1
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Chen P, Zhang J. The loci of environmental adaptation in a model eukaryote. Nat Commun 2024; 15:5672. [PMID: 38971805 PMCID: PMC11227561 DOI: 10.1038/s41467-024-50002-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 06/25/2024] [Indexed: 07/08/2024] Open
Abstract
While the underlying genetic changes have been uncovered in some cases of adaptive evolution, the lack of a systematic study prevents a general understanding of the genomic basis of adaptation. For example, it is unclear whether protein-coding or noncoding mutations are more important to adaptive evolution and whether adaptations to different environments are brought by genetic changes distributed in diverse genes and biological processes or concentrated in a core set. We here perform laboratory evolution of 3360 Saccharomyces cerevisiae populations in 252 environments of varying levels of stress. We find the yeast adaptations to be primarily fueled by large-effect coding mutations overrepresented in a relatively small gene set, despite prevalent antagonistic pleiotropy across environments. Populations generally adapt faster in more stressful environments, partly because of greater benefits of the same mutations in more stressful environments. These and other findings from this model eukaryote help unravel the genomic principles of environmental adaptation.
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Affiliation(s)
- Piaopiao Chen
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, 48109, USA
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, 48109, USA.
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2
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Jiang Q, Zhu L, Zeng H, Basang Z, Suolang Q, Huang J, Cai Y. Evolutionary adaptations generally reverse phenotypic plasticity to restore ancestral phenotypes during new environment adaptation in cattle. Ecol Evol 2024; 14:e11489. [PMID: 38840586 PMCID: PMC11150418 DOI: 10.1002/ece3.11489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 05/11/2024] [Accepted: 05/15/2024] [Indexed: 06/07/2024] Open
Abstract
Phenotype plasticity and evolution adaptations are the two main ways in which allow populations to deal with environmental changes, but the potential relationship between them remains controversial. Using a reciprocal transplant approach with cattle adapted to the Tibetan Plateau and adjacent lowlands, we aim to investigate the relative contributions of evolutionary processes and phenotypic plasticity in driving both phenotypic and transcriptomic changes under natural conditions. We observed that while numerous genetic transcriptomic changes were evident during the forward adaptation to highland environments, plastic changes predominantly facilitate the transformation of transcriptomes into a preferred state when Tibetan cattle are reintroduced to lowland habitats. Genes with ancestral plasticity are generally reversed by evolutionary adaptations and show a closer expression level to the ancestral stage in evolved Tibetan cattle. A similar trend was also observed at the phenotypes level, with a majority of biochemical and hemorheology phenotypes showing a tendency to revert to their ancestral patterns, suggesting the restoration of ancestral expression levels is a widespread evolutionary trend during adaptation. The findings of our study contribute to the debate regarding the relative contributions of plasticity and genetic changes in mammal environment adaptation. Furthermore, we highlight that the restoration of ancestral phenotypes represents a general pattern in cattle new environment adaptation.
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Affiliation(s)
- Qiang Jiang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and TechnologyNanjing Agricultural UniversityNanjingChina
- Institute of Animal Science and Veterinary MedicineShandong Academy of Agricultural SciencesJinanChina
| | - Li Zhu
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and TechnologyYunnan Agricultural UniversityKunmingChina
| | - Hao Zeng
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and TechnologyYunnan Agricultural UniversityKunmingChina
| | - Zhuzha Basang
- Institute of Animal Science and Veterinary MedicineTibet Academy of Agricultural and Animal Husbandry SciencesLhasaChina
| | - Quji Suolang
- Institute of Animal Science and Veterinary MedicineTibet Academy of Agricultural and Animal Husbandry SciencesLhasaChina
| | - Jinming Huang
- Institute of Animal Science and Veterinary MedicineShandong Academy of Agricultural SciencesJinanChina
| | - Yafei Cai
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and TechnologyNanjing Agricultural UniversityNanjingChina
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3
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She H, Hao Y, Song G, Luo X, Lei F, Zhai W, Qu Y. Gene expression plasticity followed by genetic change during colonization in a high-elevation environment. eLife 2024; 12:RP86687. [PMID: 38470231 DOI: 10.7554/elife.86687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024] Open
Abstract
Phenotypic plasticity facilitates organismal invasion of novel environments, and the resultant phenotypic change may later be modified by genetic change, so called 'plasticity first.' Herein, we quantify gene expression plasticity and regulatory adaptation in a wild bird (Eurasian Tree Sparrow) from its original lowland (ancestral stage), experimentally implemented hypoxia acclimation (plastic stage), and colonized highland (colonized stage). Using a group of co-expressed genes from the cardiac and flight muscles, respectively, we demonstrate that gene expression plasticity to hypoxia tolerance is more often reversed than reinforced at the colonized stage. By correlating gene expression change with muscle phenotypes, we show that colonized tree sparrows reduce maladaptive plasticity that largely associated with decreased hypoxia tolerance. Conversely, adaptive plasticity that is congruent with increased hypoxia tolerance is often reinforced in the colonized tree sparrows. Genes displaying large levels of reinforcement or reversion plasticity (i.e. 200% of original level) show greater genetic divergence between ancestral and colonized populations. Overall, our work demonstrates that gene expression plasticity at the initial stage of high-elevation colonization can be reversed or reinforced through selection-driven adaptive modification.
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Affiliation(s)
- Huishang She
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yan Hao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gang Song
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xu Luo
- Faculty of Biodiversity and Conservation, Southwest Forestry University, Kunming, China
| | - Fumin Lei
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Weiwei Zhai
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Yanhua Qu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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4
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Uller T, Milocco L, Isanta-Navarro J, Cornwallis CK, Feiner N. Twenty years on from Developmental Plasticity and Evolution: middle-range theories and how to test them. J Exp Biol 2024; 227:jeb246375. [PMID: 38449333 DOI: 10.1242/jeb.246375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
In Developmental Plasticity and Evolution, Mary-Jane West-Eberhard argued that the developmental mechanisms that enable organisms to respond to their environment are fundamental causes of adaptation and diversification. Twenty years after publication of this book, this once so highly controversial claim appears to have been assimilated by a wealth of studies on 'plasticity-led' evolution. However, we suggest that the role of development in explanations for adaptive evolution remains underappreciated in this body of work. By combining concepts of evolvability from evolutionary developmental biology and quantitative genetics, we outline a framework that is more appropriate to identify developmental causes of adaptive evolution. This framework demonstrates how experimental and comparative developmental biology and physiology can be leveraged to put the role of plasticity in evolution to the test.
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Affiliation(s)
- Tobias Uller
- Department of Biology, Lund University, 223 62 Lund, Sweden
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5
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Wos G, Požárová D, Kolář F. Role of phenotypic and transcriptomic plasticity in alpine adaptation of Arabidopsis arenosa. Mol Ecol 2023; 32:5771-5784. [PMID: 37728172 DOI: 10.1111/mec.17144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 08/29/2023] [Accepted: 09/11/2023] [Indexed: 09/21/2023]
Abstract
Plasticity is an important component of the response of organism to environmental changes, but whether plasticity facilitates adaptation is still largely debated. Using transcriptomic and phenotypic data, we explored the evolution of ancestral plasticity during alpine colonization in Arabidopsis arenosa. We leveraged naturally replicated adaptation in four distinct mountain regions in Central Europe. We sampled seeds from ancestral foothill and independently formed alpine populations in each region and raised them in growth chambers under conditions approximating their natural environments. We gathered RNA-seq and genetic data of 48 and 63 plants and scored vegetative and flowering traits in 203 and 272 plants respectively. Then, we compared gene expression and trait values over two treatments differing in temperature and irradiance and elevations of origin and quantified the extent of ancestral and derived plasticity. At the transcriptomic level, initial plastic changes tended to be more reinforced than reversed in adapted alpine populations. Genes showing reinforcement were involved in the stress response, developmental processes and morphogenesis and those undergoing reversion were related to the stress response (light and biotic stress). At the phenotypic level, initial plastic changes in all but one trait were also reinforced supporting a facilitating role of phenotypic plasticity during colonization of an alpine environment. Our results contrasted with previous studies that showed generally higher reversion than reinforcement and supported the idea that ancestral plasticity tends to be reinforced in the context of alpine adaptation. However, plasticity may also be the source of potential maladaptation, especially at the transcriptomic level.
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Affiliation(s)
- Guillaume Wos
- Institute of Nature Conservation Polish Academy of Sciences, Krakow, Poland
- Department of Botany, Charles University of Prague, Prague, Czech Republic
| | - Doubravka Požárová
- Department of Botany, Charles University of Prague, Prague, Czech Republic
| | - Filip Kolář
- Department of Botany, Charles University of Prague, Prague, Czech Republic
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6
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Chen P, Zhang J. Transcriptomic analysis reveals the rareness of genetic assimilation of gene expression in environmental adaptations. SCIENCE ADVANCES 2023; 9:eadi3053. [PMID: 37756399 PMCID: PMC10530075 DOI: 10.1126/sciadv.adi3053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023]
Abstract
Genetic assimilation is the evolutionary process by which an environmentally induced phenotype becomes genetically encoded and constitutive. Genetic assimilation has been proposed as a concluding step in environmental adaptation, but its prevalence has not been systematically investigated. Analyzing transcriptomic data collected upon reciprocal transplant, we address this question in the experimental evolution, domestication, or natural evolution of seven diverse species. We find that genetic assimilation of environment-induced gene expression is the exception rather than the rule and that substantially more genes retain than lose their expression plasticity upon organismal adaptations to new environments. The probability of genetic assimilation of gene expression decreases with the expression level and number of transcription factors controlling the gene, suggesting that genetic assimilation results primarily from passive losses of gene regulations that are not mutationally robust. Hence, for gene expression, our findings argue against the purported generality or importance of genetic assimilation to environmental adaptation.
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Affiliation(s)
- Piaopiao Chen
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
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7
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Ballinger MA, Mack KL, Durkin SM, Riddell EA, Nachman MW. Environmentally robust cis-regulatory changes underlie rapid climatic adaptation. Proc Natl Acad Sci U S A 2023; 120:e2214614120. [PMID: 37725649 PMCID: PMC10523592 DOI: 10.1073/pnas.2214614120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 07/26/2023] [Indexed: 09/21/2023] Open
Abstract
Changes in gene expression are thought to play a major role in adaptive evolution. While it is known that gene expression is highly sensitive to the environment, very few studies have determined the influence of genetic and environmental effects on adaptive gene expression differences in natural populations. Here, we utilize allele-specific expression to characterize cis and trans gene regulatory divergence in temperate and tropical house mice in two metabolic tissues under two thermal conditions. First, we show that gene expression divergence is pervasive between populations and across thermal conditions, with roughly 5 to 10% of genes exhibiting genotype-by-environment interactions. Second, we found that most expression divergence was due to cis-regulatory changes that were stable across temperatures. In contrast, patterns of expression plasticity were largely attributable to trans-effects, which showed greater sensitivity to temperature. Nonetheless, we found a small subset of temperature-dependent cis-regulatory changes, thereby identifying loci underlying expression plasticity. Finally, we performed scans for selection in wild house mice to identify genomic signatures of rapid adaptation. Genomic outliers were enriched in genes with evidence for cis-regulatory divergence. Notably, these genes were associated with phenotypes that affected body weight and metabolism, suggesting that cis-regulatory changes are a possible mechanism for adaptive body size evolution between populations. Our results show that gene expression plasticity, largely controlled in trans, may facilitate the colonization of new environments, but that evolved changes in gene expression are largely controlled in cis, illustrating the genetic and nongenetic mechanisms underlying the establishment of populations in new environments.
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Affiliation(s)
- Mallory A. Ballinger
- Museum of Vertebrate Zoology, University of California, Berkeley, CA94720
- Department of Integrative Biology, University of California, Berkeley, CA94720
- Department of Biology, Utah State University, Logan, UT84322
| | - Katya L. Mack
- Department of Biology, Stanford University, Stanford, CA94305
| | - Sylvia M. Durkin
- Museum of Vertebrate Zoology, University of California, Berkeley, CA94720
- Department of Integrative Biology, University of California, Berkeley, CA94720
| | - Eric A. Riddell
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA50011
| | - Michael W. Nachman
- Museum of Vertebrate Zoology, University of California, Berkeley, CA94720
- Department of Integrative Biology, University of California, Berkeley, CA94720
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8
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Jiang D, Cope AL, Zhang J, Pennell M. On the Decoupling of Evolutionary Changes in mRNA and Protein Levels. Mol Biol Evol 2023; 40:msad169. [PMID: 37498582 PMCID: PMC10411491 DOI: 10.1093/molbev/msad169] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/19/2023] [Accepted: 07/14/2023] [Indexed: 07/28/2023] Open
Abstract
Variation in gene expression across lineages is thought to explain much of the observed phenotypic variation and adaptation. The protein is closer to the target of natural selection but gene expression is typically measured as the amount of mRNA. The broad assumption that mRNA levels are good proxies for protein levels has been undermined by a number of studies reporting moderate or weak correlations between the two measures across species. One biological explanation for this discrepancy is that there has been compensatory evolution between the mRNA level and regulation of translation. However, we do not understand the evolutionary conditions necessary for this to occur nor the expected strength of the correlation between mRNA and protein levels. Here, we develop a theoretical model for the coevolution of mRNA and protein levels and investigate the dynamics of the model over time. We find that compensatory evolution is widespread when there is stabilizing selection on the protein level; this observation held true across a variety of regulatory pathways. When the protein level is under directional selection, the mRNA level of a gene and the translation rate of the same gene were negatively correlated across lineages but positively correlated across genes. These findings help explain results from comparative studies of gene expression and potentially enable researchers to disentangle biological and statistical hypotheses for the mismatch between transcriptomic and proteomic data.
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Affiliation(s)
- Daohan Jiang
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Alexander L Cope
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
- Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, USA
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Matt Pennell
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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9
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Jiang D, Cope AL, Zhang J, Pennell M. Decoupling of evolutionary changes in mRNA and protein levels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.08.536110. [PMID: 37066157 PMCID: PMC10104238 DOI: 10.1101/2023.04.08.536110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Variation in gene expression across lineages is thought to explain much of the observed phenotypic variation and adaptation. The protein is closer to the target of natural selection but gene expression is typically measured as the amount of mRNA. The broad assumption that mRNA levels are good proxies for protein levels has been undermined by a number of studies reporting moderate or weak correlations between the two measures across species. One biological explanation for this discrepancy is that there has been compensatory evolution between the mRNA level and regulation of translation. However, we do not understand the evolutionary conditions necessary for this to occur nor the expected strength of the correlation between mRNA and protein levels. Here we develop a theoretical model for the coevolution of mRNA and protein levels and investigate the dynamics of the model over time. We find that compensatory evolution is widespread when there is stabilizing selection on the protein level, which is true across a variety of regulatory pathways. When the protein level is under directional selection, the mRNA level of a gene and its translation rate of the same gene were negatively correlated across lineages but positively correlated across genes. These findings help explain results from comparative studies of gene expression and potentially enable researchers to disentangle biological and statistical hypotheses for the mismatch between transcriptomic and proteomic studies.
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Affiliation(s)
- Daohan Jiang
- Department of Quantitative and Computational Biology, University of Southern California, USA
| | | | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, USA
| | - Matt Pennell
- Department of Quantitative and Computational Biology, University of Southern California, USA
- Department of Biological Sciences, University of Southern California, USA
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10
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Kuo HC, Yao CT, Liao BY, Weng MP, Dong F, Hsu YC, Hung CM. Weak gene-gene interaction facilitates the evolution of gene expression plasticity. BMC Biol 2023; 21:57. [PMID: 36941675 PMCID: PMC10029303 DOI: 10.1186/s12915-023-01558-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/10/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND Individual organisms may exhibit phenotypic plasticity when they acclimate to different conditions. Such plastic responses may facilitate or constrain the adaptation of their descendant populations to new environments, complicating their evolutionary trajectories beyond the genetic blueprint. Intriguingly, phenotypic plasticity itself can evolve in terms of its direction and magnitude during adaptation. However, we know little about what determines the evolution of phenotypic plasticity, including gene expression plasticity. Recent laboratory-based studies suggest dominance of reversing gene expression plasticity-plastic responses that move the levels of gene expression away from the new optima. Nevertheless, evidence from natural populations is still limited. RESULTS Here, we studied gene expression plasticity and its evolution in the montane and lowland populations of an elevationally widespread songbird-the Rufous-capped Babbler (Cyanoderma ruficeps)-with reciprocal transplant experiments and transcriptomic analyses; we set common gardens at altitudes close to these populations' native ranges. We confirmed the prevalence of reversing plasticity in genes associated with altitudinal adaptation. Interestingly, we found a positive relationship between magnitude and degree of evolution in gene expression plasticity, which was pertinent to not only adaptation-associated genes but also the whole transcriptomes from multiple tissues. Furthermore, we revealed that genes with weaker expressional interactions with other genes tended to exhibit stronger plasticity and higher degree of plasticity evolution, which explains the positive magnitude-evolution relationship. CONCLUSIONS Our experimental evidence demonstrates that species may initiate their adaptation to new habitats with genes exhibiting strong expression plasticity. We also highlight the role of expression interdependence among genes in regulating the magnitude and evolution of expression plasticity. This study illuminates how the evolution of phenotypic plasticity in gene expression facilitates the adaptation of species to challenging environments in nature.
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Affiliation(s)
- Hao-Chih Kuo
- Biodiversity Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Cheng-Te Yao
- Division of Zoology, Endemic Species Research Institute, Nantou, 55244, Taiwan
| | - Ben-Yang Liao
- Institute of Population Health Sciences, National Health Research Institutes, Miaoli, 35053, Taiwan
| | - Meng-Pin Weng
- Institute of Population Health Sciences, National Health Research Institutes, Miaoli, 35053, Taiwan
| | - Feng Dong
- Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
| | - Yu-Cheng Hsu
- Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien, 97401, Taiwan
| | - Chih-Ming Hung
- Biodiversity Research Center, Academia Sinica, Taipei, 11529, Taiwan.
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11
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Wood DP, Holmberg JA, Osborne OG, Helmstetter AJ, Dunning LT, Ellison AR, Smith RJ, Lighten J, Papadopulos AST. Genetic assimilation of ancestral plasticity during parallel adaptation to zinc contamination in Silene uniflora. Nat Ecol Evol 2023; 7:414-423. [PMID: 36702857 PMCID: PMC9998271 DOI: 10.1038/s41559-022-01975-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/12/2022] [Indexed: 01/27/2023]
Abstract
Phenotypic plasticity in ancestral populations is hypothesized to facilitate adaptation, but evidence is piecemeal and often contradictory. Further, whether ancestral plasticity increases the probability of parallel adaptive changes has not been explored. The most general finding is that ancestral responses to a new environment are reversed following adaptation (known as reversion). We investigated the contribution of ancestral plasticity to adaptive evolution of gene expression in two independently evolved lineages of zinc-tolerant Silene uniflora. We found that the general pattern of reversion is driven by the absence of a widespread stress response in zinc-adapted plants compared with zinc-sensitive plants. We show that ancestral plasticity that moves expression closer to the optimum value in the new environment influences the evolution of gene expression among genes that are likely to be involved in adaptation and increases the chance that genes are recruited repeatedly during adaptation. However, despite convergence in gene expression levels between independently adapted lineages, ancestral plasticity does not influence how similar expression values of adaptive genes become. Surprisingly, we also observed that ancestral plasticity that increases fitness often becomes genetically determined and fixed, that is, genetically assimilated. These results emphasize the important role of ancestral plasticity in parallel adaptation.
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Affiliation(s)
- Daniel P Wood
- Molecular Ecology and Evolution Bangor, School of Natural Sciences, Bangor University, Environment Centre Wales, Bangor, UK
| | - Jon A Holmberg
- Molecular Ecology and Evolution Bangor, School of Natural Sciences, Bangor University, Environment Centre Wales, Bangor, UK
| | - Owen G Osborne
- Molecular Ecology and Evolution Bangor, School of Natural Sciences, Bangor University, Environment Centre Wales, Bangor, UK
| | - Andrew J Helmstetter
- Fondation pour la Recherche sur la Biodiversité - Centre for the Synthesis and Analysis of Biodiversity, Institut Bouisson Bertrand, Montpellier, France
| | - Luke T Dunning
- Ecology and Evolutionary Biology, School of Biosciences, Sheffield, UK
| | - Amy R Ellison
- Molecular Ecology and Evolution Bangor, School of Natural Sciences, Bangor University, Environment Centre Wales, Bangor, UK
| | | | - Jackie Lighten
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Alexander S T Papadopulos
- Molecular Ecology and Evolution Bangor, School of Natural Sciences, Bangor University, Environment Centre Wales, Bangor, UK.
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12
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Levis NA, McKay DJ, Pfennig DW. Disentangling the developmental origins of a novel phenotype: enhancement versus reversal of environmentally induced gene expression. Proc Biol Sci 2022; 289:20221764. [PMID: 36285495 PMCID: PMC9597403 DOI: 10.1098/rspb.2022.1764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/03/2022] [Indexed: 11/12/2022] Open
Abstract
Increasing evidence suggests that many novel traits might have originated via plasticity-led evolution (PLE). Yet, little is known of the developmental processes that underpin PLE, especially in its early stages. One such process is 'phenotypic accommodation', which occurs when, in response to a change in the environment, an organism experiences adjustments across variable parts of its phenotype that improve its fitness. Here, we asked if environmentally induced changes in gene expression are enhanced or reversed during phenotypic accommodation of a novel, complex phenotype in spadefoot toad tadpoles (Spea multiplicata). More genes than expected were affected by both the environment and phenotypic accommodation in the liver and brain. However, although phenotypic accommodation primarily reversed environmentally induced changes in gene expression in liver tissue, it enhanced these changes in brain tissue. Thus, depending on the tissue, phenotypic accommodation may either minimize functional disruption via reversal of gene expression patterns or promote novelty via enhancement of existing expression patterns. Our study thereby provides insights into the developmental origins of a novel phenotype and the incipient stages of PLE.
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Affiliation(s)
- Nicholas A. Levis
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Daniel J. McKay
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - David W. Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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13
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Liu YN, Chen RM, Pu QT, Nneji LM, Sun YB. Expression Plasticity of Transposable Elements is Highly Associated with Organismal Re-adaptation to Ancestral Environments. Genome Biol Evol 2022; 14:6596371. [PMID: 35642321 PMCID: PMC9174648 DOI: 10.1093/gbe/evac084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2022] [Indexed: 11/20/2022] Open
Abstract
Understanding the roles of phenotypic plasticity in adaptive evolution has gained recognition for decades. Studies involving multiple taxa have shown that gene expression plasticity serves as “long-term memory” to facilitate re-adaptations to ancestral environments. Nevertheless, the general pattern and the underlying genetic basis of expression plasticity remain unclear. The transposable elements (TEs) play crucial roles in gene expression regulation and are widely distributed within the genome. Given this, we re-analyzed the transcriptomic data of chicken (Gallus gallus) generated from a reciprocal transplant experiment to examine whether expression shifts of TEs are involved in the re-adaptation process. Similar to the protein-coding genes, the plastic changes of TEs overwhelmingly exceed the genetic changes in the re-adaptation process. Further, the associated TEs co-expressed with diverse genes to perform a regulatory activity. Thus, our study supports the general function of phenotypic plasticity in adaptive evolution, and suggests a regulatory functions of TEs in this process.
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Affiliation(s)
- Yan-Nan Liu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, China
| | - Rong-Mei Chen
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, China
| | - Qi-Ting Pu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, China
| | - Lotanna M Nneji
- Department of Ecology and Evolutionary Biology, Princeton University, NJ, 08544, USA
| | - Yan-Bo Sun
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming 650500, China.,Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming 650091, China
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14
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Huang Y, Lack JB, Hoppel GT, Pool JE. Gene Regulatory Evolution in Cold-Adapted Fly Populations Neutralizes Plasticity and May Undermine Genetic Canalization. Genome Biol Evol 2022; 14:evac050. [PMID: 35380655 PMCID: PMC9017818 DOI: 10.1093/gbe/evac050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2022] [Indexed: 11/12/2022] Open
Abstract
The relationships between adaptive evolution, phenotypic plasticity, and canalization remain incompletely understood. Theoretical and empirical studies have made conflicting arguments on whether adaptive evolution may enhance or oppose the plastic response. Gene regulatory traits offer excellent potential to study the relationship between plasticity and adaptation, and they can now be studied at the transcriptomic level. Here, we take advantage of three closely related pairs of natural populations of Drosophila melanogaster from contrasting thermal environments that reflect three separate instances of cold tolerance evolution. We measure the transcriptome-wide plasticity in gene expression levels and alternative splicing (intron usage) between warm and cold laboratory environments. We find that suspected adaptive changes in both gene expression and alternative splicing tend to neutralize the ancestral plastic response. Further, we investigate the hypothesis that adaptive evolution can lead to decanalization of selected gene regulatory traits. We find strong evidence that suspected adaptive gene expression (but not splicing) changes in cold-adapted populations are more vulnerable to the genetic perturbation of inbreeding than putatively neutral changes. We find some evidence that these patterns may reflect a loss of genetic canalization accompanying adaptation, although other processes including hitchhiking recessive deleterious variants may contribute as well. Our findings augment our understanding of genetic and environmental effects on gene regulation in the context of adaptive evolution.
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Affiliation(s)
- Yuheng Huang
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Justin B Lack
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Grant T Hoppel
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - John E Pool
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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15
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Josephs EB, Van Etten ML, Harkess A, Platts A, Baucom RS. Adaptive and maladaptive expression plasticity underlying herbicide resistance in an agricultural weed. Evol Lett 2021; 5:432-440. [PMID: 34367667 PMCID: PMC8327940 DOI: 10.1002/evl3.241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/29/2021] [Accepted: 05/20/2021] [Indexed: 11/09/2022] Open
Abstract
Plastic phenotypic responses to environmental change are common, yet we lack a clear understanding of the fitness consequences of these plastic responses. Here, we use the evolution of herbicide resistance in the common morning glory (Ipomoea purpurea) as a model for understanding the relative importance of adaptive and maladaptive gene expression responses to herbicide. Specifically, we compare leaf gene expression changes caused by herbicide to the expression changes that evolve in response to artificial selection for herbicide resistance. We identify a number of genes that show plastic and evolved responses to herbicide and find that for the majority of genes with both plastic and evolved responses, plastic responses appear to be adaptive. We also find that selection for herbicide response increases gene expression plasticity. Overall, these results show the importance of adaptive plasticity for herbicide resistance in a common weed and that expression changes in response to strong environmental change can be adaptive.
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Affiliation(s)
- Emily B. Josephs
- Department of Plant BiologyMichigan State UniversityEast LansingMichigan48824
- Ecology, Evolution, and Behavior ProgramMichigan State UniversityEast LansingMichigan48824
| | - Megan L. Van Etten
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichigan48109
- Biology DepartmentPennsylvania State UniversityDunmorePennsylvania18512
| | - Alex Harkess
- Department of Crop, Soil, and Environmental SciencesAuburn UniversityAuburnAlabama36849
- HudsonAlpha Institute for BiotechnologyHuntsvilleAlabama35806
| | - Adrian Platts
- Department of Plant BiologyMichigan State UniversityEast LansingMichigan48824
| | - Regina S. Baucom
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichigan48109
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16
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Purkayastha P, Pendyala K, Saxena AS, Hakimjavadi H, Chamala S, Dixit P, Baer CF, Lele TP. Reverse Plasticity Underlies Rapid Evolution by Clonal Selection within Populations of Fibroblasts Propagated on a Novel Soft Substrate. Mol Biol Evol 2021; 38:3279-3293. [PMID: 33871606 PMCID: PMC8321517 DOI: 10.1093/molbev/msab102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mechanical properties such as substrate stiffness are a ubiquitous feature of a cell’s environment. Many types of animal cells exhibit canonical phenotypic plasticity when grown on substrates of differing stiffness, in vitro and in vivo. Whether such plasticity is a multivariate optimum due to hundreds of millions of years of animal evolution, or instead is a compromise between conflicting selective demands, is unknown. We addressed these questions by means of experimental evolution of populations of mouse fibroblasts propagated for approximately 90 cell generations on soft or stiff substrates. The ancestral cells grow twice as fast on stiff substrate as on soft substrate and exhibit the canonical phenotypic plasticity. Soft-selected lines derived from a genetically diverse ancestral population increased growth rate on soft substrate to the ancestral level on stiff substrate and evolved the same multivariate phenotype. The pattern of plasticity in the soft-selected lines was opposite of the ancestral pattern, suggesting that reverse plasticity underlies the observed rapid evolution. Conversely, growth rate and phenotypes did not change in selected lines derived from clonal cells. Overall, our results suggest that the changes were the result of genetic evolution and not phenotypic plasticity per se. Whole-transcriptome analysis revealed consistent differentiation between ancestral and soft-selected populations, and that both emergent phenotypes and gene expression tended to revert in the soft-selected lines. However, the selected populations appear to have achieved the same phenotypic outcome by means of at least two distinct transcriptional architectures related to mechanotransduction and proliferation.
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Affiliation(s)
- Purboja Purkayastha
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Kavya Pendyala
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Ayush S Saxena
- Department of Biology, University of Florida, Gainesville, FL, USA
| | | | - Srikar Chamala
- University of Florida Genetics Institute, Gainesville, FL, USA
| | - Purushottam Dixit
- University of Florida Genetics Institute, Gainesville, FL, USA.,Department of Physics, University of Florida, Gainesville, FL, USA
| | - Charles F Baer
- Department of Biology, University of Florida, Gainesville, FL, USA.,University of Florida Genetics Institute, Gainesville, FL, USA
| | - Tanmay P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.,Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.,Department of Translational Medical Sciences, Texas A&M University, Houston, TX, USA
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17
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Fischer EK, Song Y, Hughes KA, Zhou W, Hoke KL. Nonparallel transcriptional divergence during parallel adaptation. Mol Ecol 2021; 30:1516-1530. [PMID: 33522041 DOI: 10.1111/mec.15823] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/17/2022]
Abstract
How underlying mechanisms bias evolution toward predictable outcomes remains an area of active debate. In this study, we leveraged phenotypic plasticity and parallel adaptation across independent lineages of Trinidadian guppies (Poecilia reticulata) to assess the predictability of gene expression evolution during parallel adaptation. Trinidadian guppies have repeatedly and independently adapted to high- and low-predation environments in the wild. We combined this natural experiment with a laboratory breeding design to attribute transcriptional variation to the genetic influences of population of origin and developmental plasticity in response to rearing with or without predators. We observed substantial gene expression plasticity, as well as the evolution of expression plasticity itself, across populations. Genes exhibiting expression plasticity within populations were more likely to also differ in expression between populations, with the direction of population differences more likely to be opposite those of plasticity. While we found more overlap than expected by chance in genes differentially expressed between high- and low-predation populations from distinct evolutionary lineages, the majority of differentially expressed genes were not shared between lineages. Our data suggest alternative transcriptional configurations associated with shared phenotypes, highlighting a role for transcriptional flexibility in the parallel phenotypic evolution of a species known for rapid adaptation.
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Affiliation(s)
- Eva K Fischer
- Department of Evolution, Ecology, and Behavior, University of Illinois, Urbana, IL, USA.,Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Youngseok Song
- Department of Statistics, Colorado State University, Fort Collins, CO, USA
| | - Kimberly A Hughes
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Wen Zhou
- Department of Statistics, Colorado State University, Fort Collins, CO, USA
| | - Kim L Hoke
- Department of Biology, Colorado State University, Fort Collins, CO, USA
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18
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Koch EL, Guillaume F. Restoring ancestral phenotypes is a general pattern in gene expression evolution during adaptation to new environments in Tribolium castaneum. Mol Ecol 2020; 29:3938-3953. [PMID: 32844494 DOI: 10.1111/mec.15607] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 06/19/2020] [Accepted: 08/10/2020] [Indexed: 12/15/2022]
Abstract
Plasticity and evolution are two processes allowing populations to respond to environmental changes, but how both are related and impact each other remains controversial. We studied plastic and evolutionary responses in gene expression of Tribolium castaneum after exposure of the beetles to new environments that differed from ancestral conditions in temperature, humidity or both. Using experimental evolution with 10 replicated lines per condition, we were able to demonstrate adaptation after 20 generations. We measured whole-transcriptome gene expression with RNA-sequencing to infer evolutionary and plastic changes. We found more evidence for changes in mean expression (shift in the intercept of reaction norms) in adapted lines than for changes in plasticity (shifts in slopes). Plasticity was mainly preserved in selected lines and was responsible for a large part of the phenotypic divergence in expression between ancestral and new conditions. However, we found that genes with the largest evolutionary changes in expression also evolved reduced plasticity and often showed expression levels closer to the ancestral stage. Results obtained in the three different conditions were similar, suggesting that restoration of ancestral expression levels during adaptation is a general evolutionary pattern. With a larger sample in the most stressful condition, we were able to detect a positive correlation between the proportion of genes with reversion of the ancestral plastic response and mean fitness per selection line.
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Affiliation(s)
- Eva L Koch
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland.,Department of Animal and Plant Science, University of Sheffield, Sheffield, UK
| | - Frédéric Guillaume
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
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19
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Huang X, Zhan A. Highly dynamic transcriptional reprogramming and shorter isoform shifts under acute stresses during biological invasions. RNA Biol 2020; 18:340-353. [PMID: 32804003 DOI: 10.1080/15476286.2020.1805904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Phenotypic plasticity has been increasingly recognized for its importance in adaptation to novel environments, and initial rapid plastic response to acute stresses usually serves as the stepping stone for future adaptation. Differential gene expression and alternative splicing have been proposed as two underlying mechanisms for rapid plastic response to environmental stresses. Here, we used an invasive model species, Ciona savignyi, to investigate the temporary plastic changes under temperature stresses on gene expression and alternative splicing. Our results revealed rapid and highly dynamic gene expression reprogramming and alternative splicing switch under acute stresses. Distinct transcriptional response profiles were triggered by two types of temperature stresses, showing resilience recovery and increasing divergence under heat and cold challenges, respectively. Interestingly, alternative exons were more inclined to be skipped under both heat and cold stresses, leading to shorter isoforms but with maintained Open Reading Frames (ORFs). Although similar response patterns were observed between differential gene expression and alternative splicing, low overlap between Differentially Expressed Genes (DEGs) and Differentially Alternative Spliced Genes (DASGs) suggests that distinct gene sets and associated functions should be involved in temperature challenges. Thus, alternative splicing should offer an additional layer of plastic response to environmental challenges. Finally, we identified key plastic genes involved in both gene expression regulation and alternative splicing. The results obtained here shed light on adaptation and accommodation mechanisms during biological invasions, particularly for acute environmental changes at early stages of biological invasions such as transport and introduction.
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Affiliation(s)
- Xuena Huang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Aibin Zhan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
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20
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Radersma R, Noble DWA, Uller T. Plasticity leaves a phenotypic signature during local adaptation. Evol Lett 2020; 4:360-370. [PMID: 32774884 PMCID: PMC7403707 DOI: 10.1002/evl3.185] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/22/2020] [Indexed: 12/31/2022] Open
Abstract
Phenotypic responses to a novel or extreme environment are initially plastic, only later to be followed by genetic change. Whether or not environmentally induced phenotypes are sufficiently recurrent and fit to leave a signature in adaptive evolution is debated. Here, we analyze multivariate data from 34 plant reciprocal transplant studies to test: (1) if plasticity is an adaptive source of developmental bias that makes locally adapted populations resemble the environmentally induced phenotypes of ancestors; and (2) if plasticity, standing phenotypic variation and genetic divergence align during local adaptation. Phenotypic variation increased marginally in foreign environments but, as predicted, the direction of ancestral plasticity was generally well aligned with the phenotypic difference between locally adapted populations, making plasticity appear to "take the lead" in adaptive evolution. Plastic responses were sometimes more extreme than the phenotypes of locally adapted plants, which can give the impression that plasticity and evolutionary adaptation oppose each other; however, environmentally induced and locally adapted phenotypes were rarely misaligned. Adaptive fine‐tuning of phenotypes—genetic accommodation—did not fall along the main axis of standing phenotypic variation or the direction of plasticity, and local adaptation did not consistently modify the direction or magnitude of plasticity. These results suggest that plasticity is a persistent source of developmental bias that shapes how plant populations adapt to environmental change, even when plasticity does not constrain how populations respond to selection.
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Affiliation(s)
- Reinder Radersma
- Department of Biology Lund University Lund Sweden.,Biometris Wageningen University & Research Wageningen The Netherlands
| | - Daniel W A Noble
- Division of Ecology and Evolution, Research School of Biology The Australian National University Canberra ACT Australia
| | - Tobias Uller
- Department of Biology Lund University Lund Sweden
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21
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Ho WC, Li D, Zhu Q, Zhang J. Phenotypic plasticity as a long-term memory easing readaptations to ancestral environments. SCIENCE ADVANCES 2020; 6:eaba3388. [PMID: 32494748 PMCID: PMC7244318 DOI: 10.1126/sciadv.aba3388] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/12/2020] [Indexed: 05/30/2023]
Abstract
Phenotypic plasticity refers to environment-induced phenotypic changes without mutation and is present in all organisms. The role of phenotypic plasticity in organismal adaptations to novel environments has attracted much attention, but its role in readaptations to ancestral environments is understudied. To address this question, we use the reciprocal transplant approach to investigate the multitissue transcriptomes of chickens adapted to the Tibetan Plateau and adjacent lowland. While many genetic transcriptomic changes had occurred in the forward adaptation to the highland, plastic changes largely transform the transcriptomes to the preferred state when Tibetan chickens are brought back to the lowland. The same trend holds for egg hatchability, a key component of the chicken fitness. These findings, along with highly similar patterns in comparable experiments of guppies and Escherichia coli, demonstrate that organisms generally "remember" their ancestral environments via phenotypic plasticity and reveal a mechanism by which past experience affects future evolution.
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Affiliation(s)
- Wei-Chin Ho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Diyan Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Qing Zhu
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
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22
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Etges WJ. Evolutionary genomics of host plant adaptation: insights from Drosophila. CURRENT OPINION IN INSECT SCIENCE 2019; 36:96-102. [PMID: 31542627 DOI: 10.1016/j.cois.2019.08.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
Variation in gene expression in response to the use of alternate host plants can reveal genetic and physiological mechanisms explaining why insect-host relationships vary from host specialism to generalism. Interpreting transcriptome variation relies on well-annotated genomes, making drosophilids valuable model systems, particularly those species with tractable ecological associations. Patterns of whole genome expression and alternate gene splicing in response to growth on different hosts have revealed expression of gene networks of known detoxification genes as well as novel functionally enriched genes of diverse metabolic and structural functions. Integrating trancriptomic responses with fitness differences and levels of phenotypic plasticity in response to alternate hosts will help to reveal the general nature of genotype-phenotype relationships.
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Affiliation(s)
- William J Etges
- Ecology, Evolution and Organismal Biology, Department of Biological Sciences, SCEN 632, 1 University of Arkansas, Fayetteville, AR 72701, USA.
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23
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Li C, Zhang J. Stop-codon read-through arises largely from molecular errors and is generally nonadaptive. PLoS Genet 2019; 15:e1008141. [PMID: 31120886 PMCID: PMC6550407 DOI: 10.1371/journal.pgen.1008141] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/05/2019] [Accepted: 04/16/2019] [Indexed: 12/02/2022] Open
Abstract
Stop-codon read-through refers to the phenomenon that a ribosome goes past the stop codon and continues translating into the otherwise untranslated region (UTR) of a transcript. Recent ribosome-profiling experiments in eukaryotes uncovered widespread stop-codon read-through that also varies among tissues, prompting the adaptive hypothesis that stop-codon read-through is an important, regulated mechanism for generating proteome diversity. Here we propose and test a competing hypothesis that stop-codon read-through arises mostly from molecular errors and is largely nonadaptive. The error hypothesis makes distinct predictions about the probability of read-through, frequency of sequence motifs for read-through, and conservation of the read-through region, each of which is supported by genome-scale data from yeasts and fruit flies. Thus, except for the few cases with demonstrated functions, stop-codon read-through is generally nonadaptive. This finding, along with other molecular errors recently quantified, reveals a much less precise or orderly cellular life than is commonly thought.
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Affiliation(s)
- Chuan Li
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States of America
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States of America
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