Département Toxicologie de l’environnement


Wir sind aktiv in der Lehre an der ETHZ und der EPFL tätig.


KurstitelKursnummer        Personen
Advanced Ecotoxicology (ETHZ)


Rik Eggen, Elisabeth Janssen,
Kristin Schirmer, Marc Suter, Ahmed Tlili
Molecular Ecotoxicology (ETHZ)


Kristin Schirmer, Stephan Fischer (Aquatox Solutions)

Basics in Ecotoxicology (ETHZ)701-0612-01-L Rik Eggen
Ecotoxicology (EPFL)ENV-306 Kristin Schirmer, Julita Stadnicka

Aktuelle Master Projekte

Characterization of Glutathione S-transferases Expression and Activity in Pac2 Zebrafish Cell Line

In vitro toxicity testing with cell culture is applied to screen chemicals and potential drug candidates for their efficacy and safety. However, the fate of chemicals within a biological system strongly depends on biotransformation reactions catalyzed by xenobiotic-metabolizing enzymes. Phase II enzymes, such as glutathione S-transferases (GSTs), can modify the chemical structure of the parent compound leading to an increase or decrease in its toxic potential. To avoid false positive or false negative results in chemical screening, it is therefore crucial to investigate possible differences in the biotransformation processes between in vitro and in vivo models.

Aim: By using established targeted proteomics methods, we aim to profile the expression of GSTs in zebrafish cell line to allow a comparison of the in vitro system with the existing data from zebrafish embryos. Furthermore, we aim to analyze the regulation of the GST isoforms on the protein level upon exposure to reference chemicals and to monitor the production of phase II metabolites (GSH-conjugates) via high resolution mass spectrometry.

Candidates will learn: (1) cell culturing techniques (2) how to prepare samples for proteomics analysis (protein extraction and tryptic digest) (3) how to carry out targeted proteomics analysis (4) exposure of cell lines to reference compounds (5) analysis of GSH-conjugates.

For further information please contact Marc Suter or Alena Tierbach  (marc.suter@eawag.ch; alena.tierbach@eawag.ch). This work will be performed at Eawag in the department of Environmental Toxicology in Dübendorf. 



Mathematical modeling of a novel in vitro system for measuring permeation
of hydrophobic and volatile chemical across a fish intestinal epithelial cell monolayer

Permeation of organic chemicals from the aquatic environment across cellular barriers is a critical step for accumulation in organisms, such as fish. To better understand the underlying processes, we aim to study the role of the fish intestine as barrier for hydrophobic and volatile chemicals. Therefore, at the department of environmental toxicology, we combined a recently developed in vitro epithelial barrier model using the rainbow trout (Oncorhynchus mykiss) intestinal cell line, RTgutGC, and a newly constructed chamber that enables stable chemical exposure concentrations.We estimated  the effective permeation of different chemicals across the intestinal epithelial monolayer and measured chemical mass in different biological and non-biological compartments of the system over time. Mathematical modeling of the experiment is now needed to determine which processes (passive diffusion, carrier-mediated influx/efflux, binding, biotransformation) are dominant for the measured chemicals and  what are their corresponding rates. 

AIM: The aim of the master project is to build a family of mathematical models that describe the permeation experiments, use model selection to find the dominant processes in the experiments with different chemicals and use the best fitting models to estimate the effective permeation coefficient.

METHODS: The candidate will use Matlab to build the models and perform parameter estimation, identifiability analysis and model selection, using algorithms available at the department for environmental toxicology. In case of extensive expertise of the student, shifting to a different modeling environment is an option.

Suitable candidates for this project are expected to hold a BSc degree in environmental sciences or a related discipline and to have sufficient experience in dynamic ODE modeling.

For further information please contact Anze Zupanic (mailto:mailto:anze.zupanic@eawag.ch). This research will be performed at the department of Environmental Toxicology in Dübendorf.



Investigating the mechanism of copper-induced hair cell toxicity in zebrafish larvae

Metals are widespread aquatic contaminants and affect aquatic wildlife in different ways. For instance, copper ions have been shown to specifically impair hair cells of the lateral line organ in fish. These cells are tiny sensors of hydrodynamic flows helping the fish to orient, detect predators and prey and communicate with conspecifics. As a consequence, some behavioral responses, such as e.g. rheotaxis, a natural behavioral reaction of fish to orient counter-flow in order to hold a fixed position in a stream, are severely affected in copper-exposed fish.

AIM: The aim of this Master thesis is to investigate the mechanism by which copper specifically affects hair cells but not other cell types in the fish. Therefore, copper distribution within the organism as well as the expression of a number of genes involved in copper transport and metabolism will be studied in order to detect differential expression in hair cells.

METHOD: To tackle this question, we are using zebrafish (Danio rerio) larvae, because of several reasons: genomic resources and genetic tools are available, their transparent larval stages are amenable to different optical techniques and their small body size allows for the continuous measurement of behavior with full control of the environment. Copper distribution within the body will be assessed using copper-specific fluorescent indicators. Gene expression will be studied by whole mount in situ hybridization in zebrafish larvae, which allows to localize gene expression to specific tissues such as e.g. hair cells, followed by bright field or confocal imaging. Gene expression will form the basis for further loss-of-function experiments and behavioral tests. Depending on the progression, the Master thesis could be extended with such functional tests.

Suitable candidates for this project are expected to hold a BSc degree in biology, environmental sciences or a related discipline and to have experience in laboratory work.

For further information please contact Colette vom Berg (Colette.vomberg@eawag.ch). This work will be performed at Eawag in the department of Environmental Toxicology in Dübendorf.