poster prize (first place) at the conference of the German Society for Protozoology, Saignelegier (Switzerland) |
2015 | Master thesis awarded by the Foundation for Hydrobiology-Limnology (Hydrobiologie-Limnologie-Stiftung fuer Gewaesserforschung), Zurich |
Dirren-Pitsch, G., Bühler, D., Salcher, M.M., Bassin, B., Le Moigne, A., Schuler, M., Pernthaler, J., and Posch, T. (2022). FISHing for ciliates: Catalyzed reporter deposition fluorescence in situ hybridization for the detection of planktonic freshwater ciliates. Frontiers in Microbiology 13. doi: 10.3389/fmicb.2022.1070232
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Frantal, D., Agatha, S., Beisser, D., Boenigk, J., Darienko, T., Dirren-Pitsch, G., Filker, S., Gruber, M., Kammerlander, B., Nachbaur, L., Scheffel, U., Stoeck, T., Qian, K., Weißenbacher, B., Pröschold, T. and Sonntag, B. (2022). Molecular Data Reveal a Cryptic Diversity in the Genus Urotricha (Alveolata, Ciliophora, Prostomatida), a Key Player in Freshwater Lakes, With Remarks on Morphology, Food Preferences, and Distribution. Frontiers in Microbiology 12. doi: 10.3389/fmicb.2021.787290
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Forster, D., Qu, Z., Pitsch, G., Bruni, E.P., Kammerlander, B., Pröschold, T., Sonntag, B., Posch, T., and Stoeck, T. (2021) Lake ecosystem robustness and resilience inferred from a climate-stressed protistan plankton network. Microorganisms 9(3):549.
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Pröschold, T., Rieser, D., Darienko, T., Nachbaur, L., Kammerlander, B., Qian, K., Pitsch, G., Bruni, E.P., Qu, Z., Forster, D., Rad-Menendez, C., Posch, T., Stoeck, T., and Sonntag, B. (2021). An integrative approach sheds new light onto the systematics and ecology of the widespread ciliate genus Coleps (Ciliophora, Prostomatea). Scientific Reports 11(1):5916. doi: 10.1038/s41598-021-84265-y
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Qu, Z., Forster, D., Bruni, E.P., Frantal, D., Kammerlander, B., Nachbaur, L., Pitsch, G., Posch, T., Pröschold, T., Teubner, K., Sonntag, B., and Stoeck, T. (2021). Aquatic food webs in deep temperate lakes: key species establish through their autecological versatility. Molecular Ecology 30(4):1053-1071
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Posch, T., Pitsch, G., and Bruni, E.P. (2020). Protists: Ciliates. In: Encyclopedia of Inland Waters, 2nd edition. Elsevier Inc.
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Pröschold, T., Pitsch, G., and Darienko, T. (2020). Micractinium tetrahymenae (Trebouxiophyceae, Chlorophyta), a New Endosymbiont Isolated from Ciliates. Diversity 12(5), 200.
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Pitsch, G., Bruni, E.P., Forster, D., Qu, Z., Sonntag, B., Stoeck, T., and Posch, T. (2019). Seasonality of Planktonic Freshwater Ciliates: Are Analyses Based on V9 Regions of the 18S rRNA Gene Correlated With Morphospecies Counts? Frontiers in Microbiology 10:248. doi: 10.3389/fmicb.2019.00248.
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Dirren, S., Pitsch, G., Silva, M.O.D., and Posch, T. (2017). Grazing of Nuclearia thermophila and Nuclearia delicatula (Nucleariidae, Opisthokonta) on the toxic cyanobacterium Planktothrix rubescens. Europ J Protistol, 60:87-101. doi:10.1016/j.ejop.2017.05.009
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Pitsch, G., Adamec, L., Dirren, S., Nitsche, F., Šimek, K., Sirová, D., and Posch, T. (2017). The Green Tetrahymena utriculariae n. sp. (Ciliophora, Oligohymenophorea) with its Endosymbiotic Algae (Micractinium sp.), Living in Traps of a Carnivorous Aquatic Plant. J Eukaryot Microbiol, 64:322-335. doi: 10.1111/jeu.12369.
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Šimek, K., Pitsch, G., Salcher, M.M., Sirová, D., Shabarová, T., Adamec, L., and Posch, T. (2017). Ecological Traits of the Algae-Bearing Tetrahymena utriculariae (Ciliophora) from Traps of the Aquatic Carnivorous Plant Utricularia reflexa. J. Eukaryot. Microbiol., 64:336-348. doi: 10.1111/jeu.12368.
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Posch, T., Eugster, B., Pomati, F., Pernthaler, J., Pitsch, G., and Eckert, E.M. (2015). Network of interactions between ciliates and phytoplankton during spring. Front. Microbiol.6: 1289. doi: 10.3389/fmicb.2015.01289
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