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Bao L, Liu Z, Sui M, Yang Z, Wang H, Chen X, Xu Y, Niu Z, Liu N, Xing Q, Bao Z, Huang X. The Glucose-Succinate Pathway: A Crucial Anaerobic Metabolic Pathway in the Scallop Chlamys farreri Experiencing Heat Stress. Int J Mol Sci 2024; 25:4741. [PMID: 38731961 PMCID: PMC11084901 DOI: 10.3390/ijms25094741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/20/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Recently, the increase in marine temperatures has become an important global marine environmental issue. The ability of energy supply in marine animals plays a crucial role in avoiding the stress of elevated temperatures. The investigation into anaerobic metabolism, an essential mechanism for regulating energy provision under heat stress, is limited in mollusks. In this study, key enzymes of four anaerobic metabolic pathways were identified in the genome of scallop Chlamys farreri, respectively including five opine dehydrogenases (CfOpDHs), two aspartate aminotransferases (CfASTs) divided into cytoplasmic (CfAST1) and mitochondrial subtype (CfAST2), and two phosphoenolpyruvate carboxykinases (CfPEPCKs) divided into a primitive type (CfPEPCK2) and a cytoplasmic subtype (CfPEPCK1). It was surprising that lactate dehydrogenase (LDH), a key enzyme in the anaerobic metabolism of the glucose-lactate pathway in vertebrates, was absent in the genome of scallops. Phylogenetic analysis verified that CfOpDHs clustered according to the phylogenetic relationships of the organisms rather than substrate specificity. Furthermore, CfOpDHs, CfASTs, and CfPEPCKs displayed distinct expression patterns throughout the developmental process and showed a prominent expression in muscle, foot, kidney, male gonad, and ganglia tissues. Notably, CfASTs displayed the highest level of expression among these genes during the developmental process and in adult tissues. Under heat stress, the expression of CfASTs exhibited a general downregulation trend in the six tissues examined. The expression of CfOpDHs also displayed a downregulation trend in most tissues, except CfOpDH1/3 in striated muscle showing significant up-regulation at some time points. Remarkably, CfPEPCK1 was significantly upregulated in all six tested tissues at almost all time points. Therefore, we speculated that the glucose-succinate pathway, catalyzed by CfPEPCK1, serves as the primary anaerobic metabolic pathway in mollusks experiencing heat stress, with CfOpDH3 catalyzing the glucose-opine pathway in striated muscle as supplementary. Additionally, the high and stable expression level of CfASTs is crucial for the maintenance of the essential functions of aspartate aminotransferase (AST). This study provides a comprehensive and systematic analysis of the key enzymes involved in anaerobic metabolism pathways, which holds significant importance in understanding the mechanism of energy supply in mollusks.
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Affiliation(s)
- Lijingjing Bao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Zhi Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Mingyi Sui
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Zujing Yang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Haoran Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Xiaofei Chen
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Yue Xu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Zehua Niu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Na Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
| | - Qiang Xing
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Zhenmin Bao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Laboratory of Tropical Marine Germplasm Resources and Breeding Engineering, Sanya Oceanographic Institution, Ocean University of China, Sanya 572000, China
| | - Xiaoting Huang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences/Academy of Future Ocean, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
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Bennett MM, DeBardlabon KM, Rinehart JP, Yocum GD, Greenlee KJ. Effects of developmental state on low-temperature physiology of the alfalfa leafcutting bee, Megachile rotundata. BULLETIN OF ENTOMOLOGICAL RESEARCH 2023; 113:299-305. [PMID: 36883790 DOI: 10.1017/s0007485321001103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The success of agriculture relies on healthy bees to pollinate crops. Commercially managed pollinators are often kept under temperature-controlled conditions to better control development and optimize field performance. One such pollinator, the alfalfa leafcutting bee, Megachile rotundata, is the most widely used solitary bee in agriculture. Problematically, very little is known about the thermal physiology of M. rotundata or the consequences of artificial thermal regimes used in commercial management practices. Therefore, we took a broad look at the thermal performance of M. rotundata across development and the effects of commonly used commercial thermal regimes on adult bee physiology. After the termination of diapause, we hypothesized thermal sensitivity would vary across pupal metamorphosis. Our data show that bees in the post-diapause quiescent stage were more tolerant of low temperatures compared to bees in active development. We found that commercial practices applied during development decrease the likelihood of a bee recovering from another bout of thermal stress in adulthood, thereby decreasing their resilience. Lastly, commercial regimes applied during development affected the number of days to adult emergence, but the time of day that adults emerged was unaffected. Our data demonstrate the complex interactions between bee development and thermal regimes used in management. This knowledge can help improve the commercial management of these bees by optimizing the thermal regimes used and the timing of their application to alleviate negative downstream effects on adult performance.
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Affiliation(s)
- Meghan M Bennett
- USDA-ARS Carl Hayden Bee Research Center, 2000 East Allen Road, Tucson, AZ 85719, USA
| | - Korie M DeBardlabon
- Biosciences Research Laboratory, USDA_ARS, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Boulevard North, Fargo, ND 58102-2765, USA
- Department of Biological Sciences, North Dakota State University, 308 Stevens Hall, P.O. Box 6050, Fargo, ND 58102, USA
| | - Joseph P Rinehart
- Biosciences Research Laboratory, USDA_ARS, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Boulevard North, Fargo, ND 58102-2765, USA
| | - George D Yocum
- Biosciences Research Laboratory, USDA_ARS, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Boulevard North, Fargo, ND 58102-2765, USA
| | - Kendra J Greenlee
- Department of Biological Sciences, North Dakota State University, 308 Stevens Hall, P.O. Box 6050, Fargo, ND 58102, USA
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Boardman L, Lockwood JL, Angilletta MJ, Krause JS, Lau JA, Loik ME, Simberloff D, Thawley CJ, Meyerson LA. The Future of Invasion Science Needs Physiology. Bioscience 2022. [DOI: 10.1093/biosci/biac080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Incorporating physiology into models of population dynamics will improve our understanding of how and why invasions succeed and cause ecological impacts, whereas others fail or remain innocuous. Targeting both organismal physiologists and invasion scientists, we detail how physiological processes affect every invasion stage, for both plants and animals, and how physiological data can be better used for studying the spatial dynamics and ecological effects of invasive species. We suggest six steps to quantify the physiological functions related to demography of nonnative species: justifying physiological traits of interest, determining ecologically appropriate time frames, identifying relevant abiotic variables, designing experimental treatments that capture covariation between abiotic variables, measuring physiological responses to these abiotic variables, and fitting statistical models to the data. We also provide brief guidance on approaches to modeling invasions. Finally, we emphasize the benefits of integrating research between communities of physiologists and invasion scientists.
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Affiliation(s)
- Leigh Boardman
- Department of Biological Sciences and with the Center for Biodiversity Research, University of Memphis , Memphis, Tennessee, United States
| | - Julie L Lockwood
- Department of Ecology, Evolution, and Natural Resources at Rutgers University , New Brunswick, New Jersey, United States
| | - Michael J Angilletta
- School of Life Sciences and with the Center for Learning Innovation in Science, Arizona State University , Tempe, Arizona, United States
| | - Jesse S Krause
- Department of Biology, University of Nevada , Reno, Nevada, United States
| | - Jennifer A Lau
- Department of Biology, Indiana University , Bloomington, Indian, United States
| | - Michael E Loik
- Environmental Studies Department, University of California , Santa Cruz, Santa Cruz, California, United States
| | - Daniel Simberloff
- Department of Ecology and Evolutionary Biology, University of Tennessee , Knoxville, Tennessee, United States
| | - Christopher J Thawley
- Department of Biological Sciences, University of Rhode Island , Kingston, Rhode Island, United States
| | - Laura A Meyerson
- Department of Natural Resources Science, University of Rhode Island , Kingston, Rhode Island, United States
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4
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Smith A, Turnbull KF, Moulton JH, Sinclair BJ. Metabolic cost of freeze-thaw and source of CO 2 production in the freeze-tolerant cricket Gryllus veletis. J Exp Biol 2021; 224:jeb234419. [PMID: 33144372 DOI: 10.1242/jeb.234419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/28/2020] [Indexed: 12/28/2022]
Abstract
Freeze-tolerant insects can survive the conversion of a substantial portion of their body water to ice. While the process of freezing induces active responses from some organisms, these responses appear absent from freeze-tolerant insects. Recovery from freezing likely requires energy expenditure to repair tissues and re-establish homeostasis, which should be evident as elevations in metabolic rate after thaw. We measured carbon dioxide (CO2) production in the spring field cricket (Gryllus veletis) as a proxy for metabolic rate during cooling, freezing and thawing and compared the metabolic costs associated with recovery from freezing and chilling. We hypothesized that freezing does not induce active responses, but that recovery from freeze-thaw is metabolically costly. We observed a burst of CO2 release at the onset of freezing in all crickets that froze, including those killed by either cyanide or an insecticide (thiacloprid), implying that the source of this CO2 was neither aerobic metabolism nor a coordinated nervous system response. These results suggest that freezing does not induce active responses from G. veletis, but may liberate buffered CO2 from hemolymph. There was a transient 'overshoot' in CO2 release during the first hour of recovery, and elevated metabolic rate at 24, 48 and 72 h, in crickets that had been frozen compared with crickets that had been chilled (but not frozen). Thus, recovery from freeze-thaw and the repair of freeze-induced damage appears metabolically costly in G. veletis, and this cost persists for several days after thawing.
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Affiliation(s)
- Adam Smith
- Department of Biology, University of Western Ontario, London, ON, Canada N6A 5B7
| | - Kurtis F Turnbull
- Department of Biology, University of Western Ontario, London, ON, Canada N6A 5B7
| | - Julian H Moulton
- Department of Organismal Biology and Ecology, Colorado College, Colorado Springs, CO 80903, USA
| | - Brent J Sinclair
- Department of Biology, University of Western Ontario, London, ON, Canada N6A 5B7
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5
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Heat tolerance and thermal preference of the copepod Tigriopus californicus are insensitive to ecologically relevant dissolved oxygen levels. Sci Rep 2020; 10:18885. [PMID: 33144656 PMCID: PMC7641137 DOI: 10.1038/s41598-020-75635-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 10/05/2020] [Indexed: 11/12/2022] Open
Abstract
Shifting climate patterns may impose novel combinations of abiotic conditions on animals, yet understanding of the present-day interactive effects of multiple stressors remains under-developed. We tested the oxygen and capacity limited thermal tolerance (OCLTT) hypothesis and quantified environmental preference of the copepod Tigriopus californicus, which inhabits rocky-shore splashpools where diel fluctuations of temperature and dissolved oxygen (DO) are substantial. Egg-mass bearing females were exposed to a 5 h heat ramp to peak temperatures of 34.1–38.0 °C crossed with each of four oxygen levels: 22, 30, 100 and 250% saturation (4.7–5.3, 5.3–6.4, 21.2–21.3, and 50.7–53.3 kPa). Survival decreased at higher temperatures but was independent of DO. The behavioral preference of females was quantified in seven combinations of gradients of both temperature (11–37 °C) and oxygen saturation (17–206% or 3.6–43.6 kPa). Females avoided high temperatures regardless of DO levels. This pattern was more pronounced when low DO coincided with high temperature. In uniform temperature treatments, the distribution shifted toward high DO levels, especially in uniform high temperature, confirming that Tigriopus can sense environmental pO2. These results question the ecological relevance of OCLTT for Tigriopus and raise the possibility of microhabitat selection being used within splashpool environments to avoid physiologically stressful combinations of conditions.
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6
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Abstract
Temperature is a critical abiotic factor shaping the distribution and abundance of species, but the mechanisms that underpin organismal thermal limits remain poorly understood. One possible mechanism underlying these limits is the failure of mitochondrial processes, as mitochondria play a crucial role in animals as the primary site of ATP production. Conventional measures of mitochondrial performance suggest that these organelles can function at temperatures much higher than those that limit whole-organism function, suggesting that they are unlikely to set organismal thermal limits. However, this conclusion is challenged by recent data connecting sequence variation in mitochondrial genes to whole-organism thermal tolerance. Here, we review the current state of knowledge of mitochondrial responses to thermal extremes and ask whether they are consistent with a role for mitochondrial function in shaping whole-organism thermal limits. The available data are fragmentary, but it is possible to draw some conclusions. There is little evidence that failure of maximal mitochondrial oxidative capacity as assessed in vitro sets thermal limits, but there is some evidence to suggest that temperature effects on ATP synthetic capacity may be important. Several studies suggest that loss of mitochondrial coupling is associated with the thermal limits for organismal growth, although this needs to be rigorously tested. Most studies have utilized isolated mitochondrial preparations to assess the effects of temperature on these organelles, and there remain many untapped opportunities to address these questions using preparations that retain more of their biological context to better connect these subcellular processes with whole-organism thermal limits.
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Affiliation(s)
- Dillon J Chung
- National Heart Lung and Blood Institute, National Institutes of Health, 10 Center Drive, Bethesda, MD 20814, USA
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
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7
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Chen C, Condon CH, Boardman L, Meagher RL, Jeffers LA, Beam A, Bailey WD, Hahn DA. Critical PO 2 as a diagnostic biomarker for the effects of low-oxygen modified and controlled atmospheres on phytosanitary irradiation treatments in the cabbage looper Trichoplusia ni (Hübner). PEST MANAGEMENT SCIENCE 2020; 76:2333-2341. [PMID: 32003078 DOI: 10.1002/ps.5768] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/24/2020] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Phytosanitary irradiation is a sustainable alternative to chemical fumigants for disinfesting fresh commodities from insect pests. However, irradiating insects in modified atmospheres with very low oxygen (<1 kPa O2 ) has repeatedly been shown to increase radioprotective response. Thus, there is a concern that modified atmosphere packaging could reduce the efficacy of phytosanitary irradiation. One hurdle slowing the widespread application of phytosanitary irradiation is a lack of knowledge about how moderate levels of hypoxia relevant to the modified atmosphere packaging of most fresh commodities (3-10 kPa O2 ) may affect phytosanitary irradiation treatments. Therefore, we hypothesize that critical PO2 (Pcrit ), the level of oxygen at which an insect's metabolism becomes impaired, can be used as a diagnostic biomarker to predict the induction of a radioprotective response. RESULTS Using the cabbage looper Trichoplusia ni (Hübner), we show that there is a substantial increase in radiation resistance when larvae are irradiated in atmospheres more hypoxic than their Pcrit (3.3 kPa O2 ). These data are consistent with our hypothesis that Pcrit could be used as a diagnostic biomarker for what levels of hypoxia may induce radioprotective effects that could impact phytosanitary irradiation treatments. CONCLUSION We propose that the relationship between Pcrit and radioprotective effects could allow us to build a framework for predicting the effects of low-oxygen atmospheres on the efficacy of phytosanitary irradiation. However, more widespread studies across pest species are still needed to test the generality of this idea.
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Affiliation(s)
- Chao Chen
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Catriona H Condon
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Leigh Boardman
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Robert L Meagher
- USDA-ARS, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL, USA
| | - Laura A Jeffers
- USDA-APHIS-PPQ Center for Plant Health Science and Technology, Raleigh, NC, USA
| | - Andrea Beam
- USDA-APHIS-PPQ Center for Plant Health Science and Technology, Miami, FL, USA
| | - Woodward D Bailey
- USDA-APHIS-PPQ Center for Plant Health Science and Technology, Miami, FL, USA
| | - Daniel A Hahn
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
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8
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Lombardi EJ, Bywater CL, White CR. The effect of ambient oxygen on the thermal performance of a cockroach, Nauphoeta cinerea. J Exp Biol 2020; 223:jeb208306. [PMID: 32366686 DOI: 10.1242/jeb.208306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 04/17/2020] [Indexed: 11/20/2022]
Abstract
The oxygen and capacity-limited thermal tolerance (OCLTT) hypothesis proposes that the thermal tolerance of an animal is shaped by its capacity to deliver oxygen in relation to oxygen demand. Studies testing this hypothesis have largely focused on measuring short-term performance responses in animals under acute exposure to critical thermal maximums. The OCLTT hypothesis, however, emphasises the importance of sustained animal performance over acute tolerance. The present study tested the effect of chronic hypoxia and hyperoxia during development on moderate to long-term performance indicators at temperatures spanning the optimal temperature for growth in the speckled cockroach, Nauphoeta cinerea In contrast to the predictions of the OCLTT hypothesis, development under hypoxia did not significantly reduce growth rate or running performance, and development under hyperoxia did not significantly increase growth rate or running performance. The effects of developmental temperature and oxygen on tracheal morphology and metabolic rate were also not consistent with OCLTT predictions, suggesting that oxygen delivery capacity is not the primary driver shaping thermal tolerance in this species. Collectively, these findings suggest that the OCLTT hypothesis does not explain moderate to long-term thermal performance in N.cinerea, which raises further questions about the generality of the hypothesis.
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Affiliation(s)
- Emily J Lombardi
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Candice L Bywater
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Craig R White
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
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González-Tokman D, Córdoba-Aguilar A, Dáttilo W, Lira-Noriega A, Sánchez-Guillén RA, Villalobos F. Insect responses to heat: physiological mechanisms, evolution and ecological implications in a warming world. Biol Rev Camb Philos Soc 2020; 95:802-821. [PMID: 32035015 DOI: 10.1111/brv.12588] [Citation(s) in RCA: 170] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 01/24/2020] [Accepted: 01/29/2020] [Indexed: 12/12/2022]
Abstract
Surviving changing climate conditions is particularly difficult for organisms such as insects that depend on environmental temperature to regulate their physiological functions. Insects are extremely threatened by global warming, since many do not have enough physiological tolerance even to survive continuous exposure to the current maximum temperatures experienced in their habitats. Here, we review literature on the physiological mechanisms that regulate responses to heat and provide heat tolerance in insects: (i) neuronal mechanisms to detect and respond to heat; (ii) metabolic responses to heat; (iii) thermoregulation; (iv) stress responses to tolerate heat; and (v) hormones that coordinate developmental and behavioural responses at warm temperatures. Our review shows that, apart from the stress response mediated by heat shock proteins, the physiological mechanisms of heat tolerance in insects remain poorly studied. Based on life-history theory, we discuss the costs of heat tolerance and the potential evolutionary mechanisms driving insect adaptations to high temperatures. Some insects may deal with ongoing global warming by the joint action of phenotypic plasticity and genetic adaptation. Plastic responses are limited and may not be by themselves enough to withstand ongoing warming trends. Although the evidence is still scarce and deserves further research in different insect taxa, genetic adaptation to high temperatures may result from rapid evolution. Finally, we emphasize the importance of incorporating physiological information for modelling species distributions and ecological interactions under global warming scenarios. This review identifies several open questions to improve our understanding of how insects respond physiologically to heat and the evolutionary and ecological consequences of those responses. Further lines of research are suggested at the species, order and class levels, with experimental and analytical approaches such as artificial selection, quantitative genetics and comparative analyses.
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Affiliation(s)
- Daniel González-Tokman
- CONACYT, CDMX, 03940, Mexico.,Red de Ecoetología, Instituto de Ecología A. C, Xalapa, 91073, Mexico
| | - Alex Córdoba-Aguilar
- Instituto de Ecología, Universidad Nacional Autónoma de México. Circuito exterior s/n Ciudad Universitaria, CDMX, 04510, Mexico
| | - Wesley Dáttilo
- Red de Ecoetología, Instituto de Ecología A. C, Xalapa, 91073, Mexico
| | - Andrés Lira-Noriega
- CONACYT, CDMX, 03940, Mexico.,Red de Estudios Moleculares Avanzados, Instituto de Ecología A. C, Xalapa, 91073, Mexico
| | | | - Fabricio Villalobos
- Red de Biología Evolutiva, Instituto de Ecología A. C, Xalapa, 91073, Mexico
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Javal M, Thomas S, Lehmann P, Barton MG, Conlong DE, Du Plessis A, Terblanche JS. The Effect of Oxygen Limitation on a Xylophagous Insect's Heat Tolerance Is Influenced by Life-Stage Through Variation in Aerobic Scope and Respiratory Anatomy. Front Physiol 2019; 10:1426. [PMID: 31824337 PMCID: PMC6879455 DOI: 10.3389/fphys.2019.01426] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 11/04/2019] [Indexed: 12/21/2022] Open
Abstract
Temperature has a profound impact on insect fitness and performance via metabolic, enzymatic or chemical reaction rate effects. However, oxygen availability can interact with these thermal responses in complex and often poorly understood ways, especially in hypoxia-adapted species. Here we test the hypothesis that thermal limits are reduced under low oxygen availability - such as might happen when key life-stages reside within plants - but also extend this test to attempt to explain that the magnitude of the effect of hypoxia depends on variation in key respiration-related parameters such as aerobic scope and respiratory morphology. Using two life-stages of a xylophagous cerambycid beetle, Cacosceles (Zelogenes) newmannii we assessed oxygen-limitation effects on metabolic performance and thermal limits. We complement these physiological assessments with high-resolution 3D (micro-computed tomography scan) morphometry in both life-stages. Results showed that although larvae and adults have similar critical thermal maxima (CTmax) under normoxia, hypoxia reduces metabolic rate in adults to a greater extent than it does in larvae, thus reducing aerobic scope in the former far more markedly. In separate experiments, we also show that adults defend a tracheal oxygen (critical) setpoint more consistently than do larvae, indicated by switching between discontinuous gas exchange cycles (DGC) and continuous respiratory patterns under experimentally manipulated oxygen levels. These effects can be explained by the fact that the volume of respiratory anatomy is positively correlated with body mass in adults but is apparently size-invariant in larvae. Thus, the two life-stages of C. newmannii display key differences in respiratory structure and function that can explain the magnitude of the effect of hypoxia on upper thermal limits.
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Affiliation(s)
- Marion Javal
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
| | - Saskia Thomas
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
| | - Philipp Lehmann
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Madeleine G. Barton
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
| | - Desmond E. Conlong
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
- South African Sugarcane Research Institute, Mount Edgecombe, South Africa
| | - Anton Du Plessis
- CT Scanner Facility, Central Analytical Facilities, Stellenbosch University, Stellenbosch, South Africa
- Physics Department, Stellenbosch University, Stellenbosch, South Africa
| | - John S. Terblanche
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
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11
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Zhu W, Meng Q, Zhang H, Wang ML, Li X, Wang HT, Zhou GL, Miao L, Qin QL, Zhang JH. Metabolomics reveals the key role of oxygen metabolism in heat susceptibility of an alpine-dwelling ghost moth, Thitarodes xiaojinensis (Lepidoptera: Hepialidae). INSECT SCIENCE 2019; 26:695-710. [PMID: 29790270 DOI: 10.1111/1744-7917.12605] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/11/2018] [Accepted: 04/30/2018] [Indexed: 06/08/2023]
Abstract
Ghost moths inhabiting the alpine meadows of the Tibetan Plateau are cold-adapted stenothermal organisms that are susceptible to heat (dead within 7 days at 27 °C exposure). Exploring the metabolic basis of their heat susceptibility would extend our understanding of the thermal biology of alpine-dwelling invertebrates. Here, gas chromatography-mass spectrometry-based metabolomics was combined with physiological and transcriptional approaches to determine the metabolic mechanisms of heat susceptibility in Thitarodes xiaojinensis larvae. The metabolomics results showed that 27 °C heat stress impaired the Krebs cycle and lipolysis in T. xiaojinensis larvae, as demonstrated by the accumulation of intermediary metabolites. In addition, carbohydrate reserves were highly and exclusively consumed, and an anaerobic product, lactate, accumulated. This evidence suggested a strong reliance on glycolysis to anaerobically generate energy. The respiration rate and enzymatic activity test results indicated a deficiency in O2 metabolism; in addition, the Krebs cycle capacity was not decreased, and the metabolic flux through aerobic pathways was limited. These findings were further supported by the occurrence of hypoxia symptoms in midgut mitochondria (vacuolation and swelling) and increased transcription of hypoxia-induced factor 1-α. Overall, heat stress caused O2 limitation and depressed the overall intensity of aerobic metabolism in ghost moths, and less efficient anaerobic glycolysis was activated to sustain their energy supply. As carbohydrates were depleted, the energy supply became deficient. Our study presents a comprehensive metabolic explanation for the heat susceptibility of ghost moths and reveals the relationship between O2 metabolism and heat susceptibility in these larvae.
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Affiliation(s)
- Wei Zhu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Department of Herpetology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Qian Meng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Huan Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Meng-Long Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xuan Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Hong-Tuo Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gui-Ling Zhou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Lin Miao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qi-Lian Qin
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Ji-Hong Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Wood C, Fitt RNL, Lancaster LT. Evolving social dynamics prime thermal tolerance during a poleward range shift. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/bly197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Connor Wood
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Robert N L Fitt
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
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Boardman L, Mitchell KA, Terblanche JS, Sørensen JG. A transcriptomics assessment of oxygen-temperature interactions reveals novel candidate genes underlying variation in thermal tolerance and survival. JOURNAL OF INSECT PHYSIOLOGY 2018; 106:179-188. [PMID: 29038013 DOI: 10.1016/j.jinsphys.2017.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/17/2017] [Accepted: 10/12/2017] [Indexed: 06/07/2023]
Abstract
While single stress responses are fairly well researched, multiple, interactive stress responses are not-despite the obvious importance thereof. Here, using D. melanogaster, we investigated the effects of simultaneous exposures to low O2 (hypoxia) and varying thermal conditions on mortality rates, estimates of thermal tolerance and the transcriptome. We used combinations of 21 (normoxia), 10 or 5kPa O2 with control (23°C), cold (4°C) or hot (31°C) temperature exposures before assaying chill coma recovery time (CCRT) and heat knock down time (HKDT) as measures of cold and heat tolerance respectively. We found that mortality was significantly affected by temperature, oxygen partial pressure (PO2) and the interaction between the two. Cold treatments resulted in low mortality (<5%), regardless of PO2 treatment; while hot treatments resulted in higher mortality (∼20%), especially at 5kPa O2 which was lethal for most flies (∼80%). Both CCRT and HKDT were significantly affected by temperature, but not PO2, of the treatments, and the interaction of temperature and PO2 was non-significant. Hot treatments led to significantly longer CCRT, and shorter HKDT in comparison to cold treatments. Global gene expression profiling provided the first transcriptome level response to the combined stress of PO2 and temperature, showing that stressful treatments resulted in higher mortality and induced transcripts that were associated with protein kinases, catabolic processes (proteases, hydrolases, peptidases) and membrane function. Several genes and pathways that may be responsible for the protective effects of combined PO2 and cold treatments were identified. We found that urate oxidase was upregulated in all three cold treatments, regardless of the PO2. Small heat shock proteins Hsp22 and Hsp23 were upregulated after both 10 and 21kPa O2-hot treatments. Collectively, the data from PO2-hot treatments suggests that hypoxia does exacerbate heat stress, through an as yet unidentified mechanism. Hsp70B and an unannotated transcript (CG6733) were significantly differentially expressed after 5kPa O2-cold and 10kPa O2-hot treatments relative to their controls. Downregulation of these transcripts was correlated with reduced thermal tolerance (longer CCRT and shorter HKDT), suggesting that these genes may be important candidates for future research.
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Affiliation(s)
- Leigh Boardman
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, South Africa.
| | - Katherine A Mitchell
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, South Africa
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, South Africa
| | - Jesper G Sørensen
- Section for Genetics, Ecology & Evolution, Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark
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