The main achievement has been establishment of a collaboration between researchers at NMBU and at University of Minnesota with a resulting application for a full 2 year project and subsequent funding through Norwegian Centennial Chair Program. Through the projects we have built network relations through discussions, competence sharing and a research visit.The experimental results from both projects will have relevance for understanding virus pathogenic mechanisms and evolution and adaption to more advanced hosts, in particular for the new generation of toti-like viruses. The results as such lay ground for disease-limiting measures as therapy and vaccination against PMCV infection/CMS disease, an important disease problem in Norwegian aquaculture. The results will also shed light on the GS-PMCLV detected in baitfish in Minnesota and increase the knowledge on its possibility to cause disease or not, which is important to avoid transmission of uncharacterized pathogens throughout USA.
The focus of the research is understand the characteristics and role in virus infection of the enigmatic ORF3-encoded protein of the viruses PMCV infecting Atlantic salmon and GS-PMCLV detected in Golden shiner, putatively related to the Totiviridae family. The protein is unique among all toti- and toti-like virus and more interestingly, does not share any homology with any other protein described to date. The protein expressed from PMCV has been studied and is cytotoxic to a number of cell types. In ongoing projects we are searching for characteristics of PMCV important for virulence and cause of clinical disease. A part of this work includes searching for genetic variants of PMCV that can relate to increased virulence and progression of clinical disease. The focus is in particular on ORF3-encoded protein and includes studies of genetic variation in wild type isolates and characteristics of the expression of different wild type variants in vitro and in vivo. Since Mor and coworkers presented the second toti-like virus with a third ORF and this had also in general closest relation to PMCV and also was found in fish, it is important to include this as a non-related wild type control in our studies on the importance of the PMCV ORF3-encoded protein.Our objective is to establish a collaboration with researchers at University of Minnesota for a project regarding comparison of the two toti-like viruses. Experimentally, the pre-proposal period will focus on initial comparison of the genetic and functional characteristics of the ORF3 encoded proteins.
The project and results has relevance for understanding virus pathogenic mechanisms, important for aquaculture and marine sciences and will lay ground for disease-limiting measures as therapy and vaccination.
