Endangered wild salmon infected by newly discovered viruses

Mordecai, Gideon J; Miller, Kristina M; Di Cicco, Emiliano; Schulze, Angela D; Kaukinen, Karia H; Ming, Tobi J; Li, Shaorong; Tabata, Amy; Teffer, Amy; Patterson, David A; Ferguson, Hugh W; Suttle, Curtis A

One of the challenges of viral discovery in fish is that the proportion of viral transcripts in vertebrate metatranscriptomic libraries is small compared to the number of transcripts from the host and other contaminating sequences (Geoghegan et al., 2018; Zhang et al., 2019) . However, we were able to achieve near-coding complete genomes for the three new viruses (Figure 1 -figure supplement 1A and B). The genomic organisation of the newly discovered viruses was consistent with related viruses in fish. For instance, SPAV has three genomic segments, as shown for other arenaviruses in fish . High-throughput RT-PCR screening of >6000 wild juvenile Chinook and sockeye salmon showed dissimilar geographical distributions of infected fish, reflecting differences in epidemiological patterns of transmission and infection dynamics for each of the viruses ( Figure 2) .