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Jiménez-Padilla Y, Adewusi B, Lachance MA, Sinclair BJ. Live yeasts accelerate Drosophila melanogaster larval development. J Exp Biol 2024; 227:jeb247932. [PMID: 39234635 PMCID: PMC11463955 DOI: 10.1242/jeb.247932] [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: 05/01/2024] [Accepted: 08/28/2024] [Indexed: 09/06/2024]
Abstract
Insect guts house a complex community of microbes that affect host physiology, performance and behavior. Gut microbiome research has largely focused on bacteria-host symbioses and paid less attention to other taxa, such as yeasts. We found that axenic Drosophila melanogaster (reared free of microbes) develops from egg to adult more slowly (ca. 13 days) than those with a natural microbiota (ca. 11.5 days). Here, we showed that live yeasts are present and reproducing in the guts of flies and that the fast development time can be restored by inoculating larvae with a single yeast species (either Saccharomyces cerevisiae or Lachancea kluyveri). Nutritional supplements (either heat-killed yeasts, or a mix of essential vitamins and amino acids) slightly sped the development of axenic flies (to ca. 12.5 days), but not to the same extent as live yeasts. During the first two instars, this acceleration appears to result from additional macronutrient availability, but during the third instar, when most growth occurs, live yeasts increased feeding rate, implying an effect mediated by the gut-brain axis. Thus, the fly-yeast interaction extends beyond yeasts-as-food to yeasts as beneficial interactive symbionts.
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Affiliation(s)
| | - Babafemi Adewusi
- Department of Biology, University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Marc-André Lachance
- Department of Biology, University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Brent J. Sinclair
- Department of Biology, University of Western Ontario, London, Ontario N6A 5B7, Canada
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2
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Jiménez-Padilla Y, Chan Y, Aletta MS, Lachance MA, Simon AF. The effect of microbiome on social spacing in Drosophila melanogaster depends on genetic background and sex. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001270. [PMID: 39381640 PMCID: PMC11461029 DOI: 10.17912/micropub.biology.001270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/14/2024] [Accepted: 09/09/2024] [Indexed: 10/10/2024]
Abstract
The gut microbiome modulates many essential functions including metabolism, immunity, and behaviour. Specifically, within behaviour, social behaviours such as sociability, aggregation, mating preference, avoidance, oviposition, and aggression are known to be regulated in part by this host-microbiome relationship. Here, we show the microbiome's role in the determination of social spacing in a sex- and genotype-specific manner. Future work can be done on characterizing the microbiome in each of these fly strains to identify the species of microbes present as well as their abundance.
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Affiliation(s)
| | - Yen Chan
- Biology Department, University of Western Ontario, London, Ontario, Canada
| | - M. Sol Aletta
- Biology Department, University of Western Ontario, London, Ontario, Canada
| | | | - Anne F Simon
- Biology Department, University of Western Ontario, London, Ontario, Canada
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3
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Helou B, Ritchie MW, MacMillan HA, Andersen MK. Dietary potassium and cold acclimation additively increase cold tolerance in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2024; 159:104701. [PMID: 39251183 DOI: 10.1016/j.jinsphys.2024.104701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 08/01/2024] [Accepted: 09/04/2024] [Indexed: 09/11/2024]
Abstract
In the cold, chill susceptible insects lose the ability to regulate ionic and osmotic gradients. This leads to hemolymph hyperkalemia that drives a debilitating loss of cell membrane polarization, triggering cell death pathways and causing organismal injury. Biotic and abiotic factors can modulate insect cold tolerance by impacting the ability to mitigate or prevent this cascade of events. In the present study, we test the combined and isolated effects of dietary manipulations and thermal acclimation on cold tolerance in fruit flies. Specifically, we acclimated adult Drosophila melanogaster to 15 or 25 °C and fed them either a K+-loaded diet or a control diet. We then tested the ability of these flies to recover from and survive a cold exposure, as well as their capacity to protect transmembrane K+ gradients, and intracellular Na+ concentration. As predicted, cold-exposed flies experienced hemolymph hyperkalemia and cold-acclimated flies had improved cold tolerance due to an improved maintenance of the hemolymph K+ concentration at low temperature. Feeding on a high-K+ diet improved cold tolerance additively, but paradoxically reduced the ability to maintain extracellular K+ concentrations. Cold-acclimation and K+-feeding additively increased the intracellular K+ concentration, aiding in maintenance of the transmembrane K+ gradient during cold exposure despite cold-induced hemolymph hyperkalemia. There was no effect of acclimation or diet on intracellular Na+ concentration. These findings suggest intracellular K+ loading and reduced muscle membrane K+ sensitivity as mechanisms through which cold-acclimated and K+-fed flies are able to tolerate hemolymph hyperkalemia.
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Affiliation(s)
- Bassam Helou
- Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Marshall W Ritchie
- Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Heath A MacMillan
- Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - Mads Kuhlmann Andersen
- Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada; Department of Biology, Aarhus University, 8000 Aarhus C, Denmark.
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4
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Ratz T, Chechi TS, Dimopoulou AI, Sedlmair SD, Tuni C. Heatwaves inflict reproductive but not survival costs to male insects. J Exp Biol 2024; 227:jeb246698. [PMID: 38436413 DOI: 10.1242/jeb.246698] [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: 08/31/2023] [Accepted: 02/27/2024] [Indexed: 03/05/2024]
Abstract
Climate change is having a dramatic effect on the environment, with rising global temperatures and more frequent extreme climatic events, such as heatwaves, that can hamper organisms' biological functions. Although it is clear that sudden and extreme temperatures can damage reproductive processes, there is limited understanding of the effects of heatwaves on male mating behaviour and reproductive success. We tested for the effects of heat stress induced by ecologically relevant heatwaves (33°C and 39°C for five consecutive days) on the mating behaviour, reproductive success, body mass and survival of male field crickets Gryllus bimaculatus, paired with untreated females. We predicted life-history and reproductive costs would increase with increasing heatwave intensity. Consistent with our expectations, males exposed to the highest heatwave temperature produced the fewest offspring, while having to increase courtship effort to successfully mate. Males also gained relatively more weight following heatwave exposure. Given that we found no difference in lifetime survival, our results suggest a potential trade-off in resource allocation between somatic maintenance and reproductive investment. Taken together, our findings indicate that sublethal effects of heatwaves could reduce the growth and persistence of animal populations by negatively impacting reproductive rates. These findings highlight the need for considering thermal ecologies, life history and behaviour to better understand the consequences of extreme climatic events on individuals and populations.
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Affiliation(s)
- Tom Ratz
- Department of Biology, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstraße 190, 8057 Zürich, Switzerland
| | - Tejinder Singh Chechi
- Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Aliki-Ioanna Dimopoulou
- Department of Biology, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Stephanie Daniela Sedlmair
- Department of Biology, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Cristina Tuni
- Department of Biology, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
- Department of Life Sciences and Systems Biology, University of Turin, Via Accademia Albertina 13, 10123 Torino, Italy
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5
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Ajayi OM, Oyen KJ, Davies B, Finch G, Piller BD, Harmeyer AA, Wendeln K, Perretta C, Rosendale AJ, Benoit JB. Egg hatching success is influenced by the time of thermal stress in four hard tick species. JOURNAL OF MEDICAL ENTOMOLOGY 2024; 61:110-120. [PMID: 37889857 PMCID: PMC10784778 DOI: 10.1093/jme/tjad142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 10/02/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023]
Abstract
Ticks are blood-feeding arthropods responsible for the transmission of disease-causing pathogens to a wide range of vertebrate hosts, including livestock and humans. Tick-borne diseases have been implicated in significant economic losses to livestock production, and this threat will increase as these obligate parasites widen their geographical ranges. Similar to other ectotherms, thermal stress due to changing global temperatures has been shown to influence tick survival and distribution. However, studies on the influence of extreme temperatures in ticks have focused on advanced, mobile stages, ignoring immobile stages that cannot move to more favorable microhabitats. In this study, low- and high-temperature regimens were assessed in relation to egg viability for hard tick species-Amblyomma maculatum (Gulf Coast tick), Ixodes scapularis (black-legged tick), Dermacentor variabilis (American dog tick), and Rhipicephalus sanguineus (Brown dog tick). Tick eggs exposed early in development (freshly laid during early embryo development) were significantly more susceptible to thermal stress when compared with those exposed later in development (late embryo development denoted by a fecal spot). Based on our studies, differences in egg hatching success among treatments were greater than in hatching success when comparing species. Lastly, there was evidence of extreme thermal exposure significantly altering the hatching times of tick eggs for specific treatments. These results provide insights into the critical period for tick egg viability in relation to thermal exposure and tick survival associated with stress and climate change.
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Affiliation(s)
- Oluwaseun M Ajayi
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Kennan J Oyen
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
- Animal Diseases Research Unit, USDA-ARS, 3003 ADBF, Pullman, WA, USA
| | - Benjamin Davies
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Geoffrey Finch
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Benjamin D Piller
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Alison A Harmeyer
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Katherine Wendeln
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Carlie Perretta
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Andrew J Rosendale
- Biology Department, Mount St. Joseph University, Cincinnati, OH 45233, USA
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA
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6
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Earls KN, Campbell JB, Rinehart JP, Greenlee KJ. Effects of temperature on metabolic rate during metamorphosis in the alfalfa leafcutting bee. Biol Open 2023; 12:bio060213. [PMID: 38156711 PMCID: PMC10805150 DOI: 10.1242/bio.060213] [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: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
Spring conditions, especially in temperate regions, may fluctuate abruptly and drastically. Environmental variability can expose organisms to temperatures outside of their optimal thermal ranges. For ectotherms, sudden changes in temperature may cause short- and long-term physiological effects, including changes in respiration, morphology, and reproduction. Exposure to variable temperatures during active development, which is likely to occur for insects developing in spring, can cause detrimental effects. Using the alfalfa leafcutting bee, Megachile rotundata, we aimed to determine if oxygen consumption could be measured using a new system and to test the hypothesis that female and male M. rotundata have a thermal performance curve with a wide optimal range. Oxygen consumption of M. rotundata pupae was measured across a large range of temperatures (6-48°C) using an optical oxygen sensor in a closed respirometry system. Absolute and mass-specific metabolic rates were calculated and compared between bees that were extracted from their brood cells and those remaining in the brood cell to determine whether pupae could be accurately measured inside their brood cells. The metabolic response to temperature was non-linear, which is an assumption of a thermal performance curve; however, the predicted negative slope at higher temperatures was not observed. Despite sexual dimorphism in body mass, sex differences only occurred in mass-specific metabolic rates. Higher metabolic rates in males may be attributed to faster development times, which could explain why there were no differences in absolute metabolic rate measurements. Understanding the physiological and ecological effects of thermal environmental variability on M. rotundata will help to better predict their response to climate change.
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Affiliation(s)
- Kayla N. Earls
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
| | - Jacob B. Campbell
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
| | - Joseph P. Rinehart
- Edward T. Schafer Agricultural Research Center, US Department of Agriculture/Agricultural Research Station, Fargo, ND 58102,USA
| | - Kendra J. Greenlee
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
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7
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Lubawy J, Chowański SP, Colinet H, Słocińska M. Mitochondrial metabolism and oxidative stress in the tropical cockroach under fluctuating thermal regimes. J Exp Biol 2023; 226:jeb246287. [PMID: 37589559 DOI: 10.1242/jeb.246287] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/08/2023] [Indexed: 08/18/2023]
Abstract
The cockroach Gromphadorhina coquereliana can survive at low temperatures under extensive periods of cold stress. To assess energy management and insect adaptation in response to cold, we measured mitochondrial activity and oxidative stress in muscle and fat body tissues from G. coquereliana under a fluctuating thermal regime (FTR; stressed at 4°C for 3 h on 3 consecutive days, with or without 24 h recovery). Compared with our earlier work showing that a single exposure to cold significantly affects mitochondrial parameters, here, repeated exposure to cold triggered an acclimatory response, resulting in unchanged mitochondrial bioenergetics. Immediately after cold exposure, we observed an increase in the overall pool of ATP and a decrease in typical antioxidant enzyme activity. We also observed decreased activity of uncoupling protein 4 in muscle mitochondria. After 24 h of recovery, we observed an increase in expression of antioxidant enzymes in muscles and the fat body and a significant increase in the expression of UCP4 and HSP70 in the latter. This indicates that processes related to energy conversion and disturbance under cold stress may trigger different protective mechanisms in these tissues, and that these mechanisms must be activated to restore insect homeostasis. The mitochondrial parameters and enzymatic assays suggest that mitochondria are not affected during FTR but oxidative stress markers are decreased, and a 24 h recovery period allows for the restoration of redox and energy homeostasis, especially in the fat body. This confirms the crucial role of the fat body in intermediary metabolism and energy management in insects and in the response to repeated thermal stress.
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Affiliation(s)
- Jan Lubawy
- Department of Animal Physiology and Developmental Biology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - Szymon P Chowański
- Department of Animal Physiology and Developmental Biology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - Hervé Colinet
- ECOBIO - UMR 6553, Université de Rennes 1, CNRS, Rennes 35042, France
| | - Małgorzata Słocińska
- Department of Animal Physiology and Developmental Biology, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznań, Poland
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8
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Mbande A, Mutamiswa R, Chidawanyika F. Ontogenetic responses of physiological fitness in Spodoptera frugiperda (Lepidoptera: Noctuidae) in response to repeated cold exposure. BULLETIN OF ENTOMOLOGICAL RESEARCH 2023; 113:449-455. [PMID: 37587795 DOI: 10.1017/s0007485323000111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
In this era of global climate change, intrinsic rapid and evolutionary responses of invasive agricultural pests to thermal variability are of concern given the potential implications on their biogeography and dire consequences on human food security. For insects, chill coma recovery time (CCRT) and critical thermal minima (CTmin), the point at which neuromuscular coordination is lost following cold exposure, remain good indices for cold tolerance. Using laboratory-reared Spodoptera frugiperda (Lepidoptera: Noctuidae), we explored cold tolerance repeated exposure across life stages of this invasive insect pest. Specifically, we measured their CTmin and CCRT across four consecutive assays, each 24 h apart. In addition, we assessed body water content (BWC) and body lipid content (BLC) of the life stages. Our results showed that CTmin improved with repeated exposure in 5th instar larvae, virgin males and females while CCRT improved in 4th, 5th and 6th instar larvae following repeated cold exposure. In addition, the results revealed evidence of cold hardening in this invasive insect pest. However, there was no correlation between cold tolerance and BWC as well as BLC. Our results show capacity for cold hardening and population persistence of S. frugiperda in cooler environments. This suggests potential of fall armyworm (FAW) to withstand considerable harsh winter environments typical of its recently invaded geographic range in sub-Saharan Africa.
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Affiliation(s)
- Abongile Mbande
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
| | - Reyard Mutamiswa
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
- Tugwi-Mukosi Multidisciplinary Research Institute, Midlands State University, Gweru, Zimbabwe
- Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Frank Chidawanyika
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
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9
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Luo D, Liu Q, Wang J, Jashenko R, Ji R. Transcriptome Analysis of the Differentially Expressed Heat-resistant Genes between Calliptamus italicus and Gomphocerus sibiricus. ENVIRONMENTAL ENTOMOLOGY 2023; 52:129-137. [PMID: 36511506 PMCID: PMC9936262 DOI: 10.1093/ee/nvac099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Indexed: 06/17/2023]
Abstract
Calliptamus italicus and Gomphocerus sibiricus are indicator species in Xinjiang's low-altitude (700-1,900 m) and high-altitude (2,000-3,400 m) grasslands, respectively. C. italicus is tolerant to high-temperature stress, with its semilethal temperature (LT50) being 10.5°C higher than that of G. sibiricus. The two locust species were subjected to high-temperature stress to explore the molecular mechanisms and differences in high temperature tolerance between the two locust species. Next, the next generation sequencing (NGS) data were mapped to reference transcripts obtained using single molecule real Time (SMRT) sequencing to construct a nonparameter transcriptome. The transcriptomic response of these two locust species displayed different patterns. C. italicus had 126 differentially expressed genes (DEGs), with 59 and 67 being significantly up-regulated and down-regulated, respectively. The heat shock protein (Hsp) genes were highly expressed upon two locust species exposure to high-temperature stress, with Hsp70 being expressed the most. G. sibiricus had 86 DEGs, of which 45 were significantly up-regulated and 41 significantly down-regulated. In addition, the expression of the key enzyme encoding gene Myo-inositol oxygenase (MIOX) in inositol degradation was the highest in G. sibiricus. In the KEGG pathway, the biological processes and metabolic pathways were the most enriched pathways in C. italicus and G. sibiricus, respectively. Moreover, the quantitative fluorescence results were consistent with the transcriptome results, implying that the transcriptome results were accurate. The findings in this study provide valuable information for future research exploring the evolution mechanisms of heat resistance in C. italicus and G. sibiricus.
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Affiliation(s)
- Di Luo
- International Research Center for the Collaborative Management of Cross-Border Pests in Central Asia, Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, College of Life Sciences, Xinjiang Normal University, Urumqi 830054, China
| | - Qian Liu
- International Research Center for the Collaborative Management of Cross-Border Pests in Central Asia, Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, College of Life Sciences, Xinjiang Normal University, Urumqi 830054, China
| | - Jinfeng Wang
- International Research Center for the Collaborative Management of Cross-Border Pests in Central Asia, Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, College of Life Sciences, Xinjiang Normal University, Urumqi 830054, China
| | - Roman Jashenko
- Al-Farabi Kazakh National University, Almaty 050038, Kazakhstan
| | - Rong Ji
- Corresponding author, e-mail:
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10
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De La Torre AM, López-Martínez G. Anoxia hormesis improves performance and longevity at the expense of fitness in a classic life history trade-off. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159629. [PMID: 36280058 DOI: 10.1016/j.scitotenv.2022.159629] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/04/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Hormesis occurs as a result of biphasic dose relationship resulting in stimulatory responses at low doses and inhibitory ones at high doses. In this framework, environmental factors are often studied to understand how this exposure benefits the animal. In the current study we used anoxia, the total absence of oxygen, as the most extreme version of low oxygen hormesis. Our goal was to determine the dose, the extent of the effect, and the cost of that response in Tenebrio molitor. We identified that the hormetic range (1 to 3 h of anoxia) was similar to that of other insects. Individuals that were exposed to 3 h had high emergence, increased activity throughout life, and lived longer. Beetles that experienced 1 h of anoxia performed better than the controls while the 6-h group had compromised performance. These boosts in performance at 3 h were accompanied by significant costs. Treated individuals had a delay in development and once matured they had decreased fitness. There were also transgenerational effects of hormesis and F1 beetles also experienced a delay in development. Additionally, the F1 generation had decreased developmental completion (i.e., stress-induced developmental halt). Our data suggests that anoxia hormesis triggers a trade-off where individuals benefiting from improved performance and living longer experience a decrease in reproduction.
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Affiliation(s)
- Alyssa M De La Torre
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, United States of America; College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, United States of America
| | - Giancarlo López-Martínez
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, United States of America; Department of Biological Sciences, North Dakota State University, Fargo, ND 58102, United States of America.
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11
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Andersen MK, Robertson RM, MacMillan HA. Plasticity in Na+/K+-ATPase thermal kinetics drives variation in the temperature of cold-induced neural shutdown of adult Drosophila melanogaster. J Exp Biol 2022; 225:285893. [PMID: 36477887 DOI: 10.1242/jeb.244923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022]
Abstract
Most insects can acclimate to changes in their thermal environment and counteract temperature effects on neuromuscular function. At the critical thermal minimum, a spreading depolarization (SD) event silences central neurons, but the temperature at which this event occurs can be altered through acclimation. SD is triggered by an inability to maintain ion homeostasis in the extracellular space in the brain and is characterized by a rapid surge in extracellular K+ concentration, implicating ion pump and channel function. Here, we focused on the role of the Na+/K+-ATPase specifically in lowering the SD temperature in cold-acclimated Drosophila melanogaster. After first confirming cold acclimation altered SD onset, we investigated the dependency of the SD event on Na+/K+-ATPase activity by injecting the inhibitor ouabain into the head of the flies to induce SD over a range of temperatures. Latency to SD followed the pattern of a thermal performance curve, but cold acclimation resulted in a left-shift of the curve to an extent similar to its effect on the SD temperature. With Na+/K+-ATPase activity assays and immunoblots, we found that cold-acclimated flies have ion pumps that are less sensitive to temperature, but do not differ in their overall abundance in the brain. Combined, these findings suggest a key role for plasticity in Na+/K+-ATPase thermal sensitivity in maintaining central nervous system function in the cold, and more broadly highlight that a single ion pump can be an important determinant of whether insects can respond to their environment to remain active at low temperatures.
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Affiliation(s)
| | | | - Heath A MacMillan
- Department of Biology, Carleton University, Ottawa, ON, Canada, K1S 5B6
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12
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Green L, Coronado-Zamora M, Radío S, Rech GE, Salces-Ortiz J, González J. The genomic basis of copper tolerance in Drosophila is shaped by a complex interplay of regulatory and environmental factors. BMC Biol 2022; 20:275. [PMID: 36482348 PMCID: PMC9733279 DOI: 10.1186/s12915-022-01479-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 11/24/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Escalation in industrialization and anthropogenic activity have resulted in an increase of pollutants released into the environment. Of these pollutants, heavy metals such as copper are particularly concerning due to their bio-accumulative nature. Due to its highly heterogeneous distribution and its dual nature as an essential micronutrient and toxic element, the genetic basis of copper tolerance is likely shaped by a complex interplay of genetic and environmental factors. RESULTS In this study, we utilized the natural variation present in multiple populations of Drosophila melanogaster collected across Europe to screen for variation in copper tolerance. We found that latitude and the degree of urbanization at the collection sites, rather than any other combination of environmental factors, were linked to copper tolerance. While previously identified copper-related genes were not differentially expressed in tolerant vs. sensitive strains, genes involved in metabolism, reproduction, and protease induction contributed to the differential stress response. Additionally, the greatest transcriptomic and physiological responses to copper toxicity were seen in the midgut, where we found that preservation of gut acidity is strongly linked to greater tolerance. Finally, we identified transposable element insertions likely to play a role in copper stress response. CONCLUSIONS Overall, by combining genome-wide approaches with environmental association analysis, and functional analysis of candidate genes, our study provides a unique perspective on the genetic and environmental factors that shape copper tolerance in natural D. melanogaster populations and identifies new genes, transposable elements, and physiological traits involved in this complex phenotype.
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Affiliation(s)
- Llewellyn Green
- grid.5612.00000 0001 2172 2676Institute of Evolutionary Biology, CSIC, Universitat Pompeu Fabra, Barcelona, Spain
| | - Marta Coronado-Zamora
- grid.5612.00000 0001 2172 2676Institute of Evolutionary Biology, CSIC, Universitat Pompeu Fabra, Barcelona, Spain
| | - Santiago Radío
- grid.5612.00000 0001 2172 2676Institute of Evolutionary Biology, CSIC, Universitat Pompeu Fabra, Barcelona, Spain
| | - Gabriel E. Rech
- grid.5612.00000 0001 2172 2676Institute of Evolutionary Biology, CSIC, Universitat Pompeu Fabra, Barcelona, Spain
| | - Judit Salces-Ortiz
- grid.5612.00000 0001 2172 2676Institute of Evolutionary Biology, CSIC, Universitat Pompeu Fabra, Barcelona, Spain
| | - Josefa González
- grid.5612.00000 0001 2172 2676Institute of Evolutionary Biology, CSIC, Universitat Pompeu Fabra, Barcelona, Spain
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13
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Kefford BJ, Ghalambor CK, Dewenter B, Poff NL, Hughes J, Reich J, Thompson R. Acute, diel, and annual temperature variability and the thermal biology of ectotherms. GLOBAL CHANGE BIOLOGY 2022; 28:6872-6888. [PMID: 36177681 PMCID: PMC9828456 DOI: 10.1111/gcb.16453] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Global warming is increasing mean temperatures and altering temperature variability at multiple temporal scales. To better understand the consequences of changes in thermal variability for ectotherms it is necessary to consider thermal variation at different time scales (i.e., acute, diel, and annual) and the responses of organisms within and across generations. Thermodynamics constrain acute responses to temperature, but within these constraints and over longer time periods, organisms have the scope to adaptively acclimate or evolve. Yet, hypotheses and predictions about responses to future warming tend not to explicitly consider the temporal scale at which temperature varies. Here, focusing on multicellular ectothermic animals, we argue that consideration of multiple processes and constraints associated with various timescales is necessary to better understand how altered thermal variability because of climate change will affect ectotherms.
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Affiliation(s)
- Ben J. Kefford
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Cameron K. Ghalambor
- Department of Biology and Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
- Department of Biology, Centre for Biodiversity Dynamics (CBD)Norwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Beatrice Dewenter
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - N. LeRoy Poff
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
- Department of Biology and Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
| | - Jane Hughes
- Australian Rivers InstituteGriffith UniversityNathanQueenslandAustralia
| | - Jollene Reich
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Ross Thompson
- Centre for Applied Water Science, Institute for Applied EcologyUniversity of CanberraCanberraAustralian Capital TerritoryAustralia
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14
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Park MG, Delphia CM, Prince C, Yocum GD, Rinehart JP, O’Neill KM, Burkle LA, Bowsher JH, Greenlee KJ. Effects of Temperature and Wildflower Strips on Survival and Macronutrient Stores of the Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae) Under Extended Cold Storage. ENVIRONMENTAL ENTOMOLOGY 2022; 51:958-968. [PMID: 35964238 PMCID: PMC9585370 DOI: 10.1093/ee/nvac062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Megachile rotundata (F.) is an important pollinator of alfalfa in the United States. Enhancing landscapes with wildflowers is a primary strategy for conserving pollinators and may improve the sustainability of M. rotundata. Changing cold storage temperatures from a traditionally static thermal regime (STR) to a fluctuating thermal regime (FTR) improves overwintering success and extends M. rotundata's shelf life and pollination window. Whether floral resources enhance overwintering survival and/or interact with a thermal regime are unknown. We tested the combined effects of enhancing alfalfa fields with wildflowers and thermal regime on survival and macronutrient stores under extended cold storage (i.e., beyond one season). Megachile rotundata adults were released in alfalfa plots with and without wildflower strips. Completed nests were harvested in September and stored in STR. After a year, cells were randomly assigned to remain in STR for 6 months or in FTR for a year of extended cold storage; emergence rates were observed monthly. Macronutrient levels of emerged females were assessed. FTR improved M. rotundata survival but there was no measurable effect of wildflower strips on overwintering success or nutrient stores. Timing of nest establishment emerged as a key factor: offspring produced late in the season had lower winter survival and dry body mass. Sugars and glycogen stores increased under FTR but not STR. Trehalose levels were similar across treatments. Total lipid stores depleted faster under FTR. While wildflowers did not improve M. rotundata survival, our findings provide mechanistic insight into benefits and potential costs of FTR for this important pollinator.
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Affiliation(s)
| | - Casey M Delphia
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
- Montana Entomology Collection, Marsh Labs, Montana State University, Bozeman, MT, USA
| | - Cassandra Prince
- Edward T. Schafer Agricultural Research Center, Biosciences Research Laboratory, Fargo, ND, USA
| | - George D Yocum
- Edward T. Schafer Agricultural Research Center, Biosciences Research Laboratory, Fargo, ND, USA
| | - Joseph P Rinehart
- Edward T. Schafer Agricultural Research Center, Biosciences Research Laboratory, Fargo, ND, USA
| | - Kevin M O’Neill
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Laura A Burkle
- Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Julia H Bowsher
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
| | - Kendra J Greenlee
- Department of Biological Sciences, North Dakota State University, Fargo, ND, USA
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15
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Geffroy B. Energy as the cornerstone of environmentally driven sex allocation. Trends Endocrinol Metab 2022; 33:670-679. [PMID: 35934660 DOI: 10.1016/j.tem.2022.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 11/18/2022]
Abstract
In recent years, observations of distinct organisms have linked the quality of the environment experienced by a given individual and the sex it will develop. In most described cases, facing relatively harsh conditions resulted in masculinization, while thriving in favorable conditions promoted the development of an ovary. This was shown indistinctively in some species presenting a genetic sex determination (GSD), which were able to sex-reverse, and in species with an environmental sex determination (ESD) system. However, this pattern strongly depends on evolutionary constrains and is detected only when females need more energy for reproduction. Here, I describe the mechanisms involved in this environmentally driven sex allocation (EDSA), which involves two main energy pathways, lipid and carbohydrate metabolism. These pathways act through various enzymes and are not necessarily independent of the previously known transducers of environmental signals in species with ESD: calcium-redox, epigenetic, and stress regulation pathways. Overall, there is evidence of a link between energy level and the sexual fate of individuals of various species, including reptiles, fish, amphibians, insects, and nematodes. As energy pathways are evolutionarily conserved, this knowledge opens new avenues to advance our understanding of the mechanisms that allow animals to adapt their sex according to the local environment.
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Affiliation(s)
- Benjamin Geffroy
- MARBEC, Univ Montpellier, Ifremer, IRD, CNRS, Montpellier, France.
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16
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Canal Domenech B, Seipelt A, Fricke C. Reproductive Ecology of Drosophila obscura: A Cold Adapted Species. ENVIRONMENTAL ENTOMOLOGY 2022; 51:595-604. [PMID: 35390142 DOI: 10.1093/ee/nvac022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Indexed: 06/14/2023]
Abstract
The study of insect reproductive ecology is essential to determine species distributions and fate under changing environments. Species adapted to harsh environments are good examples to investigate the reproductive mechanisms that allow them to cope with the challenging conditions. We here focus on studying for the first time the reproductive ecology of a cold-adapted Drosophila obscura (Diptera: Drosophilidae) strain collected in Finland (subarctic climate region). We tested several reproductive traits such as fertility and fecundity to observe the onset of reproduction and gauge when sexual maturity is reached in both males and females. We combined these measures with an analysis of changes of their reproductive organs shortly after eclosion. We found that males matured several days before females and that this process was underpinned by female egg maturation and male accessory gland growth, while sperm was already present in two-day old males. This delayed maturation is not observed to the same extent in other closely related species and might be a signature of exposure to harsh environments. Whether this delay is an adaptation to cope with variation in resource availability or prolonged unfavorable temperatures is though not clear. Finally, our study adds to the set of reproductive mechanisms used by cold adapted species and the information presented here contributes to understanding the breadth of Drosophila reproductive ecology.
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Affiliation(s)
- Berta Canal Domenech
- Institute for Evolution and Biodiversity, University of Muenster, Muenster, Germany
- Muenster Graduate School of Evolution, University of Muenster, Muenster, Germany
| | - Aileen Seipelt
- Institute for Evolution and Biodiversity, University of Muenster, Muenster, Germany
| | - Claudia Fricke
- Institute for Evolution and Biodiversity, University of Muenster, Muenster, Germany
- Institute for Zoology, University of Halle-Wittenberg, Halle (Saale), Germany
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17
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Jhan PK, Lee KY. Developing extreme heat acclimation in Bemisia tabaci Mediterranean (Hemiptera: Aleyrodidae). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2022; 110:e21890. [PMID: 35322468 DOI: 10.1002/arch.21890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
Bemisia tabaci Mediterranean (MED) is a highly invasive cryptic species complex found in the world's tropical, subtropical, and temperate regions. It is a severe pest of various crops and a vector of plant pathogenic viruses, particularly geminiviruses. Thermal acclimation of insects is a critical for the survival in unfavorable temperature condition. We observed that great survival rate of B. tabaci MED at the uncontrolled greenhouse which had fluctuating temperature condition (FTC) from 10°C to 60°C in spring and summer season. Our study showed that while B. tabaci MED reared under FTC for 10 weeks from April to June, its survival rate was gradually increased when heat shock was treated 50°C for 0.5 h. In contrast, the same heat shock treatment was lethal in the colony reared under constant temperature condition (CTC) at the controlled insectary. After being acclimated, the lethal temperatures LT50 , LT95 , and LT100 under CTC were 47.7°C, 50.1°C, and 50.3°C, whereas those under FTC were 59.8°C, 62.7°C, and 63.0°C, respectively. In addition, we observed that the transcript levels of three investigated heat shock protein (HSP) genes (hsp20, hsp70, and hsp90) were lower under FTC than under CTC. This study suggests that B. tabaci MED retains high heat acclimation ability, making it tolerant of extreme thermal conditions.
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Affiliation(s)
- Pijush Kanti Jhan
- Division of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, Republic of Korea
- Department of Agriculture, Noakhali Science and Technology University, Noakhali, Bangladesh
| | - Kyeong-Yeoll Lee
- Division of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, Republic of Korea
- Institute of Plant Medicine, Kyungpook National University, Daegu, Republic of Korea
- Institute of Agricultural Science and Technology, Kyungpook National University, Daegu, Republic of Korea
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18
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Wu P, Head ML, Liu C, Haseeb M, Zhang R. The high invasion success of fall armyworm is related to life-history strategies across a range of stressful temperatures. PEST MANAGEMENT SCIENCE 2022; 78:2398-2404. [PMID: 35277917 DOI: 10.1002/ps.6867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 03/03/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Insects living in unfavorably high or low temperatures are predicted to display a fast or slow life-history strategy. Here, we examined life histories of fall armyworm (FAW), a globally important invasive species with a broad ecological niche, at five constant temperatures of 13, 19, 25, 31 and 37°C, to study life-history responses to different temperatures. RESULTS In our experiment, FAW had lower lifetime fecundity at unfavorable temperatures, a finding that is consistent with the idea that FAW can shift resources from reproduction to other functions under stressful conditions-such as heat or cold tolerance. Given the adverse effects of stressful temperatures, life-history strategies arise from individuals having limited remaining resources to allocate towards vital functions like survival or reproduction. Here we show plasticity in life-history strategies adopted at different temperatures. Rather than simply varying along a fast-slow continuum, FAW at unfavorably high temperatures exhibited lower daily fecundity and longer reproductive lifespans, and at unfavorably low temperatures showed a shorter peak in reproduction later in life, compared with FAW at 25°C. Such patterns, if adaptive, could suggest a strategy mitigating reproductive and mortality risk in unfavorable environments, however, this remains to be tested. CONCLUSION Our analysis suggests that the high invasion success of FAW may result from their ability to adjust life-history strategies, across a range of stressful temperatures, in a way that reduces not only mortality, but also fecundity loss. The adoption of such strategies may be instrumental for the global invasion success of FAW. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Pengxiang Wu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Megan L Head
- Division of Ecology and Evolution, Australian National University, Canberra, Australia
| | - Chang Liu
- Entomology and Nematology Department, University of Florida, Gainesville, FL, USA
| | - Muhammad Haseeb
- Center for Biological Control, Florida A&M University, Tallahassee, FL, USA
| | - Runzhi Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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19
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Li GY, Zhang ZQ. Age-specific mortality and fecundity of a spider mite under diet restriction and delayed mating. INSECT SCIENCE 2022; 29:889-899. [PMID: 34264548 DOI: 10.1111/1744-7917.12948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/03/2021] [Accepted: 06/20/2021] [Indexed: 06/13/2023]
Abstract
Numerous experimental life-history studies on aging are mainly baised on two classical models-fruit fly Drosophila melanogaster (Meigen) and nematode Caenorhabditis elegans (Maupas)-with relatively little attention given to other organisms with different life-history characters. Two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) differs from many other arthropods in that the females continue their growth in the early adult stage and can reproduce sexually and asexually. In this study, the influences of dietary restriction and delayed mating on the aging patterns of the spider mite were examined with the prevailing survival and reproduction trade-off hypothesis of aging being tested. Significant sex-specific responses of the spider mites were found. The females showed longevity extension on diet restriction (fasting for 2 days in every 4 days) compared with their counterparts being fed ad libitum, and after delayed mating for 9 days, while the males displayed a decrease in lifespan when experiencing diet restriction but were not significantly influenced by delayed mating. Path analysis was used to investigate the relationship between mite survival and reproduction traits, including longevity, female lifetime reproduction, age at first reproduction, early reproductive efforts and late reproductive efforts, yielding no evidence for trade-offs between these life-history traits. The additive effects of dietary restriction and delayed mating in lifespan extension of female spider mites were confirmed, proving that diet restriction is a robust anti-aging intervention, and that later onset of reproduction can prolong adult lifespan in females.
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Affiliation(s)
- Guang-Yun Li
- Centre for Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Manaaki Whenua-Landcare Research, Auckland, New Zealand
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Zhi-Qiang Zhang
- Centre for Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Manaaki Whenua-Landcare Research, Auckland, New Zealand
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20
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Home range size and habitat quality affect breeding success but not parental investment in barn owl males. Sci Rep 2022; 12:6516. [PMID: 35444196 PMCID: PMC9021228 DOI: 10.1038/s41598-022-10324-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/30/2022] [Indexed: 12/04/2022] Open
Abstract
Life-history theory predicts that parents should balance their limited resources to maximize lifetime fitness, limiting their investment in current reproduction when the fitness value of current progeny is lower than that gained by producing offspring in the future. Here, we examined whether male barn owls (Tyto alba) breeding in low-quality habitats increased their parental effort to successfully complete offspring rearing or limited their investment by paying a fitness cost while saving energy for the future. We equipped 128 males with GPS devices between 2016 and 2020 to collect information on home range size, habitat composition, food provisioning rate to the brood and nightly distances covered. We also recorded nestlings’ growth and survival, as well as males’ body mass variation and future reproductive success. Males living in lower-quality habitats exploited bigger home ranges compared to individuals whose nests were settled in prey-rich habitats. They fed their brood less frequently, while covering longer nightly distance, resulting in a slower growth of late-hatched nestlings and ultimately in a lower fledging success. As males did not differ in body mass variation or future reproductive success our findings suggest that males hunting in home ranges with less prey-rich structures do not jeopardize future reproduction by investing disproportionately larger resources to compensate for their current low home range quality.
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21
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Engell Dahl J, Renault D. Ecophysiological Responses of the Lesser Mealworm Alphitobius diaperinus Exposed to Desiccating Conditions. Front Physiol 2022; 13:826458. [PMID: 35283797 PMCID: PMC8905145 DOI: 10.3389/fphys.2022.826458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/17/2022] [Indexed: 12/05/2022] Open
Abstract
In order to improve predictions of the impacts of climate change on insects, this study aimed to uncover how exposure to dry conditions can affect the biology of the invasive pest beetle Alphitobius diaperinus in terms of longevity, activity, water content, metabolic profiles, and fecundity. We measured desiccation resistance in adults of A. diaperinus by recording the time the beetles could survive desiccation stress. We found that the species was highly desiccation resistant, with about 50% of the insects exposed to desiccation being able to survive for 30 days, and some individuals even survived for up to 50 days at 10% ± 2 relative humidity. There was no evidence of active upregulation of sugars or other metabolites which the beetles could have used to better tolerate desiccation. Food deprivation affected both control (food deprivation, no desiccation) and treatment (food deprivation, desiccation) groups, as their metabolic phenotypes changed similarly after 1 week of treatment. Also, the activity of beetles from both control and desiccation treatments was similarly increased 2 weeks after the experiment had started. Even if there were no changes in the metabolic phenotypes of the insects experiencing desiccating conditions, beetles exposed to desiccation for 8 days had a significantly reduced reproductive output as compared with control insects. This result indicated a physiological cost of drought resistance or repair of stress-incurred damages. The exact nature of that effect (e.g., direct or indirect physiological costs) has not yet been described for tenebrionid beetles and should be investigated in future studies.
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Affiliation(s)
- Julie Engell Dahl
- Université de Rennes, CNRS, EcoBio (Ecosystèmes, Biodiversité, Évolution)—UMR 6553, Rennes, France
- Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - David Renault
- Université de Rennes, CNRS, EcoBio (Ecosystèmes, Biodiversité, Évolution)—UMR 6553, Rennes, France
- Institut Universitaire de France, Paris, France
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22
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Scharf I, Segal D, Bar A, Gottlieb D. Negative effects of fluctuating temperatures around the optimal temperature on reproduction and survival of the red flour beetle. J Therm Biol 2022; 103:103165. [PMID: 35027185 DOI: 10.1016/j.jtherbio.2021.103165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 12/06/2021] [Accepted: 12/16/2021] [Indexed: 10/19/2022]
Abstract
Whereas the vast majority of animals in nature experience daily or seasonal thermal fluctuations, most laboratory experiments use constant temperatures. We examined the effect of fluctuating temperatures on reproduction and survival under starvation, two important components of fitness. We used the red flour beetle as a model organism, which is a significant pest in grain mills around the world. Fluctuations around the optimal temperature were always negative for the adult survival under starvation. The effect of thermal fluctuations on the number of offspring reaching adulthood was negative as well but increased with the extent of exposure. It was the strongest when the adult parents were kept and the offspring were raised under fluctuating temperatures. However, the later the offspring were exposed to fluctuations during their development, the weaker the effect of fluctuating temperatures was. Moreover, raising the parents under fluctuating temperatures but keeping them after pupation at constant temperatures fully alleviated the negative effects of fluctuations on the offspring. Finally, we demonstrate that keeping the parents a few days under fluctuating temperatures is required to induce negative effects on the number of offspring reaching adulthood. Our study disentangles between the effects of thermal fluctuations experienced during the parental and offspring stage thus contributing to the ongoing research of insects under fluctuating temperatures.
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Affiliation(s)
- Inon Scharf
- School of Zoology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
| | - Daniella Segal
- School of Zoology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Adi Bar
- School of Zoology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Daphna Gottlieb
- Department of Food Science, Institute of Post-Harvest and Food Science, The Volcani Center, ARO, Israel
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23
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Denny MW, Dowd WW. Elevated Salinity Rapidly Confers Cross-Tolerance to High Temperature in a Splash-Pool Copepod. Integr Org Biol 2022; 4:obac037. [PMID: 36003414 PMCID: PMC9394168 DOI: 10.1093/iob/obac037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/07/2022] [Accepted: 08/04/2022] [Indexed: 12/11/2022] Open
Abstract
Accurate forecasting of organismal responses to climate change requires a deep mechanistic understanding of how physiology responds to present-day variation in the physical environment. However, the road to physiological enlightenment is fraught with complications: predictable environmental fluctuations of any single factor are often accompanied by substantial stochastic variation and rare extreme events, and several factors may interact to affect physiology. Lacking sufficient knowledge of temporal patterns of co-variation in multiple environmental stressors, biologists struggle to design and implement realistic and relevant laboratory experiments. In this study, we directly address these issues, using measurements of the thermal tolerance of freshly collected animals and long-term field records of environmental conditions to explore how the splash-pool copepod Tigriopus californicus adjusts its physiology as its environment changes. Salinity and daily maximum temperature-two dominant environmental stressors experienced by T. californicus-are extraordinarily variable and unpredictable more than 2-3 days in advance. However, they substantially co-vary such that when temperature is high salinity is also likely to be high. Copepods appear to take advantage of this correlation: median lethal temperature of field-collected copepods increases by 7.5°C over a roughly 120 parts-per-thousand range of ambient salinity. Complementary laboratory experiments show that exposure to a single sublethal thermal event or to an abrupt shift in salinity also elicits rapid augmentation of heat tolerance via physiological plasticity, although the effect of salinity dwarfs that of temperature. These results suggest that T. californicus's physiology keeps pace with the rapid, unpredictable fluctuations of its hypervariable physical environment by responding to the cues provided by recent sublethal stress and, more importantly, by leveraging the mechanistic cross-talk between responses to salinity and heat stress.
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Affiliation(s)
| | - W Wesley Dowd
- School of Biological Sciences, Washington State University, 100 Dairy Road, Eastlick G81, Pullman, WA99164, USA
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24
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Fitness Analysis and Transcriptome Profiling Following Repeated Mild Heat Stress of Varying Frequency in Drosophila melanogaster Females. BIOLOGY 2021; 10:biology10121323. [PMID: 34943239 PMCID: PMC8698867 DOI: 10.3390/biology10121323] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary We studied the effect of mild heat stress (38 °C, 1 h) occurring once a day or once a week on D. melanogaster fertility, longevity, body composition metabolism and differential gene expression in fat body and adjacent tissues. Weekly stress in the first two weeks did not affect longevity but caused a decrease in fat content and an increase in the total level of fertility. Daily stress caused a significant longevity, fertility and fat content decrease, but an increase in carbohydrate levels compared with the control group. These data agree well with the results of transcriptome analysis, which demonstrated significant changes in expression levels of genes involved in proteolysis/digestion following daily stress. Heat shock protein 23 and stress-inducible humoral factor Turandot gene network are also involved. It is notable that daily and weekly heat stress resulted in different changes in metabolism, fitness and differential gene expression. Abstract Understanding how repeated stress affects metabolic and physiological functions in the long run is of crucial importance for evaluating anthropogenic pressure on the environment. We investigated fertility, longevity and metabolism in D. melanogaster females exposed to short-term heat stress (38 °C, 1 h) repeated daily or weekly. Daily stress was shown to cause a significant decrease in both fertility and longevity, as well as in body mass and triglyceride (fat) content, but a significant increase in trehalose and glucose content. Weekly stress did not affect longevity and carbohydrate metabolism but resulted in a significant decrease in body mass and fat content. Weekly stress did not affect the total level of fertility, despite sharp fertility drops on the exact days of stressing. However, stressing insects weekly, only in the first two weeks after eclosion, caused a significant increase in the total level of fertility. The analysis of differentially expressed genes in the fat bodies and adjacent tissues of researched groups with the use of RNA-Seq profiling revealed changes in signal pathways related to proteolysis/digestion, heat shock protein 23, and in the tightly linked stress-inducible humoral factor Turandot gene network.
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25
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O'Neill E, Davis HE, MacMillan HA. A lack of repeatability creates the illusion of a trade-off between basal and plastic cold tolerance. Proc Biol Sci 2021; 288:20212121. [PMID: 34875191 PMCID: PMC8651406 DOI: 10.1098/rspb.2021.2121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/17/2021] [Indexed: 01/10/2023] Open
Abstract
The thermotolerance-plasticity trade-off hypothesis predicts that ectotherms with greater basal thermal tolerance have a lower acclimation capacity. This hypothesis has been tested at both high and low temperatures but the results often conflict. If basal tolerance constrains plasticity (e.g. through shared mechanisms that create physiological constraints), it should be evident at the level of the individual, provided the trait measured is repeatable. Here, we used chill-coma onset temperature and chill-coma recovery time (CCO and CCRT; non-lethal thermal limits) to quantify cold tolerance of Drosophila melanogaster across two trials (pre- and post-acclimation). Cold acclimation improved cold tolerance, as expected, but individual measurements of CCO and CCRT in non-acclimated flies were not (or only slightly) repeatable. Surprisingly, however, there was still a strong correlation between basal tolerance and plasticity in cold-acclimated flies. We argue that this relationship is a statistical artefact (specifically, a manifestation of regression to the mean; RTM) and does not reflect a true trade-off or physiological constraint. Thermal tolerance trade-off patterns in previous studies that used similar methodology are thus likely to be impacted by RTM. Moving forward, controlling and/or correcting for RTM effects is critical to determining whether such a trade-off or physiological constraint exists.
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Affiliation(s)
- Erica O'Neill
- Department of Biology, Carleton University, ON K1S 5B6, Canada
| | - Hannah E. Davis
- Department of Biology, Carleton University, ON K1S 5B6, Canada
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Neu A, Fischer K. Indications for rapid evolution of trait means and thermal plasticity in range-expanding populations of a butterfly. J Evol Biol 2021; 35:124-133. [PMID: 34860427 DOI: 10.1111/jeb.13969] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 01/03/2023]
Abstract
Currently, poleward range expansions are observed in many taxa, often in response to anthropogenic climate change. At the expanding front, populations likely face cooler and more variable temperature conditions, imposing thermal selection. This may result in changes in trait means or plasticity, the relative contribution of which is not well understood. We, here, investigate evolutionary change in range-expanding populations of the butterfly Pieris mannii, by comparing populations from the core and the newly established northern range under laboratory conditions. We observed both changes in trait means and in thermal reaction norms. Range-expanding populations showed a more rapid development, potentially indicative of counter-gradient variation and an increased cold tolerance compared with core populations. Genotype-environment interactions prevailed in all associated traits, such that the above differences were restricted to cooler environmental conditions. In range-expanding populations, plasticity was decreased in developmental traits enabling relatively rapid growth even under cooler conditions but increased in cold tolerance arguably promoting higher activity under thermally challenging conditions. Notably, these changes must have occurred within a time period of ca. 10 years only. Our results suggest, in line with contemporary theory, that the evolution of plasticity may play a hitherto underestimated role for adaptation to climatic variation. However, rather than generally increased or decreased levels of plasticity, our results indicate fine-tuned, trait-specific evolutionary responses to increase fitness in novel environments.
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Affiliation(s)
- Anika Neu
- Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
| | - Klaus Fischer
- Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
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Earls KN, Porter MS, Rinehart JP, Greenlee KJ. Thermal history of alfalfa leafcutting bees affects nesting and diapause incidence. J Exp Biol 2021; 224:272604. [PMID: 34694400 DOI: 10.1242/jeb.243242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/20/2021] [Indexed: 11/20/2022]
Abstract
Variable spring temperatures may expose developing insects to sublethal conditions, resulting in long-term consequences. The alfalfa leafcutting bee, Megachile rotundata, overwinters as a prepupa inside a brood cell, resuming development in spring. During these immobile stages of development, bees must tolerate unfavorable temperatures. In this study, we tested how exposure to low temperature stress during development affects subsequent reproduction and characteristics of the F1 generation. Developing male and female M. rotundata were exposed to either constant (6°C) or fluctuating (1 h day-1 at 20°C) low temperature stress for 1 week, during the pupal stage, to mimic a spring cold snap. Treated adults were marked and released into field cages, and reproductive output was compared with that of untreated control bees. Exposure to low temperatures during the pupal stage had mixed effects on reproduction and offspring characteristics. Females treated with fluctuating low temperatures were more likely to nest compared with control bees or those exposed to constant low temperature stress. Sublethal effects may have contributed to low nesting rates of bees exposed to constant low temperatures. Females from that group that were able to nest had fewer, larger offspring with high viability, suggesting a trade-off. Interestingly, offspring of bees exposed to fluctuating low temperatures were more likely to enter diapause, indicating that thermal history of parents, even during development, is an important factor in diapause determination.
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Affiliation(s)
- Kayla N Earls
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
| | - Monique S Porter
- Department of Biochemistry and Molecular Biology, Penn State University, State College, PA 16801, USA
| | - Joseph P Rinehart
- Edward T. Schafer Agricultural Research Center, U.S. Department of Agriculture/Agricultural Research Station, Fargo, ND 58102, USA
| | - Kendra J Greenlee
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
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Xu H, Niu C. Effect of maternal ammonia stress on population dynamics of the rotifer Brachionus calyciflorus offspring. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 239:105960. [PMID: 34500379 DOI: 10.1016/j.aquatox.2021.105960] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Maternal effects play important roles in phenotypic variations among individuals and are thus considered to regulate population performance in responses to environmental stress. High ammonia levels are known to suppress population growth of the rotifer Brachionus calyciflorus. However, it remains unclear whether maternal environmental ammonia stress influences the offspring phenotypic variation and, if so, how it affects the offspring population dynamics in the rotifer. The present work examined variations in life history, morphology, feeding and digestive activities of B. calyciflorus offspring affected by maternal ammonia stress and the effect of the above variations on offspring population dynamics. We observed increased fitness in the offspring population affected by the cumulative maternal effect. There was a trade-off between offspring (F1) survival and reproductive investment under maternal (F0) ammonia stress. Population growth of the offspring possibly increased via decreasing body size and posterolateral spine length while enhancing cellulase activity. Moreover, the absence of the posterolateral spine of the rotifer was a sensitive response to maternal ammonia stress. These findings underscore maternal environmental stress as an important source of phenotypic variations and highlight these multiple responses work together to affect population dynamics.
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Affiliation(s)
- Huanhuan Xu
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China
| | - Cuijuan Niu
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing 100875, China.
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Effects of Constant versus Fluctuating Temperatures on Fitness Indicators of the Aphid Dysaphis plantaginea and the Parasitoid Aphidius matricariae. INSECTS 2021; 12:insects12100855. [PMID: 34680624 PMCID: PMC8539785 DOI: 10.3390/insects12100855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 11/29/2022]
Abstract
Simple Summary Like all organisms, insects encounter temperatures that fluctuate on different time scales: within a day, between days, or throughout the seasons. However, most studies on the impact of temperature on insect physiology, behavior, morphology, or ecology have focused on constant temperatures tested in the laboratory. In our study, we wanted to know if fluctuating temperatures during the day (7–17 °C, average 12 °C) can affect insects differently compared to a constant temperature of 12 °C. We used, as a model, the apple aphid Dysaphis plantaginea, a major threat to apple orchards worldwide, and its parasitoid Aphidius matricariae, which is used in biological control. We found that many traits—but not all—were affected. In particular, the fluctuating thermal regime reduced the development time of aphids and parasitoids, improved the rate of parasitism, and tended (albeit slightly) to increase the longevity of both species. In contrast, we did not find strong effects on morphological traits. Our results can be used to better predict how these agronomically important insects behave in orchards, how ecologically-relevant fluctuating temperatures affect host–parasitoid relationships, and ultimately what the implications are in the context of climate change and biological control. Abstract Testing fluctuating rather than constant temperatures is likely to produce more realistic datasets, as they are ecologically more similar to what arthropods experience in nature. In this study, we evaluated the impact of three constant thermal regimes (7, 12, and 17 °C) and one fluctuating thermal regime (7–17 °C with a mean of 12 °C) on fitness indicators in the rosy apple aphid Dysaphis plantaginea, a major pest of apple orchards, and the parasitoid Aphidius matricariae, one of its natural enemies used in mass release biological control strategies. For some—but not all—traits, the fluctuating 7–17 °C regime was beneficial to insects compared to the constant 12 °C regime. Both aphid and parasitoid development times were shortened under the fluctuating regime, and there was a clear trend towards an increased longevity under the fluctuating regime. The fecundity, mass, and size were affected by the mean temperature, but only the mass of aphids was higher at 7–17 °C than at a constant 12 °C. Parasitism rates, but not emergence rates, were higher under the fluctuating regime than under the constant 12 °C regime. Results are discussed within the framework of insect thermal ecology and Jensen’s inequality. We conclude that incorporating thermal fluctuations in ecological studies could allow for the more accurate consideration of how temperature affects host–parasitoid interactions and insect responses to temperature change over time.
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Pottier P, Burke S, Drobniak SM, Lagisz M, Nakagawa S. Sexual (in)equality? A meta‐analysis of sex differences in thermal acclimation capacity across ectotherms. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13899] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Patrice Pottier
- Ecology & Evolution Research Centre School of Biological, Earth and Environmental Sciences The University of New South Wales Sydney NSW Australia
| | - Samantha Burke
- Ecology & Evolution Research Centre School of Biological, Earth and Environmental Sciences The University of New South Wales Sydney NSW Australia
| | - Szymon M. Drobniak
- Ecology & Evolution Research Centre School of Biological, Earth and Environmental Sciences The University of New South Wales Sydney NSW Australia
- Institute of Environmental Sciences Jagiellonian University Kraków Poland
| | - Malgorzata Lagisz
- Ecology & Evolution Research Centre School of Biological, Earth and Environmental Sciences The University of New South Wales Sydney NSW Australia
| | - Shinichi Nakagawa
- Ecology & Evolution Research Centre School of Biological, Earth and Environmental Sciences The University of New South Wales Sydney NSW Australia
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Chipchase KM, Enders AM, Jacobs EG, Hughes MR, Killian KA. Effect of a single cold stress exposure on the reproductive behavior of male crickets. JOURNAL OF INSECT PHYSIOLOGY 2021; 133:104287. [PMID: 34302838 DOI: 10.1016/j.jinsphys.2021.104287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/17/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Cold stress is an important abiotic factor that can impact insect physiology, behavior, and overall fitness. Upon exposure to cold temperature, many insects enter a reversible state of immobility called chill coma. If the cold stress is brief and mild enough, insects can recover and regain full mobility upon return to warmer temperatures. However, the long-term impact of sublethal cold stress on insect behavior has been understudied. Here, sexually naïve adult male Acheta domesticus crickets were exposed to a single 0 °C cold stress for 6 h. One week later, the ability of these males to mate with a female was examined. For mating trials, a cold stressed male cricket was paired with a non-cold stressed, control female. Control pairs were comprised of a non-cold stressed control male and control female. Cold exposed males were less successful at mating than control males because most did not carry a spermatophore at the time of their mating trials. However, when these cold stressed males were allowed 1 h of chemosensory contact with a female, most produced a spermatophore. Males that produced spermatophores were given the opportunity to mate once with a female, and stressed males that successfully mated sired as many offspring as did control males. However, our results support that a single cold stress exposure can negatively impact the reproductive fitness of male crickets since it reduced their capacity to carry spermatophores and, as a consequence, to attract females.
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Affiliation(s)
- Kathryn M Chipchase
- Department of Biology, 258 Pearson Hall, Miami University, Oxford, OH 45056, USA
| | - Alexa M Enders
- Department of Biology, 258 Pearson Hall, Miami University, Oxford, OH 45056, USA
| | - Elizabeth G Jacobs
- Department of Biology, 258 Pearson Hall, Miami University, Oxford, OH 45056, USA
| | - Michael R Hughes
- Department of Biology, 258 Pearson Hall, Miami University, Oxford, OH 45056, USA
| | - Kathleen A Killian
- Department of Biology, 258 Pearson Hall, Miami University, Oxford, OH 45056, USA.
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Harms NE, Knight IA, Pratt PD, Reddy AM, Mukherjee A, Gong P, Coetzee J, Raghu S, Diaz R. Climate Mismatch between Introduced Biological Control Agents and Their Invasive Host Plants: Improving Biological Control of Tropical Weeds in Temperate Regions. INSECTS 2021; 12:insects12060549. [PMID: 34204761 PMCID: PMC8231509 DOI: 10.3390/insects12060549] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/20/2021] [Accepted: 06/07/2021] [Indexed: 12/15/2022]
Abstract
Simple Summary Mismatched distributions between biological control agents and their host plants occur for a variety of reasons but are often linked to climate, specifically differences in their low-temperature tolerances. How to measure and use low-temperature tolerances of control agents to inform agent prioritization, selection for redistribution, or predict efficacy is vitally important, but has not been previously synthesized in a single source. We discuss causes of climate mismatches between agents and target weeds, the traditional and non-traditional approaches that could be used to decrease the degree of mismatch and improve control, and regulatory issues to consider when taking such approaches. We also discuss the variety of cold tolerance metrics, their measurement and ecological value, and the types of modeling that can be carried out to improve predictions about potential distributions of agents. We also briefly touch on molecular bases for cold tolerance and opportunities for improving cold tolerance of agents using modern molecular tools. Abstract Many weed biological control programs suffer from large-scale spatial variation in success due to restricted distributions or abundances of agents in temperate climates. For some of the world’s worst aquatic weeds, agents are established but overwintering conditions limit their survival in higher latitudes or elevations. The resulting need is for new or improved site- or region-specific biological control tools. Here, we review this challenge with a focus on low-temperature limitations of agents and propose a roadmap for improving success. Investigations across spatial scales, from global (e.g., foreign exploration), to local (selective breeding), to individual organisms (molecular modification), are discussed. A combination of traditional (foreign) and non-traditional (introduced range) exploration may lead to the discovery and development of better-adapted agent genotypes. A multivariate approach using ecologically relevant metrics to quantify and compare cold tolerance among agent populations is likely required. These data can be used to inform environmental niche modeling combined with mechanistic modeling of species’ fundamental climate niches and life histories to predict where, when, and at what abundance agents will occur. Finally, synthetic and systems biology approaches in conjunction with advanced modern genomics, gene silencing and gene editing technologies may be used to identify and alter the expression of genes enhancing cold tolerance, but this technology in the context of weed biological control has not been fully explored.
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Affiliation(s)
- Nathan E. Harms
- Aquatic Ecology and Invasive Species Branch, Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS 39180, USA;
- Correspondence: ; Tel.: +01-601-634-2976
| | - Ian A. Knight
- Aquatic Ecology and Invasive Species Branch, Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS 39180, USA;
| | - Paul D. Pratt
- Invasive Species and Pollinator Health Research Unit, United States Department of Agriculture, Agricultural Research Service, Albany, CA 94710, USA; (P.D.P.); (A.M.R.)
| | - Angelica M. Reddy
- Invasive Species and Pollinator Health Research Unit, United States Department of Agriculture, Agricultural Research Service, Albany, CA 94710, USA; (P.D.P.); (A.M.R.)
| | | | - Ping Gong
- Environmental Processes Branch, Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS 39180, USA;
| | - Julie Coetzee
- Centre for Biological Control, Botany Department, Rhodes University, Grahamstown 6140, South Africa;
| | - S. Raghu
- CSIRO Health & Biosecurity, Brisbane 4001, Australia;
| | - Rodrigo Diaz
- Department of Entomology, Louisiana State University, Baton Rouge, LA 70803, USA;
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White MA, Chen DS, Wolfner MF. She's got nerve: roles of octopamine in insect female reproduction. J Neurogenet 2021; 35:132-153. [PMID: 33909537 DOI: 10.1080/01677063.2020.1868457] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The biogenic monoamine octopamine (OA) is a crucial regulator of invertebrate physiology and behavior. Since its discovery in the 1950s in octopus salivary glands, OA has been implicated in many biological processes among diverse invertebrate lineages. It can act as a neurotransmitter, neuromodulator and neurohormone in a variety of biological contexts, and can mediate processes including feeding, sleep, locomotion, flight, learning, memory, and aggression. Here, we focus on the roles of OA in female reproduction in insects. OA is produced in the octopaminergic neurons that innervate the female reproductive tract (RT). It exerts its effects by binding to receptors throughout the RT to generate tissue- and region-specific outcomes. OA signaling regulates oogenesis, ovulation, sperm storage, and reproductive behaviors in response to the female's internal state and external conditions. Mating profoundly changes a female's physiology and behavior. The female's OA signaling system interacts with, and is modified by, male molecules transferred during mating to elicit a subset of the post-mating changes. Since the role of OA in female reproduction is best characterized in the fruit fly Drosophila melanogaster, we focus our discussion on this species but include discussion of OA in other insect species whenever relevant. We conclude by proposing areas for future research to further the understanding of OA's involvement in female reproduction in insects.
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Affiliation(s)
- Melissa A White
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Dawn S Chen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
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Rau V, Korb J. The effect of environmental stress on ageing in a termite species with low social complexity. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190739. [PMID: 33678015 PMCID: PMC7938165 DOI: 10.1098/rstb.2019.0739] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2020] [Indexed: 01/04/2023] Open
Abstract
Social insects seem to have overcome the almost universal trade-off between fecundity and longevity as queens can be highly fecund and at the same time reach lifespans of decades. By contrast, their non-reproducing workers are often short-lived. One hypothesis to explain the long lifespan of queens is that they are better protected against stress than their workers. However, evidence is controversial and experimental studies are scarce. We aimed at manipulating environmental stress and ageing by exposing colonies of the less-socially complex termite Cryptotermes secundus to temperature regimes that differed in variance. In contrast with expectation, constant temperatures imposed more stress than variable temperatures. Survival of queens and workers as well as queens' fecundity were partly reduced under constant conditions and both castes showed signs of ageing in the transcriptome signature under constant conditions. There was a clear oxidative stress defence signal under constant conditions that was, surprisingly, stronger for workers than queens. We discuss how our results relate to social complexity. We argue that workers that are totipotent to become reproductives, like in C. secundus, should invest more in 'anti-ageing' mechanisms than sterile workers because the former can still reproduce and have not reached maturity yet. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'
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Affiliation(s)
- Veronika Rau
- Evolutionary Biology and Ecology, University of Freiburg, Hauptstrasse 1, 79104 Freiburg (Brsg.), Germany
| | - Judith Korb
- Evolutionary Biology and Ecology, University of Freiburg, Hauptstrasse 1, 79104 Freiburg (Brsg.), Germany
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35
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Littler AS, Garcia MJ, Teets NM. Laboratory diet influences cold tolerance in a genotype-dependent manner in Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2021; 257:110948. [PMID: 33819503 DOI: 10.1016/j.cbpa.2021.110948] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/08/2021] [Accepted: 03/30/2021] [Indexed: 11/25/2022]
Abstract
Cold stress can reduce insect fitness and is an important determinant of species distributions and responses to climate change. Cold tolerance is influenced by genotype and environmental conditions, with factors such as day length and temperature having a particularly strong influence. Recent studies also indicate that diet impacts cold tolerance, but it is unclear whether diet-mediated shifts in cold tolerance are consistent across distinct genotypes. The goal of this study was to determine the extent to which commonly used artificial diets influence cold tolerance in Drosophila melanogaster, and whether these effects are consistent across genetically distinct lines. Specifically, we tested the impact of different fly diets on 1) ability to survive cold stress, 2) critical thermal minimum (CTmin), and 3) the ability to maintain reproduction after cold stress. Experiments were conducted across six isogenic lines from the Drosophila Genetic Reference Panel, and these lines were reared on different fly diets. Cold shock survival, CTmin, and reproductive output pre- and post-cold exposure varied considerably across diet and genotype combinations, suggesting strong genotype by environment interactions shape nutritionally mediated changes in cold tolerance. For example, in some lines cold shock survival remained consistently high or low across diets, while in others cold shock survival ranged from 5% to 75% depending on diet. Ultimately, these results add to a growing literature that cold tolerance is shaped by complex interactions between genotype and environment and inform practical considerations when selecting a laboratory diet for thermal tolerance experiments in Drosophila.
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Affiliation(s)
- Aerianna S Littler
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington 40546, United States of America
| | - Mark J Garcia
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington 40546, United States of America; Department of Biology, College of Arts & Sciences, University of Louisiana at Lafayette, Lafayette, LA 70506, United States of America.
| | - Nicholas M Teets
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington 40546, United States of America
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Neu A, Beaulieu M, Fischer K. Limits on optimal decision making: host plant selection is not altered by high temperatures in a butterfly. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Cheslock A, Andersen MK, MacMillan HA. Thermal acclimation alters Na +/K +-ATPase activity in a tissue-specific manner in Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2021; 256:110934. [PMID: 33684554 DOI: 10.1016/j.cbpa.2021.110934] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 10/22/2022]
Abstract
Insects, like the model species Drosophila melanogaster, lose neuromuscular function and enter a state of paralysis (chill coma) at a population- and species-specific low temperature threshold that is decreased by cold acclimation. Entry into this coma is related to a spreading depolarization in the central nervous system, while recovery involves restoration of electrochemical gradients across muscle cell membranes. The Na+/K+-ATPase helps maintain ion balance and membrane potential in both the brain and hemolymph (surrounding muscles), and changes in thermal tolerance traits have therefore been hypothesized to be closely linked to variation in the expression and/or activity of this pump in multiple tissues. Here, we tested this hypothesis by measuring activity and thermal sensitivity of the Na+/K+-ATPase at the tagma-specific level (head, thorax and abdomen) in warm- (25 °C) and cold-acclimated (15 °C) flies by measuring Na+/K+-ATPase activity at 15, 20, and 25 °C. We relate differences in pump activity to differences in chill coma temperature, spreading depolarization temperature, and thermal dependence of muscle cell polarization. Differences in pump activity and thermal sensitivity induced by cold acclimation varied in a tissue-specific manner: While thermal sensitivity remained unchanged, cold-acclimated flies had decreased Na+/K+-ATPase activity in the thorax (mainly muscle) and head (mainly composed of brain). We argue that these changes may assist in maintenance of K+ homeostasis and membrane potential across muscle membranes, and discuss how reduced Na+/K+-ATPase activity in the brain may counterintuitively help insects delay coma onset in the cold.
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Locally adapted gut microbiomes mediate host stress tolerance. ISME JOURNAL 2021; 15:2401-2414. [PMID: 33658622 PMCID: PMC8319338 DOI: 10.1038/s41396-021-00940-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 01/29/2021] [Accepted: 02/11/2021] [Indexed: 01/04/2023]
Abstract
While evidence for the role of the microbiome in shaping host stress tolerance is becoming well-established, to what extent this depends on the interaction between the host and its local microbiome is less clear. Therefore, we investigated whether locally adapted gut microbiomes affect host stress tolerance. In the water flea Daphnia magna, we studied if the host performs better when receiving a microbiome from their source region than from another region when facing a stressful condition, more in particular exposure to the toxic cyanobacteria Microcystis aeruginosa. Therefore, a reciprocal transplant experiment was performed in which recipient, germ-free D. magna, isolated from different ponds, received a donor microbiome from sympatric or allopatric D. magna that were pre-exposed to toxic cyanobacteria or not. We tested for effects on host life history traits and gut microbiome composition. Our data indicate that Daphnia interact with particular microbial strains mediating local adaptation in host stress tolerance. Most recipient D. magna individuals performed better when inoculated with sympatric than with allopatric microbiomes. This effect was most pronounced when the donors were pre-exposed to the toxic cyanobacteria, but this effect was also pond and genotype dependent. We discuss how this host fitness benefit is associated with microbiome diversity patterns.
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Sokolova I. Bioenergetics in environmental adaptation and stress tolerance of aquatic ectotherms: linking physiology and ecology in a multi-stressor landscape. J Exp Biol 2021; 224:224/Suppl_1/jeb236802. [PMID: 33627464 DOI: 10.1242/jeb.236802] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Energy metabolism (encompassing energy assimilation, conversion and utilization) plays a central role in all life processes and serves as a link between the organismal physiology, behavior and ecology. Metabolic rates define the physiological and life-history performance of an organism, have direct implications for Darwinian fitness, and affect ecologically relevant traits such as the trophic relationships, productivity and ecosystem engineering functions. Natural environmental variability and anthropogenic changes expose aquatic ectotherms to multiple stressors that can strongly affect their energy metabolism and thereby modify the energy fluxes within an organism and in the ecosystem. This Review focuses on the role of bioenergetic disturbances and metabolic adjustments in responses to multiple stressors (especially the general cellular stress response), provides examples of the effects of multiple stressors on energy intake, assimilation, conversion and expenditure, and discusses the conceptual and quantitative approaches to identify and mechanistically explain the energy trade-offs in multiple stressor scenarios, and link the cellular and organismal bioenergetics with fitness, productivity and/or ecological functions of aquatic ectotherms.
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Affiliation(s)
- Inna Sokolova
- Marine Biology Department, Institute of Biological Sciences, University of Rostock, 18059 Rostock, Germany .,Department of Maritime Systems, Interdisciplinary Faculty, University of Rostock, 18059 Rostock, Germany
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40
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Thermal adaptations of adults and eggs in the Arctic seed bug Nysius groenlandicus (Insecta: Hemiptera) from South Greenland. Polar Biol 2021. [DOI: 10.1007/s00300-021-02807-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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41
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The Influence of Socioeconomic Factors on Households’ Vulnerability to Climate Change in Semiarid Towns of Mopani, South Africa. CLIMATE 2021. [DOI: 10.3390/cli9010013] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The changing climate and its current rate, frequency, as well as its life-threatening impacts are undoubtedly abnormal and globally worrisome. Its effects are expected to be severely different across segments of the society. It is disposed to leaving no facet of human endeavor immune, particularly in vulnerable cities of developing countries where there is dearth of empirical studies. For the context-specific nature of climate change impacts and place-based character of vulnerability, this study explores the influence of socioeconomic attributes on household vulnerability in Mopani District northeast of South Africa to provide basis for targeting, formulating, evaluating, and monitoring adaptation policies, programs, and projects. The study adopted a multistage random sampling to draw 500 households from six towns in Mopani District, Limpopo Province. Mixed methods approach was used for data collection, while Household Vulnerability Index (HVI) was estimated using principal component analysis and regressed with socioeconomic attributes. The study reveals that climate is changing with high HVI across selected towns. It further depicted that age and marital status have positive and significant relationships with HVI, while gender and educational levels have inverse and significant relationship with HVI in some towns. The study recommends the need for municipalities to partner with private sector to empower household and mainstream micro level coping strategies in urban planning across the district.
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Ritchie MW, Dawson JW, MacMillan HA. A simple and dynamic thermal gradient device for measuring thermal performance in small ectotherms. CURRENT RESEARCH IN INSECT SCIENCE 2021; 1:100005. [PMID: 36003593 PMCID: PMC9387499 DOI: 10.1016/j.cris.2020.100005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 10/27/2022]
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Garcia MJ, Littler AS, Sriram A, Teets NM. Distinct cold tolerance traits independently vary across genotypes in Drosophila melanogaster. Evolution 2020; 74:1437-1450. [PMID: 32463118 DOI: 10.1111/evo.14025] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 05/25/2020] [Indexed: 12/27/2022]
Abstract
Cold tolerance, the ability to cope with low temperature stress, is a critical adaptation in thermally variable environments. An individual's cold tolerance comprises several traits including minimum temperatures for growth and activity, ability to survive severe cold, and ability to resume normal function after cold subsides. Across species, these traits are correlated, suggesting they were shaped by shared evolutionary processes or possibly share physiological mechanisms. However, the extent to which cold tolerance traits and their associated mechanisms covary within populations has not been assessed. We measured five cold tolerance traits-critical thermal minimum, chill coma recovery, short- and long-term cold tolerance, and cold-induced changes in locomotor behavior-along with cold-induced expression of two genes with possible roles in cold tolerance (heat shock protein 70 and frost)-across 12 lines of Drosophila melanogaster derived from a single population. We observed significant genetic variation in all traits, but few were correlated across genotypes, and these correlations were sex-specific. Further, cold-induced gene expression varied by genotype, but there was no evidence supporting our hypothesis that cold-hardy lines would have either higher baseline expression or induction of stress genes. These results suggest cold tolerance traits possess unique mechanisms and have the capacity to evolve independently.
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Affiliation(s)
- Mark J Garcia
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, 40546
| | - Aerianna S Littler
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, 40546
| | - Aditya Sriram
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, 40546
| | - Nicholas M Teets
- Department of Entomology, College of Agriculture, Food, and Environment, University of Kentucky, Lexington, Kentucky, 40546
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El-Saadi MI, Ritchie MW, Davis HE, MacMillan HA. Warm periods in repeated cold stresses protect Drosophila against ionoregulatory collapse, chilling injury, and reproductive deficits. JOURNAL OF INSECT PHYSIOLOGY 2020; 123:104055. [PMID: 32380094 DOI: 10.1016/j.jinsphys.2020.104055] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
In some insects, repeated cold stresses, characterized by warm periods that interrupt a sustained cold period, have been found to yield survival benefits over continuous cold stresses, but at the cost of reproduction. During a cold stress, chill susceptible insects like Drosophila melanogaster suffer from a loss of ion and water balance, and the current model of recovery from chilling posits that re-establishment of ion homeostasis begins upon return to a warm environment, but that it takes minutes to hours for an insect to fully restore homeostasis. Following this ionoregulatory model of chill coma recovery, we predicted that the longer the duration of the warm periods between cold stresses, the better a fly will endure a subsequent chill coma event and the more likely they will be to survive. We also predicted, however, that this recovery may lead to reduced fecundity, possibly due to allocation of energy reserves away from reproduction. Here, female D.melanogaster were treated to a long continuous cold stress (25 h at 0 °C), or experienced the same total time in the cold with repeated short (15 min), or long (120 min) breaks at 22 °C. We found that warm periods in general improved survival outcomes, and individuals that recovered for more time in between cold periods had significantly lower rates of injury, faster recovery from chill coma, and produced greater, rather than fewer, offspring. These improvements in chill tolerance were associated with mitigation of ionoregulatory collapse, as flies that experienced either short or long warm periods better maintained low hemolymph [K+]. Thus, warm periods that interrupt cold periods improve cold tolerance and fertility in D. melanogaster females relative to a single sustained cold stress, potentially because this time allows for recovery of ion and water homeostasis.
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Affiliation(s)
| | | | - Hannah E Davis
- Department of Biology, Carleton University, Ottawa K1S 5B6, Canada
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Teets NM, Gantz JD, Kawarasaki Y. Rapid cold hardening: ecological relevance, physiological mechanisms and new perspectives. ACTA ACUST UNITED AC 2020; 223:223/3/jeb203448. [PMID: 32051174 DOI: 10.1242/jeb.203448] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rapid cold hardening (RCH) is a type of phenotypic plasticity that allows ectotherms to quickly enhance cold tolerance in response to brief chilling (lasting minutes to hours). In this Review, we summarize the current state of knowledge of this important phenotype and provide new directions for research. As one of the fastest adaptive responses to temperature known, RCH allows ectotherms to cope with sudden cold snaps and to optimize their performance during diurnal cooling cycles. RCH and similar phenotypes have been observed across a diversity of ectotherms, including crustaceans, terrestrial arthropods, amphibians, reptiles, and fish. In addition to its well-defined role in enhancing survival to extreme cold, RCH also protects against nonlethal cold injury by preserving essential functions following cold stress, such as locomotion, reproduction, and energy balance. The capacity for RCH varies across species and across genotypes of the same species, indicating that RCH can be shaped by selection and is likely favored in thermally variable environments. Mechanistically, RCH is distinct from other rapid stress responses in that it typically does not involve synthesis of new gene products; rather, the existing cellular machinery regulates RCH through post-translational signaling mechanisms. However, the protective mechanisms that enhance cold hardiness are largely unknown. We provide evidence that RCH can be induced by multiple triggers in addition to low temperature, and that rapidly induced tolerance and cross-tolerance to a variety of environmental stressors may be a general feature of stress responses that requires further investigation.
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Affiliation(s)
- Nicholas M Teets
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA
| | - J D Gantz
- Biology Department, Hendrix College, Conway, AK 72032, USA
| | - Yuta Kawarasaki
- Department of Biology, Gustavus Adolphus College, Saint Peter, MN 56082, USA
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Nadeau EAW, Teets NM. Evidence for a rapid cold hardening response in cultured Drosophila S2 cells. ACTA ACUST UNITED AC 2020; 223:jeb.212613. [PMID: 31862846 DOI: 10.1242/jeb.212613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/18/2019] [Indexed: 11/20/2022]
Abstract
The ability to quickly respond to changes in environmental temperature is critical for organisms living in thermally variable environments. To cope with sudden drops in temperature, insects and other ectotherms are capable of rapid cold hardening (RCH), in which mild chilling significantly enhances cold tolerance within minutes. While the ecological significance of RCH is well established, the mechanisms underlying RCH are still poorly understood. Previous work has demonstrated that RCH is regulated at the cellular level by post-translational signaling mechanisms, and here we tested the hypothesis that cultured cells are capable of RCH. A 2 h cold shock at -8°C significantly reduced the metabolic viability of Drosophila S2 cells, but pre-treatment with RCH at 4°C for 2 h prevented this decrease in viability. Thus, S2 cells are capable of RCH in a similar manner to whole insects and provide a new system for investigating the cell biology of RCH.
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Affiliation(s)
- Emily A W Nadeau
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA
| | - Nicholas M Teets
- Department of Entomology, University of Kentucky, Lexington, KY 40546, USA
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Chan KYK, Tong CSD. Temporal variability modulates pH impact on larval sea urchin development: Themed Issue Article: Biomechanics and Climate Change. CONSERVATION PHYSIOLOGY 2020; 8:coaa008. [PMID: 32274060 PMCID: PMC7132065 DOI: 10.1093/conphys/coaa008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 12/01/2019] [Accepted: 01/22/2020] [Indexed: 05/11/2023]
Abstract
Coastal organisms reside in highly dynamic habitats. Global climate change is expected to alter not only the mean of the physical conditions experienced but also the frequencies and/or the magnitude of fluctuations of environmental factors. Understanding responses in an ecologically relevant context is essential for formulating management strategies. In particular, there are increasing suggestions that exposure to fluctuations could alleviate the impact of climate change-related stressors by selecting for plasticity that may help acclimatization to future conditions. However, it remains unclear whether the presence of fluctuations alone is sufficient to confer such effects or whether the pattern of the fluctuations matters. Therefore, we investigated the role of frequency and initial conditions of the fluctuations on performance by exposing larval sea urchin Heliocidaris crassispina to either constant or fluctuating pH. Reduced pH alone (pH 7.3 vs 8.0) did not affect larval mortality but reduced the growth of larval arms in the static pH treatments. Changes in morphology could affect the swimming mechanics for these small organisms, and geometric morphometric analysis further suggested an overall shape change such that acidified larvae had more U-shaped bodies and shorter arms, which would help maintain stability in moving water. The relative negative impact of lower pH, computed as log response ratio, on larval arm development was smaller when larvae were exposed to pH fluctuations, especially when the change was less frequent (48- vs 24-h cycle). Furthermore, larvae experiencing an initial pH drop, i.e. those where the cycle started at pH 8.0, were more negatively impacted compared with those kept at an initial pH of 7.3 before the cycling started. Our observations suggest that larval responses to climate change stress could not be easily predicted from mean conditions. Instead, to better predict organismal performance in the future ocean, monitoring and investigation of the role of real-time environmental fluctuations along the dispersive pathway is key.
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Affiliation(s)
- Kit Yu Karen Chan
- Corresponding author: Biology Department, Swarthmore College, Swarthmore, PA, USA. Tel: 610-328-8051.
| | - Chun Sang Daniel Tong
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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Livingston DB, Patel H, Donini A, MacMillan HA. Active transport of brilliant blue FCF across the Drosophila midgut and Malpighian tubule epithelia. Comp Biochem Physiol A Mol Integr Physiol 2020; 239:110588. [DOI: 10.1016/j.cbpa.2019.110588] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/05/2019] [Accepted: 10/07/2019] [Indexed: 01/02/2023]
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Zhang YB, Yang AP, Zhang GF, Liu WX, Wan FH. Effects of Simulated Heat Waves on Life History Traits of a Host Feeding Parasitoid. INSECTS 2019; 10:insects10120419. [PMID: 31771090 PMCID: PMC6955777 DOI: 10.3390/insects10120419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 06/10/2023]
Abstract
The frequency and amplitude of heat waves are predicted to increase under future climate change conditions. We still lack a detailed understanding of how changes in the frequency and amplitude of heat waves are linked to the life history traits and biocontrol efficiency of host-feeding parasitoids. In the present study, we simulated a series of heat waves as a function of amplitude and frequency to investigate the effects on the life history traits of the host-feeding parasitoid Eretmocerus hayati. We found that both the amplitude and frequency of heat waves significantly affected the adult phenotypes. In the low-amplitude heat wave group, the frequency of heat waves did not change the life history traits of the parasitoid; however, when the heat amplitude reached 42 °C, medium (four times/week) and high frequencies (seven times/week) of heat waves detrimentally affected these parameters. Hence, these findings suggest that to obtain optimal biological control with this parasitoid, we need to carefully monitor heat wave pattern (especially the amplitude and frequency) over the short term (usually 7-10 days) before releasing a host-feeding parasitoid.
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Affiliation(s)
- Yi-Bo Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Y.-B.Z.); (A.-P.Y.); (G.-F.Z.); (W.-X.L.)
- Scientific Observing and Experimental Station of Crop Pests in Guilin, Ministry of Agriculture, Guilin 541302, China
| | - An-Pei Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Y.-B.Z.); (A.-P.Y.); (G.-F.Z.); (W.-X.L.)
- Institute of Plant Protection, Xinjiang Academy of Agricultural Science, Urumqi 830091, China
| | - Gui-Fen Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Y.-B.Z.); (A.-P.Y.); (G.-F.Z.); (W.-X.L.)
| | - Wan-Xue Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Y.-B.Z.); (A.-P.Y.); (G.-F.Z.); (W.-X.L.)
| | - Fang-Hao Wan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Y.-B.Z.); (A.-P.Y.); (G.-F.Z.); (W.-X.L.)
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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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