Effects of eco-toxicology on Zebra fish

Rasoul Nourizadeh-Lillabadi has shown that zebra fish can be used as models in order to study the effects of eco-toxicology on fish indigenous to Norway. The toxic substances used in the research project come from water effluent from the offshore industry and from organic material that had accumulated in the liver of burbot fish in the lakes of Mjøsa and Losna.

Zebra fish are small aquarium fish which are increasingly used in several different fields: in pure biological research, as a model for disease in humans, in the industrial testing of medicines and now also in eco-toxicology research.

For a number of these fields, it is essential to have access to precise micro matrix analyses that can be reproduced. Micro matrix is a technology that is used to measure the quantity of many different gene products (mRNA) in one individual experiment.

Nourizadeh began work on his PhD by establishing a micro matrix analysis for use on zebra fish. At a later stage in his research, the method was used to study changes in the gene expression of zebra fish when they were exposed to two different kinds of eco-toxins.

In the first study, the zebra fish were exposed to a mixture of polyaromatic hydrocarbon (PHAs) and alkyl phenolate present in water effluent from the Norwegian oil and gas industry. In the second study, the zebra fish were exposed to natural compounds of persistent, organic pollutants which had accumulated in the liver of burbot fish in the lakes of Mjøsa and Losna.

During these periods of exposure, effects such as mortality rates, foetus deformations and changes in body weight, gender distribution and sexual maturation were observed. These effects agreed with the changes found in gene expression. For example, the gene analyses in both studies revealed that the toxins had an effect on the reproduction system as well as on the fat and carbohydrate metabolism of the zebra fish.

Rasoul Nourizadeh-Lillabadi presented his doctoral thesis on 14th December 2009 at The Norwegian School of Veterinary Science. The thesis is entitled: "Genome-wide gene expression profiling in the zebra fish (Danio rerio) model: studies with focus on eco-toxicology and functional genomics."