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Fitness Analysis and Transcriptome Profiling Following Repeated Mild Heat Stress of Varying Frequency in Drosophila melanogaster Females. BIOLOGY 2021; 10:biology10121323. [PMID: 34943239 PMCID: PMC8698867 DOI: 10.3390/biology10121323] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary We studied the effect of mild heat stress (38 °C, 1 h) occurring once a day or once a week on D. melanogaster fertility, longevity, body composition metabolism and differential gene expression in fat body and adjacent tissues. Weekly stress in the first two weeks did not affect longevity but caused a decrease in fat content and an increase in the total level of fertility. Daily stress caused a significant longevity, fertility and fat content decrease, but an increase in carbohydrate levels compared with the control group. These data agree well with the results of transcriptome analysis, which demonstrated significant changes in expression levels of genes involved in proteolysis/digestion following daily stress. Heat shock protein 23 and stress-inducible humoral factor Turandot gene network are also involved. It is notable that daily and weekly heat stress resulted in different changes in metabolism, fitness and differential gene expression. Abstract Understanding how repeated stress affects metabolic and physiological functions in the long run is of crucial importance for evaluating anthropogenic pressure on the environment. We investigated fertility, longevity and metabolism in D. melanogaster females exposed to short-term heat stress (38 °C, 1 h) repeated daily or weekly. Daily stress was shown to cause a significant decrease in both fertility and longevity, as well as in body mass and triglyceride (fat) content, but a significant increase in trehalose and glucose content. Weekly stress did not affect longevity and carbohydrate metabolism but resulted in a significant decrease in body mass and fat content. Weekly stress did not affect the total level of fertility, despite sharp fertility drops on the exact days of stressing. However, stressing insects weekly, only in the first two weeks after eclosion, caused a significant increase in the total level of fertility. The analysis of differentially expressed genes in the fat bodies and adjacent tissues of researched groups with the use of RNA-Seq profiling revealed changes in signal pathways related to proteolysis/digestion, heat shock protein 23, and in the tightly linked stress-inducible humoral factor Turandot gene network.
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Goh GH, Blache D, Mark PJ, Kennington WJ, Maloney SK. Daily temperature cycles prolong lifespan and have sex-specific effects on peripheral clock gene expression in Drosophila melanogaster. J Exp Biol 2021; 224:237805. [PMID: 33758022 DOI: 10.1242/jeb.233213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 03/17/2021] [Indexed: 12/14/2022]
Abstract
Circadian rhythms optimize health by coordinating the timing of physiological processes to match predictable daily environmental challenges. The circadian rhythm of body temperature is thought to be an important modulator of molecular clocks in peripheral tissues, but how daily temperature cycles affect physiological function is unclear. Here, we examined the effect of constant temperature (Tcon, 25°C) and cycling temperature (Tcyc, 28°C:22°C during light:dark) paradigms on lifespan of Drosophila melanogaster, and the expression of clock genes, heat shock protein 83 (Hsp83), Frost (Fst) and senescence marker protein-30 (smp-30). Male and female D. melanogaster housed at Tcyc had longer median lifespans than those housed at Tcon. Tcyc induced robust Hsp83 rhythms and rescued the age-related decrease in smp-30 expression that was observed in flies at Tcon, potentially indicating an increased capacity to cope with age-related cellular stress. Ageing under Tcon led to a decrease in the amplitude of expression of all clock genes in the bodies of male flies, except for cyc, which was non-rhythmic, and for per and cry in female flies. Strikingly, housing under Tcyc conditions rescued the age-related decrease in amplitude of all clock genes, and generated rhythmicity in cyc expression, in the male flies, but not the female flies. The results suggest that ambient temperature rhythms modulate D. melanogaster lifespan, and that the amplitude of clock gene expression in peripheral body clocks may be a potential link between temperature rhythms and longevity in male D. melanogaster. Longevity due to Tcyc appeared predominantly independent of clock gene amplitude in female D. melanogaster.
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Affiliation(s)
- Grace H Goh
- School of Human Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Dominique Blache
- School of Agriculture and Environment, University of Western Australia, Crawley, WA 6009, Australia
| | - Peter J Mark
- School of Human Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - W Jason Kennington
- School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Shane K Maloney
- School of Human Sciences, University of Western Australia, Crawley, WA 6009, Australia
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3
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Lecheta MC, Awde DN, O’Leary TS, Unfried LN, Jacobs NA, Whitlock MH, McCabe E, Powers B, Bora K, Waters JS, Axen HJ, Frietze S, Lockwood BL, Teets NM, Cahan SH. Integrating GWAS and Transcriptomics to Identify the Molecular Underpinnings of Thermal Stress Responses in Drosophila melanogaster. Front Genet 2020; 11:658. [PMID: 32655626 PMCID: PMC7324644 DOI: 10.3389/fgene.2020.00658] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
Thermal tolerance of an organism depends on both the ability to dynamically adjust to a thermal stress and preparatory developmental processes that enhance thermal resistance. However, the extent to which standing genetic variation in thermal tolerance alleles influence dynamic stress responses vs. preparatory processes is unknown. Here, using the model species Drosophila melanogaster, we used a combination of Genome Wide Association mapping (GWAS) and transcriptomic profiling to characterize whether genes associated with thermal tolerance are primarily involved in dynamic stress responses or preparatory processes that influence physiological condition at the time of thermal stress. To test our hypotheses, we measured the critical thermal minimum (CTmin) and critical thermal maximum (CTmax) of 100 lines of the Drosophila Genetic Reference Panel (DGRP) and used GWAS to identify loci that explain variation in thermal limits. We observed greater variation in lower thermal limits, with CTmin ranging from 1.81 to 8.60°C, while CTmax ranged from 38.74 to 40.64°C. We identified 151 and 99 distinct genes associated with CTmin and CTmax, respectively, and there was strong support that these genes are involved in both dynamic responses to thermal stress and preparatory processes that increase thermal resistance. Many of the genes identified by GWAS were involved in the direct transcriptional response to thermal stress (72/151 for cold; 59/99 for heat), and overall GWAS candidates were more likely to be differentially expressed than other genes. Further, several GWAS candidates were regulatory genes that may participate in the regulation of stress responses, and gene ontologies related to development and morphogenesis were enriched, suggesting many of these genes influence thermal tolerance through effects on development and physiological status. Overall, our results suggest that thermal tolerance alleles can influence both dynamic plastic responses to thermal stress and preparatory processes that improve thermal resistance. These results also have utility for directly comparing GWAS and transcriptomic approaches for identifying candidate genes associated with thermal tolerance.
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Affiliation(s)
- Melise C. Lecheta
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - David N. Awde
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Thomas S. O’Leary
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Laura N. Unfried
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Nicholas A. Jacobs
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Miles H. Whitlock
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Eleanor McCabe
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Beck Powers
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Katie Bora
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - James S. Waters
- Department of Biology, Providence College, Providence, RI, United States
| | - Heather J. Axen
- Department of Biology and Biomedical Sciences, Salve Regina College, Providence, RI, United States
| | - Seth Frietze
- Department of Biomedical and Health Sciences, University of Vermont, Burlington, VT, United States
| | - Brent L. Lockwood
- Department of Biology, University of Vermont, Burlington, VT, United States
| | - Nicholas M. Teets
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| | - Sara H. Cahan
- Department of Biology, University of Vermont, Burlington, VT, United States
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Tsuboyama K, Osaki T, Matsuura-Suzuki E, Kozuka-Hata H, Okada Y, Oyama M, Ikeuchi Y, Iwasaki S, Tomari Y. A widespread family of heat-resistant obscure (Hero) proteins protect against protein instability and aggregation. PLoS Biol 2020; 18:e3000632. [PMID: 32163402 PMCID: PMC7067378 DOI: 10.1371/journal.pbio.3000632] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/05/2020] [Indexed: 01/08/2023] Open
Abstract
Proteins are typically denatured and aggregated by heating at near-boiling temperature. Exceptions to this principle include highly disordered and heat-resistant proteins found in extremophiles, which help these organisms tolerate extreme conditions such as drying, freezing, and high salinity. In contrast, the functions of heat-soluble proteins in non-extremophilic organisms including humans remain largely unexplored. Here, we report that heat-resistant obscure (Hero) proteins, which remain soluble after boiling at 95°C, are widespread in Drosophila and humans. Hero proteins are hydrophilic and highly charged, and function to stabilize various "client" proteins, protecting them from denaturation even under stress conditions such as heat shock, desiccation, and exposure to organic solvents. Hero proteins can also block several different types of pathological protein aggregations in cells and in Drosophila strains that model neurodegenerative diseases. Moreover, Hero proteins can extend life span of Drosophila. Our study reveals that organisms naturally use Hero proteins as molecular shields to stabilize protein functions, highlighting their biotechnological and therapeutic potential.
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Affiliation(s)
- Kotaro Tsuboyama
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Tatsuya Osaki
- Biomolecular and Cellular Engineering laboratory, Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, Japan
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Eriko Matsuura-Suzuki
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, Japan
| | - Hiroko Kozuka-Hata
- Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Yuki Okada
- Laboratory of Pathology and Development, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Masaaki Oyama
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Medical Proteomics Laboratory, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Yoshiho Ikeuchi
- Biomolecular and Cellular Engineering laboratory, Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, Japan
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Shintaro Iwasaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, Japan
| | - Yukihide Tomari
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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Boardman L, Mitchell KA, Terblanche JS, Sørensen JG. A transcriptomics assessment of oxygen-temperature interactions reveals novel candidate genes underlying variation in thermal tolerance and survival. JOURNAL OF INSECT PHYSIOLOGY 2018; 106:179-188. [PMID: 29038013 DOI: 10.1016/j.jinsphys.2017.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/17/2017] [Accepted: 10/12/2017] [Indexed: 06/07/2023]
Abstract
While single stress responses are fairly well researched, multiple, interactive stress responses are not-despite the obvious importance thereof. Here, using D. melanogaster, we investigated the effects of simultaneous exposures to low O2 (hypoxia) and varying thermal conditions on mortality rates, estimates of thermal tolerance and the transcriptome. We used combinations of 21 (normoxia), 10 or 5kPa O2 with control (23°C), cold (4°C) or hot (31°C) temperature exposures before assaying chill coma recovery time (CCRT) and heat knock down time (HKDT) as measures of cold and heat tolerance respectively. We found that mortality was significantly affected by temperature, oxygen partial pressure (PO2) and the interaction between the two. Cold treatments resulted in low mortality (<5%), regardless of PO2 treatment; while hot treatments resulted in higher mortality (∼20%), especially at 5kPa O2 which was lethal for most flies (∼80%). Both CCRT and HKDT were significantly affected by temperature, but not PO2, of the treatments, and the interaction of temperature and PO2 was non-significant. Hot treatments led to significantly longer CCRT, and shorter HKDT in comparison to cold treatments. Global gene expression profiling provided the first transcriptome level response to the combined stress of PO2 and temperature, showing that stressful treatments resulted in higher mortality and induced transcripts that were associated with protein kinases, catabolic processes (proteases, hydrolases, peptidases) and membrane function. Several genes and pathways that may be responsible for the protective effects of combined PO2 and cold treatments were identified. We found that urate oxidase was upregulated in all three cold treatments, regardless of the PO2. Small heat shock proteins Hsp22 and Hsp23 were upregulated after both 10 and 21kPa O2-hot treatments. Collectively, the data from PO2-hot treatments suggests that hypoxia does exacerbate heat stress, through an as yet unidentified mechanism. Hsp70B and an unannotated transcript (CG6733) were significantly differentially expressed after 5kPa O2-cold and 10kPa O2-hot treatments relative to their controls. Downregulation of these transcripts was correlated with reduced thermal tolerance (longer CCRT and shorter HKDT), suggesting that these genes may be important candidates for future research.
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Affiliation(s)
- Leigh Boardman
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, South Africa.
| | - Katherine A Mitchell
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, South Africa
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosch University, South Africa
| | - Jesper G Sørensen
- Section for Genetics, Ecology & Evolution, Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark
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Sharma V, Kohli S, Brahmachari V. Correlation between desiccation stress response and epigenetic modifications of genes in Drosophila melanogaster: An example of environment-epigenome interaction. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:1058-1068. [PMID: 28801151 DOI: 10.1016/j.bbagrm.2017.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/05/2017] [Accepted: 08/05/2017] [Indexed: 01/12/2023]
Abstract
Animals from different phyla including arthropods tolerate water stress to different extent. This tolerance is accompanied by biochemical changes which in turn are due to transcriptional alteration. The changes in transcription can be an indirect effect on some of the genes, ensuing from the effect of stress on the regulators of transcription including epigenetic regulators. Within this paradigm, we investigated the correlation between stress response and epigenetic modification underlying gene expression modulation during desiccation stress in Canton-S. We report altered resistance of flies in desiccation stress for heterozygote mutants of PcG and TrxG members. Pc/+ mutant shows lower survival, while ash1/+ mutants show higher survival under desiccation stress as compared to Canton-S. We detect expression alteration in stress related genes as well the genes of the Polycomb and trithorax complex in Canton-S subjected to desiccation stress. Concomitant with this, there is an altered enrichment of H3K27me3 and H3K4me3 at the upstream regions of the stress responsive genes. The enrichment of activating mark, H3K4me3, is higher in non-stress condition. H3K27me3, the repressive mark, is more pronounced under stress condition, which in turn, can be correlated with the binding of Pc. Our results show that desiccation stress induces dynamic switching in expression and enrichment of PcG and TrxG in the upstream region of genes, which correlates with histone modifications. We provide evidence that epigenetic modulation could be one of the mechanisms to adapt to the desiccation stress in Drosophila. Thus, our study proposes the interaction of epigenome and environmental factors.
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Affiliation(s)
- Vineeta Sharma
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, New Delhi 110 007, India.
| | - Surbhi Kohli
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, New Delhi 110 007, India
| | - Vani Brahmachari
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, New Delhi 110 007, India
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7
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Newman CE, Toxopeus J, Udaka H, Ahn S, Martynowicz DM, Graether SP, Sinclair BJ, Percival-Smith A. CRISPR-induced null alleles show that Frost protects Drosophila melanogaster reproduction after cold exposure. J Exp Biol 2017; 220:3344-3354. [DOI: 10.1242/jeb.160176] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/09/2017] [Indexed: 12/20/2022]
Abstract
The ability to survive and reproduce after cold exposure is important in all kingdoms of life. However, even in a sophisticated genetic model system like Drosophila melanogaster, few genes have been identified as functioning in cold tolerance. The accumulation of the Frost (Fst) gene transcript increases after cold exposure, making it a good candidate for a gene that has a role in cold tolerance. However, despite extensive RNAi knockdown analysis, no role in cold tolerance has been assigned to Fst. CRISPR is an effective technique for completely knocking down genes, and less likely to produce off-target effects than GAL4-UAS RNAi systems. We have used CRISPR-mediated homologous recombination to generate Fst null alleles, and these Fst alleles uncovered a requirement for FST protein in maintaining female fecundity following cold exposure. However, FST does not have a direct role in survival following cold exposure. FST mRNA accumulates in the Malpighian tubules, and the FST protein is a highly disordered protein with a putative signal peptide for export from the cell. Future work is needed to determine whether FST is exported from the Malpighian tubules and directly interacts with female reproductive tissues post-cold exposure, or if it is required for other repair/recovery functions that indirectly alter energy allocation to reproduction.
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Affiliation(s)
- Claire E. Newman
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Jantina Toxopeus
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Hiroko Udaka
- Department of Biology, University of Western Ontario, London, ON, Canada
- Present Address: Department of Zoology, Kyoto University, Kyoto, Japan
| | - Soohyun Ahn
- Department of Biology, University of Western Ontario, London, ON, Canada
- Present Address: Melbourne Dental School, University of Melbourne, Melbourne, VIC, Australia
| | - David M. Martynowicz
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Steffen P. Graether
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Brent J. Sinclair
- Department of Biology, University of Western Ontario, London, ON, Canada
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Mathur V, Schmidt PS. Adaptive patterns of phenotypic plasticity in laboratory and field environments in Drosophila melanogaster. Evolution 2016; 71:465-474. [PMID: 27925178 DOI: 10.1111/evo.13144] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 11/08/2016] [Accepted: 11/13/2016] [Indexed: 01/19/2023]
Abstract
Identifying mechanisms of adaptation to variable environments is essential in developing a comprehensive understanding of evolutionary dynamics in natural populations. Phenotypic plasticity allows for phenotypic change in response to changes in the environment, and as such may play a major role in adaptation to environmental heterogeneity. Here, the plasticity of stress response in Drosophila melanogaster originating from two distinct geographic regions and ecological habitats was examined. Adults were given a short-term, 5-day exposure to combinations of temperature and photoperiod to elicit a plastic response for three fundamental aspects of stress tolerance that vary adaptively with geography. This was replicated both in the laboratory and in outdoor enclosures in the field. In the laboratory, geographic origin was the primary determinant of the stress response. Temperature and the interaction between temperature and photoperiod also significantly affected stress resistance. In the outdoor enclosures, plasticity was distinct among traits and between geographic regions. These results demonstrate that short-term exposure of adults to ecologically relevant environmental cues results in predictable effects on multiple aspects of fitness. These patterns of plasticity vary among traits and are highly distinct between the two examined geographic regions, consistent with patterns of local adaptation to climate and associated environmental parameters.
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Affiliation(s)
- Vinayak Mathur
- Department of Biology, University of Pennsylvania, 433 S. University Avenue, Philadelphia, Pennsylvania, 19104.,Current Address: Department of Biology, Georgetown University, Washington, District of Columbia, 20057
| | - Paul S Schmidt
- Department of Biology, University of Pennsylvania, 433 S. University Avenue, Philadelphia, Pennsylvania, 19104
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Merenciano M, Ullastres A, de Cara MAR, Barrón MG, González J. Multiple Independent Retroelement Insertions in the Promoter of a Stress Response Gene Have Variable Molecular and Functional Effects in Drosophila. PLoS Genet 2016; 12:e1006249. [PMID: 27517860 PMCID: PMC4982627 DOI: 10.1371/journal.pgen.1006249] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 07/18/2016] [Indexed: 12/20/2022] Open
Abstract
Promoters are structurally and functionally diverse gene regulatory regions. The presence or absence of sequence motifs and the spacing between the motifs defines the properties of promoters. Recent alternative promoter usage analyses in Drosophila melanogaster revealed that transposable elements significantly contribute to promote diversity. In this work, we analyzed in detail one of the transposable element insertions, named FBti0019985, that has been co-opted to drive expression of CG18446, a candidate stress response gene. We analyzed strains from different natural populations and we found that besides FBti0019985, there are another eight independent transposable elements inserted in the proximal promoter region of CG18446. All nine insertions are solo-LTRs that belong to the roo family. We analyzed the sequence of the nine roo insertions and we investigated whether the different insertions were functionally equivalent by performing 5'-RACE, gene expression, and cold-stress survival experiments. We found that different insertions have different molecular and functional consequences. The exact position where the transposable elements are inserted matters, as they all showed highly conserved sequences but only two of the analyzed insertions provided alternative transcription start sites, and only the FBti0019985 insertion consistently affects CG18446 expression. The phenotypic consequences of the different insertions also vary: only FBti0019985 was associated with cold-stress tolerance. Interestingly, the only previous report of transposable elements inserting repeatedly and independently in a promoter region in D. melanogaster, were also located upstream of a stress response gene. Our results suggest that functional validation of individual structural variants is needed to resolve the complexity of insertion clusters.
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Affiliation(s)
- Miriam Merenciano
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona. Spain
| | - Anna Ullastres
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona. Spain
| | - M. A. R. de Cara
- Laboratoire d’Eco-anthropologie et Ethnobiologie, UMR 7206, CNRS/MNHN/Universite Paris 7, Museum National d’Histoire Naturelle, F-75116 Paris, France
| | - Maite G. Barrón
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona. Spain
| | - Josefa González
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona. Spain
- * E-mail:
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von Heckel K, Stephan W, Hutter S. Canalization of gene expression is a major signature of regulatory cold adaptation in temperate Drosophila melanogaster. BMC Genomics 2016; 17:574. [PMID: 27502401 PMCID: PMC4977637 DOI: 10.1186/s12864-016-2866-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 06/30/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Transcriptome analysis may provide means to investigate the underlying genetic causes of shared and divergent phenotypes in different populations and help to identify potential targets of adaptive evolution. Applying RNA sequencing to whole male Drosophila melanogaster from the ancestral tropical African environment and a very recently colonized cold-temperate European environment at both standard laboratory conditions and following a cold shock, we seek to uncover the transcriptional basis of cold adaptation. RESULTS In both the ancestral and the derived populations, the predominant characteristic of the cold shock response is the swift and massive upregulation of heat shock proteins and other chaperones. Although we find ~25 % of the genome to be differentially expressed following a cold shock, only relatively few genes (n = 16) are up- or down-regulated in a population-specific way. Intriguingly, 14 of these 16 genes show a greater degree of differential expression in the African population. Likewise, there is an excess of genes with particularly strong cold-induced changes in expression in Africa on a genome-wide scale. CONCLUSIONS The analysis of the transcriptional cold shock response most prominently reveals an upregulation of components of a general stress response, which is conserved over many taxa and triggered by a plethora of stressors. Despite the overall response being fairly similar in both populations, there is a definite excess of genes with a strong cold-induced fold-change in Africa. This is consistent with a detrimental deregulation or an overshooting stress response. Thus, the canalization of European gene expression might be responsible for the increased cold tolerance of European flies.
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Affiliation(s)
- Korbinian von Heckel
- Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Wolfgang Stephan
- Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Stephan Hutter
- Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany
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The Drosophila melanogaster Muc68E Mucin Gene Influences Adult Size, Starvation Tolerance, and Cold Recovery. G3-GENES GENOMES GENETICS 2016; 6:1841-51. [PMID: 27172221 PMCID: PMC4938639 DOI: 10.1534/g3.116.029934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Mucins have been implicated in many different biological processes, such as protection from mechanical damage, microorganisms, and toxic molecules, as well as providing a luminal scaffold during development. Nevertheless, it is conceivable that mucins have the potential to modulate food absorption as well, and thus contribute to the definition of several important phenotypic traits. Here we show that the Drosophila melanogaster Muc68E gene is 40- to 60-million-yr old, and is present in Drosophila species of the subgenus Sophophora only. The central repeat region of this gene is fast evolving, and shows evidence for repeated expansions/contractions. This and/or frequent gene conversion events lead to the homogenization of its repeats. The amino acid pattern P[ED][ED][ST][ST][ST] is found in the repeat region of Muc68E proteins from all Drosophila species studied, and can occur multiple times within a single conserved repeat block, and thus may have functional significance. Muc68E is a nonessential gene under laboratory conditions, but Muc68E mutant flies are smaller and lighter than controls at birth. However, at 4 d of age, Muc68E mutants are heavier, recover faster from chill-coma, and are more resistant to starvation than control flies, although they have the same percentage of lipids as controls. Mutant flies have enlarged abdominal size 1 d after chill-coma recovery, which is associated with higher lipid content. These results suggest that Muc68E has a role in metabolism modulation, food absorption, and/or feeding patterns in larvae and adults, and under normal and stress conditions. Such biological function is novel for mucin genes.
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Xiao R, Wang L, Cao Y, Zhang G. Transcriptome response to temperature stress in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae). Ecol Evol 2016; 6:3540-3554. [PMID: 27127612 PMCID: PMC4842027 DOI: 10.1002/ece3.2142] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/25/2016] [Accepted: 03/27/2016] [Indexed: 12/21/2022] Open
Abstract
The wolf spider Pardosa pseudoannulata is a dominant predator in paddy ecosystem and an important biological control agent of rice pests. Temperature represents a primary factor influencing its biology and behavior, although the underlying molecular mechanisms remain unknown. To understand the response of P. pseudoannulata to temperature stress, we performed comparative transcriptome analyses of spider adults exposed to 10°C and 40°C for 12 h. We obtained 67,725 assembled unigenes, 21,765 of which were annotated in P. pseudoannulata transcriptome libraries, and identified 905 and 834 genes significantly up- or down-regulated by temperature stress. Functional categorization revealed the differential regulation of transcription, signal transduction, and metabolism processes. Calcium signaling pathway and metabolic pathway involving respiratory chain components played important roles in adapting to low temperature, whereas at high temperature, oxidative phosphorylation and amino acid metabolism were critical. Differentially expressed ribosomal protein genes contributed to temperature stress adaptation, and heat shock genes were significantly up-regulated. This study represents the first report of transcriptome identification related to the Araneae species in response to temperature stress. These results will greatly facilitate our understanding of the physiological and biochemical mechanisms of spiders in response to temperature stress.
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Affiliation(s)
- Rong Xiao
- State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Liang Wang
- State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Yingshuai Cao
- State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
| | - Guren Zhang
- State Key Laboratory for BiocontrolSun Yat‐sen UniversityGuangzhouChina
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Identification, genomic organization and expression profiles of four heat shock protein genes in the western flower thrips, Frankliniella occidentalis. J Therm Biol 2016; 57:110-8. [PMID: 27033046 DOI: 10.1016/j.jtherbio.2016.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 03/11/2016] [Accepted: 03/13/2016] [Indexed: 11/21/2022]
Abstract
The western flower thrips, Frankliniella occidentalis, is an important invasive pest with a strong tolerance for extreme temperatures; however, the molecular mechanisms that regulate thermotolerance in this insect remain unclear. In this study, four heat shock protein genes were cloned from F. occidentalis and named Fohsp90, Fohsc701, Fohsc702 and Fohsp60. These four Hsps exhibited typical characteristics of heat shock proteins. Subcellular localization signals and phylogenetic analysis indicated that FoHsp90 and FoHsc701 localize to the cytosol, whereas FoHsc702 and FoHsp60 were located in the endoplasmic reticulum and mitochondria, respectively. Analysis of genomic sequences revealed the presence of introns in the four genes (three, four, seven, and five introns for Fohsp90, Fohsc701, Fohsc702 and Fohsp60, respectively). Both the number and position of introns in these four genes were quite different from analogous genes in other species. qRT-PCR indicated that the four Fohsps were detected in second-stage larvae, one-day-old pupae, and one-day-old adults, and mRNA expression levels were lowest in larvae and highest in pupae. Fohsc701 and Fohsc702 possessed similar expression patterns and were not induced by cold or heat stress. Expression of Fohsp60 was significantly elevated by heat, and Fohsp90 was rapidly up-regulated after exposure to both cold and heat stress. Exposure to -8°C had no effect on expression of the four Fohsps; however, expression of Fohsp90 and Fohsp60 was highest after a 2-h incubation at 39°C. Furthermore, cold and heat hardening led to significant up-regulation of the four Fohsps compared to their respective controls. Collectively, our results indicate that the four FoHsps contribute to insect development and also function in rapid cold or heat hardening; furthermore, FoHsp90 and FoHsp60 contribute to thermotolerance in F. occidentalis.
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Purać J, Kojić D, Petri E, Popović ŽD, Grubor-Lajšić G, Blagojević DP. Cold Adaptation Responses in Insects and Other Arthropods: An “Omics” Approach. SHORT VIEWS ON INSECT GENOMICS AND PROTEOMICS 2016. [DOI: 10.1007/978-3-319-24244-6_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Štětina T, Koštál V, Korbelová J. The Role of Inducible Hsp70, and Other Heat Shock Proteins, in Adaptive Complex of Cold Tolerance of the Fruit Fly (Drosophila melanogaster). PLoS One 2015; 10:e0128976. [PMID: 26034990 PMCID: PMC4452724 DOI: 10.1371/journal.pone.0128976] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/01/2015] [Indexed: 12/14/2022] Open
Abstract
Background The ubiquitous occurrence of inducible Heat Shock Proteins (Hsps) up-regulation in response to cold-acclimation and/or to cold shock, including massive increase of Hsp70 mRNA levels, often led to hasty interpretations of its role in the repair of cold injury expressed as protein denaturation or misfolding. So far, direct functional analyses in Drosophila melanogaster and other insects brought either limited or no support for such interpretations. In this paper, we analyze the cold tolerance and the expression levels of 24 different mRNA transcripts of the Hsps complex and related genes in response to cold in two strains of D. melanogaster: the wild-type and the Hsp70- null mutant lacking all six copies of Hsp70 gene. Principal Findings We found that larvae of both strains show similar patterns of Hsps complex gene expression in response to long-term cold-acclimation and during recovery from chronic cold exposures or acute cold shocks. No transcriptional compensation for missing Hsp70 gene was seen in Hsp70- strain. The cold-induced Hsps gene expression is most probably regulated by alternative splice variants C and D of the Heat Shock Factor. The cold tolerance in Hsp70- null mutants was clearly impaired only when the larvae were exposed to severe acute cold shock. No differences in mortality were found between two strains when the larvae were exposed to relatively mild doses of cold, either chronic exposures to 0°C or acute cold shocks at temperatures down to -4°C. Conclusions The up-regulated expression of a complex of inducible Hsps genes, and Hsp70 mRNA in particular, is tightly associated with cold-acclimation and cold exposure in D. melanogaster. Genetic elimination of Hsp70 up-regulation response has no effect on survival of chronic exposures to 0°C or mild acute cold shocks, while it negatively affects survival after severe acute cold shocks at temperaures below -8°C.
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Affiliation(s)
- Tomáš Štětina
- Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Vladimír Koštál
- Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
- * E-mail:
| | - Jaroslava Korbelová
- Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
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16
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Luo S, Ahola V, Shu C, Xu C, Wang R. Heat shock protein 70 gene family in the Glanville fritillary butterfly and their response to thermal stress. Gene 2015; 556:132-41. [DOI: 10.1016/j.gene.2014.11.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/05/2014] [Accepted: 11/20/2014] [Indexed: 12/13/2022]
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17
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Luo S, Chong Wong S, Xu C, Hanski I, Wang R, Lehtonen R. Phenotypic plasticity in thermal tolerance in the Glanville fritillary butterfly. J Therm Biol 2014; 42:33-9. [DOI: 10.1016/j.jtherbio.2014.02.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/21/2014] [Accepted: 02/24/2014] [Indexed: 11/25/2022]
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Kleynhans E, Mitchell KA, Conlong DE, Terblanche JS. Evolved variation in cold tolerance among populations of Eldana saccharina (Lepidoptera: Pyralidae) in South Africa. J Evol Biol 2014; 27:1149-59. [PMID: 24773121 DOI: 10.1111/jeb.12390] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/10/2014] [Accepted: 03/28/2014] [Indexed: 11/30/2022]
Abstract
Among-population variation in chill-coma onset temperature (CTmin ) is thought to reflect natural selection for local microclimatic conditions. However, few studies have investigated the evolutionary importance of cold tolerance limits in natural populations. Here, using a common-environment approach, we show pronounced variation in CTmin (± 4 °C) across the geographic range of a nonoverwintering crop pest, Eldana saccharina. The outcomes of this study provide two notable results in the context of evolved chill-coma variation: (1) CTmin differs significantly between geographic lines and is significantly positively correlated with local climates, and (2) there is a stable genetic architecture underlying CTmin trait variation, likely representing four key genes. Crosses between the most and least cold-tolerant geographic lines confirmed a genetic component to CTmin trait variation. Slower developmental time in the most cold-tolerant population suggests that local adaptation involves fitness costs; however, it confers fitness benefits in that environment. A significant reduction in phenotypic plasticity in the laboratory population suggests that plasticity of this trait is costly to maintain but also likely necessary for field survival. These results are significant for understanding field population adaption to novel environments, whereas further work is needed to dissect the underlying mechanism and gene(s) responsible.
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Affiliation(s)
- E Kleynhans
- Department of Conservation Ecology and Entomology, Centre for Invasion Biology, Faculty of AgriSciences, Stellenbosch University, Stellenbosch, South Africa
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Hernández-Sánchez IE, Martynowicz DM, Rodríguez-Hernández AA, Pérez-Morales MB, Graether SP, Jiménez-Bremont JF. A dehydrin-dehydrin interaction: the case of SK3 from Opuntia streptacantha. FRONTIERS IN PLANT SCIENCE 2014; 5:520. [PMID: 25346739 PMCID: PMC4193212 DOI: 10.3389/fpls.2014.00520] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/15/2014] [Indexed: 05/11/2023]
Abstract
Dehydrins belongs to a large group of highly hydrophilic proteins known as Late Embryogenesis Abundant (LEA) proteins. It is well known that dehydrins are intrinsically disordered plant proteins that accumulate during the late stages of embryogenesis and in response to abiotic stresses; however, the molecular mechanisms by which their functions are carried out are still unclear. We have previously reported that transgenic Arabidopsis plants overexpressing an Opuntia streptacantha SK3 dehydrin (OpsDHN1) show enhanced tolerance to freezing stress. Herein, we show using a split-ubiquitin yeast two-hybrid system that OpsDHN1 dimerizes. We found that the deletion of regions containing K-segments and the histidine-rich region in the OpsDHN1 protein affects dimer formation. Not surprisingly, in silico protein sequence analysis suggests that OpsDHN1 is an intrinsically disordered protein, an observation that was confirmed by circular dichroism and gel filtration of the recombinantly expressed protein. The addition of zinc triggered the association of recombinantly expressed OpsDHN1 protein, likely through its histidine-rich motif. These data brings new insights about the molecular mechanism of the OpsDHN1 SK3-dehydrin.
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Affiliation(s)
- Itzell E. Hernández-Sánchez
- Laboratorio de Estudios Moleculares de Respuesta a Estrés en Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica ACTangamanga, México
| | - David M. Martynowicz
- Department of Molecular and Cellular Biology, University of GuelphGuelph, ON, Canada
| | - Aida A. Rodríguez-Hernández
- Laboratorio de Estudios Moleculares de Respuesta a Estrés en Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica ACTangamanga, México
| | - Maria B. Pérez-Morales
- Laboratorio de Estudios Moleculares de Respuesta a Estrés en Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica ACTangamanga, México
| | - Steffen P. Graether
- Department of Molecular and Cellular Biology, University of GuelphGuelph, ON, Canada
| | - Juan F. Jiménez-Bremont
- Laboratorio de Estudios Moleculares de Respuesta a Estrés en Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica ACTangamanga, México
- *Correspondence: Juan F. Jiménez-Bremont, Laboratorio de Estudios Moleculares de Respuesta a Estrés en Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica AC, Camino a la Presa de San Jose No. 2055 Lomas 4a Seccion Cp 78216, AP 3-74 Tangamanga, San Luis Potosi, Mexico e-mail:
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Udaka H, Percival-Smith A, Sinclair BJ. Increased abundance of frost mRNA during recovery from cold stress is not essential for cold tolerance in adult Drosophila melanogaster. INSECT MOLECULAR BIOLOGY 2013; 22:541-550. [PMID: 23901849 DOI: 10.1111/imb.12044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Frost (Fst) is a candidate gene associated with the response to cold in Drosophila melanogaster because Fst mRNA accumulation increases during recovery from low temperature exposure. We investigated the contribution of Fst expression to chill-coma recovery time, acute cold tolerance and rapid cold hardening (RCH) in adult D. melanogaster by knocking down Fst mRNA expression using GAL4/UAS-mediated RNA interference. In this experiment, four UAS-Fst and one tubulin-GAL4 lines were used. We predicted that if Fst is essential for cold tolerance phenotypes, flies with low Fst mRNA levels should be less cold tolerant than flies with normal levels of cold-induced Fst mRNA. Cold-induced Fst abundance and recovery time from chill-coma were not negatively correlated in male or female flies. Survival of 2 h exposures to sub-zero temperatures in Fst knockdown lines was not lower than that in a control line. Moreover, a low temperature pretreatment increased survival of severe cold exposure in flies regardless of Fst abundance level during recovery from cold stress, suggesting that Fst expression is not essential for RCH. Thus, cold-induced Fst accumulation is not essential for cold tolerance measured as chill-coma recovery time, survival to acute cold stress and RCH response in adult D. melanogaster.
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Affiliation(s)
- H Udaka
- Department of Biology, The University of Western Ontario, London, ON, Canada.
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21
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Dunning LT, Dennis AB, Park D, Sinclair BJ, Newcomb RD, Buckley TR. Identification of cold-responsive genes in a New Zealand alpine stick insect using RNA-Seq. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2013; 8:24-31. [DOI: 10.1016/j.cbd.2012.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/19/2012] [Accepted: 10/20/2012] [Indexed: 12/22/2022]
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22
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Kobey RL, Montooth KL. Mortality from desiccation contributes to a genotype-temperature interaction for cold survival in Drosophila melanogaster. ACTA ACUST UNITED AC 2012. [PMID: 23197100 DOI: 10.1242/jeb.076539] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Survival at cold temperatures is a complex trait, primarily because of the fact that the physiological cause of injury may differ across degrees of cold exposure experienced within the lifetime of an ectothermic individual. In order to better understand how chill-sensitive insects experience and adapt to low temperatures, we investigated the physiological basis for cold survival across a range of temperature exposures from -4 to 6°C in five genetic lines of the fruit fly Drosophila melanogaster. Genetic effects on cold survival were temperature dependent and resulted in a significant genotype-temperature interaction for survival across cold temperature exposures that differ by as little as 2°C. We investigated desiccation as a potential mechanism of injury across these temperature exposures. Flies were dehydrated following exposures near 6°C, whereas flies were not dehydrated following exposures near -4°C. Furthermore, decreasing humidity during cold exposure decreased survival, and increasing humidity during cold exposure increased survival at 6°C, but not at -4°C. These results support the conclusion that in D. melanogaster there are multiple physiological mechanisms of cold-induced mortality across relatively small differences in temperature, and that desiccation contributes to mortality for exposures near 6°C but not for subzero temperatures. Because D. melanogaster has recently expanded its range from tropical to temperate latitudes, the complex physiologies underlying cold tolerance are likely to be important traits in the recent evolutionary history of this fruit fly.
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Affiliation(s)
- Robert L Kobey
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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23
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Armstrong GAB, Rodríguez EC, Meldrum Robertson R. Cold hardening modulates K+ homeostasis in the brain of Drosophila melanogaster during chill coma. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1511-1516. [PMID: 23017334 DOI: 10.1016/j.jinsphys.2012.09.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 09/10/2012] [Accepted: 09/11/2012] [Indexed: 06/01/2023]
Abstract
Environmental temperature is one of the most important abiotic factors affecting insect behaviour; virtually all physiological processes, including those which regulate nervous system function, are affected. At both low and high temperature extremes insects enter a coma during which individuals do not display behaviour and are unresponsive to stimulation. We investigated neurophysiological correlates of chill and hyperthermic coma in Drosophila melanogaster. Coma resulting from anoxia causes a profound loss of K(+) homeostasis characterized by a surge in extracellular K(+) concentration ([K(+)](o)) in the brain. We recorded [K(+)](o) in the brain during exposure to both low and high temperatures and observed a similar surge in [K(+)](o) which recovered to baseline concentrations following return to room temperature. We also found that rapid cold hardening (RCH) using a cold pretreatment (4°C for 2h; 2h recovery at room temperature) increased the peak brain [K(+)](o) reached during a subsequent chill coma and increased the rates of accumulation and clearance of [K(+)](o). We conclude that RCH preserves K(+) homeostasis in the fly brain during exposure to cold by reducing the temperature sensitivity of the rates of homeostatic processes.
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Affiliation(s)
- Gary A B Armstrong
- Department of Biology, Queen's University, Kingston, ON, Canada K7L 3N6.
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24
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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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25
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Hoffmann AA, Blacket MJ, McKechnie SW, Rako L, Schiffer M, Rane RV, Good RT, Robin C, Lee SF. A proline repeat polymorphism of the Frost gene of Drosophila melanogaster showing clinal variation but not associated with cold resistance. INSECT MOLECULAR BIOLOGY 2012; 21:437-445. [PMID: 22708613 DOI: 10.1111/j.1365-2583.2012.01149.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Genetic polymorphisms underlying adaptive shifts in thermal responses are poorly known even though studies are providing a detailed understanding of these responses at the cellular and physiological levels. The Frost gene of Drosophila melanogaster is a prime candidate for thermal adaptation; it is up-regulated under cold stress and knockdown of this gene influences cold resistance. Here we describe an amino-acid INDEL polymorphism in proline repeat number in the structural component of this gene. The two main repeats, accounting for more than 90% of alleles in eastern Australia, show a strong clinal pattern; the 6P allele was at a high frequency in tropical locations, and the 10P allele was common in temperate populations. However, the frequency of these alleles was not associated with three different assays of cold resistance. Adult transcription level of Frost was also unrelated to cold resistance as measured through post chill coma mobility. The functional significance of the proline repeat polymorphism therefore remains unclear despite its clinal pattern. The data also demonstrate the feasibility of using Roche/454 sequencing for establishing clinal patterns.
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Affiliation(s)
- A A Hoffmann
- Department of Genetics, Bio21 Institute, The University of Melbourne, Melbourne, Victoria, Australia School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
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26
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Tattersall GJ, Sinclair BJ, Withers PC, Fields PA, Seebacher F, Cooper CE, Maloney SK. Coping with Thermal Challenges: Physiological Adaptations to Environmental Temperatures. Compr Physiol 2012; 2:2151-202. [DOI: 10.1002/cphy.c110055] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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27
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Bing X, Zhang J, Sinclair BJ. A comparison of Frost expression among species and life stages of Drosophila. INSECT MOLECULAR BIOLOGY 2012; 21:31-39. [PMID: 21955087 DOI: 10.1111/j.1365-2583.2011.01108.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Frost (Fst) is a gene associated with cold exposure in Drosophila melanogaster. We used real-time PCR to assess whether cold exposure induces expression of Fst in 10 different life stages of D. melanogaster, and adults of seven other Drosophila species. We exposed groups of individuals to 0 °C (2 h), followed by 1 h recovery (22 °C). Frost was significantly upregulated in response to cold in eggs, third instar larvae, and 2- and 5-day-old male and female adults in D. melanogaster. Life stages in which cold did not upregulate Fst had high constitutive expression. Frost is located on the opposite strand of an intron of Diuretic hormone (DH), but cold exposure did not upregulate DH. Frost orthologues were identified in six other species within the Melanogaster group (Drosophila sechellia, Drosophila simulans, Drosophila yakuba, Drosophila erecta, Drosophila ananassae and Drosophila mauritiana). Frost orthologues were upregulated in response to cold exposure in both sexes in adults of all of these species. The predicted structure of a putative Frost consensus protein shows highly conserved tandem repeats of motifs involved in cell signalling (PEST and TRAF2), suggesting that Fst might encode an adaptor protein involved in acute stress or apoptosis signalling in vivo.
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Affiliation(s)
- X Bing
- Department of Biology, The University of Western Ontario, London, ON, Canada
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28
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Colinet H, Sciaussat D, Bozzolan F, Bowler K. Rapid decline of cold tolerance at young age is associated with expression of stress genes in Drosophila melanogaster. J Exp Biol 2012; 216:253-9. [DOI: 10.1242/jeb.076216] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Summary
Many endogenous factors influence thermal tolerance of insects. Among these, age contributes an important source of variation. Heat tolerance is typically high in newly-enclosed insects, before declining dramatically. It is not known whether this phenomenon relates to cold tolerance also. In addition, the underlying mechanisms of this variation are unresolved. In this study we tested whether cold tolerance declines in Drosophila melanogaster females aged from 0 to 5 days. We also assessed whether expression (basal and induced) of eight stress genes (hsp22, hsp23, hsp40, hsp68, hsp70Aa, hsp83, Starvin and Frost) varied post-eclosion in correspondence with changes found cold tolerance. We report that cold tolerance was very high at eclosion and then it rapidly declined in young flies. hsp23 and hsp68 showed a dramatic age-related variation of basal expression that was associated with cold tolerance proxies. Significant age-related plasticity of cold-induced expression was also found for hsp22, hsp23, hsp68, hsp70Aa, Frost and Starvin. hsp22 and hsp70Aa induced expression was high in newly-enclosed phenotypes before declining dramatically, whilst opposite age-related patterns were found for hsp23, hsp68, Starvin and Frost. This study shows a marked within-stage variation in cold tolerance. The involvement of the stress genes in setting basal thermal tolerance is discussed.
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Affiliation(s)
- Hervé Colinet
- Université Catholique de Louvain, Belgium; Université de Rennes, France
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Zhang J, Marshall KE, Westwood JT, Clark MS, Sinclair BJ. Divergent transcriptomic responses to repeated and single cold exposures in Drosophila melanogaster. J Exp Biol 2011; 214:4021-9. [DOI: 10.1242/jeb.059535] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SUMMARY
Insects in the field are exposed to multiple bouts of cold, and there is increasing evidence that the fitness consequences of repeated cold exposure differ from the impacts of a single cold exposure. We tested the hypothesis that different kinds of cold exposure (in this case, single short, prolonged and repeated cold exposure) would result in differential gene expression. We exposed 3 day old adult female wild-type Drosophila melanogaster (Diptera: Drosophilidae) to –0.5°C for a single 2 h exposure, a single 10 h exposure, or five 2 h exposures on consecutive days, and extracted RNA after 6 h of recovery. Global gene expression was quantified using an oligonucleotide microarray and validated with real-time PCR using different biological replicates. We identified 76 genes upregulated in response to multiple cold exposure, 69 in response to prolonged cold exposure and 20 genes upregulated in response to a single short cold exposure, with a small amount of overlap between treatments. Three genes – Turandot A, Hephaestus and CG11374 – were upregulated in response to all three cold exposure treatments. Key functional groups upregulated include genes associated with muscle structure and function, the immune response, stress response, carbohydrate metabolism and egg production. We conclude that cold exposure has wide-ranging effects on gene expression in D. melanogaster and that increased duration or frequency of cold exposure has impacts different to those of a single short cold exposure. This has important implications for extrapolating laboratory studies of insect overwintering that are based on only a single cold exposure.
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Affiliation(s)
- Jian Zhang
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - Katie E. Marshall
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - J. Timothy Westwood
- Canadian Drosophila Microarray Centre, Department of Biology, The University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Melody S. Clark
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB1 9XU, UK
| | - Brent J. Sinclair
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
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Reis M, Vieira CP, Morales-Hojas R, Aguiar B, Rocha H, Schlötterer C, Vieira J. A comparative study of the short term cold resistance response in distantly related Drosophila species: the role of regucalcin and frost. PLoS One 2011; 6:e25520. [PMID: 21991316 PMCID: PMC3184994 DOI: 10.1371/journal.pone.0025520] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 09/05/2011] [Indexed: 01/24/2023] Open
Abstract
The molecular basis of short term cold resistance (indexed as chill-coma recovery time) has been mostly addressed in D. melanogaster, where candidate genes (Dca (also known as smp-30) and Frost (Fst)) have been identified. Nevertheless, in Drosophila, the ability to tolerate short term exposure to low temperatures evolved several times independently. Therefore, it is unclear whether variation in the same candidate genes is also responsible for short term cold resistance in distantly related Drosophila species. It should be noted that Dca is a candidate gene for cold resistance in the Sophophora subgenus only, since there is no orthologous gene copy in the Drosophila subgenus. Here we show that, in D. americana (Drosophila subgenus), there is a north-south gradient for a variant at the 5′ non-coding region of regucalcin (a Dca-like gene; in D. melanogaster the proteins encoded by the two genes share 71.9% amino acid identities) but in our D. americana F2 association experiment there is no association between this polymorphism and chill-coma recovery times. Moreover, we found no convincing evidence that this gene is up-regulated after cold shock in both D. americana and D. melanogaster. Size variation in the Fst PEST domain (putatively involved in rapid protein degradation) is observed when comparing distantly related Drosophila species, and is associated with short term cold resistance differences in D. americana. Nevertheless, this effect is likely through body size variation. Moreover, we show that, even at two hours after cold shock, when up-regulation of this gene is maximal in D. melanogaster (about 48 fold expression change), in D. americana this gene is only moderately up-regulated (about 3 fold expression change). Our work thus shows that there are important differences regarding the molecular basis of cold resistance in distantly related Drosophila species.
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Affiliation(s)
- Micael Reis
- IBMC-Instituto de Biologia Celular e Molecular, University of Porto, Porto, Portugal
| | - Cristina P. Vieira
- IBMC-Instituto de Biologia Celular e Molecular, University of Porto, Porto, Portugal
| | - Ramiro Morales-Hojas
- IBMC-Instituto de Biologia Celular e Molecular, University of Porto, Porto, Portugal
| | - Bruno Aguiar
- IBMC-Instituto de Biologia Celular e Molecular, University of Porto, Porto, Portugal
| | - Hélder Rocha
- IBMC-Instituto de Biologia Celular e Molecular, University of Porto, Porto, Portugal
| | | | - Jorge Vieira
- IBMC-Instituto de Biologia Celular e Molecular, University of Porto, Porto, Portugal
- * E-mail:
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31
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Svetec N, Werzner A, Wilches R, Pavlidis P, Alvarez-Castro JM, Broman KW, Metzler D, Stephan W. Identification of X-linked quantitative trait loci affecting cold tolerance in Drosophila melanogaster and fine mapping by selective sweep analysis. Mol Ecol 2010; 20:530-44. [PMID: 21199023 DOI: 10.1111/j.1365-294x.2010.04951.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Drosophila melanogaster is a cosmopolitan species that colonizes a great variety of environments. One trait that shows abundant evidence for naturally segregating genetic variance in different populations of D. melanogaster is cold tolerance. Previous work has found quantitative trait loci (QTL) exclusively on the second and the third chromosomes. To gain insight into the genetic architecture of cold tolerance on the X chromosome and to compare the results with our analyses of selective sweeps, a mapping population was derived from a cross between substitution lines that solely differed in the origin of their X chromosome: one originates from a European inbred line and the other one from an African inbred line. We found a total of six QTL for cold tolerance factors on the X chromosome of D. melanogaster. Although the composite interval mapping revealed slightly different QTL profiles between sexes, a coherent model suggests that most QTL overlapped between sexes, and each explained around 5-14% of the genetic variance (which may be slightly overestimated). The allelic effects were largely additive, but we also detected two significant interactions. Taken together, this provides evidence for multiple QTL that are spread along the entire X chromosome and whose effects range from low to intermediate. One detected transgressive QTL influences cold tolerance in different ways for the two sexes. While females benefit from the European allele increasing their cold tolerance, males tend to do better with the African allele. Finally, using selective sweep mapping, the candidate gene CG16700 for cold tolerance colocalizing with a QTL was identified.
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Affiliation(s)
- Nicolas Svetec
- Section of Evolutionary Biology, Biocenter, University of Munich, 82152 Planegg-Martinsried, Germany
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32
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Udaka H, Ueda C, Goto SG. Survival rate and expression of Heat-shock protein 70 and Frost genes after temperature stress in Drosophila melanogaster lines that are selected for recovery time from temperature coma. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1889-1894. [PMID: 20713057 DOI: 10.1016/j.jinsphys.2010.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 08/06/2010] [Accepted: 08/06/2010] [Indexed: 05/29/2023]
Abstract
In this study, we investigated the physiological mechanisms underlying temperature tolerance using Drosophila melanogaster lines with rapid, intermediate, or slow recovery from heat or chill coma that were established by artificial selection or by free recombination without selection. Specifically, we focused on the relationships among their recovery from heat or chill coma, survival after severe heat or cold, and survival enhanced by rapid cold hardening (RCH) or heat hardening. The recovery time from heat coma was not related to the survival rate after severe heat. The line with rapid recovery from chill coma showed a higher survival rate after severe cold exposure, and therefore the same mechanisms are likely to underlie these phenotypes. The recovery time from chill coma and survival rate after severe cold were unrelated to RCH-enhanced survival. We also examined the expression of two genes, Heat-shock protein 70 (Hsp70) and Frost, in these lines to understand the contribution of these stress-inducible genes to intraspecific variation in recovery from temperature coma. The line showing rapid recovery from heat coma did not exhibit higher expression of Hsp70 and Frost. In addition, Hsp70 and Frost transcription levels were not correlated with the recovery time from chill coma. Thus, Hsp70 and Frost transcriptional regulation was not involved in the intraspecific variation in recovery from temperature coma.
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Affiliation(s)
- Hiroko Udaka
- Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558 8585, Japan
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33
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Genetic variation in senescence marker protein-30 is associated with natural variation in cold tolerance in Drosophila. Genet Res (Camb) 2010; 92:103-13. [PMID: 20515514 DOI: 10.1017/s0016672310000108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A comprehensive understanding of the genetic basis of phenotypic adaptation in nature requires the identification of the functional allelic variation underlying adaptive phenotypes. The manner in which organisms respond to temperature extremes is an adaptation in many species. In the current study, we investigate the role of molecular variation in senescence marker protein-30 (Smp-30) on natural phenotypic variation in cold tolerance in Drosophila melanogaster. Smp-30 encodes a product that is thought to be involved in the regulation of Ca2+ ion homeostasis and has been shown previously to be differentially expressed in response to cold stress. Thus, we sought to assess whether molecular variation in Smp-30 was associated with natural phenotypic variation in cold tolerance in a panel of naturally derived inbred lines from a population in Raleigh, North Carolina. We identified four non-coding polymorphisms that were strongly associated with natural phenotypic variation in cold tolerance. Interestingly, two polymorphisms that were in close proximity to one another (2 bp apart) exhibited opposite phenotypic effects. Consistent with the maintenance of a pair of antagonistically acting polymorphisms, tests of molecular evolution identified a significant excess of maintained variation in this region, suggesting balancing selection is acting to maintain this variation. These results suggest that multiple mutations in non-coding regions can have significant effects on phenotypic variation in adaptive traits within natural populations, and that balancing selection can maintain polymorphisms with opposite effects on phenotypic variation.
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Mechanisms of suspended animation are revealed by transcript profiling of diapause in the flesh fly. Proc Natl Acad Sci U S A 2010; 107:14909-14. [PMID: 20668242 DOI: 10.1073/pnas.1007075107] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diapause is a widespread adaptation to seasonality across invertebrate taxa. It is critical for persistence in seasonal environments, synchronizing life histories with favorable, resource-rich conditions and mitigating exposure to harsh environments. Despite some promising recent progress, however, we still know very little about the molecular modifications underlying diapause. We used transcriptional profiling to identify key groups of genes and pathways differentially regulated during pupal diapause, dynamically regulated across diapause development, and differentially regulated after diapause was pharmacologically terminated in the flesh fly Sarcophaga crassipalpis. We describe major shifts in stress axes, endocrine signaling, and metabolism that accompany diapause, several of which appear to be common features of dormancy in other taxa. To assess whether invertebrates with different diapause strategies have converged toward similar transcriptional profiles, we use archived expression data to compare the pupal diapause of S. crassipalpis with the adult reproductive diapause of Drosophila melanogaster and the larval dauer of Caenorhabditis elegans. Although dormant invertebrates converge on a few similar physiological phenotypes including metabolic depression and stress resistance, we find little transcriptional similarity among dormancies across species, suggesting that there may be many transcriptional strategies for producing physiologically similar dormancy responses.
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35
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Functional characterization of the Frost gene in Drosophila melanogaster: importance for recovery from chill coma. PLoS One 2010; 5:e10925. [PMID: 20532197 PMCID: PMC2880008 DOI: 10.1371/journal.pone.0010925] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 05/12/2010] [Indexed: 11/25/2022] Open
Abstract
Background Almost all animals, including insects, need to adapt to temperature fluctuations. The molecular basis of thermal adaptation is not well understood, although a number of candidate genes have been proposed. However, a functional link between candidate genes and thermal tolerance has rarely been established. The gene Frost (Fst) was first discovered when Drosophila flies were exposed to cold stress, but the biological function(s) of Fst has so far not been characterized. Because Fst is up-regulated after a cold stress, we tested whether it was essential for chill-coma recovery. Methodology/Principal Findings A marked increase in Fst expression was detected (by RT-PCR) during recovery from cold stress, peaking at 42-fold after 2 h. The GAL4/UAS system was used to knock down expression of Fst and recovery ability was assessed in transgenic adults following 12 h of chill coma at 0°C. The ability to recover from cold stress (short-, medium- and long-term) was significantly altered in the transgenic adults that had Fst silenced. These findings show that Fst plays an essential role in the recovery from chill coma in both males and females. Conclusions/Significance The Frost gene is essential for cold tolerance in Drosophila melanogaster and may play an important role in thermal adaptation.
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Fernández-Ayala DJM, Chen S, Kemppainen E, O'Dell KMC, Jacobs HT. Gene expression in a Drosophila model of mitochondrial disease. PLoS One 2010; 5:e8549. [PMID: 20066047 PMCID: PMC2798955 DOI: 10.1371/journal.pone.0008549] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 11/28/2009] [Indexed: 01/12/2023] Open
Abstract
Background A point mutation in the Drosophila gene technical knockout (tko), encoding mitoribosomal protein S12, was previously shown to cause a phenotype of respiratory chain deficiency, developmental delay, and neurological abnormalities similar to those presented in many human mitochondrial disorders, as well as defective courtship behavior. Methodology/Principal Findings Here, we describe a transcriptome-wide analysis of gene expression in tko25t mutant flies that revealed systematic and compensatory changes in the expression of genes connected with metabolism, including up-regulation of lactate dehydrogenase and of many genes involved in the catabolism of fats and proteins, and various anaplerotic pathways. Gut-specific enzymes involved in the primary mobilization of dietary fats and proteins, as well as a number of transport functions, were also strongly up-regulated, consistent with the idea that oxidative phosphorylation OXPHOS dysfunction is perceived physiologically as a starvation for particular biomolecules. In addition, many stress-response genes were induced. Other changes may reflect a signature of developmental delay, notably a down-regulation of genes connected with reproduction, including gametogenesis, as well as courtship behavior in males; logically this represents a programmed response to a mitochondrially generated starvation signal. The underlying signalling pathway, if conserved, could influence many physiological processes in response to nutritional stress, although any such pathway involved remains unidentified. Conclusions/Significance These studies indicate that general and organ-specific metabolism is transformed in response to mitochondrial dysfunction, including digestive and absorptive functions, and give important clues as to how novel therapeutic strategies for mitochondrial disorders might be developed.
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Affiliation(s)
| | - Shanjun Chen
- Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Esko Kemppainen
- Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Kevin M. C. O'Dell
- Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Howard T. Jacobs
- Institute of Medical Technology and Tampere University Hospital, University of Tampere, Tampere, Finland
- Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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Zsindely N, Pankotai T, Ujfaludi Z, Lakatos D, Komonyi O, Bodai L, Tora L, Boros IM. The loss of histone H3 lysine 9 acetylation due to dSAGA-specific dAda2b mutation influences the expression of only a small subset of genes. Nucleic Acids Res 2009; 37:6665-80. [PMID: 19740772 PMCID: PMC2777428 DOI: 10.1093/nar/gkp722] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In Drosophila, the dADA2b-containing dSAGA complex is involved in histone H3 lysine 9 and 14 acetylation. Curiously, although the lysine 9- and 14-acetylated histone H3 levels are drastically reduced in dAda2b mutants, these animals survive until a late developmental stage. To study the molecular consequences of the loss of histone H3 lysine 9 and 14 acetylation, we compared the total messenger ribonucleic acid (mRNA) profiles of wild type and dAda2b mutant animals at two developmental stages. Global gene expression profiling indicates that the loss of dSAGA-specific H3 lysine 9 and 14 acetylation results in the expression change (up- or down-regulation) of a rather small subset of genes and does not cause a general transcription de-regulation. Among the genes up-regulated in dAda2b mutants, particularly high numbers are those which play roles in antimicrobial defense mechanisms. Results of chromatin immunoprecipitation experiments indicate that in dAda2b mutants, the lysine 9-acetylated histone H3 levels are decreased both at dSAGA up- and down-regulated genes. In contrast to that, in the promoters of dSAGA-independent ribosomal protein genes a high level of histone H3K9ac is maintained in dAda2b mutants. Our data suggest that by acetylating H3 at lysine 9, dSAGA modifies Pol II accessibility to specific promoters differently.
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Affiliation(s)
- Nóra Zsindely
- Chromatin Research Group of HAS, Department of Biochemistry and Molecular Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary
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38
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Telonis-Scott M, Hallas R, McKechnie SW, Wee CW, Hoffmann AA. Selection for cold resistance alters gene transcript levels in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:549-555. [PMID: 19232407 DOI: 10.1016/j.jinsphys.2009.01.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/20/2009] [Accepted: 01/23/2009] [Indexed: 05/27/2023]
Abstract
Microarrays have been used to examine changes in gene expression underlying responses to selection for increased stress resistance in Drosophila melanogaster, but changes in expression patterns associated with increased resistance to cold stress have not been previously reported. Here we describe such changes in basal expression levels in replicate lines following selection for increased resistance to chill coma stress. We found significant up- or down-regulation of expression in 94 genes on the Affymetrix Genome 2.0 array. Quantitative RT-PCR was used to confirm changes in expression of six genes. Some of the identified genes had previously been associated with stress resistance but no previously identified candidate genes for cold resistance showed altered patterns of expression. Seven differentially expressed genes that form a tight chromosomal cluster and an unlinked gene AnnX may be potentially important for cold adaptation in natural populations. Artificial selection for chill coma resistance therefore altered basal patterns of gene expression, but we failed to link these changes to plastic changes in expression under cold stress or to previously identified candidate genes for components of cold resistance.
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Affiliation(s)
- M Telonis-Scott
- Centre for Environmental Stress and Adaptation Research, Department of Genetics, University of Melbourne, Vic, Australia
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39
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How insects survive the cold: molecular mechanisms—a review. J Comp Physiol B 2008; 178:917-33. [DOI: 10.1007/s00360-008-0286-4] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 05/12/2008] [Accepted: 06/10/2008] [Indexed: 12/25/2022]
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40
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Schmidt PS, Paaby AB. REPRODUCTIVE DIAPAUSE AND LIFE-HISTORY CLINES IN NORTH AMERICAN POPULATIONS OF DROSOPHILA MELANOGASTER. Evolution 2008; 62:1204-15. [PMID: 18298646 DOI: 10.1111/j.1558-5646.2008.00351.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul S Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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41
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Milton CC, Partridge L. Brief carbon dioxide exposure blocks heat hardening but not cold acclimation in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2008; 54:32-40. [PMID: 17884085 DOI: 10.1016/j.jinsphys.2007.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 08/04/2007] [Accepted: 08/04/2007] [Indexed: 05/17/2023]
Abstract
Carbon dioxide is a commonly used anaesthetic in Drosophila research. While any detrimental effects of CO2 exposure on behaviour or traits are largely unknown, a recent study observed significant effects of CO2 exposure on rapid cold hardening and chill-coma recovery in Drosophila melanogaster. In this study we investigated the effect of a brief CO2 exposure on heat hardening and cold acclimation in D. melanogaster, measuring heat knockdown and chill-coma recovery times of flies exposed to CO2 for 1 min after hardening or acclimation. CO2 anaesthesia had a significant negative effect on heat hardening, with heat knockdown rates in hardened flies completely reduced to those of controls after CO2 exposure. Chill-coma recovery rates also significantly increased in acclimated flies that were exposed to CO2, although not to the same extent seen in the heat populations. CO2 exposure had no impact on heat knockdown rates of control flies, while there was a significant negative effect of the anaesthetic on chill-coma recovery rates of control flies. In light of these results, we suggest that CO2 should not be used after hardening in heat resistance assays due to the complete reversal of the heat hardening process upon exposure to CO2.
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Affiliation(s)
- Claire C Milton
- Department of Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK.
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42
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Rako L, Blacket MJ, McKechnie SW, Hoffmann AA. Candidate genes and thermal phenotypes: identifying ecologically important genetic variation for thermotolerance in the Australian Drosophila melanogaster cline. Mol Ecol 2007; 16:2948-57. [PMID: 17614909 DOI: 10.1111/j.1365-294x.2007.03332.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clinal variation in traits often reflects climatic adaptation; in Drosophila melanogaster clinal variation provides an opportunity to link variation in chromosomal inversions, microsatellite loci and various candidate genes to adaptive variation in traits. We undertook association studies with crosses from a single population of D. melanogaster from eastern Australia to investigate the association between genetic markers and traits showing clinal variation. By genotyping parents and phenotyping offspring, we minimized genotyping costs but had the power to detect association between markers and quantitative traits. Consistent with prior studies, we found strong associations between the clinal chromosomal inversion In(3R)Payne and markers within it, as well as among these markers. We also found an association between In(3L)Payne and one marker located within this inversion. Of the five predicted associations between markers and traits, four were detected (increased heat, decreased cold resistance and body size with the heat shock gene hsr-omega S, increased cold resistance with the inversion In(3L)Payne), while one was not detected (heat resistance and the heat shock gene hsp68). In a set of eight exploratory tests, we detected one positive association (between hsp23a and heat resistance) but no associations of heat resistance with alleles at the hsp26, hsp83, Desat 2, alpha-Gpdh, hsp70 loci, while cold resistance was not associated with Frost and Dca loci. These results confirm interactions between hsr-omega and thermal resistance, as well as between In(3L)Payne and cold resistance, but do not provide evidence for associations between thermal responses and alleles at other clinically varying marker genes.
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Affiliation(s)
- Lea Rako
- Centre for Environmental Stress and Adaptation Research, Department of Genetics, University of Melbourne, Parkville, Victoria 3010, Australia
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43
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Huang LH, Kang L. Cloning and interspecific altered expression of heat shock protein genes in two leafminer species in response to thermal stress. INSECT MOLECULAR BIOLOGY 2007; 16:491-500. [PMID: 17651238 DOI: 10.1111/j.1365-2583.2007.00744.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Studies have demonstrated differences in temperature tolerance between two Liriomyza species, L. huidobrensis and L. sativae. To investigate whether the heat shock proteins (Hsps) in the two species have different expression profiles during temperature stress, we cloned hsp90, 70, 60, 40 and 20, and analysed their expression profiles across temperature gradients by real-time quantitative PCR and Western blotting. The results revealed that the number of TATA-box-like elements and A/T-rich insertion/deletions within the 5' UTRs of the hsps are different in the two species. The temperatures for onset (T(on)) or maximal (T(max)) induction of hsp expression in L. huidobrensis were generally 2.5-10 degrees C lower than those in L. sativae, and the T(on) were highly consistent with the temperature limits of the northern boundary of the range of these two leafminer species. These studies confirmed, in terms of gene expression levels, that L. huidobrensis is more cold tolerant than L. sativae, which is more heat tolerant, and suggest that the T(on) (or T(max)) of hsps can represent the differences in temperature tolerance of these two leafminer species, and may be used to determine their natural geographical distribution limits.
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Affiliation(s)
- Li-Hua Huang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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44
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Sinclair BJ, Gibbs AG, Roberts SP. Gene transcription during exposure to, and recovery from, cold and desiccation stress in Drosophila melanogaster. INSECT MOLECULAR BIOLOGY 2007; 16:435-43. [PMID: 17506850 DOI: 10.1111/j.1365-2583.2007.00739.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We exposed adult male Drosophila melanogaster to cold, desiccation or starvation, and examined expression of several genes during exposure and recovery. Frost was expressed during recovery from cold, and was up-regulated during desiccation. Desiccation and starvation (but not cold) elicited increased expression of the senescence-related gene smp-30. Desat2 decreased during recovery from desiccation, but not in response to starvation or cold. Hsp70 expression increased after 1 h of recovery from cold exposure, but was unchanged in response to desiccation or starvation stress, and Hsp23 levels did not respond to any of the stressors. We conclude that D. melanogaster's responses to cold and desiccation are quite different and that care must be taken to separate exposure and recovery when studying responses to environmental stress.
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Affiliation(s)
- B J Sinclair
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA
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45
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Norry FM, Gomez FH, Loeschcke V. Knockdown resistance to heat stress and slow recovery from chill coma are genetically associated in a quantitative trait locus region of chromosome 2 inDrosophila melanogaster. Mol Ecol 2007; 16:3274-84. [PMID: 17651203 DOI: 10.1111/j.1365-294x.2007.03335.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In insects, two ecologically relevant traits of thermal adaptation are knockdown resistance to high temperature (KRHT) and chill-coma recovery (CCR). Chromosome 2 of Drosophila melanogaster was tested for quantitative trait loci (QTL) affecting both CCR and KRHT in backcrosses between homosequential lines that are fixed for the standard (noninverted) sequence of this autosome. These lines were obtained by artificial selection on KRHT and subsequent inbreeding from a stock that was derived from a single wild population. Heat-induced expression of the 70KD heat-shock protein (Hsp70) was also examined for variation between the lines. Composite interval mapping was performed for each trait on each reciprocal backcross, identifying one QTL region in the middle of chromosome 2 for both KRHT and CCR. The largest estimates of additive effects were found in pericentromeric regions of chromosome 2, accounting for 10-14% (CCR) and 10-17% (KRHT) of the phenotypic variance in BC populations. No QTL was found in the region of the heat-shock factor (hsf) gene. However, the two parental lines have diverged in the heat-induced Hsp70 expression. Distribution of KRHT QTL on chromosome 2 was similar between this study based on crosses between lines selected from a single wild population and previous work based on crosses between selection lines from different continents. Colocalized QTL showed a trade-off association between CCR and KRHT, which should be the result of either multiple, tightly linked trait-specific genes or a single gene with pleiotropic effects on the traits. We discuss candidate loci contained within the QTL regions.
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Affiliation(s)
- Fabian M Norry
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C-1428-EHA, Buenos Aires, Argentina
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46
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Thermal evolution of gene expression profiles in Drosophila subobscura. BMC Evol Biol 2007; 7:42. [PMID: 17371595 PMCID: PMC1847442 DOI: 10.1186/1471-2148-7-42] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Accepted: 03/19/2007] [Indexed: 11/17/2022] Open
Abstract
Background Despite its pervasiveness, the genetic basis of adaptation resulting in variation directly or indirectly related to temperature (climatic) gradients is poorly understood. By using 3-fold replicated laboratory thermal stocks covering much of the physiologically tolerable temperature range for the temperate (i.e., cold tolerant) species Drosophila subobscura we have assessed whole-genome transcriptional responses after three years of thermal adaptation, when the populations had already diverged for inversion frequencies, pre-adult life history components, and morphological traits. Total mRNA from each population was compared to a reference pool mRNA in a standard, highly replicated two-colour competitive hybridization experiment using cDNA microarrays. Results A total of 306 (6.6%) cDNA clones were identified as 'differentially expressed' (following a false discovery rate correction) after contrasting the two furthest apart thermal selection regimes (i.e., 13°C vs . 22°C), also including four previously reported candidate genes for thermotolerance in Drosophila (Hsp26, Hsp68, Fst, and Treh). On the other hand, correlated patterns of gene expression were similar in cold- and warm-adapted populations. Analysis of functional categories defined by the Gene Ontology project point to an overrepresentation of genes involved in carbohydrate metabolism, nucleic acids metabolism and regulation of transcription among other categories. Although the location of differently expressed genes was approximately at random with respect to chromosomes, a physical mapping of 88 probes to the polytene chromosomes of D. subobscura has shown that a larger than expected number mapped inside inverted chromosomal segments. Conclusion Our data suggest that a sizeable number of genes appear to be involved in thermal adaptation in Drosophila, with a substantial fraction implicated in metabolism. This apparently illustrates the formidable challenge to understanding the adaptive evolution of complex trait variation. Furthermore, some clustering of genes within inverted chromosomal sections was detected. Disentangling the effects of inversions will be obviously required in any future approach if we want to identify the relevant candidate genes.
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Rako L, Anderson AR, Sgrò CM, Stocker AJ, Hoffmann AA. The association between inversion In(3R)Payne and clinally varying traits in Drosophila melanogaster. Genetica 2007; 128:373-84. [PMID: 17028965 DOI: 10.1007/s10709-006-7375-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Accepted: 02/14/2006] [Indexed: 11/24/2022]
Abstract
In Drosophila melanogaster, inversion In(3R)Payne increases in frequency towards low latitudes and has been putatively associated with variation in size and thermal resistance, traits that also vary clinally. To assess the association between size and inversion, we obtained isofemale lines of inverted and standard karyotype of In(3R)Payne from the ends of the Australian D. melanogaster east coast cline. In the northern population, there was a significant association between In(3R)Payne and body size, with standard lines from this population being relatively larger than inverted lines. In contrast, the inversion had no influence on development time or cold resistance. We strengthened our findings further in a separate study with flies from populations from the middle of the cline as well as from the cline ends. These flies were scored for wing size and the presence of In(3R)Payne using a molecular marker. In females, the inversion accounted for around 30% of the size difference between cline ends, while in males the equivalent figure was 60%. Adaptive shifts in size but not in the other traits are therefore likely to have involved genes closely associated with In(3R)Payne. Because the size difference between karyotypes was similar in different populations, there was no evidence for coadaptation within populations.
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Affiliation(s)
- L Rako
- Department of Genetics Centre for Environmental Stress and Adaptation Research-CESAR, The University of Melbourne, 3010, Parkville, Vic, Australia.
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Morgan TJ, Mackay TFC. Quantitative trait loci for thermotolerance phenotypes in Drosophila melanogaster. Heredity (Edinb) 2006; 96:232-42. [PMID: 16404413 DOI: 10.1038/sj.hdy.6800786] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
For insects, temperature is a major environmental variable that can influence an individual's behavioral activities and fitness. Drosophila melanogaster is a cosmopolitan species that has had great success in adapting to and colonizing diverse thermal niches. This adaptation and colonization has resulted in complex patterns of genetic variation in thermotolerance phenotypes in nature. Although extensive work has been conducted documenting patterns of genetic variation, substantially less is known about the genomic regions or genes that underlie this ecologically and evolutionarily important genetic variation. To begin to understand and identify the genes controlling thermotolerance phenotypes, we have used a mapping population of recombinant inbred (RI) lines to map quantitative trait loci (QTL) that affect variation in both heat- and cold-stress resistance. The mapping population was derived from a cross between two lines of D. melanogaster (Oregon-R and 2b) that were not selected for thermotolerance phenotypes, but exhibit significant genetic divergence for both phenotypes. Using a design in which each RI line was backcrossed to both parental lines, we mapped seven QTL affecting thermotolerance on the second and third chromosomes. Three of the QTL influence cold-stress resistance and four affect heat-stress resistance. Most of the QTL were trait or sex specific, suggesting that overlapping but generally unique genetic architectures underlie resistance to low- and high-temperature extremes. Each QTL explained between 5 and 14% of the genetic variance among lines, and degrees of dominance ranged from completely additive to partial dominance. Potential thermotolerance candidate loci contained within our QTL regions are identified and discussed.
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Affiliation(s)
- T J Morgan
- Department of Genetics, North Carolina State University, Campus Box 7614, Raleigh, NC 27695-7414, USA.
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Rako L, Hoffmann AA. Complexity of the cold acclimation response in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2006; 52:94-104. [PMID: 16257412 DOI: 10.1016/j.jinsphys.2005.09.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 09/22/2005] [Accepted: 09/22/2005] [Indexed: 05/05/2023]
Abstract
Insects can increase their resistance to cold stress when they are exposed to non-lethal conditions prior to the stress; these plastic responses are normally described only in terms of immediate effects on mortality. Here we examine in Drosophila melanogaster the short- and longer-term effects of different conditions on several measures of cold resistance, but particularly chill coma recovery. Short-term exposure to sublethal temperature (cold hardening) did not decrease chill coma recovery times even though it decreased mortality. Exposure to 12 degrees C for 2 days (acclimation) decreased chill coma recovery times for a range of stressful temperatures when flies were cultured at 25 degrees C, but did not usually affect recovery times when flies were cultured at 19 degrees C. In contrast, 2-day exposure to 12 degrees C decreased mortality regardless of rearing temperature. Rearing at 19 degrees C decreased mortality and chill coma recovery time relative to rearing at 25 degrees C. Acclimation increased the eclosion rate of eggs from stressed females, but did not affect development time or size of the offspring. These results indicate that plastic responses to cold in D. melanogaster are complex when resistance is scored in different ways, and that effects can extend across generations.
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Affiliation(s)
- Lea Rako
- Centre for Environmental Stress and Adaptation Research, Department of Genetics, The University of Melbourne, Parkville, Vic 3010, Australia.
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Qin W, Neal SJ, Robertson RM, Westwood JT, Walker VK. Cold hardening and transcriptional change in Drosophila melanogaster. INSECT MOLECULAR BIOLOGY 2005; 14:607-13. [PMID: 16313561 DOI: 10.1111/j.1365-2583.2005.00589.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Cold hardening treatment - a brief exposure to low temperatures - can protect certain insects against subsequent exposure to temperatures sufficiently low to cause damage or lethality. Microarray analysis to examine the changes in transcript abundance associated with cold hardening treatment (0 degrees C for 2 h followed by 30 min recovery at 25 degrees C) was undertaken in Drosophila melanogaster in order to gain insight into this phenomenon. Transcripts associated with 36 genes were identified, a subset of which appeared to be also differentially expressed after heat shock treatment. Quantitative RT-PCR was used to independently determine transcript abundance of a subset of these sequences. Taken together, these assays suggest that stress proteins, including Hsp23, Hsp26, Hsp83 and Frost as well as membrane-associated proteins may contribute to the cold hardening response.
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Affiliation(s)
- W Qin
- Department of Biology, Queen's University, Ontario, Canada
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