Defence mechanisms of fish with different sensitivity towards heavy metals: Interaction and dynamics of proteins and hormones

Despite recent improvements of water quality in Belgium, there is a historic pollution of heavy metals in the aquatic environment. Different sensitivities of fish towards this metal pollution have been reported. Within this project, we will investigate the differences between rainbow trout (Oncorhynchus mykiss), carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio) in dealing with the effects of copper exposure. These fish species differ in their tolerance to copper, but the underlying mechanisms have not yet been revealed. Fish will be exposed to two sublethal exposure-conditions; one similar concentration for every fish species and one concentration which is the 10% LC50 96h value for each fish species. After 1h, 12h, 24h, 3days, 1 week and 1 month gill and plasma samples are taken. The intracellular proteome of gill cells as well as the hormonal balance, the role of hormonal influences and oxidative stress conditions during exposure will be evaluated by use of techniques such as iTRAQ, 2DIGE, immunoassays, Real-time PCR and a number of enzymatic assays. When proteome-profiles are constructed and quantitative and qualitative changes in expression of proteins are unravelled, we can search for differentially expressed proteins which can serve as biomarkers.
With this project we want to obtain a better insight in the differences of the intracellular physiological and molecular responses in our test species and develop a sensitive biomarker for detection of metal toxicity in aquatic organisms.