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Nature Communications Feb 2024Animals must sense and acclimatize to environmental temperatures for survival, yet their thermosensing mechanisms other than transient receptor potential (TRP) channels...
Animals must sense and acclimatize to environmental temperatures for survival, yet their thermosensing mechanisms other than transient receptor potential (TRP) channels remain poorly understood. We identify a trimeric G protein-coupled receptor (GPCR), SRH-40, which confers thermosensitivity in sensory neurons regulating temperature acclimatization in Caenorhabditis elegans. Systematic knockdown of 1000 GPCRs by RNAi reveals GPCRs involved in temperature acclimatization, among which srh-40 is highly expressed in the ADL sensory neuron, a temperature-responsive chemosensory neuron, where TRP channels act as accessorial thermoreceptors. In vivo Ca imaging demonstrates that an srh-40 mutation reduced the temperature sensitivity of ADL, resulting in supranormal temperature acclimatization. Ectopically expressing SRH-40 in a non-warmth-sensing gustatory neuron confers temperature responses. Moreover, temperature-dependent SRH-40 activation is reconstituted in Drosophila S2R+ cells. Overall, SRH-40 may be involved in thermosensory signaling underlying temperature acclimatization. We propose a dual thermosensing machinery through a GPCR and TRP channels in a single sensory neuron.
Topics: Animals; Caenorhabditis elegans; Temperature; Sensory Receptor Cells; Caenorhabditis elegans Proteins; Acclimatization; Receptors, G-Protein-Coupled
PubMed: 38396085
DOI: 10.1038/s41467-024-46042-z -
Environmental Research Jan 2023This study elucidated the changes in the short-term response to organic load shocks of the anaerobic digestion (AD) microbiome acclimatized to a simple substrate and a...
This study elucidated the changes in the short-term response to organic load shocks of the anaerobic digestion (AD) microbiome acclimatized to a simple substrate and a complex substrate. Batch vial reactors were inoculated with AD sludge acclimatized to either a simple (starch and hipolypeptone) or a complex (dog food and starch) substrate, both with carbon-to-nitrogen ratio of 25. Organic loads in the form of an easily degradable substrate mix (starch and hipolypeptone) with concentrations varying from 0 to 5 g VS/L were applied to the reactors. Runs utilizing the inoculum acclimatized to a complex substrate sustained its methane productivity despite the high organic load shocks which the inoculum acclimatized to a simple substrate was unable to handle efficiently. The alpha-diversity of the microbiome decreased with increase in organic load for inoculum acclimatized with a simple substrate but was unaffected for the case of the inoculum acclimatized with a complex substrate. LactobacillalesandCloacimonadales were inferred to be major players in starch degradation pathways for the inoculum acclimatized using a simple substrate as predicted by the bioinformatics package PICRUSt2. However, acclimatizing using a complex substrate did not support their growth and were replaced by Coriobacteriales which provided higher flexibility in terms of the predicted regulated metabolic functions. The predicted functional regulation of Synergistales and Syntrophales increased with acclimatization using a complex substrate which also showed increase in the flexibility of the microbiome towards handling organic load shocks. Acetoclastic pathway was upregulated with increase in organic load regardless of the acclimatization substrate while the hydrogenotrophic pathway was downregulated. Overall, acclimatization using a complex substrate increased the robustness and flexibility of the microbiome towards organic load shocks.
Topics: Animals; Dogs; Anaerobiosis; Bioreactors; Methane; Sewage; Microbiota; Acclimatization; Starch
PubMed: 36343710
DOI: 10.1016/j.envres.2022.114722 -
Die Naturwissenschaften Oct 2017The physiological compensation of animals in changing environments through acclimatization has long been considered to be of minor importance in tropical ectotherms due...
The physiological compensation of animals in changing environments through acclimatization has long been considered to be of minor importance in tropical ectotherms due to more stable climatic conditions compared to temperate regions. Contrasting this assumption are reports about a range of metabolic adjustments in tropical species, especially during the last two decades from field acclimatized animals. Metabolic rates are strongly linked to temperature in ectotherms but they also reflect energetic requirements and restrictions. We therefore postulate that the observed variety of acclimatization patterns in tropical reptiles results from an interaction of multiple influences, including food and water availability, rather than from thermal constraints alone. We present new data from two sympatric Malagasy lizards with contrasting acclimatization patterns and, complemented with an extensive literature search, discuss the variety of acclimatization patterns in tropical reptiles with regard to thermal and energetic influences. This broad consideration of constraints allows a rearrangement of apparently controversial patterns into a scheme of decreasing metabolic costs, including two new categories for selective and selective inverse acclimatization, where metabolic shifts are restricted to body temperatures below those preferred during activity.
Topics: Acclimatization; Animals; Energy Metabolism; Lizards; Temperature; Tropical Climate
PubMed: 29028069
DOI: 10.1007/s00114-017-1506-0 -
Bioresource Technology Aug 2019The organic fraction of municipal solid waste (OFMSW) is an abundant and sustainable substrate for the anaerobic digestion (AD) process, yet ammonia released during...
Acclimatization contributes to stable anaerobic digestion of organic fraction of municipal solid waste under extreme ammonia levels: Focusing on microbial community dynamics.
The organic fraction of municipal solid waste (OFMSW) is an abundant and sustainable substrate for the anaerobic digestion (AD) process, yet ammonia released during OFMSW hydrolysis could result in suboptimal biogas production. Acclimatized ammonia tolerant microorganisms offer an efficient way to alleviate ammonia inhibition during AD. This study aimed to achieve an efficient AD of OFMSW under extreme ammonia levels and elucidate the dynamics of the acclimatized microbial community. Thus, two mesophilic continuous stirred tank reactors (CSTR), fed only with OFMSW, were successfully acclimatized up to 8.5 g NH-N/L, and their methane yields fluctuated <10%, compared to the methane yields without ammonia addition. Microbiological analyses showed that Methanosaeta concilii and Methanosarcina soligelidi were the dominant methanogens at low and high ammonia levels, respectively. Whilst, a unique metabolic pathway shift, from aceticlastic to hydrogenotrophic methanogenesis, of M. soligelidi was identified during the acclimatization process.
Topics: Acclimatization; Ammonia; Anaerobiosis; Bioreactors; Methane; Microbiota; Solid Waste
PubMed: 31030070
DOI: 10.1016/j.biortech.2019.121376 -
PloS One 2016The aim of this study was to understand the acclimatization mechanisms of photosynthetic apparatus in Brachypodium pinnatum (L.) P. Beauv grass during its expansion....
The aim of this study was to understand the acclimatization mechanisms of photosynthetic apparatus in Brachypodium pinnatum (L.) P. Beauv grass during its expansion. Twelve populations differentiated by age: young (30-50 years old), intermediate age (ca. 100 y) and old (>300 y) were studied. It was confirmed that the decrease of the number of genotypes as a result of environmental stress and competition were reflected in changes in chlorophyll fluorescence (ChlF) parameters. The old stands were dominated by a few genotypes which seem to be the best acclimatized to the self-shading/competition by lowering their photosynthetic performance during light-phase of photosynthesis. On the other hand, the 'high-speed' photosynthetic rate observed in the young populations can be seen as acclimatization to very adverse conditions. Our results clearly confirm that ChlF is a powerful method of inferring physiological mechanisms of the expansion of tor grass. The Principal Component and Redundancy Analyses, followed with k-means classification, allowed to find the differentiation of groups of distinct ChlF parameters and enabled us to relate them to changes in genotypic diversity of populations. We conclude that the plastic morphological and physiological response to changeable habitat light conditions with its optimum in half-shade refers to its forest-steppe origin.
Topics: Acclimatization; Brachypodium; Forests; Grassland; Photosynthesis; Photosynthetic Reaction Center Complex Proteins
PubMed: 27275605
DOI: 10.1371/journal.pone.0156201 -
Journal of Applied Physiology... Nov 2017High altitudes (>8,000 ft or 2,500 m) provide an experiment of nature for measuring adaptation and the physiological processes involved. Studies conducted over the past... (Review)
Review
High altitudes (>8,000 ft or 2,500 m) provide an experiment of nature for measuring adaptation and the physiological processes involved. Studies conducted over the past ~25 years in Andeans, Tibetans, and, less often, Ethiopians show varied but distinct O transport traits from those of acclimatized newcomers, providing indirect evidence for genetic adaptation to high altitude. Short-term (acclimatization, developmental) and long-term (genetic) responses to high altitude exhibit a temporal gradient such that, although all influence O content, the latter also improve O delivery and metabolism. Much has been learned concerning the underlying physiological processes, but additional studies are needed on the regulation of blood flow and O utilization. Direct evidence of genetic adaptation comes from single-nucleotide polymorphism (SNP)-based genome scans and whole genome sequencing studies that have identified gene regions acted upon by natural selection. Efforts have begun to understand the connections between the two with Andean studies on the genetic factors raising uterine blood flow, fetal growth, and susceptibility to Chronic Mountain Sickness and Tibetan studies on genes serving to lower hemoglobin and pulmonary arterial pressure. Critical for future studies will be the selection of phenotypes with demonstrable effects on reproductive success, the calculation of actual fitness costs, and greater inclusion of women among the subjects being studied. The well-characterized nature of the O transport system, the presence of multiple long-resident populations, and relevance for understanding hypoxic disorders in all persons underscore the importance of understanding how evolutionary adaptation to high altitude has occurred. Variation in O transport characteristics among Andean, Tibetan, and, when available, Ethiopian high-altitude residents supports the existence of genetic adaptations that improve the distribution of blood flow to vital organs and the efficiency of O utilization. Genome scans and whole genome sequencing studies implicate a broad range of gene regions. Future studies are needed using phenotypes of clear relevance for reproductive success for determining the mechanisms by which naturally selected genes are acting.
Topics: Acclimatization; Altitude; Arterial Pressure; Ethiopia; Hemoglobins; Humans; Hypoxia; Oxygen; Phenotype; Polymorphism, Single Nucleotide; Selection, Genetic; South America; Tibet
PubMed: 28860167
DOI: 10.1152/japplphysiol.00321.2017 -
PloS One 2014Ocean acidification (OA) has important implications for the persistence of coral reef ecosystems, due to potentially negative effects on biomineralization. Many coral...
Ocean acidification (OA) has important implications for the persistence of coral reef ecosystems, due to potentially negative effects on biomineralization. Many coral reefs are dynamic with respect to carbonate chemistry, and experience fluctuations in pCO₂ that exceed OA projections for the near future. To understand the influence of dynamic pCO₂ on an important reef calcifier, we tested the response of the crustose coralline alga Porolithon onkodes to oscillating pCO₂. Individuals were exposed to ambient (400 µatm), high (660 µatm), or variable pCO₂ (oscillating between 400/660 µatm) treatments for 14 days. To explore the potential for coralline acclimatization, we collected individuals from low and high pCO₂ variability sites (upstream and downstream respectively) on a back reef characterized by unidirectional water flow in Moorea, French Polynesia. We quantified the effects of treatment on algal calcification by measuring the change in buoyant weight, and on algal metabolism by conducting sealed incubations to measure rates of photosynthesis and respiration. Net photosynthesis was higher in the ambient treatment than the variable treatment, regardless of habitat origin, and there was no effect on respiration or gross photosynthesis. Exposure to high pCO₂ decreased P. onkodes calcification by >70%, regardless of the original habitat. In the variable treatment, corallines from the high variability habitat calcified 42% more than corallines from the low variability habitat. The significance of the original habitat for the coralline calcification response to variable, high pCO₂ indicates that individuals existing in dynamic pCO₂ habitats may be acclimatized to OA within the scope of in situ variability. These results highlight the importance of accounting for natural pCO₂ variability in OA manipulations, and provide insight into the potential for plasticity in habitat and species-specific responses to changing ocean chemistry.
Topics: Acclimatization; Animals; Anthozoa; Carbon Dioxide; Ecosystem; Oceans and Seas; Rhodophyta
PubMed: 24505305
DOI: 10.1371/journal.pone.0087678 -
Science (New York, N.Y.) Jun 1960Experimentally naive albino rats begin to press a lever for short bursts of radiant heat earlier in a 16-hour session at 2 degrees C than rats that have been living at...
Experimentally naive albino rats begin to press a lever for short bursts of radiant heat earlier in a 16-hour session at 2 degrees C than rats that have been living at this temperature for about a month. This difference reflects the different rates at which body temperature in the cold falls in acclimatized and nonacclimatized animals.
Topics: Acclimatization; Animals; Cold Temperature; Male; Rats
PubMed: 14414442
DOI: 10.1126/science.131.3417.1891 -
Acta Physiologica (Oxford, England) Jul 2017
Topics: Acclimatization; Altitude; Altitude Sickness; Humans
PubMed: 28498559
DOI: 10.1111/apha.12894 -
The Journal of Experimental Biology Aug 2019Seasonal thermal remodelling (acclimatization) and laboratory thermal remodelling (acclimation) can induce different physiological changes in ectothermic animals. As...
Seasonal thermal remodelling (acclimatization) and laboratory thermal remodelling (acclimation) can induce different physiological changes in ectothermic animals. As global temperatures are changing at an increasing rate, there is urgency to understand the compensatory abilities of key organs such as the heart to adjust under natural conditions. Thus, the aim of the present study was to directly compare the acclimatization and acclimatory response within a single eurythermal fish species, the European shorthorn sculpin (). We used current- and voltage-clamp to measure ionic current densities in both isolated atrial and ventricular myocytes from three groups of fish: (1) summer-caught fish kept at 12°C ('summer-acclimated'); (2) summer-caught fish kept at 3°C ('cold acclimated'); and (3) fish caught in March ('winter-acclimatized'). At a common test temperature of 7.5°C, action potential (AP) was shortened by both winter acclimatization and cold acclimation compared with summer acclimation; however, winter acclimatization caused a greater shortening than did cold acclimation. Shortening of AP was achieved mostly by a significant increase in repolarizing current density ( and ) following winter acclimatization, with cold acclimation having only minor effects. Compared with summer acclimation, the depolarizing L-type calcium current () was larger following winter acclimatization, but again, there was no effect of cold acclimation on Interestingly, the other depolarizing current, , was downregulated at low temperatures. Our further analysis shows that ionic current remodelling is primarily due to changes in ion channel density rather than current kinetics. In summary, acclimatization profoundly modified the electrical activity of the sculpin heart while acclimation to the same temperature for >1.5 months produced very limited remodelling effects.
Topics: Acclimatization; Action Potentials; Animals; Fishes; Hot Temperature; Myocytes, Cardiac; Seasons; Thermotolerance
PubMed: 31315933
DOI: 10.1242/jeb.202242