LUMPFISH GENOME MAPPED

Lumpfish genome mapped. The entire DNA sequence encoding the genes (genome) of the lumpfish (lumpsucker) has now been mapped, enabling the study of all the genes that contribute to traits such as growth, disease resistance and sea lice appetite with much greater precision than before.

Lumpfish have the potential of being hugely important to the salmon farm industry as a natural means for controlling for sea lice.

Sequencing of the lumpfish genome can have benefits for both the industry and research institutions for various research purposes, says senior scientist at AquaGen, Tim Martin Knutsen. He has been working on the gene sequence in close collaboration with Tina Graceline and Matthew Kent from CIGENE (NMBU).

An important milestone of great importance in the breeding programme and egg production is that the genes for gender determination seem to have been found. This can help in identifying gender differences in growth and lice grazing, something little is known about today. Such knowledge can also be used to select female fish for early breeding and reduce the use of male fish that do not contribute positively to breeding programmes or egg production, says senior scientist at AquaGen, Maren Mommens.

The broodstock is to be raised at Namdal Rensefisk, which now, in collaboration with AquaGen, completes a state-of-the-art breeding plant for lumpfish of NOK 80 million in Flatanger, Norway.

AquaGen has also developed a search tool consisting of 70,000 gene markers used to detect differences in DNA encoding important traits. This marker set has a high resolution and is the first to be designed for lumpfish. Together with the genome sequence and information about where the different genes are placed in the genome, the marker set enables scientists to look for important genes with high precision, says Knutsen.

During winter 2018 scientists will start a challenge test with the bacterial diseases atypical furunculosis and vibriosis, where they will investigate whether there are genetic differences between individual lumpfish in the resistance to these diseases. They are also studying lumpfish that are kept together with salmon in AquaGen’s own seawater facilities. Researchers are counting how many lice each of the lumpfish have eaten while taking a tissue sample for DNA analysis. In this way it can be determined whether lumpfish with high lice appetite have special genetic variants that can be selectively bred, says Mommens.

Mapping of the lumpfish’s genome is part of the research project ‘New species, new properties, new possibilities’ which will run in the period 2017-2019. The project is funded by NMBU, Vaxxinova, AquaGen and the Research Council of Norway.