101
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Sørensen JG, Kristensen TN, Overgaard J. Evolutionary and ecological patterns of thermal acclimation capacity in Drosophila: is it important for keeping up with climate change? CURRENT OPINION IN INSECT SCIENCE 2016; 17:98-104. [PMID: 27720081 DOI: 10.1016/j.cois.2016.08.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 08/05/2016] [Indexed: 05/26/2023]
Abstract
Phenotypic plasticity of temperature tolerance (thermal acclimation) is often highlighted as an important component of the acute and evolutionary adaptation to temperatures in insects. For this reason, it is often suggested that thermal acclimation ability could be important for buffering the consequences of climate change. Based on data from Drosophila we discuss if and how phenotypic plasticity is likely to mitigate the effects of climate change. We conclude that plasticity of upper thermal limits is small in magnitude, evolves slowly and that acclimation ability is weakly correlated with latitude and environmental heterogeneity. Accordingly plasticity in upper thermal limits is unlikely to effectively buffer effects of global warming for species already close to their upper thermal boundaries.
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Affiliation(s)
- Jesper Givskov Sørensen
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114, 8000 Aarhus C, Denmark.
| | - Torsten Nygaard Kristensen
- Department of Chemistry and Bioscience, Section for Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg, Denmark
| | - Johannes Overgaard
- Department of Bioscience, Section for Zoophysiology, Aarhus University, C.F. Møllers Alle 3, Building 1131, 8000 Aarhus, Denmark
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102
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Clemson AS, Sgrò CM, Telonis-Scott M. Thermal plasticity in Drosophila melanogaster populations from eastern Australia: quantitative traits to transcripts. J Evol Biol 2016; 29:2447-2463. [PMID: 27542565 DOI: 10.1111/jeb.12969] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/19/2016] [Accepted: 08/17/2016] [Indexed: 12/19/2022]
Abstract
The flexibility afforded to genotypes in different environments by phenotypic plasticity is of interest to biologists studying thermal adaptation because of the thermal lability of many traits. Differences in thermal performance and reaction norms can provide insight into the evolution of thermal adaptation to explore broader questions such as species distributions and persistence under climate change. One approach is to study the effects of temperature on fitness, morphological and more recently gene expression traits in populations from different climatic origins. The diverse climatic conditions experienced by Drosophila melanogaster along the eastern Australian temperate-tropical gradient are ideal given the high degree of continuous trait differentiation, but reaction norm variation has not been well studied in this system. Here, we reared a tropical and temperate population from the ends of the gradient over six developmental temperatures and examined reaction norm variation for five quantitative traits including thermal performance for fecundity, and reaction norms for thermotolerance, body size, viability and 23 transcript-level traits. Despite genetic variation for some quantitative traits, we found no differentiation between the populations for fecundity thermal optima and breadth, and the reaction norms for the other traits were largely parallel, supporting previous work suggesting that thermal evolution occurs by changes in trait means rather than by reaction norm shifts. We examined reaction norm variation in our expanded thermal regime for a gene set shown to previously exhibit GxE for expression plasticity in east Australian flies, as well as key heat-shock genes. Although there were differences in curvature between the populations suggesting a higher degree of thermal plasticity in expression patterns than for the quantitative traits, we found little evidence to support a role for genetic variation in maintaining expression plasticity.
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Affiliation(s)
- A S Clemson
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
| | - C M Sgrò
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
| | - M Telonis-Scott
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
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103
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Andrew SC, Kemp DJ. Stress tolerance in a novel system: Genetic and environmental sources of (co)variation for cold tolerance in the butterfly
Eurema smilax. AUSTRAL ECOL 2016. [DOI: 10.1111/aec.12341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Samuel C. Andrew
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
| | - Darrell J. Kemp
- Department of Biological Sciences Macquarie University Sydney New South Wales 2109 Australia
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104
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Heerwaarden B, Kellermann V, Sgrò CM. Limited scope for plasticity to increase upper thermal limits. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12687] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Belinda Heerwaarden
- School of Biological Sciences Monash University Melbourne Vic. 3800 Australia
| | - Vanessa Kellermann
- School of Biological Sciences Monash University Melbourne Vic. 3800 Australia
| | - Carla M. Sgrò
- School of Biological Sciences Monash University Melbourne Vic. 3800 Australia
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105
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Scharf I, Daniel A, MacMillan HA, Katz N. The effect of fasting and body reserves on cold tolerance in 2 pit-building insect predators. Curr Zool 2016; 63:287-294. [PMID: 29491987 PMCID: PMC5804172 DOI: 10.1093/cz/zow049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 04/11/2016] [Indexed: 01/15/2023] Open
Abstract
Pit-building antlions and wormlions are 2 distantly-related insect species, whose larvae construct pits in loose soil to trap small arthropod prey. This convergent evolution of natural histories has led to additional similarities in their natural history and ecology, and thus, these 2 species encounter similar abiotic stress (such as periodic starvation) in their natural habitat. Here, we measured the cold tolerance of the 2 species and examined whether recent feeding or food deprivation, as well as body composition (body mass and lipid content) and condition (quantified as mass-to-size residuals) affect their cold tolerance. In contrast to other insects, in which food deprivation either enhanced or impaired cold tolerance, prolonged fasting had no effect on the cold tolerance of either species, which had similar cold tolerance. The 2 species differed, however, in how cold tolerance related to body mass and lipid content: although body mass was positively correlated with the wormlion cold tolerance, lipid content was a more reliable predictor of cold tolerance in the antlions. Cold tolerance also underwent greater change with ontogeny in wormlions than in antlions. We discuss possible reasons for this lack of effect of food deprivation on both species' cold tolerance, such as their high starvation tolerance (being sit-and-wait predators).
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Affiliation(s)
- Inon Scharf
- Department of Zoology, Faculty of Life Sciences, Tel Aviv University, POB 39040, 69978 Tel Aviv, Israel and
| | - Alma Daniel
- Department of Zoology, Faculty of Life Sciences, Tel Aviv University, POB 39040, 69978 Tel Aviv, Israel and
| | | | - Noa Katz
- Department of Zoology, Faculty of Life Sciences, Tel Aviv University, POB 39040, 69978 Tel Aviv, Israel and
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106
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Gunderson AR, Stillman JH. Plasticity in thermal tolerance has limited potential to buffer ectotherms from global warming. Proc Biol Sci 2016; 282:20150401. [PMID: 25994676 DOI: 10.1098/rspb.2015.0401] [Citation(s) in RCA: 419] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Global warming is increasing the overheating risk for many organisms, though the potential for plasticity in thermal tolerance to mitigate this risk is largely unknown. In part, this shortcoming stems from a lack of knowledge about global and taxonomic patterns of variation in tolerance plasticity. To address this critical issue, we test leading hypotheses for broad-scale variation in ectotherm tolerance plasticity using a dataset that includes vertebrate and invertebrate taxa from terrestrial, freshwater and marine habitats. Contrary to expectation, plasticity in heat tolerance was unrelated to latitude or thermal seasonality. However, plasticity in cold tolerance is associated with thermal seasonality in some habitat types. In addition, aquatic taxa have approximately twice the plasticity of terrestrial taxa. Based on the observed patterns of variation in tolerance plasticity, we propose that limited potential for behavioural plasticity (i.e. behavioural thermoregulation) favours the evolution of greater plasticity in physiological traits, consistent with the 'Bogert effect'. Finally, we find that all ectotherms have relatively low acclimation in thermal tolerance and demonstrate that overheating risk will be minimally reduced by acclimation in even the most plastic groups. Our analysis indicates that behavioural and evolutionary mechanisms will be critical in allowing ectotherms to buffer themselves from extreme temperatures.
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Affiliation(s)
- Alex R Gunderson
- Romberg Tiburon Center, San Francisco State University, 3150 Paradise Drive, Tiburon, CA 94920, USA Department of Integrative Biology, University of California, 1005 Valley Life Sciences Building #3140, Berkeley, CA 94720-3140, USA
| | - Jonathon H Stillman
- Romberg Tiburon Center, San Francisco State University, 3150 Paradise Drive, Tiburon, CA 94920, USA Department of Integrative Biology, University of California, 1005 Valley Life Sciences Building #3140, Berkeley, CA 94720-3140, USA
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107
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Gibert P, Hill M, Pascual M, Plantamp C, Terblanche JS, Yassin A, Sgrò CM. Drosophila as models to understand the adaptive process during invasion. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1087-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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108
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Esperk T, Kjaersgaard A, Walters RJ, Berger D, Blanckenhorn WU. Plastic and evolutionary responses to heat stress in a temperate dung fly: negative correlation between basal and induced heat tolerance? J Evol Biol 2016; 29:900-15. [PMID: 26801318 DOI: 10.1111/jeb.12832] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/13/2016] [Accepted: 01/15/2016] [Indexed: 01/15/2023]
Abstract
Extreme weather events such as heat waves are becoming more frequent and intense. Populations can cope with elevated heat stress by evolving higher basal heat tolerance (evolutionary response) and/or stronger induced heat tolerance (plastic response). However, there is ongoing debate about whether basal and induced heat tolerance are negatively correlated and whether adaptive potential in heat tolerance is sufficient under ongoing climate warming. To evaluate the evolutionary potential of basal and induced heat tolerance, we performed experimental evolution on a temperate source population of the dung fly Sepsis punctum. Offspring of flies adapted to three thermal selection regimes (Hot, Cold and Reference) were subjected to acute heat stress after having been exposed to either a hot-acclimation or non-acclimation pretreatment. As different traits may respond differently to temperature stress, several physiological and life history traits were assessed. Condition dependence of the response was evaluated by exposing juveniles to different levels of developmental (food restriction/rearing density) stress. Heat knockdown times were highest, whereas acclimation effects were lowest in the Hot selection regime, indicating a negative association between basal and induced heat tolerance. However, survival, adult longevity, fecundity and fertility did not show such a pattern. Acclimation had positive effects in heat-shocked flies, but in the absence of heat stress hot-acclimated flies had reduced life spans relative to non-acclimated ones, thereby revealing a potential cost of acclimation. Moreover, body size positively affected heat tolerance and unstressed individuals were less prone to heat stress than stressed flies, offering support for energetic costs associated with heat tolerance. Overall, our results indicate that heat tolerance of temperate insects can evolve under rising temperatures, but this response could be limited by a negative relationship between basal and induced thermotolerance, and may involve some but not other fitness-related traits.
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Affiliation(s)
- T Esperk
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia.,Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - A Kjaersgaard
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - R J Walters
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,School of Biological Sciences, University of Reading, Reading, UK
| | - D Berger
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - W U Blanckenhorn
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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109
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van Heerwaarden B, Malmberg M, Sgrò CM. Increases in the evolutionary potential of upper thermal limits under warmer temperatures in two rainforestDrosophilaspecies. Evolution 2016; 70:456-64. [DOI: 10.1111/evo.12843] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/25/2015] [Accepted: 11/20/2015] [Indexed: 01/01/2023]
Affiliation(s)
| | - Michelle Malmberg
- School of Biological Sciences; Monash University; Clayton 3800 Melbourne Australia
- Department of Applied Systems Biology; La Trobe University; Bundoora 3083 Melbourne Australia
| | - Carla M. Sgrò
- School of Biological Sciences; Monash University; Clayton 3800 Melbourne Australia
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110
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Phillips BL, Muñoz MM, Hatcher A, Macdonald SL, Llewelyn J, Lucy V, Moritz C. Heat hardening in a tropical lizard: geographic variation explained by the predictability and variance in environmental temperatures. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12609] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ben L. Phillips
- School of Biosciences University of Melbourne Melbourne Vic. 3010 Australia
- Centre for Tropical Biodiversity and Climate Change James Cook University Townsville Qld 4811 Australia
| | - Martha M. Muñoz
- Research School of Biology Australian National University Canberra ACT 2601 Australia
| | - Amberlee Hatcher
- Centre for Tropical Biodiversity and Climate Change James Cook University Townsville Qld 4811 Australia
| | - Stewart L. Macdonald
- Centre for Tropical Biodiversity and Climate Change James Cook University Townsville Qld 4811 Australia
- Land and Water Flagship CSIRO Townsville Qld 4811 Australia
| | - John Llewelyn
- Centre for Tropical Biodiversity and Climate Change James Cook University Townsville Qld 4811 Australia
- Land and Water Flagship CSIRO Townsville Qld 4811 Australia
| | - Vanessa Lucy
- School of Biosciences University of Melbourne Melbourne Vic. 3010 Australia
| | - Craig Moritz
- Research School of Biology Australian National University Canberra ACT 2601 Australia
- The Centre for Biodiversity Analysis Australian National University Canberra ACT 2601 Australia
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111
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Sgrò CM, Terblanche JS, Hoffmann AA. What Can Plasticity Contribute to Insect Responses to Climate Change? ANNUAL REVIEW OF ENTOMOLOGY 2015; 61:433-51. [PMID: 26667379 DOI: 10.1146/annurev-ento-010715-023859] [Citation(s) in RCA: 250] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Plastic responses figure prominently in discussions on insect adaptation to climate change. Here we review the different types of plastic responses and whether they contribute much to adaptation. Under climate change, plastic responses involving diapause are often critical for population persistence, but key diapause responses under dry and hot conditions remain poorly understood. Climate variability can impose large fitness costs on insects showing diapause and other life cycle responses, threatening population persistence. In response to stressful climatic conditions, insects also undergo ontogenetic changes including hardening and acclimation. Environmental conditions experienced across developmental stages or by prior generations can influence hardening and acclimation, although evidence for the latter remains weak. Costs and constraints influence patterns of plasticity across insect clades, but they are poorly understood within field contexts. Plastic responses and their evolution should be considered when predicting vulnerability to climate change-but meaningful empirical data lag behind theory.
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Affiliation(s)
- Carla M Sgrò
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia;
| | - John S Terblanche
- Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland 7602, South Africa;
| | - Ary A Hoffmann
- School of BioSciences, Bio21 Institute, University of Melbourne, Melbourne 3010, Australia;
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112
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Kellermann V, Hoffmann AA, Kristensen TN, Moghadam NN, Loeschcke V. Experimental Evolution under Fluctuating Thermal Conditions Does Not Reproduce Patterns of Adaptive Clinal Differentiation in Drosophila melanogaster. Am Nat 2015; 186:582-93. [PMID: 26655772 DOI: 10.1086/683252] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Experimental evolution can be a useful tool for testing the impact of environmental factors on adaptive changes in populations, and this approach is being increasingly used to understand the potential for evolutionary responses in populations under changing climates. However, selective factors will often be more complex in natural populations than in laboratory environments and produce different patterns of adaptive differentiation. Here we test the ability of laboratory experimental evolution under different temperature cycles to reproduce well-known patterns of clinal variation in Drosophila melanogaster. Six fluctuating thermal regimes mimicking the natural temperature conditions along the east coast of Australia were initiated. Contrary to expectations, on the basis of field patterns there was no evidence for adaptation to thermal regimes as reflected by changes in cold and heat resistance after 1-3 years of laboratory natural selection. While laboratory evolution led to changes in starvation resistance, development time, and body size, patterns were not consistent with those seen in natural populations. These findings highlight the complexity of factors affecting trait evolution in natural populations and indicate that caution is required when inferring likely evolutionary responses from the outcome of experimental evolution studies.
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Affiliation(s)
- Vanessa Kellermann
- Department of Bioscience, Aarhus University, Ny Munkegade 114-116, DK-8000 Aarhus C, Denmark
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113
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Castañeda LE, Rezende EL, Santos M. Heat tolerance in Drosophila subobscura along a latitudinal gradient: Contrasting patterns between plastic and genetic responses. Evolution 2015; 69:2721-34. [PMID: 26292981 DOI: 10.1111/evo.12757] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/13/2015] [Accepted: 08/11/2015] [Indexed: 01/17/2023]
Abstract
Susceptibility to global warming relies on how thermal tolerances respond to increasing temperatures through plasticity or evolution. Climatic adaptation can be assessed by examining the geographic variation in thermal-related traits. We studied latitudinal patterns in heat tolerance in Drosophila subobscura reared at two temperatures. We used four static stressful temperatures to estimate the thermal death time (TDT) curves, and two ramping assays with fast and slow heating rates. Thermal death time curves allow estimation of the critical thermal maximum (CT(max)), by extrapolating to the temperature that would knock down the flies almost "instantaneously," and the thermal sensitivity to increasing stressful temperatures. We found a positive latitudinal cline for CT(max), but no clinal pattern for knockdown temperatures estimated from the ramping assays. Although high-latitude populations were more tolerant to an acute heat stress, they were also more sensitive to prolonged exposure to less stressful temperatures, supporting a trade-off between acute and chronic heat tolerances. Conversely, developmental plasticity did not affect CT(max) but increased the tolerance to chronic heat exposition. The patterns observed from the TDT curves help to understand why the relationship between heat tolerance and latitude depends on the methodology used and, therefore, these curves provide a more complete and reliable measurement of heat tolerance.
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Affiliation(s)
- Luis E Castañeda
- Instituto de Ecología y Biodiversidad (IEB-Chile), Casilla 653, Santiago, Chile. .,Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, PO 5090000, Valdivia, Chile.
| | - Enrico L Rezende
- Department of Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, United Kingdom
| | - Mauro Santos
- Departament de Genètica i de Microbiologia, Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Universitat Autonòma de Barcelona, 08193, Bellaterra (Barcelona), Spain
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114
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Hangartner S, Hoffmann AA. Evolutionary potential of multiple measures of upper thermal tolerance in
D
rosophila melanogaster. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12499] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sandra Hangartner
- School of BioSciences The University of Melbourne 30 Flemington Road Parkville Vic.3010 Australia
- School of Biological Sciences Monash University, Clayton Campus Building 18Vic.3800 Australia
| | - Ary A. Hoffmann
- School of BioSciences The University of Melbourne 30 Flemington Road Parkville Vic.3010 Australia
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115
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116
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Telonis-Scott M, Clemson AS, Johnson TK, Sgrò CM. Spatial analysis of gene regulation reveals new insights into the molecular basis of upper thermal limits. Mol Ecol 2014; 23:6135-51. [PMID: 25401770 DOI: 10.1111/mec.13000] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 11/06/2014] [Accepted: 11/13/2014] [Indexed: 12/11/2022]
Abstract
The cellular stress response has long been the primary model for studying the molecular basis of thermal adaptation, yet the link between gene expression, RNA metabolism and physiological responses to thermal stress remains largely unexplored. We address this by comparing the transcriptional and physiological responses of three geographically distinct populations of Drosophila melanogaster from eastern Australia in response to, and recovery from, a severe heat stress with and without a prestress hardening treatment. We focus on starvin (stv), recently identified as an important thermally responsive gene. Intriguingly, stv encodes seven transcripts from alternative transcription sites and alternative splicing, yet appears to be rapidly heat inducible. First, we show genetic differences in upper thermal limits of the populations tested. We then demonstrate that the stv locus does not ubiquitously respond to thermal stress but is expressed as three distinct thermal and temporal RNA phenotypes (isoforms). The shorter transcript isoforms are rapidly upregulated under stress in all populations and show similar molecular signatures to heat-shock proteins. Multiple stress exposures seem to generate a reserve of pre-mRNAs, effectively 'priming' the cells for subsequent stress. Remarkably, we demonstrate a bypass in the splicing blockade in these isoforms, suggesting an essential role for these transcripts under heat stress. Temporal profiles for the weakly heat responsive stv isoform subset show opposing patterns in the two most divergent populations. Innate and induced transcriptome responses to hyperthermia are complex, and warrant moving beyond gene-level analyses.
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Affiliation(s)
- Marina Telonis-Scott
- School of Biological Sciences, Monash University, Clayton, Vic., 3800, Australia
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117
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Lü ZC, Gao QL, Wan FH, Yu H, Guo JY. Increased survival and prolonged longevity mainly contribute to the temperature-adaptive evolutionary strategy in invasive Bemisia tabaci (Hemiptera: Aleyrodidae) Middle East Asia Minor 1. JOURNAL OF INSECT SCIENCE (ONLINE) 2014; 14:143. [PMID: 25347834 PMCID: PMC5443472 DOI: 10.1093/jisesa/ieu005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 05/01/2013] [Indexed: 06/04/2023]
Abstract
With increasing global climate change, analyses of stress-inducing conditions have important significance in ecological adaptation and the biological distribution of species. To reveal the difference in temperature-adaptive strategy between Turpan and Beijing populations of Bemisia tabaci (Gennadius) Middle East Asia Minor 1 (MEAM1) under high-temperature stress conditions, we compared thermal tolerance and life history traits between Beijing and Turpan populations of MEAM1 after exposure to different heat shock treatments for different times. The experimental design reflected the nature of heat stress conditions suffered by MEAM1. The results showed that eggs, red-eyed pupae, and adults of the Turpan population were more heat tolerant than those of the Beijing population under the same stress conditions. Additionally, it was found that longevity and F1 adult survival rate were significantly higher in the Turpan population than in the Beijing population after heat shock stress, but egg number and F1 female ratio were not significantly different between Turpan population and Beijing population. Overall, it was suggested that heat tolerance and longevity traits were the most relevant for climate characteristics and not reproductive traits, and improved heat tolerance and prolonged longevity were important adaptive strategies that helped MEAM1 to survive in harsh high-temperature conditions such as Turpan arid desert climate. The present results provided further insight into the modes of heat tolerance and the ways in which survival and longevity traits respond to environmental selection pressures.
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Affiliation(s)
- Zhi-Chuang Lü
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China
| | - Qing-Lei Gao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China
| | - Fang-Hao Wan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China Center for Management of Invasive Alien Species, Ministry of Agriculture, Beijing 100193, China
| | - Hao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China Department of Entomology, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, China
| | - Jian-Ying Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China Center for Management of Invasive Alien Species, Ministry of Agriculture, Beijing 100193, China
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118
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Wallace GT, Kim TL, Neufeld CJ. Interpopulational variation in the cold tolerance of a broadly distributed marine copepod. CONSERVATION PHYSIOLOGY 2014; 2:cou041. [PMID: 27293662 PMCID: PMC4732475 DOI: 10.1093/conphys/cou041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 08/14/2014] [Accepted: 08/19/2014] [Indexed: 06/06/2023]
Abstract
Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change.
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Affiliation(s)
- Gemma T. Wallace
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Biology Department, Whitman College, Walla Walla, WA 99362, USA
| | - Tiffany L. Kim
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Environmental Sciences, Northwestern University, Evanston, IL 60208, USA
| | - Christopher J. Neufeld
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Quest University Canada, Squamish, BC, Canada VB8 0N8
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119
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van Heerwaarden B, Lee RFH, Overgaard J, Sgrò CM. No patterns in thermal plasticity along a latitudinal gradient in Drosophila simulans from eastern Australia. J Evol Biol 2014; 27:2541-53. [PMID: 25262984 DOI: 10.1111/jeb.12510] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/03/2014] [Accepted: 09/07/2014] [Indexed: 11/27/2022]
Abstract
Phenotypic plasticity may be an important initial mechanism to counter environmental change, yet we know relatively little about the evolution of plasticity in nature. Species with widespread distributions are expected to have evolved higher levels of plasticity compared with those with more restricted, tropical distributions. At the intraspecific level, temperate populations are expected to have evolved higher levels of plasticity than their tropical counterparts. However, empirical support for these expectations is limited. In addition, no studies have comprehensively examined the evolution of thermal plasticity across life stages. Using populations of Drosophila simulans collected from a latitudinal cline spanning the entire east coast of Australia, we assessed thermal plasticity, measured as hardening capacity (the difference between basal and hardened thermal tolerance) for multiple measures of heat and cold tolerance across both adult and larval stages of development. This allowed us to explicitly ask whether the evolution of thermal plasticity is favoured in more variable, temperate environments. We found no relationship between thermal plasticity and latitude, providing little support for the hypothesis that temperate populations have evolved higher levels of thermal plasticity than their tropical counterparts. With the exception of adult heat survival, we also found no association between plasticity and ten climatic variables, indicating that the evolution of thermal plasticity is not easily predicted by the type of environment that a particular population occupies. We discuss these results in the context of the role of plasticity in a warming climate.
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Affiliation(s)
- B van Heerwaarden
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
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120
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Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2014; 175:46-56. [PMID: 24845200 DOI: 10.1016/j.cbpa.2014.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 11/20/2022]
Abstract
Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster.
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121
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Díaz F, Muñoz-Valencia V, Juvinao-Quintero DL, Manzano-Martínez MR, Toro-Perea N, Cárdenas-Henao H, Hoffmann AA. Evidence for adaptive divergence of thermal responses among Bemisia tabaci populations from tropical Colombia following a recent invasion. J Evol Biol 2014; 27:1160-71. [PMID: 24800647 DOI: 10.1111/jeb.12387] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 03/11/2014] [Accepted: 03/30/2014] [Indexed: 11/29/2022]
Abstract
There is an increasing evidence that populations of ectotherms can diverge genetically in response to different climatic conditions, both within their native range and (in the case of invasive species) in their new range. Here, we test for such divergence in invasive whitefly Bemisia tabaci populations in tropical Colombia, by considering heritable variation within and between populations in survival and fecundity under temperature stress, and by comparing population differences with patterns established from putatively neutral microsatellite markers. We detected significant differences among populations linked to mean temperature (for survival) and temperature variation (for fecundity) in local environments. A QST - FST analysis indicated that phenotypic divergence was often larger than neutral expectations (QST > FST ). Particularly, for survival after a sublethal heat shock, this divergence remained linked to the local mean temperature after controlling for neutral divergence. These findings point to rapid adaptation in invasive whitefly likely to contribute to its success as a pest species. Ongoing evolutionary divergence also provides challenges in predicting the likely impact of Bemisia in invaded regions.
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Affiliation(s)
- F Díaz
- Department of Biology, Universidad del Valle, Cali, Colombia
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122
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Affiliation(s)
- Enrico L. Rezende
- Department of Life Sciences; University of Roehampton; Holybourne Avenue London SW15 4JD UK
| | - Luis E. Castañeda
- Instituto de Ecología y Biodiversidad (IEB); Universidad de Chile; Casilla 653 Santiago Chile
- Instituto de Ciencias Ambientales y Evolutivas; Universidad Austral de Chile; PO 5090000 Valdivia Chile
| | - Mauro Santos
- Departament de Genètica i de Microbiologia; Grup de Biologia Evolutiva (GBE); Universitat Autònoma de Barcelona; 08193 Bellaterra (Barcelona) Spain
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123
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Parkash R, Ranga P. Seasonal changes in humidity impact drought resistance in tropical Drosophila leontia: Testing developmental effects of thermal versus humidity changes. Comp Biochem Physiol A Mol Integr Physiol 2014; 169:33-43. [DOI: 10.1016/j.cbpa.2013.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 12/06/2013] [Accepted: 12/07/2013] [Indexed: 11/26/2022]
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124
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Fallis LC, Fanara JJ, Morgan TJ. Developmental thermal plasticity among Drosophila melanogaster populations. J Evol Biol 2014; 27:557-64. [PMID: 26230171 DOI: 10.1111/jeb.12321] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/16/2013] [Accepted: 12/17/2013] [Indexed: 11/30/2022]
Abstract
Many biotic and abiotic variables influence the dispersal and distribution of organisms. Temperature has a major role in determining these patterns because it changes daily, seasonally and spatially, and these fluctuations have a significant impact on an organism's behaviour and fitness. Most ecologically relevant phenotypes that are adaptive are also complex and thus they are influenced by many underlying loci that interact with the environment. In this study, we quantified the degree of thermal phenotypic plasticity within and among populations by measuring chill-coma recovery times of lines reared from egg to adult at two different environmental temperatures. We used sixty genotypes from six natural populations of Drosophila melanogaster sampled along a latitudinal gradient in South America. We found significant variation in thermal plasticity both within and among populations. All populations exhibit a cold acclimation response, with flies reared at lower temperatures having increased resistance to cold. We tested a series of environmental parameters against the variation in population mean thermal plasticity and discovered the mean thermal plasticity was significantly correlated with altitude of origin of the population. Pairing our data with previous experiments on viability fitness assays in the same populations in fixed and variable environments suggests an adaptive role of this thermal plasticity in variable laboratory environments. Altogether, these data demonstrate abundant variation in adaptive thermal plasticity within and among populations.
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Affiliation(s)
- L C Fallis
- The Division of Biology, The Ecological Genomics Institute, Kansas State University, Manhattan, KS, USA
| | - J J Fanara
- Departamento de Ecologia, Genetica y Evolucion-IEGEBA (CONICET-UBA), FCEN, UBA, Buenos Aires, Argentina
| | - T J Morgan
- The Division of Biology, The Ecological Genomics Institute, Kansas State University, Manhattan, KS, USA
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125
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Cockerell FE, Sgrò CM, McKechnie SW. Latitudinal clines in heat tolerance, protein synthesis rate and transcript level of a candidate gene in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2014; 60:136-144. [PMID: 24333150 DOI: 10.1016/j.jinsphys.2013.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 11/27/2013] [Accepted: 12/03/2013] [Indexed: 06/03/2023]
Abstract
The occurrence of climatic adaptation in Drosophila melanogaster is highlighted by the presence of latitudinal clines in several quantitative traits, particularly clines in adult heat knockdown tolerance that is higher in tropical populations. However the presence of latitudinal patterns in physiological characteristics that may underlie these traits have rarely been assessed. Protein synthesis has been implicated as an important physiological process that influences thermal tolerance, and this has not been examined in a clinal context. Here, we characterise latitudinal variation in D. melanogaster from eastern Australia in both adult heat knockdown tolerance and rates of protein synthesis following rearing at both 25 °C, approximating summer conditions, and 18 °C approximating winter development. We also examined clinal variation in the predominant nuclear transcript of the heat-inducible RNA gene hsr-omega, which has been implicated in regulating protein synthesis. We find significant clines in heat-hardened tolerance when cultured at both 18 and 25 °C - tolerance increased towards the low latitude tropics. Rates of protein synthesis measured in ovarian tissue also associated negatively with latitude, however the presence of the clines depended on rearing temperature and heat stress conditions. Finally, omega-n levels measured without heat stress showed a positive linear cline. When measured after a mild heat stress higher levels of omega-n were detected and the clinal pattern became parabolic - mid-latitude populations had lower levels of the transcript. While congruent latitudinal trends were detected for these three traits, only a low level of positive association was detected between protein synthesis and thermal tolerance providing little evidence that these traits are related at the level of cellular physiology. However the new clinal patterns of protein synthesis and hsr-omega variation suggest that these variables exert important influences on traits involved with latitudinal climatic adaptation.
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Affiliation(s)
- Fiona E Cockerell
- School of Biological Sciences, Monash University, Wellington Rd, Clayton 3800, Melbourne, Australia.
| | - Carla M Sgrò
- School of Biological Sciences, Monash University, Wellington Rd, Clayton 3800, Melbourne, Australia
| | - Stephen W McKechnie
- School of Biological Sciences, Monash University, Wellington Rd, Clayton 3800, Melbourne, Australia
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126
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Blackburn S, Kellmermann V, van Heerwaarden B, Sgrò CM. Evolutionary capacity of upper thermal limits: beyond single trait assessments. J Exp Biol 2014; 217:1918-24. [DOI: 10.1242/jeb.099184] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Thermal tolerance is an important factor influencing the distribution of ectotherms, but we still have limited understanding of the ability of species to evolve different thermal limits. Recent studies suggest that species may have limited capaity to evolve higher themal limits in response to slower, more ecologically relevant rates of warming. However these conclusions are based on univarite estimates of adaptive capacity. To test these findings within an explicitly multivariate context, we used a paternal half-sibling breeding design to estimate the multivariate evolutionary potential for upper thermal limits in Drosophila melanogaster. We assessed heat tolerance using static (basal and hardened) and ramping assays. Additive genetic variances were significantly different from zero only for the static measures of heat tolerance. Our G matrix analysis revealed that any response to selection for increased heat tolerance will largely be driven by static basal and hardened heat tolerance, with minimal contribution from ramping heat tolerance. These results suggest that the capacity to evolve upper thermal limits in nature may depend on the type of thermal stress experienced.
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127
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Yampolsky LY, Schaer TMM, Ebert D. Adaptive phenotypic plasticity and local adaptation for temperature tolerance in freshwater zooplankton. Proc Biol Sci 2013; 281:20132744. [PMID: 24352948 DOI: 10.1098/rspb.2013.2744] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many organisms have geographical distributions extending from the tropics to near polar regions or can experience up to 30°C temperature variation within the lifespan of an individual. Two forms of evolutionary adaptation to such wide ranges in ambient temperatures are frequently discussed: local adaptation and phenotypic plasticity. The freshwater planktonic crustacean Daphnia magna, whose range extends from South Africa to near arctic sites, shows strong phenotypic and genotypic variation in response to temperature. In this study, we use D. magna clones from 22 populations (one clone per population) ranging from latitude 0° (Kenya) to 66° North (White Sea) to explore the contributions of phenotypic plasticity and local adaptation to high temperature tolerance. Temperature tolerance was studied as knockout time (time until immobilization, T(imm)) at 37°C in clones acclimatized to either 20°C or 28°C. Acclimatization to 28°C strongly increased T(imm), testifying to adaptive phenotypic plasticity. At the same time, Timm significantly correlated with average high temperature at the clones' sites of origin, suggesting local adaptation. As earlier studies have found that haemoglobin expression contributes to temperature tolerance, we also quantified haemoglobin concentration in experimental animals and found that both acclimatization temperature (AccT) and temperature at the site of origin are positively correlated with haemoglobin concentration. Furthermore, Daphnia from warmer climates upregulate haemoglobin much more strongly in response to AccT, suggesting local adaptation for plasticity in haemoglobin expression. Our results show that both local adaptation and phenotypic plasticity contribute to temperature tolerance, and elucidate a possible role of haemoglobin in mediating these effects that differs along a cold-warm gradient.
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Affiliation(s)
- Lev Y Yampolsky
- Department of Biological Sciences, East Tennessee State University, , Johnson City, TN 37614-1710, USA, Zoological Institute, Basel University, , Vesalgasse 1, Basel 4051, Switzerland
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128
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Capacity for protein synthesis following heat stimulus of Drosophila associates with heat tolerance but does not underlie the latitudinal tolerance cline. J Therm Biol 2013. [DOI: 10.1016/j.jtherbio.2013.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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129
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Parkash R, Ranga P. Divergence for tolerance to thermal-stress related traits in two Drosophila species of immigrans group. J Therm Biol 2013. [DOI: 10.1016/j.jtherbio.2013.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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130
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Andrew NR, Hart RA, Jung MP, Hemmings Z, Terblanche JS. Can temperate insects take the heat? A case study of the physiological and behavioural responses in a common ant, Iridomyrmex purpureus (Formicidae), with potential climate change. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:870-880. [PMID: 23806604 DOI: 10.1016/j.jinsphys.2013.06.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 06/06/2013] [Accepted: 06/07/2013] [Indexed: 06/02/2023]
Abstract
Insects in temperate regions are predicted to be at low risk of climate change relative to tropical species. However, these assumptions have generally been poorly examined in all regions, and such forecasting fails to account for microclimatic variation and behavioural optimisation. Here, we test how a population of the dominant ant species, Iridomyrmex purpureus, from temperate Australia responds to thermal stress. We show that ants regularly forage for short periods (minutes) at soil temperatures well above their upper thermal limits (upper lethal temperature = 45.8 ± 1.3°C; CT(max) = 46.1°C) determined over slightly longer periods (hours) and do not show any signs of a classic thermal performance curve in voluntary locomotion across soil surface temperatures of 18.6-57°C (equating to a body temperature of 24.5-43.1°C). Although ants were present all year round, and dynamically altered several aspects of their thermal biology to cope with low temperatures and seasonal variation, temperature-dependence of running speed remained invariant and ants were unable to elevate high temperature tolerance using plastic responses. Measurements of microclimate temperature were higher than ant body temperatures during the hottest part of the day, but exhibited a stronger relationship with each other than air temperatures from the closest weather station. Generally close associations of ant activity and performance with microclimatic conditions, possibly to maximise foraging times, suggest I. purpureus displays highly opportunistic thermal responses and readily adjusts behaviour to cope with high trail temperatures. Increasing frequency or duration of high temperatures is therefore likely to result in an immediate reduction in foraging efficiency. In summary, these results suggest that (1) soil-dwelling temperate insect populations may be at higher risks of thermal stress with increased frequency or duration of high temperatures resulting from climate change than previously thought, however, behavioural cues may be able to compensate to some extent; and (2) indices of climate change-related thermal stress, warming tolerance and thermal safety margin, are strongly influenced by the scale of climate metrics employed.
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Affiliation(s)
- Nigel R Andrew
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia.
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131
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Thuiller W, Münkemüller T, Lavergne S, Mouillot D, Mouquet N, Schiffers K, Gravel D. A road map for integrating eco-evolutionary processes into biodiversity models. Ecol Lett 2013; 16 Suppl 1:94-105. [PMID: 23679011 PMCID: PMC3790307 DOI: 10.1111/ele.12104] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 02/08/2013] [Accepted: 02/15/2013] [Indexed: 12/19/2022]
Abstract
The demand for projections of the future distribution of biodiversity has triggered an upsurge in modelling at the crossroads between ecology and evolution. Despite the enthusiasm around these so-called biodiversity models, most approaches are still criticised for not integrating key processes known to shape species ranges and community structure. Developing an integrative modelling framework for biodiversity distribution promises to improve the reliability of predictions and to give a better understanding of the eco-evolutionary dynamics of species and communities under changing environments. In this article, we briefly review some eco-evolutionary processes and interplays among them, which are essential to provide reliable projections of species distributions and community structure. We identify gaps in theory, quantitative knowledge and data availability hampering the development of an integrated modelling framework. We argue that model development relying on a strong theoretical foundation is essential to inspire new models, manage complexity and maintain tractability. We support our argument with an example of a novel integrated model for species distribution modelling, derived from metapopulation theory, which accounts for abiotic constraints, dispersal, biotic interactions and evolution under changing environmental conditions. We hope such a perspective will motivate exciting and novel research, and challenge others to improve on our proposed approach.
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Affiliation(s)
- Wilfried Thuiller
- Laboratoire d'Ecologie Alpine, UMR CNRS 5553, Université J. Fourier, Grenoble I, BP 53, Grenoble Cedex 9, 38041, France.
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132
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van Heerwaarden B, Sgrò CM. Multivariate analysis of adaptive capacity for upper thermal limits in Drosophila simulans. J Evol Biol 2013; 26:800-9. [PMID: 23517493 DOI: 10.1111/jeb.12090] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 11/22/2012] [Accepted: 11/24/2012] [Indexed: 10/27/2022]
Abstract
Thermal tolerance is an important factor influencing the distribution of ectotherms, but our understanding of the ability of species to evolve different thermal limits is limited. Based on univariate measures of adaptive capacity, it has recently been suggested that species may have limited evolutionary potential to extend their upper thermal limits under ramping temperature conditions that better reflect heat stress in nature. To test these findings more broadly, we used a paternal half-sibling breeding design to estimate the multivariate evolutionary potential for upper thermal limits in Drosophila simulans. We assessed heat tolerance using static (basal and hardened) and ramping assays. Our analyses revealed significant evolutionary potential for all three measures of heat tolerance. Additive genetic variances were significantly different from zero for all three traits. Our G matrix analysis revealed that all three traits would contribute to a response to selection for increased heat tolerance. Significant additive genetic covariances and additive genetic correlations between static basal and hardened heat-knockdown time, marginally nonsignificant between static basal and ramping heat-knockdown time, indicate that direct and correlated responses to selection for increased upper thermal limits are possible. Thus, combinations of all three traits will contribute to the evolution of upper thermal limits in response to selection imposed by a warming climate. Reliance on univariate estimates of evolutionary potential may not provide accurate insight into the ability of organisms to evolve upper thermal limits in nature.
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Affiliation(s)
- B van Heerwaarden
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
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133
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McCue MD, De Los Santos R. Upper thermal limits of insects are not the result of insufficient oxygen delivery. Physiol Biochem Zool 2013; 86:257-65. [PMID: 23434785 DOI: 10.1086/669932] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Most natural environments experience fluctuating temperatures that acutely affect an organism's physiology and ultimately a species' biogeographic distribution. Here we examine whether oxygen delivery to tissues becomes limiting as body temperature increases and eventually causes death at upper lethal temperatures. Because of the limited direct, experimental evidence supporting this possibility in terrestrial arthropods, we explored the effect of ambient oxygen availability on the thermotolerance of insects representing six species (Acheta domesticus, Hippodamia convergens, Gromphadorhina portentosa, Pogonomyrmex occidentalis, Tenebrio molitor, and Zophobus morio), four taxonomic orders (Blattodea, Coleoptera, Hymenoptera, and Orthoptera), and multiple life stages (e.g., adults vs. larvae or nymphs). The survival curves of insects exposed to temperatures (45° or 50°C) under normoxic conditions (21% O(2)) were compared with those measured under altered oxygen levels (0%, 10%, 35%, and 95% O(2)). Kaplan-Meier log rank analyses followed by Holm-Sidak pairwise comparisons revealed that (1) anoxia sharply diminished survival times in all groups studied, (2) thermotolerance under moderate hyperoxia (35% O(2)) or moderate hypoxia (10% O(2)) was the same as or lower than that under normoxia, (3) half of the experimental treatments involving extreme hyperoxia (95% O(2)) caused reduced thermotolerance, and (4) thermotolerance differed with developmental stage. Adult G. portentosa exhibited much higher thermotolerance than their first-instar nymphs, but responses from larval and adult Z. morio were equivocal. We conclude that some factor(s) separate from oxygen delivery is responsible for death of insects at upper lethal temperatures.
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Affiliation(s)
- Marshall D McCue
- Department of Biological Sciences, St. Mary's University, One Camino Santa Maria, San Antonio, TX 78228, USA.
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134
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Vorhees AS, Gray EM, Bradley TJ. Thermal resistance and performance correlate with climate in populations of a widespread mosquito. Physiol Biochem Zool 2012; 86:73-81. [PMID: 23303322 DOI: 10.1086/668851] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The abundance and success of widely distributed species across variable environments make them suitable models for exploring which traits will be important for resilience to climate change. Using a widespread mosquito species, Culex tarsalis, we have investigated population-level variation in the critical thermal maximum (CT(max)) and the metabolic response to temperature (MR-T). Adult female C. tarsalis were sampled from three sites representing thermally distinct habitats in California, and flow-through respirometry was used to determine CT(max) and MR-T relationships. CT(max) differed significantly among the three populations and correlated positively with maximum temperatures at each site but not with mean temperatures. Culex tarsalis from our cool-temperature, high-altitude site had significantly higher metabolic rates at each test temperature compared with the two populations from warmer sites, consistent with previous examples of thermal compensation in ectothermic animals inhabiting cold climates. The MR-T slope was steepest in mosquitoes inhabiting the site with the lowest temperature variability, while shallower slopes were exhibited by mosquitoes from the two sites with higher thermal variability. Our results show the extent to which local populations may differentiate within their respective environments and suggest that plasticity in thermal tolerance traits may play a role in mediating resilience to climate change. Furthermore, our study highlights the importance of thermal variability and extremes rather than average temperatures for the evolution of thermal traits.
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Affiliation(s)
- Ashley S Vorhees
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA.
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135
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Ramniwas S, Kajla B. Divergent strategy for adaptation to drought stress in two sibling species of montium species subgroup: Drosophila kikkawai and Drosophila leontia. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1525-1533. [PMID: 23022537 DOI: 10.1016/j.jinsphys.2012.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 08/09/2012] [Accepted: 08/16/2012] [Indexed: 06/01/2023]
Abstract
Drosophila leontia (warm adapted) has been considered as a sister species of Drosophila kikkawai (sub-cosmopolitan) with a very similar morphology. We found divergent strategies for coping with desiccation stress in these two species of montium subgroup. Interestingly, in contrast to clinal variation for body melanization in D. kikkawai, cuticular lipid mass showed a positive cline in D. leontia across a latitudinal transect. On the basis of isofemale line analysis, within population trait variability in cuticular lipid mass per fly is positively correlated with desiccation resistance and negatively correlated with cuticular water loss in D. leontia. A comparative analysis of water budget of these two species showed that higher abdominal melanization, reduced rate of water loss and greater dehydration tolerance confer higher desiccation resistance in D. kikkawai while the reduced rate of water loss is the only possible mechanism to enhance desiccation tolerance in D. leontia. The use of organic solvents has supported water proofing role of cuticular lipids in D. leontia but not in D. kikkawai. Thus, we may suggest that body melanization and cuticular lipids may represent alternative strategies for coping with dehydration stress in melanic versus non-melanic drosophilids. In both these species, carbohydrates were utilized under desiccation stress but a higher level of stored carbohydrates was evident in D. kikkawai. Further, we found increase desiccation resistance in D. kikkawai through acclimation while D. leontia lacks such a response. Thus, species specific divergence in water balance related traits in these species are consistent with their adaptations to wet and dry habitats.
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Affiliation(s)
- Seema Ramniwas
- Department of Genetics, Maharshi Dayanand University, Type IV/35, M.D.U., Campus, Rohtak 124001, India.
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136
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Sinclair BJ, Williams CM, Terblanche JS. Variation in Thermal Performance among Insect Populations. Physiol Biochem Zool 2012; 85:594-606. [DOI: 10.1086/665388] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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137
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Santos M, Castañeda LE, Rezende EL. Keeping pace with climate change: what is wrong with the evolutionary potential of upper thermal limits? Ecol Evol 2012; 2:2866-80. [PMID: 23170220 PMCID: PMC3501637 DOI: 10.1002/ece3.385] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 08/20/2012] [Accepted: 08/27/2012] [Indexed: 11/10/2022] Open
Abstract
The potential of populations to evolve in response to ongoing climate change is partly conditioned by the presence of heritable genetic variation in relevant physiological traits. Recent research suggests that Drosophila melanogaster exhibits negligible heritability, hence little evolutionary potential in heat tolerance when measured under slow heating rates that presumably mimic conditions in nature. Here, we study the effects of directional selection for increased heat tolerance using Drosophila as a model system. We combine a physiological model to simulate thermal tolerance assays with multilocus models for quantitative traits. Our simulations show that, whereas the evolutionary response of the genetically determined upper thermal limit (CTmax) is independent of methodological context, the response in knockdown temperatures varies with measurement protocol and is substantially (up to 50%) lower than for CTmax. Realized heritabilities of knockdown temperature may grossly underestimate the true heritability of CTmax. For instance, assuming that the true heritability of CTmax in the base population is h(2) = 0.25, realized heritabilities of knockdown temperature are around 0.08-0.16 depending on heating rate. These effects are higher in slow heating assays, suggesting that flawed methodology might explain the apparently limited evolutionary potential of cosmopolitan D. melanogaster.
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Affiliation(s)
- Mauro Santos
- Departament de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autònoma de Barcelona 08193, Bellaterra, Barcelona, Spain
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138
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Upper thermal limits of Drosophila are linked to species distributions and strongly constrained phylogenetically. Proc Natl Acad Sci U S A 2012; 109:16228-33. [PMID: 22988106 DOI: 10.1073/pnas.1207553109] [Citation(s) in RCA: 331] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Upper thermal limits vary less than lower limits among related species of terrestrial ectotherms. This pattern may reflect weak or uniform selection on upper limits, or alternatively tight evolutionary constraints. We investigated this issue in 94 Drosophila species from diverse climates and reared in a common environment to control for plastic effects that may confound species comparisons. We found substantial variation in upper thermal limits among species, negatively correlated with annual precipitation at the central point of their distribution and also with the interaction between precipitation and maximum temperature, showing that heat resistance is an important determinant of Drosophila species distributions. Species from hot and relatively dry regions had higher resistance, whereas resistance was uncorrelated with temperature in wetter regions. Using a suite of analyses we showed that phylogenetic signal in heat resistance reflects phylogenetic inertia rather than common selection pressures. Current species distributions are therefore more likely to reflect environmental sorting of lineages rather than local adaptation. Similar to previous studies, thermal safety margins were small at low latitudes, with safety margins smallest for species occupying both humid and dry tropical environments. Thus, species from a range of environments are likely to be at risk owing to climate change. Together these findings suggest that this group of insects is unlikely to buffer global change effects through marked evolutionary changes, highlighting the importance of facilitating range shifts for maintaining biodiversity.
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139
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Abstract
The rapid rate of current global climate change is having strong effects on many species and, at least in some cases, is driving evolution, particularly when changes in conditions alter patterns of selection. Climate change thus provides an opportunity for the study of the genetic basis of adaptation. Such studies include a variety of observational and experimental approaches, such as sampling across clines, artificial evolution experiments, and resurrection studies. These approaches can be combined with a number of techniques in genetics and genomics, including association and mapping analyses, genome scans, and transcription profiling. Recent research has revealed a number of candidate genes potentially involved in climate change adaptation and has also illustrated that genetic regulatory networks and epigenetic effects may be particularly relevant for evolution driven by climate change. Although genetic and genomic data are rapidly accumulating, we still have much to learn about the genetic architecture of climate change adaptation.
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Affiliation(s)
- Steven J Franks
- Department of Biological Sciences, Fordham University, Bronx, New York 10458, USA.
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140
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Hoffmann AA, Chown SL, Clusella-Trullas S. Upper thermal limits in terrestrial ectotherms: how constrained are they? Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.02036.x] [Citation(s) in RCA: 447] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Ary A. Hoffmann
- Departments of Zoology and Genetics; Bio21 Institute; The University of Melbourne; 30 Flemington Road; Parkville; Victoria; 3052; Australia
| | | | - Susana Clusella-Trullas
- Department of Botany and Zoology; Centre for Invasion Biology; Stellenbosch University; Private Bag X1; Matieland; 7602; South Africa
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141
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van Heerwaarden B, Lee RFH, Wegener B, Weeks AR, Sgró CM. Complex patterns of local adaptation in heat tolerance in Drosophila simulans from eastern Australia. J Evol Biol 2012; 25:1765-78. [PMID: 22775577 DOI: 10.1111/j.1420-9101.2012.02564.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/27/2012] [Accepted: 05/16/2012] [Indexed: 10/28/2022]
Abstract
Latitudinal clines are considered a powerful means of investigating evolutionary responses to climatic selection in nature. However, most clinal studies of climatic adaptation in Drosophila have involved species that contain cosmopolitan inversion polymorphisms that show clinal patterns themselves, making it difficult to determine whether the traits or inversions are under selection. Further, although climatic selection is unlikely to act on only one life stage in metamorphic organisms, a few studies have examined clinal patterns across life stages. Finally, clinal patterns of heat tolerance may also depend on the assay used. To unravel these potentially confounding effects on clinal patterns of thermal tolerance, we examined adult and larval heat tolerance traits in populations of Drosophila simulans from eastern Australia using static and dynamic (ramping 0.06 °C min(-1)) assays. We also used microsatellites markers to clarify whether demographic factors or selection are responsible for population differentiation along clines. Significant cubic clinal patterns were observed for adult static basal, hardened and dynamic heat knockdown time and static basal heat survival in larvae. In contrast, static, hardened larval heat survival increased linearly with latitude whereas no clinal association was found for larval ramping survival. Significant associations between adult and larval traits and climatic variables, and low population differentiation at microsatellite loci, suggest a role for climatic selection, rather than demographic processes, in generating these clinal patterns. Our results suggest that adaptation to thermal stress may be species and life-stage specific, complicating our efforts to understand the evolutionary responses to selection for increasing thermotolerance.
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Affiliation(s)
- B van Heerwaarden
- School of Biological Sciences, Monash University, Melbourne, Vic., Australia
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142
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WILLIAMS BR, VAN HEERWAARDEN B, DOWLING DK, SGRÒ CM. A multivariate test of evolutionary constraints for thermal tolerance in Drosophila melanogaster. J Evol Biol 2012; 25:1415-26. [DOI: 10.1111/j.1420-9101.2012.02536.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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143
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BUBLIY OA, KRISTENSEN TN, KELLERMANN V, LOESCHCKE V. Humidity affects genetic architecture of heat resistance in Drosophila melanogaster. J Evol Biol 2012; 25:1180-8. [DOI: 10.1111/j.1420-9101.2012.02506.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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144
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Parkash R, Aggarwal DD, Ranga P, Singh D. Divergent strategies for adaptation to desiccation stress in two Drosophila species of immigrans group. J Comp Physiol B 2012; 182:751-69. [PMID: 22407357 DOI: 10.1007/s00360-012-0655-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 02/20/2012] [Accepted: 02/21/2012] [Indexed: 11/29/2022]
Abstract
Water balance mechanisms have been investigated in desert Drosophila species of the subgenus Drosophila from North America, but changes in mesic species of subgenus Drosophila from other continents have received lesser attention. We found divergent strategies for coping with desiccation stress in two species of immigrans group--D. immigrans and D. nasuta. In contrast to clinal variation for body melanization in D. immigrans, cuticular lipid mass showed a positive cline in D. nasuta across a latitudinal transect (10°46'-31°43'N). Based on isofemale lines variability, body melanization showed positive correlation with desiccation resistance in D. immigrans but not in D. nasuta. The use of organic solvents has supported water proofing role of cuticular lipids in D. nasuta but not in D. immigrans. A comparative analysis of water budget of these two species showed that higher water content, reduced rate of water loss and greater dehydration tolerance confer higher desiccation resistance in D. immigrans while the reduced rate of water loss is the only possible mechanism to enhance desiccation tolerance in D. nasuta. We found that carbohydrates act as metabolic fuel during desiccation stress in both the species, whereas their rates of utilization differ significantly between these two species. Further, acclimation to dehydration stress improved desiccation resistance due to increase in the level of carbohydrates in D. immigrans but not in D. nasuta. Thus, populations of D. immigrans and D. nasuta have evolved different water balance mechanisms under shared environmental conditions. Multiple measures of desiccation resistance in D. immigrans but reduction in water loss in D. nasuta are consistent with their different levels of adaptive responses to wet and dry conditions on the Indian subcontinent.
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Affiliation(s)
- Ravi Parkash
- Department of Genetics, Maharshi Dayanand University, Type IV/35, M.D.U, Campus, Rohtak 124001, India.
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145
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Overgaard J, Kristensen TN, Sørensen JG. Validity of thermal ramping assays used to assess thermal tolerance in arthropods. PLoS One 2012; 7:e32758. [PMID: 22427876 PMCID: PMC3302897 DOI: 10.1371/journal.pone.0032758] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 01/30/2012] [Indexed: 11/23/2022] Open
Abstract
Proper assessment of environmental resistance of animals is critical for the ability of researchers to understand how variation in environmental conditions influence population and species abundance. This is also the case for studies of upper thermal limits in insects, where researchers studying animals under laboratory conditions must select appropriate methodology on which conclusions can be drawn. Ideally these methods should precisely estimate the trait of interest and also be biological meaningful. In an attempt to develop such tests it has been proposed that thermal ramping assays are useful assays for small insects because they incorporate an ecologically relevant gradual temperature change. However, recent model-based papers have suggested that estimates of thermal resistance may be strongly confounded by simultaneous starvation and dehydration stress. In the present study we empirically test these model predictions using two sets of independent experiments. We clearly demonstrate that results from ramping assays of small insects (Drosophila melanogaster) are not compromised by starvation- or dehydration-stress. Firstly we show that the mild disturbance of water and energy balance of D. melanogaster experienced during the ramping tests does not confound heat tolerance estimates. Secondly we show that flies pre-exposed to starvation and dehydration have “normal” heat tolerance and that resistance to heat stress is independent of the energetic and water status of the flies. On the basis of our results we discuss the assumptions used in recent model papers and present arguments as to why the ramping assay is both a valid and ecologically relevant way to measure thermal resistance in insects.
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146
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Ribeiro PL, Camacho A, Navas CA. Considerations for assessing maximum critical temperatures in small ectothermic animals: insights from leaf-cutting ants. PLoS One 2012; 7:e32083. [PMID: 22384147 PMCID: PMC3286443 DOI: 10.1371/journal.pone.0032083] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/19/2012] [Indexed: 11/19/2022] Open
Abstract
The thermal limits of individual animals were originally proposed as a link between animal physiology and thermal ecology. Although this link is valid in theory, the evaluation of physiological tolerances involves some problems that are the focus of this study. One rationale was that heating rates shall influence upper critical limits, so that ecological thermal limits need to consider experimental heating rates. In addition, if thermal limits are not surpassed in experiments, subsequent tests of the same individual should yield similar results or produce evidence of hardening. Finally, several non-controlled variables such as time under experimental conditions and procedures may affect results. To analyze these issues we conducted an integrative study of upper critical temperatures in a single species, the ant Atta sexdens rubropiosa, an animal model providing large numbers of individuals of diverse sizes but similar genetic makeup. Our specific aims were to test the 1) influence of heating rates in the experimental evaluation of upper critical temperature, 2) assumptions of absence of physical damage and reproducibility, and 3) sources of variance often overlooked in the thermal-limits literature; and 4) to introduce some experimental approaches that may help researchers to separate physiological and methodological issues. The upper thermal limits were influenced by both heating rates and body mass. In the latter case, the effect was physiological rather than methodological. The critical temperature decreased during subsequent tests performed on the same individual ants, even one week after the initial test. Accordingly, upper thermal limits may have been overestimated by our (and typical) protocols. Heating rates, body mass, procedures independent of temperature and other variables may affect the estimation of upper critical temperatures. Therefore, based on our data, we offer suggestions to enhance the quality of measurements, and offer recommendations to authors aiming to compile and analyze databases from the literature.
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Affiliation(s)
- Pedro Leite Ribeiro
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
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147
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Rezende EL, Santos M. Comment on ‘Ecologically relevant measures of tolerance to potentially lethal temperatures’. J Exp Biol 2012; 215:702-3. [DOI: 10.1242/jeb.067835] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Enrico L. Rezende
- Departament de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
| | - Mauro Santos
- Departament de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
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148
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Calabria G, Dolgova O, Rego C, Castañeda LE, Rezende EL, Balanyà J, Pascual M, Sørensen JG, Loeschcke V, Santos M. Hsp70 protein levels and thermotolerance in Drosophila subobscura: a reassessment of the thermal co-adaptation hypothesis. J Evol Biol 2012; 25:691-700. [PMID: 22300519 DOI: 10.1111/j.1420-9101.2012.02463.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Theory predicts that geographic variation in traits and genes associated with climatic adaptation may be initially driven by the correlated evolution of thermal preference and thermal sensitivity. This assumes that an organism's preferred body temperature corresponds with the thermal optimum in which performance is maximized; hence, shifts in thermal preferences affect the subsequent evolution of thermal-related traits. Drosophila subobscura evolved worldwide latitudinal clines in several traits including chromosome inversion frequencies, with some polymorphic inversions being apparently associated with thermal preference and thermal tolerance. Here we show that flies carrying the warm-climate chromosome arrangement O(3+4) have higher basal protein levels of Hsp70 than their cold-climate O(st) counterparts, but this difference disappears after heat hardening. O(3+4) carriers are also more heat tolerant, although it is difficult to conclude from our results that this is causally linked to their higher basal levels of Hsp70. The observed patterns are consistent with the thermal co-adaptation hypothesis and suggest that the interplay between behaviour and physiology underlies latitudinal and seasonal shifts in inversion frequencies.
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Affiliation(s)
- Gemma Calabria
- Departament de Genètica, Grup de Biologia Evolutiva/Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona, Spain.
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149
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Bozinovic F, Calosi P, Spicer JI. Physiological Correlates of Geographic Range in Animals. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2011. [DOI: 10.1146/annurev-ecolsys-102710-145055] [Citation(s) in RCA: 287] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Francisco Bozinovic
- Center for Advanced Studies in Ecology and Biodiversity, Laboratorio Internacional de Cambio Global, and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, CP 6513677, Chile;
| | - Piero Calosi
- Marine Biology and Ecology Research Center, School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon PL3 8AA, United Kingdom
| | - John I. Spicer
- Marine Biology and Ecology Research Center, School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon PL3 8AA, United Kingdom
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150
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Terblanche JS, Hoffmann AA, Mitchell KA, Rako L, le Roux PC, Chown SL. Ecologically relevant measures of tolerance to potentially lethal temperatures. J Exp Biol 2011; 214:3713-25. [DOI: 10.1242/jeb.061283] [Citation(s) in RCA: 301] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
The acute thermal tolerance of ectotherms has been measured in a variety of ways; these include assays where organisms are shifted abruptly to stressful temperatures and assays where organisms experience temperatures that are ramped more slowly to stressful levels. Ramping assays are thought to be more relevant to natural conditions where sudden abrupt shifts are unlikely to occur often, but it has been argued that thermal limits established under ramping conditions are underestimates of true thermal limits because stresses due to starvation and/or desiccation can arise under ramping. These confounding effects might also impact the variance and heritability of thermal tolerance. We argue here that ramping assays are useful in capturing aspects of ecological relevance even though there is potential for confounding effects of other stresses that can also influence thermal limits in nature. Moreover, we show that the levels of desiccation and starvation experienced by ectotherms in ramping assays will often be minor unless the assays involve small animals and last for many hours. Empirical data illustrate that the combined effects of food and humidity on thermal limits under ramping and sudden shifts to stressful conditions are unpredictable; in Drosophila melanogaster the presence of food decreased rather than increased thermal limits, whereas in Ceratitis capitata they had little impact. The literature provides examples where thermal limits are increased under ramping presumably because of the potential for physiological changes leading to acclimation. It is unclear whether heritabilities and population differentiation will necessarily be lower under ramping because of confounding effects. Although it is important to clearly define experimental methods, particularly when undertaking comparative assessments, and to understand potential confounding effects, thermotolerance assays based on ramping remain an important tool for understanding and predicting species responses to environmental change. An important area for further development is to identify the impact of rates of temperature change under field and laboratory conditions.
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Affiliation(s)
- John S. Terblanche
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Ary A. Hoffmann
- The University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, Victoria 3052, Australia
| | - Katherine A. Mitchell
- The University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, Victoria 3052, Australia
| | - Lea Rako
- The University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, Victoria 3052, Australia
| | - Peter C. le Roux
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Steven L. Chown
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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