Project description:To characterise the transcriptional response in brain of Sockeye Salmon (Oncorhynchus nerka) that were persistently infected with infectious hematopoietic necrosis virus (IHNV) and to determine whether carrying the IHNV affects the ability to respond to other immunological challenges we compared the brain transcriptome of IHNV carriers, IHNV-negative survivors, and naïve Sockeye Salmon that were never exposed to IHNV. In addition we determined the transcriptional changes among carriers, survivors and naïve fish in their response to the viral mimic polyriboinosinic polyribocytidylic acid (poly(I:C)), using the cGRASP 44K salmon oligoarray.
Project description:a salmonid microarray was used to characterize environmentally-regulated shifts in gene expression between ocean and river habitats in gill and liver tissues of wild migrating adult Pacific sockeye salmon (Oncorhynchus nerka). To correlate gene expression with survival, non-lethal biopsy sampling of gill tissue and microarray-based profiling was combined with biotelemetry and genetic stock identification so that transcriptomic profiles could be compared between fish reaching spawning grounds and presumed mortalities.
Project description:The main findings of the current study were that exposing adult sockeye salmon Oncorhynchus nerka to a warm temperature that they regularly encounter during their river migration induced an mRNA-level heat shock response that is exacerbated with swimming. Similar immune defense-related responses were also observed. Microarray analyses revealed that 347 genes were differentially expressed between the cold (12-13° C) and warm (18-19° C) treated fish (P < 0.01), with stress response (GO:0006950; P = 0.014) and response to fungus (GO:0009620; P = 0.003) elevated with warm treatment, while expression for genes involved in oxidative phosphorylation (GO:0006119; P = 0.0019) and electron transport chain (GO:0022900; P = 0.00043) increased in cold-treated fish. By studying single genes with RT-qPCR, warm treatment fish from the Chilko population of O. nerka induced expression of heat shock protein (hsp) 90α, hsp90β and hsp30, as well as interferon-inducible protein (P < 0.05). A Nechako population of O. nerka with a narrower thermal tolerance window than the Chilko population showed even more pronounced responses to the warm treatment. In conclusion, it appears that during their once-in-the-lifetime migration these adult sockeye salmon encounter conditions that induce several cellular defense mechanisms. As river temperatures continue to increase, it remains to be seen whether or not these cellular defenses provide enough protection for all sockeye salmon populations.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature.
Project description:The main findings of the current study were that exposing adult sockeye salmon Oncorhynchus nerka to a warm temperature that they regularly encounter during their river migration induced an mRNA-level heat shock response that is exacerbated with swimming. Similar immune defense-related responses were also observed. Microarray analyses revealed that 347 genes were differentially expressed between the cold (12-13M-BM-0 C) and warm (18-19M-BM-0 C) treated fish (P < 0.01), with stress response (GO:0006950; P = 0.014) and response to fungus (GO:0009620; P = 0.003) elevated with warm treatment, while expression for genes involved in oxidative phosphorylation (GO:0006119; P = 0.0019) and electron transport chain (GO:0022900; P = 0.00043) increased in cold-treated fish. By studying single genes with RT-qPCR, warm treatment fish from the Chilko population of O. nerka induced expression of heat shock protein (hsp) 90M-NM-1, hsp90M-NM-2 and hsp30, as well as interferon-inducible protein (P < 0.05). A Nechako population of O. nerka with a narrower thermal tolerance window than the Chilko population showed even more pronounced responses to the warm treatment. In conclusion, it appears that during their once-in-the-lifetime migration these adult sockeye salmon encounter conditions that induce several cellular defense mechanisms. As river temperatures continue to increase, it remains to be seen whether or not these cellular defenses provide enough protection for all sockeye salmon populations. Two condition experiment; cold treated fish vs. warm treated fish, n=4 in both group
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature. Ninety-eight samples from three separate temperature exposure studies were analyzed on ninety-eight microarrays, using a common reference design, with multiple biological replicates for each temperature condition for each year of the experiment.
Project description:Characterizing a common cellular stress response (CSR) to high water temperature across species and populations is necessary for identifying the capacity of Pacific salmon (Oncorhynchus spp.) to persist in current and future climate warming scenarios, especially for populations at the southern periphery of their species' distributions. In this study, populations of wild adult pink (O. gorbuscha) and sockeye (O. nerka) salmon from the Fraser River, British Columbia, Canada, were experimentally treated to an ecologically relevant 'cool' or 'warm' water temperature to uncover common transcriptomic responses to elevated water temperature. Ninety-eight samples from three separate temperature exposure studies were analyzed on ninety-eight microarrays, using a common reference design, with multiple biological replicates for each temperature condition for each year of the experiment.