A novel variant of the infectious salmon anaemia virus (ISAV) haemagglutinin gene suggests mechanisms for virus diversity.

Abstract

A novel variant of the highly polymorphic region of the infectious salmon anaemia virus (ISAV) haemagglutinin gene was obtained from a wild adult salmon returning to a river on the East coast of Scotland. The predicted amino acid sequence contained all motifs previously found in ISAV isolates. This discovery provides further evidence for a pool of the virus in the marine environment and suggests that deletion may be employed to generate diversity of ISAV. The prospect of large scale variation in this gene has implications for the methods employed to analyse relationships between ISAV isolates.