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Immune response genes and pathogen presence predict migration survival in wild salmon smolts


Jeffries, KM and Hinch, SG and Gale, MK and Clark, TD and Lotto, AG and Casselman, MT and Li, S and Rechisky, EL and Porter, AD and Welch, DW and Miller, KM, Immune response genes and pathogen presence predict migration survival in wild salmon smolts, Molecular Ecology, 23, (23) pp. 5803-5815. ISSN 0962-1083 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 John Wiley & Sons Ltd

DOI: doi:10.1111/mec.12980


We present the first data to link physiological responses and pathogen presence with subsequent fate during migration of wild salmonid smolts. We tagged and non-lethally sampled gill tissue from sockeye salmon (Oncorhynchus nerka) smolts as they left their nursery lake (Chilko Lake, BC, Canada) to compare gene expression profiles and freshwater pathogen loads with migration success over the first ~1150 km of their migration to the North Pacific Ocean using acoustic telemetry. Fifteen per cent of smolts were never detected again after release, and these fish had gene expression profiles consistent with an immune response to one or more viral pathogens compared with fish that survived their freshwater migration. Among the significantly upregulated genes of the fish that were never detected postrelease were MX (interferon-induced GTP-binding protein Mx) and STAT1 (signal transducer and activator of transcription 1-alpha/beta), which are characteristic of a type I interferon response to viral pathogens. The most commonly detected pathogen in the smolts leaving the nursery lake was infectious haematopoietic necrosis virus (IHNV). Collectively, these data show that some of the fish assumed to have died after leaving the nursery lake appeared to be responding to one or more viral pathogens and had elevated stress levels that could have contributed to some of the mortality shortly after release. We present the first evidence that changes in gene expression may be predictive of some of the freshwater migration mortality in wild salmonid smolts.

Item Details

Item Type:Refereed Article
Keywords:acoustic telemetry, gene expression, Oncorhynchus nerka, smolt mortality, sockeye salmon
Research Division:Biological Sciences
Research Group:Zoology
Research Field:Animal behaviour
Objective Division:Environmental Management
Objective Group:Coastal and estuarine systems and management
Objective Field:Coastal or estuarine biodiversity
UTAS Author:Clark, TD (Dr Timothy Clark)
ID Code:103297
Year Published:2014
Web of Science® Times Cited:71
Deposited By:IMAS Research and Education Centre
Deposited On:2015-10-02
Last Modified:2017-11-01

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