On the 23rd June 2006, PhD student Sissel Kjøglum, who works for Aqua Gen, presented her doctoral thesis for a PhD-degree at the Norwegian School of Veterinary Science. Her dissertation was on ”Associations between major histocompatibility complex (MHC) and disease resistance in Atlantic salmon (Salmo salar L.)". This research project makes it possible for Aqua Gen to increase its efforts to breed healthy and robust fish.

Sissel Kjøglum has been a research fellow in a user-controlled project in which the Norwegian School of Veterinary Science was the research institution. The project has received external funding from The Norwegian Research Council. Through this project immune genes in Atlantic salmon have been identified that are of importance for its resistance to infectious diseases. By using this genetic information Aqua Gen can now improve its selective breeding for increased disease resistance, which will contribute to improved profitability in the salmon industry.

Sissel Kjøglum flanked by her two supervisors at The Norwegian School of Veterinary Science.

Traditional breeding has focussed on creating a salmon with high growth rate and late maturation. In the mid-1990s Aqua Gen, as the first breeding company in aquaculture, implemented techniques that make the selection for increased resistance against infectious diseases possible. The techniques used are based on testing the siblings of selection candidates using challenge tests. This project has identified genetic markers for disease resistance, by using these the selection of highly resistant brood fish can be performed with DNA analysis. This can give a more effective and precise selection than the challenge tests used to date..

Sissel Kjøglum has studied genes in the major histocompatibility complex (MHC). These genes play a pivotal role in the immune system in mammals and birds. This study along with others shows that this also applies to the defence against several infectious diseases in salmon.

By analysing a large number of fish from challenge tests for furunculosis, infectious salmon anaemia (ISA) and infectious pancreatic necrosis (IPN), Kjøglum has found variants of MHC genes that render the highest resistance against the relevant diseases. Based on MHC in Atlantic salmon, she has also outlined different aspects related to implementing molecular information in breeding programs. Aqua Gen will now include this new knowledge in its operational breeding scheme and thus be able to supply the salmon industry with a seed that renders even higher resistance to infectious diseases.