Thermal Plasticity in the Burst Swimming of Bufo bankorensis Larvae

AbstractLake Baikal is inhabited by more than 300 endemic amphipod species, which are narrowly adapted to certain thermal niches due to the high interspecific competition. In contrast, the surrounding freshwater fauna is commonly represented by species with large-scale distribution and high phenotypic thermal plasticity. Here, we investigated the thermal plasticity of the energy metabolism in two closely-related endemic amphipod species from Lake Baikal (Eulimnogammarus verrucosus; stenothermal and Eulimnogammarus cyaneus; eurythermal) and the ubiquitous Holarctic amphipod Gammarus lacustris (eurythermal) by exposure to a summer warming scenario (6–23.6 °C; 0.8 °C d−1). In concert with routine metabolic rates, activities of key metabolic enzymes increased strongly with temperature up to 15 °C in E. verrucosus, whereupon they leveled off (except for lactate dehydrogenase). In contrast, exponential increases were seen in E. cyaneus and G. lacustris throughout the thermal trial (Q10-values: 1.6–3.7). Cytochrome-c-oxidase, lactate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase activities were found to be higher in G. lacustris than in E. cyaneus, especially at the highest experimental temperature (23.6 °C). Decreasing gene expression levels revealed some thermal compensation in E. cyaneus but not in G. lacustris. In all species, shifts in enzyme activities favored glycolytic energy generation in the warmth. The congruent temperature-dependencies of enzyme activities and routine metabolism in E. verrucosus indicate a strong feedback-regulation of enzymatic activities by whole organism responses. The species-specific thermal reaction norms reflect the different ecological niches, including the spatial distribution, distinct thermal behavior such as temperature-dependent migration, movement activity, and mating season.

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Intra‐population variation in reproductive timing co‐varies with thermal plasticity of offspring performance in perch ( Perca fluviatilis )

Journal of Animal Ecology ◽

10.1111/1365-2656.13542 ◽

2021 ◽

Author(s):

Marcus Hall ◽

Oscar Nordahl ◽

Per Larsson ◽

Anders Forsman ◽

Petter Tibblin

Keyword(s):

Perca Fluviatilis ◽

Population Variation ◽

Reproductive Timing ◽

Offspring Performance ◽

Thermal Plasticity ◽

Perch Perca Fluviatilis

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Thermal plasticity of the cardiorespiratory system provides cross-tolerance protection to fish exposed to elevated nitrate

Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology ◽

10.1016/j.cbpc.2020.108920 ◽

2021 ◽

Vol 240 ◽

pp. 108920

Author(s):

Daniel F. Gomez Isaza ◽

Rebecca L. Cramp ◽

Craig E. Franklin

Keyword(s):

Cross Tolerance ◽

Cardiorespiratory System ◽

Thermal Plasticity

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DNA methyltransferase 3a mediates developmental thermal plasticity

BMC Biology ◽

10.1186/s12915-020-00942-w ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Isabella Loughland ◽

Alexander Little ◽

Frank Seebacher

Keyword(s):

Environmental Change ◽

Dna Methyltransferase ◽

Developmental Plasticity ◽

Citrate Synthase ◽

Thermal Sensitivity ◽

Short Term ◽

Cold Temperatures ◽

Knock Out ◽

Thermal Plasticity ◽

Dna Methyltransferase 3A

Abstract Background Thermal plasticity is pivotal for evolution in changing climates and in mediating resilience to its potentially negative effects. The efficacy to respond to environmental change depends on underlying mechanisms. DNA methylation induced by DNA methyltransferase 3 enzymes in the germline or during early embryonic development may be correlated with responses to environmental change. This developmental plasticity can interact with reversible acclimation within adult organisms, which would increase the speed of response and could alleviate potential mismatches between parental or early embryonic environments and those experienced at later life stages. Our aim was to determine whether there is a causative relationship between DNMT3 enzyme and developmental thermal plasticity and whether either or both interact with short-term acclimation to alter fitness and thermal responses in zebrafish (Danio rerio). Results We developed a novel DNMT3a knock-out model to show that sequential knock-out of DNA methyltransferase 3a isoforms (DNMT3aa−/− and DNMT3aa−/−ab−/−) additively decreased survival and increased deformities when cold developmental temperatures in zebrafish offspring mismatched warm temperatures experienced by parents. Interestingly, short-term cold acclimation of parents before breeding rescued DNMT3a knock-out offspring by restoring survival at cold temperatures. DNMT3a knock-out genotype interacted with developmental temperatures to modify thermal performance curves in offspring, where at least one DNMT3a isoform was necessary to buffer locomotion from increasing temperatures. The thermal sensitivity of citrate synthase activity, an indicator of mitochondrial density, was less severely affected by DNMT3a knock-out, but there was nonetheless a significant interaction between genotype and developmental temperatures. Conclusions Our results show that DNMT3a regulates developmental thermal plasticity and that the phenotypic effects of different DNMT3a isoforms are additive. However, DNMT3a interacts with other mechanisms, such as histone (de)acetylation, induced during short-term acclimation to buffer phenotypes from environmental change. Interactions between these mechanisms make phenotypic compensation for climate change more efficient and make it less likely that thermal plasticity incurs a cost resulting from environmental mismatches.

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Effects of a gradual increase in temperature on the antioxidant defense system and plasma metabolic parameters in Antarctic fish Notothenia rossii

10.21203/rs.3.rs-160120/v1 ◽

2021 ◽

Author(s):

Angela Carolina Guillen ◽

Marcelo Eduardo Borges ◽

Tatiana Herrerias ◽

Priscila Krebsbach Kandalski ◽

Maria Rosa Dmengeon Pedreiro de Souza ◽

...

Keyword(s):

Gradual Increase ◽

Kidney Tissue ◽

Antarctic Fish ◽

Gill Tissue ◽

Stress Factors ◽

Antioxidant Defenses ◽

Acclimation Temperature ◽

Plasma Parameters ◽

Thermal Plasticity ◽

Notothenia Rossii

Abstract Antarctica is considered a thermally stable ecosystem; however, climate studies point to increases in air and surface water temperatures in this region. These thermal changes may affect the biological processes of animals inhabiting such regions because they are stress factors and may promote metabolic changes, rendering the animals more vulnerable to oxidative damage. Plasma parameters are also good indicators of stress and allow analysis of the metabolic status of fish under temperature increases. The present study assessed the effect of acclimation temperature on the levels of plasma, osmoregulatory and oxidative metabolism parameters and antioxidant defenses in kidney, gill, liver and brain tissues of Notothenia rossii subjected to gradual temperature changes of 0.5°C/day until reaching temperatures of 2, 4, 6 and 8°C. Under the effect of the 0.5°C/day acclimation rate, gill tissue showed increased glutathione-S-transferase (GST) activity, and kidney tissue showed increased H⁺-ATPase at 9 days of the experiment (2°C). In the liver, consistent increases in the MDA concentration as an indicator of lipid peroxidation (9 (2°C),13 (4°C),17 (6°C) and 21 (6°C) days) were noted, as well as an increase in GSH at 9 days (2°C). In plasma, gradual decreases in the concentrations of total proteins and globulins were observed. These responses indicate the presence of thermal plasticity and an attempt at regulation to mitigate thermal stress. The changes showed that a gradual increase in temperature may cause opposite responses to the thermal shock model in N. rossii.

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