scholarly journals Molecular and physiological responses predict acclimation limits in juvenile brook trout (Salvelinus fontinalis)

2020 ◽  
Author(s):  
Theresa E. Mackey ◽  
Caleb T. Hasler ◽  
Travis Durhack ◽  
Jennifer D. Jeffrey ◽  
Camille J. Macnaughton ◽  
...  
Keyword(s):  
Heat Shock ◽  
Metabolic Rate ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Transcript Abundance ◽  
Acclimation Temperature ◽  
Temperature Threshold ◽  
Plasma Parameters ◽  
Muscle Lactate ◽  
Air Exposure

AbstractBrook trout (Salvelinus fontinalis) populations are at risk of exposure to high water temperatures in the species’ native range in eastern North America. We quantified the physiological and molecular responses of juvenile brook trout to six acclimation temperatures that span the thermal distribution of the species (5, 10, 15, 20, 23, and 25°C). Using quantitative PCR (qPCR), we measured the mRNA transcript abundance of temperature-induced cellular stress genes to identify a potential sub-lethal temperature threshold for brook trout between 20–23°C. Brook trout exhibited an upregulation of stress-related genes (heat shock protein 90-beta; heat shock cognate 71 kDa protein; glutathione peroxidase 1) and a downregulation of transcription factors and osmoregulation-related genes (Na+/K+/2Cl− co-transporter-1-a; nuclear protein 1) at temperatures ≥20°C. We also used respirometry to assess the effects of the acclimation temperatures on oxygen consumption. Standard metabolic rate results indicated that energy expenditure was higher at temperatures ≥20°C. We then examined the effects of acclimation temperature on metabolic rate and blood plasma parameters in fish exposed to an acute exhaustive exercise and air exposure stress. Fish acclimated to temperatures ≥20°C exhibited elevated levels of plasma cortisol, muscle lactate, and plasma glucose after exposure to the acute stressors. After 24 h of recovery, fish showed longer metabolic recovery times at 15 and 20°C and cortisol levels remaining elevated at temperatures ≥20°C. Our findings suggest that brook trout may have a limited ability to acclimate to temperatures >20°C and increases in temperatures beyond 20°C may impact brook trout populations.

scholarly journals Molecular and physiological responses predict acclimation limits in juvenile brook trout (Salvelinus fontinalis)

2021 ◽  
Vol 224 (16) ◽  
Author(s):  
Theresa E. Mackey ◽  
Caleb T. Hasler ◽  
Travis Durhack ◽  
Jennifer D. Jeffrey ◽  
Camille J. Macnaughton ◽  
...  
Keyword(s):  
Heat Shock ◽  
High Temperatures ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acute Stress ◽  
Physiological Responses ◽  
Heat Shock Protein 90 ◽  
Acclimation Temperature ◽  
Muscle Lactate ◽  
Air Exposure

ABSTRACT Understanding the resilience of ectotherms to high temperatures is essential because of the influence of climate change on aquatic ecosystems. The ability of species to acclimate to high temperatures may determine whether populations can persist in their native ranges. We examined physiological and molecular responses of juvenile brook trout (Salvelinus fontinalis) to six acclimation temperatures (5, 10, 15, 20, 23 and 25°C) that span the thermal distribution of the species to predict acclimation limits. Brook trout exhibited an upregulation of stress-related mRNA transcripts (heat shock protein 90-beta, heat shock cognate 71 kDa protein, glutathione peroxidase 1) and downregulation of transcription factors and osmoregulation-related transcripts (nuclear protein 1, Na+/K+/2Cl− co-transporter-1-a) at temperatures ≥20°C. We then examined the effects of acclimation temperature on metabolic rate (MR) and physiological parameters in fish exposed to an acute exhaustive exercise and air exposure stress. Fish acclimated to temperatures ≥20°C exhibited elevated plasma cortisol and glucose, and muscle lactate after exposure to the acute stress. Fish exhibited longer MR recovery times at 15 and 20°C compared with the 5 and 10°C groups; however, cortisol levels remained elevated at temperatures ≥20°C after 24 h. Oxygen consumption in fish acclimated to 23°C recovered quickest after exposure to acute stress. Standard MR was highest and factorial aerobic scope was lowest for fish held at temperatures ≥20°C. Our findings demonstrate how molecular and physiological responses predict acclimation limits in a freshwater fish as the brook trout in the present study had a limited ability to acclimate to temperatures beyond 20°C.

Triploidy induced by heat shock in brook trout (Salvelinus fontinalis)

Aquaculture ◽  
1991 ◽  
Vol 92 ◽  
pp. 305-311 ◽  
Author(s):  
Pierre Dubé ◽  
Jean-Marie Blanc ◽  
Michel Chouinard ◽  
Joël de la Noüe
Keyword(s):  
Heat Shock ◽  
Brook Trout ◽  
Salvelinus Fontinalis

The influence of temperature on histological and radiochemical measurements of thyroid activity in the eastern brook trout, Salvelinus fontinalis Mitchell

1968 ◽  
Vol 46 (1) ◽  
pp. 1-9 ◽  
Author(s):  
D. E. Drury ◽  
J. G. Eales
Keyword(s):  
Epithelial Cell ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acclimation Temperature ◽  
Thyroid Follicle ◽  
Thyroid Activity ◽  
Cell Height ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
T Values

Histological and radiochemical techniques for assessing thyroid activity were compared on yearling brook trout acclimated at 5, 12, and 15 °C.The mean thyroid follicle epithelial cell height was 7.4 μ (range 6.0–8.6 μ) at 5 °C; 3.5 μ (range 2.9–3.9 μ) at 12 °C, and 2.3 μ (range 1.9–2.9 μ) at 15 °C. Assuming that a taller epithelial cell height indicates greater thyroid activity, then an inverse relationship between thyroid activity and acclimation temperature exists.Both the uptake of radioiodide by the thyroid (T/S) and the clearance of radioiodide from the serum were greater at higher temperatures. Serum PB125I production was negligible within 8 days after radioiodide injection and the conversion ratio could not be applied as an index of thyroid function, Assuming, however, that the thyroid radioiodide uptake is an index of thyroid activity, then there is a direct relationship between thyroid activity and acclimation temperature.In view of the marked discrepancy between these histological and radiochemical techniques, fractional rates of turnover of serum thyroxine were compared by determining the biological half-life (t½) for serum PB125I after L-thyroxine-125I intraperitoneal injection at different temperatures. The serum PB125I clearance curves were complex and tentative t½ values of 18.0 days (5 °C, 3.2 days (12 °C), and 1.5 days (15 °C) were obtained. These results indicate a more rapid serum PBI turnover at higher temperatures and support the radiochemical measurements.

Red blood cell Hsp 70 mRNA and protein as bio-indicators of temperature stress in the brook trout (Salvelinus fontinalis)

2003 ◽  
Vol 60 (4) ◽  
pp. 460-470 ◽  
Author(s):  
Susan G Lund ◽  
Mervyn E.A Lund ◽  
Bruce L Tufts
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Heat Shock Response ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Hsp 70 ◽  
Protein Levels ◽  
Shock Response

The purpose of this study was to examine the heat shock protein (Hsp) 70 mRNA and protein response in several tissues of Miramichi brook trout (Salvelinus fontinalis) under both acute and extended heat stress conditions to determine the utility of the red blood cell (rbc) heat shock response as a biomarker of sublethal temperature stress. Red blood cells consistently produced one of the highest responses of all of the tissues examined. Recovery of Hsp 70 mRNA following acute temperature increase required between 24 h and 48 h. In contrast, Hsp 70 protein levels remained significantly elevated for more than 48 h after the heat stress was terminated. During a 6-day extended (23°C) heat stress, rbc Hsp 70 mRNA returned to control levels between 72 and 144 h, whereas Hsp 70 protein was still significantly elevated after 6 days. Thus, although Hsp 70 mRNA proved to be a more sensitive indicator of heat stress in all tissues examined, Hsp 70 protein levels were more sustained. This study confirms the utility of rbcs as a biomarker tissue of thermal stress in fish and indicates that water temperatures presently being reached in brook trout habitats in Canada are capable of inducing a significant heat shock response in this species.

Influence of acclimation temperature on rate constants for thyroid uptake of iodide by brook trout, Salvelinus fontinalis (Mitchill)

1971 ◽  
Vol 49 (5) ◽  
pp. 783-786 ◽  
Author(s):  
Carolyn D. Smith ◽  
J. G. Eales
Keyword(s):  
Rate Constant ◽  
Rate Constants ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acclimation Temperature ◽  
Thyroid Activity ◽  
Iodide Uptake ◽  
Individual Fish ◽  
Thyroid Uptake

A procedure for determining the rate constant for thyroid iodide uptake for fish is described.Rate constants for thyroid iodide uptake in brook trout agreed with previously used indices of thyroid activity (T/S and CR) in indicating a more active thyroid at 16C than 10C.At both temperatures radioiodide metabolism was extremely slow with considerable variation between individual fish. These features may be attributed to the high and variable serum stable iodide level in this species.

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