Transcriptome patterns and blood physiology associated with homing success of sockeye salmon during their final stage of marine migration

• Published in: Canadian journal of fisheries and aquatic sciences 2018-09, Vol.75 (9), p.1511-1524
• Main Authors: Drenner, S. Matthew, Hinch, Scott G, Furey, Nathan B, Clark, Timothy D, Li, Shaorong, Ming, Tobi, Jeffries, Ken M, Patterson, David A, Cooke, Steven J, Robichaud, David, Welch, David W, Farrell, Anthony P, Miller, Kristina M
• Format: Article
• Language: English
• Subjects: Anadromous migrations; Animal homing; Aquatic sciences; Bio-assays; Biological activity; Biological data; Biological sampling; Biological stress; Biopsy; Biosynthesis; Biotelemetry; Blood; DNA microarrays; Fish; Fresh water; Freshwater; Freshwater environments; Freshwater fish; Gene expression; Genes; Genetic aspects; Genetics; Genomes; Homing; Homing behavior; Immunity; Infections; Infectious diseases; Laboratory experimentation; Marine; Metabolism; Microbiological analysis; Microbiology; Migration; Migratory animals; Migratory species; Mortality; Natural mortality; Oncorhynchus nerka; Philopatry; Physiological aspects; Physiology; Polymerase chain reaction; Protein biosynthesis; Protein synthesis; Protein turnover; Proteins; Rivers; RNA; Salmon; Salmoniformes; Sockeye salmon; Sonic tags; Spawning; Spawning migrations; Stress; Stresses; Studies; Survival; Tagging; Tests; Zoological research
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/cjfas-2017-0391

To better understand the mechanisms that lead to marine mortality of homing adult sockeye salmon (Oncorhynchus nerka), gill and blood biopsies were used in combination with biotelemetry to demonstrate how survival to freshwater entry is related to gene expression and physiological indices of stress. Microarray analysis of gene expression indicated multiple biological processes, including immune and stress responses, protein biosynthesis, and metabolism. Quantitative reversetranscriptase polymerase chain reaction (qRT-PCR) analysis indicated fish with upregulation of genes related to stress and infection had higher marine survival compared with fish without this genomic signature. We proposed that higher marine survival of potentially stressed and immune compromised fish can be explained by stressed and infected fish being highly motivated to enter fresh water, leading to enhanced marine survival. However, once in a river, stressed and immune compromised fish could suffer higher mortality because of premature river entry. Overall, this study supports the idea that infection and stress are important biological processes influencing behaviour and fate of sockeye salmon during homing migrations.