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Sinclair BJ, Saruhashi S, Terblanche JS. Integrating water balance mechanisms into predictions of insect responses to climate change. J Exp Biol 2024; 227:jeb247167. [PMID: 38779934 DOI: 10.1242/jeb.247167] [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] [Indexed: 05/25/2024]
Abstract
Efficient water balance is key to insect success. However, the hygric environment is changing with climate change; although there are compelling models of thermal vulnerability, water balance is often neglected in predictions. Insects survive desiccating conditions by reducing water loss, increasing their total amount of water (and replenishing it) and increasing their tolerance of dehydration. The physiology underlying these traits is reasonably well understood, as are the sources of variation and phenotypic plasticity. However, water balance and thermal tolerance intersect at high temperatures, such that mortality is sometimes determined by dehydration, rather than heat (especially during long exposures in dry conditions). Furthermore, water balance and thermal tolerance sometimes interact to determine survival. In this Commentary, we propose identifying a threshold where the cause of mortality shifts between dehydration and temperature, and that it should be possible to predict this threshold from trait measurements (and perhaps eventually a priori from physiological or -omic markers).
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Affiliation(s)
- Brent J Sinclair
- Department of Biology, Western University, London, ON, CanadaN6A 5B7
| | - Stefane Saruhashi
- Department of Biology, Western University, London, ON, CanadaN6A 5B7
| | - John S Terblanche
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Stellenbosch University, Matieland 7602, South Africa
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2
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Wang Y, Ferveur JF, Moussian B. Eco-genetics of desiccation resistance in Drosophila. Biol Rev Camb Philos Soc 2021; 96:1421-1440. [PMID: 33754475 DOI: 10.1111/brv.12709] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 12/18/2022]
Abstract
Climate change globally perturbs water circulation thereby influencing ecosystems including cultivated land. Both harmful and beneficial species of insects are likely to be vulnerable to such changes in climate. As small animals with a disadvantageous surface area to body mass ratio, they face a risk of desiccation. A number of behavioural, physiological and genetic strategies are deployed to solve these problems during adaptation in various Drosophila species. Over 100 desiccation-related genes have been identified in laboratory and wild populations of the cosmopolitan fruit fly Drosophila melanogaster and its sister species in large-scale and single-gene approaches. These genes are involved in water sensing and homeostasis, and barrier formation and function via the production and composition of surface lipids and via pigmentation. Interestingly, the genetic strategy implemented in a given population appears to be unpredictable. In part, this may be due to different experimental approaches in different studies. The observed variability may also reflect a rich standing genetic variation in Drosophila allowing a quasi-random choice of response strategies through soft-sweep events, although further studies are needed to unravel any underlying principles. These findings underline that D. melanogaster is a robust species well adapted to resist climate change-related desiccation. The rich data obtained in Drosophila research provide a framework to address and understand desiccation resistance in other insects. Through the application of powerful genetic tools in the model organism D. melanogaster, the functions of desiccation-related genes revealed by correlative studies can be tested and the underlying molecular mechanisms of desiccation tolerance understood. The combination of the wealth of available data and its genetic accessibility makes Drosophila an ideal bioindicator. Accumulation of data on desiccation resistance in Drosophila may allow us to create a world map of genetic evolution in response to climate change in an insect genome. Ultimately these efforts may provide guidelines for dealing with the effects of climate-related perturbations on insect population dynamics in the future.
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Affiliation(s)
- Yiwen Wang
- Interfaculty Institute of Cell Biology, Section Animal Genetics, University of Tübingen, Auf der Morgenstelle 15, Tübingen, 72076, Germany.,School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, China
| | - Jean-François Ferveur
- Centre des Sciences du Goût et de l'Alimentation, UMR-CNRS 6265, Université de Bourgogne, 6, Bd Gabriel, Dijon, 21000, France
| | - Bernard Moussian
- Interfaculty Institute of Cell Biology, Section Animal Genetics, University of Tübingen, Auf der Morgenstelle 15, Tübingen, 72076, Germany.,Institute of Biology Valrose, Université Côte d'Azur, CNRS, Inserm, Parc Valrose, Nice CEDEX 2, 06108, France
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Hoffmann AA, Sgrò CM. Comparative studies of critical physiological limits and vulnerability to environmental extremes in small ectotherms: How much environmental control is needed? Integr Zool 2019; 13:355-371. [PMID: 29168624 PMCID: PMC6099205 DOI: 10.1111/1749-4877.12297] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Researchers and practitioners are increasingly using comparative assessments of critical thermal and physiological limits to assess the relative vulnerability of ectothermic species to extreme thermal and aridity conditions occurring under climate change. In most assessments of vulnerability, critical limits are compared across taxa exposed to different environmental and developmental conditions. However, many aspects of vulnerability should ideally be compared when species are exposed to the same environmental conditions, allowing a partitioning of sources of variation such as used in quantitative genetics. This is particularly important when assessing the importance of different types of plasticity to critical limits, using phylogenetic analyses to test for evolutionary constraints, isolating genetic variants that contribute to limits, characterizing evolutionary interactions among traits limiting adaptive responses, and when assessing the role of cross generation effects. However, vulnerability assessments based on critical thermal/physiological limits also need to take place within a context that is relevant to field conditions, which is not easily provided under controlled environmental conditions where behavior, microhabitat, stress exposure rates and other factors will differ from field conditions. There are ways of reconciling these requirements, such as by taking organisms from controlled environments and then testing their performance under field conditions (or vice versa). While comparisons under controlled environments are challenging for many taxa, assessments of critical thermal limits and vulnerability will always be incomplete unless environmental effects within and across generations are considered, and where the ecological relevance of assays measuring critical limits can be established.
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Affiliation(s)
- Ary A Hoffmann
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, Australia
| | - Carla M Sgrò
- School of Biological Sciences, Monash University, Melbourne, Australia
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Girish TN, Pradeep BE, Parkash R. Heat and humidity induced plastic changes in body lipids and starvation resistance in the tropical Zaprionus indianus of wet - dry seasons. J Exp Biol 2018; 221:jeb.174482. [DOI: 10.1242/jeb.174482] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/20/2018] [Indexed: 02/03/2023]
Abstract
Insects from tropical wet or dry seasons are likely to cope starvation stress through plastic changes (developmental as well as adult acclimation) in energy metabolites. Control and experimental groups of flies of Zaprionus indianus were reared under wet or dry conditions but adults were acclimated at different thermal or humidity conditions. Adult flies of control group were acclimated at 27°C and low (50% RH) or high (60% RH) humidity. For experimental groups, adult flies were acclimated at 32℃ for 1 to 6 days and under low (40% RH) or high (70% RH). For humidity acclimation, adult flies were acclimated at 27°C but under low (40% RH) or high (70% RH) for 1 to 6 days. Plastic changes in experimental groups as compared to control group (developmental as well as adult acclimation) revealed significant accumulation of body lipids due to thermal or humidity acclimation of wet season flies but low humidity acclimation did not change the level of body lipids in dry season flies. Starvation resistance and body lipids were higher in the males of dry season but in the females of wet season. Adult acclimation under thermal or humidity conditions exhibited changes in the rate of utilization of body lipids, carbohydrates and proteins. Adult acclimation of wet or dry season flies revealed plastic changes in mean daily fecundity; and a reduction in fecundity under starvation. Thus, thermal or humidity acclimation of adults revealed plastic changes in energy metabolites to support starvation resistance of wet or dry seasons flies.
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Affiliation(s)
- T. N. Girish
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam - 515134, India
| | - B. E. Pradeep
- Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam - 515134, India
| | - Ravi Parkash
- Department of Genetics, Maharshi Dayanand University, Rohtak- 124001, India
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Gotcha N, Terblanche JS, Nyamukondiwa C. Plasticity and cross-tolerance to heterogeneous environments: divergent stress responses co-evolved in an African fruit fly. J Evol Biol 2017; 31:98-110. [PMID: 29080375 DOI: 10.1111/jeb.13201] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/10/2017] [Accepted: 10/17/2017] [Indexed: 01/16/2023]
Abstract
Plastic adjustments of physiological tolerance to a particular stressor can result in fitness benefits for resistance that might manifest not only in that same environment but also be advantageous when faced with alternative environmental stressors, a phenomenon termed 'cross-tolerance'. The nature and magnitude of cross-tolerance responses can provide important insights into the underlying genetic architecture, potential constraints on or versatility of an organism's stress responses. In this study, we tested for cross-tolerance to a suite of abiotic factors that likely contribute to setting insect population dynamics and geographic range limits: heat, cold, desiccation and starvation resistance in adult Ceratitis rosa following acclimation to all these isolated individual conditions prior to stress assays. Traits of stress resistance scored included critical thermal (activity) limits, chill coma recovery time (CCRT), heat knockdown time (HKDT), desiccation and starvation resistance. In agreement with other studies, we found that acclimation to one stress typically increased resistance for that same stress experienced later in life. A more novel outcome, however, is that here we also found substantial evidence for cross-tolerance. For example, we found an improvement in heat tolerance (critical thermal maxima, CTmax ) following starvation or desiccation hardening and improved desiccation resistance following cold acclimation, indicating pronounced cross-tolerance to these environmental stressors for the traits examined. We also found that two different traits of the same stress resistance differed in their responsiveness to the same stress conditions (e.g. HKDT was less cross-resistant than CTmax ). The results of this study have two major implications that are of broader importance: (i) that these traits likely co-evolved to cope with diverse or simultaneous stressors, and (ii) that a set of common underlying physiological mechanisms might exist between apparently divergent stress responses in this species. This species may prove to be a valuable model for future work on the evolutionary and mechanistic basis of cross-tolerance.
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Affiliation(s)
- N Gotcha
- Department of Biological Sciences and Biotechnology Sciences, Botswana International University of Science and Technology (BIUST), Palapye, Botswana
| | - J S Terblanche
- Department of Conservation Ecology and Entomology, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
| | - C Nyamukondiwa
- Department of Biological Sciences and Biotechnology Sciences, Botswana International University of Science and Technology (BIUST), Palapye, Botswana
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Lambhod C, Pathak A, Munjal AK, Parkash R. Tropical Drosophila ananassae of wet-dry seasons show cross resistance to heat, drought and starvation. Biol Open 2017; 6:1698-1706. [PMID: 29141954 PMCID: PMC5703618 DOI: 10.1242/bio.029728] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Plastic responses to multiple environmental stressors in wet or dry seasonal populations of tropical Drosophila species have received less attention. We tested plastic effects of heat hardening, acclimation to drought or starvation, and changes in trehalose, proline and body lipids in Drosophila ananassae flies reared under wet or dry season-specific conditions. Wet season flies revealed significant increase in heat knockdown, starvation resistance and body lipids after heat hardening. However, accumulation of proline was observed only after desiccation acclimation of dry season flies while wet season flies elicited no proline but trehalose only. Therefore, drought-induced proline can be a marker metabolite for dry-season flies. Further, partial utilization of proline and trehalose under heat hardening reflects their possible thermoprotective effects. Heat hardening elicited cross-protection to starvation stress. Stressor-specific accumulation or utilization as well as rates of metabolic change for each energy metabolite were significantly higher in wet-season flies than dry-season flies. Energy metabolite changes due to inter-related stressors (heat versus desiccation or starvation) resulted in possible maintenance of energetic homeostasis in wet- or dry-season flies. Thus, low or high humidity-induced plastic changes in energy metabolites can provide cross-protection to seasonally varying climatic stressors. Summary: In the tropical Drosophila ananassae, low or high humidity-induced plastic changes in energy metabolites provide cross-protection to seasonally varying climatic stressors.
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Affiliation(s)
| | - Ankita Pathak
- Department of Genetics, Maharshi Dayanand University, Rohtak 124001, India.,Department of Biochemistry and Genetics, Barkatullah University, Bhopal 462026, India
| | - Ashok K Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal 462026, India
| | - Ravi Parkash
- Department of Genetics, Maharshi Dayanand University, Rohtak 124001, India
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Xiao W, Chen P, Xiao J, Wang L, Liu T, Wu Y, Dong F, Jiang Y, Pan M, Zhang Y, Lu C. Comparative transcriptome profiling of a thermal resistant vs. sensitive silkworm strain in response to high temperature under stressful humidity condition. PLoS One 2017; 12:e0177641. [PMID: 28542312 PMCID: PMC5436693 DOI: 10.1371/journal.pone.0177641] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/01/2017] [Indexed: 11/25/2022] Open
Abstract
Thermotolerance is important particularly for poikilotherms such as insects. Understanding the mechanisms by which insects respond to high temperatures can provide insights into their adaptation to the environment. Therefore, in this study, we performed a transcriptome analysis of two silkworm strains with significantly different resistance to heat as well as humidity; the thermo-resistant strain 7532 and the thermos-sensitive strain Knobbed. We identified in total 4,944 differentially expressed genes (DEGs) using RNA-Seq. Among these, 4,390 were annotated and 554 were novel. Gene Ontology (GO) analysis of 747 DEGs identified between RT_48h (Resistant strain with high-temperature Treatment for 48 hours) and ST_48h (Sensitive strain with high-temperature Treatment for 48 hours) showed significant enrichment of 12 GO terms including metabolic process, extracellular region and serine-type peptidase activity. Moreover, we discovered 12 DEGs that may contribute to the heat-humidity stress response in the silkworm. Our data clearly showed that 48h post-exposure may be a critical time point for silkworm to respond to high temperature and humidity. These results provide insights into the genes and biological processes involved in high temperature and humidity tolerance in the silkworm, and advance our understanding of thermal tolerance in insects.
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Affiliation(s)
- Wenfu Xiao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
- Sericultural Research Institute Sichuan Academy of Agricultural Sciences, Sichuan Nanchong, China
| | - Peng Chen
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Jinshu Xiao
- Sericultural Research Institute Sichuan Academy of Agricultural Sciences, Sichuan Nanchong, China
| | - La Wang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Taihang Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Yunfei Wu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Feifan Dong
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Yaming Jiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Minhui Pan
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Youhong Zhang
- Sericultural Research Institute Sichuan Academy of Agricultural Sciences, Sichuan Nanchong, China
- * E-mail: (CL); (YZ)
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
- * E-mail: (CL); (YZ)
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Lyons CL, Coetzee M, Terblanche JS, Chown SL. Desiccation tolerance as a function of age, sex, humidity and temperature in adults of the African malaria vectors Anopheles arabiensis and Anopheles funestus. ACTA ACUST UNITED AC 2014; 217:3823-33. [PMID: 25267846 DOI: 10.1242/jeb.104638] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Adult mosquito survival is strongly temperature and moisture dependent. Few studies have investigated the interacting effects of these variables on adult survival and how this differs among the sexes and with age, despite the importance of such information for population dynamic models. For these reasons, the desiccation tolerance of Anopheles arabiensis Patton and Anopheles funestus Giles males and females of three different ages was assessed under three combinations of temperature and humidity. Females were more desiccation tolerant than males, surviving for longer periods than males under all experimental conditions. In addition, younger adults were more tolerant of desiccation than older groups. Both species showed reduced water loss rate (WLR) as the primary mechanism by which they tolerate desiccation. Although A. arabiensis is often considered to be the more arid-adapted of the two species, it showed lower survival times and higher WLR than A. funestus. The current information could improve population dynamic models of these vectors, given that adult survival information for such models is relatively sparse.
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Affiliation(s)
- Candice L Lyons
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Maureen Coetzee
- Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland 7602, South Africa
| | - Steven L Chown
- School of Biological Sciences, Monash University, VIC 3800, Australia
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