The gene responsible for Infectious pancreatic necrosis (IPN) resistance in salmon has been identified by Norwegian biologists at AquaGen.
The collaborative Atlantic Salmon genome project, which began in 2010, revealed the gene that codes IPN resistance in salmon has two mutations that prevent the virus from infecting salmon cells.
IPN is a common viral disease and is one that has been responsible for significant losses in salmon farming. It has been proven to be difficult to control by vaccination or other preventative or loss-reduction measures adopted over the years.
After years of research and analysis, AquaGen found that the trait is mostly controlled by a single area on the genome and a test was developed that used gene markers to identify IPN resistant and IPN susceptible fish. These markers were put to use in the production of eggs that were delivered to salmon farmers from 2009 onwards.
After remaining stable at around 200 outbreaks annually for decades in Norway, it was a low as 50 outbreaks in 2013 due to the use of the IPN-QTL eggs.
The mechanism behind IPN resistance shows that salmon do not have a single, but two mutations that are both able to make salmon resistant to IPN. These two mutations are located in the same gene, and there is now evidence that this gene is actually a necessary component of the mechanism the virus uses to get into salmon cells.
It is hoped that the reference genome for salmon will provide important information of great benefit to the salmon farming in the future.
