title: Viral fitness does not correlate with three genotype displacement events involving infectious hematopoietic necrosis virus.
abstract: Viral genotype displacement events are characterized by the replacement of a previously dominant virus genotype by a novel genotype of the same virus species in a given geographic region. We examine here the fitness of three pairs of infectious hematopoietic necrosis virus (IHNV) genotypes involved in three major genotype displacement events in Washington state over the last 30 years to determine whether increased virus fitness correlates with displacement. Fitness was assessed using in vivo assays to measure viral replication in single infection, simultaneous co-infection, and sequential superinfection in the natural host, steelhead trout. In addition, virion stability of each genotype was measured in freshwater and seawater environments at various temperatures. By these methods, we found no correlation between increased viral fitness and displacement in the field. These results suggest that other pressures likely exist in the field with important consequences for IHNV evolution.
authors: University of Washington, Seattle, WA, USA; U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA, USA. Electronic address: kella@uw.edu.
authors: Alison M
authors: AM
authors: Kell
authors: University of Washington, Seattle, WA, USA; U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA, USA.
authors: Andrew R
authors: AR
authors: Wargo
authors: University of Washington, Seattle, WA, USA; U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA, USA.
authors: Gael
authors: G
authors: Kurath
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000821:virology*; D005838:Genotype; D029142:Infectious hematopoietic necrosis virus / Q000145:classification / Q000235:genetics* / Q000502:physiology; D017686:Oncorhynchus mykiss / Q000821:virology; D011995:Recombination, Genetic; D018353:Rhabdoviridae Infections / Q000662:veterinary* / Q000821:virology; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication
chemical_list: D014764:Viral Proteins
keywords: Fitness; Genotype displacement; In vivo competition; Infectious hematopoietic necrosis virus; RNA virus; Virus evolution