Transmission of IPNV from artificially infected salmon broodstock and evaluation of effects on fry

This project will aim at studying the mechanisms of vertical transmission of IPN virus from broodstock fish to offspring. An artificial challenge model will be used whereby the parent fish are infected artificially using well-characterised strains of IPNV known to establish persistent infections. Salmon broodstock from the Norwegian wild salmon live gene bank that have been tested over years and found free of IPNV will be artificially infected and compared to non-infected broodstock with the same origin. A new method for group marking of eyed eggs will be used to enable cohabitant testing. The groups will be compared for different traits : - Vertical transmission from IPNV-positive parental fish to fry - Horisontal spread of virus to co-habitating, virus-negative fry The study aims at elucidating the role of virus transmission from covertly infected broodstock to fry, regardless of the mechanisms involved. The results obtained can be used to evaluate effect(s) of broodstock testing as a strategy to reduce the occurrence of IPNV in farmed Atlantic salmon.