Somatic gene transfer in European sea bass (Dicentrarchus labrax): Optimal fish conditions and exogenous control of foreign genes

摘要

The introduction of naked plasmid DNA in the somatic tissue of an adult organism was established as a system for transient gene transfer years ago. The genes contained in the plasmid are efficiently expressed and expression can be maintained over long periods of time. In the present work, we established this technique for an aquacultured marine fish, European sea bass (Dicentrarchus labrax). The target tissue was muscle and the delivery method used was direct injection of the plasmid DNA. The maximum expression of the introduced gene was detected 5 days after the injection with an optimal dose of 25 mu g. The efficiency of this method had a clear dependence on water temperature and muscle condition. Different systems previously used in mammals for the improvement of DNA uptake in muscle cells have not worked properly in fish. However, we found that electroporation improved DNA uptake in fish reared at low temperatures. Use of this technique allowed us to evaluate the tetracycline-regulated gene expression system for its use in a marine fish for the first time. All together, these data provide the foundations for undertaking future applications for DNA vaccination or gene therapy in European sea bass