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Sample records for crop phenotypic plasticity

  1. Phenotypic plasticity and its genetic regulation for yield, nitrogen fixation and δ13C in chickpea crops under varying water regimes.

    PubMed

    Sadras, Victor O; Lake, Lachlan; Li, Yongle; Farquharson, Elizabeth A; Sutton, Tim

    2016-07-01

    We measured yield components, nitrogen fixation, soil nitrogen uptake and carbon isotope composition (δ(13)C) in a collection of chickpea genotypes grown in environments where water availability was the main source of yield variation. We aimed to quantify the phenotypic plasticity of these traits using variance ratios, and to explore their genetic basis using FST genome scan. Fifty-five genes in three genomic regions were found to be under selection for plasticity of yield; 54 genes in four genomic regions for the plasticity of seeds per m(2); 48 genes in four genomic regions for the plasticity of δ(13)C; 54 genes in two genomic regions for plasticity of flowering time; 48 genes in five genomic regions for plasticity of nitrogen fixation and 49 genes in three genomic regions for plasticity of nitrogen uptake from soil. Plasticity of yield was related to plasticity of nitrogen uptake from soil, and unrelated to plasticity of nitrogen fixation, highlighting the need for closer attention to nitrogen uptake in legumes. Whereas the theoretical link between δ(13)C and transpiration efficiency is strong, the actual link with yield is erratic due to trade-offs and scaling issues. Genes associated with plasticity of δ(13)C were identified that may help to untangle the δ(13)C-yield relationship. Combining a plasticity perspective to deal with complex G×E interactions with FST genome scan may help understand and improve both crop adaptation to stress and yield potential. PMID:27296246

  2. Plant phenotypic plasticity in a changing climate.

    PubMed

    Nicotra, A B; Atkin, O K; Bonser, S P; Davidson, A M; Finnegan, E J; Mathesius, U; Poot, P; Purugganan, M D; Richards, C L; Valladares, F; van Kleunen, M

    2010-12-01

    Climate change is altering the availability of resources and the conditions that are crucial to plant performance. One way plants will respond to these changes is through environmentally induced shifts in phenotype (phenotypic plasticity). Understanding plastic responses is crucial for predicting and managing the effects of climate change on native species as well as crop plants. Here, we provide a toolbox with definitions of key theoretical elements and a synthesis of the current understanding of the molecular and genetic mechanisms underlying plasticity relevant to climate change. By bringing ecological, evolutionary, physiological and molecular perspectives together, we hope to provide clear directives for future research and stimulate cross-disciplinary dialogue on the relevance of phenotypic plasticity under climate change. PMID:20970368

  3. [Plasticity of the cellular phenotype].

    PubMed

    Chneiweiss, Hervé

    2011-01-01

    The tragical consequences of the Hiroshima and Nagasaki atomic bombs in 1945 were to lead to the discovery of hematopoietic stem cells and their phenotypic plasticity, in response to environmental factors. These concepts were much later extended to the founding cells of other tissues. In the following collection of articles, the mechanisms underlying this plasticity, at the frontiers of developmental biology and oncology, are illustrated in the case of various cell types of neural origin and of some tumours. PMID:21501574

  4. Evolution of phenotypic plasticity in colonizing species.

    PubMed

    Lande, Russell

    2015-05-01

    I elaborate an hypothesis to explain inconsistent empirical findings comparing phenotypic plasticity in colonizing populations or species with plasticity from their native or ancestral range. Quantitative genetic theory on the evolution of plasticity reveals that colonization of a novel environment can cause a transient increase in plasticity: a rapid initial increase in plasticity accelerates evolution of a new optimal phenotype, followed by slow genetic assimilation of the new phenotype and reduction of plasticity. An association of colonization with increased plasticity depends on the difference in the optimal phenotype between ancestral and colonized environments, the difference in mean, variance and predictability of the environment, the cost of plasticity, and the time elapsed since colonization. The relative importance of these parameters depends on whether a phenotypic character develops by one-shot plasticity to a constant adult phenotype or by labile plasticity involving continuous and reversible development throughout adult life. PMID:25558898

  5. Phenotypic plasticity in bacterial plasmids.

    PubMed Central

    Turner, Paul E

    2004-01-01

    Plasmid pB15 was previously shown to evolve increased horizontal (infectious) transfer at the expense of reduced vertical (intergenerational) transfer and vice versa, a key trade-off assumed in theories of parasite virulence. Whereas the models predict that susceptible host abundance should determine which mode of transfer is selectively favored, host density failed to mediate the trade-off in pB15. One possibility is that the plasmid's transfer deviates from the assumption that horizontal spread (conjugation) occurs in direct proportion to cell density. I tested this hypothesis using Escherichia coli/pB15 associations in laboratory serial culture. Contrary to most models of plasmid transfer kinetics, my data show that pB15 invades static (nonshaking) bacterial cultures only at intermediate densities. The results can be explained by phenotypic plasticity in traits governing plasmid transfer. As cells become more numerous, the plasmid's conjugative transfer unexpectedly declines, while the trade-off between transmission routes causes vertical transfer to increase. Thus, at intermediate densities the plasmid's horizontal transfer can offset selection against plasmid-bearing cells, but at high densities pB15 conjugates so poorly that it cannot invade. I discuss adaptive vs. nonadaptive causes for the phenotypic plasticity, as well as potential mechanisms that may lead to complex transfer dynamics of plasmids in liquid environments. PMID:15166133

  6. Regulatory mechanisms link phenotypic plasticity to evolvability.

    PubMed

    van Gestel, Jordi; Weissing, Franz J

    2016-01-01

    Organisms have a remarkable capacity to respond to environmental change. They can either respond directly, by means of phenotypic plasticity, or they can slowly adapt through evolution. Yet, how phenotypic plasticity links to evolutionary adaptability is largely unknown. Current studies of plasticity tend to adopt a phenomenological reaction norm (RN) approach, which neglects the mechanisms underlying plasticity. Focusing on a concrete question - the optimal timing of bacterial sporulation - we here also consider a mechanistic approach, the evolution of a gene regulatory network (GRN) underlying plasticity. Using individual-based simulations, we compare the RN and GRN approach and find a number of striking differences. Most importantly, the GRN model results in a much higher diversity of responsive strategies than the RN model. We show that each of the evolved strategies is pre-adapted to a unique set of unseen environmental conditions. The regulatory mechanisms that control plasticity therefore critically link phenotypic plasticity to the adaptive potential of biological populations. PMID:27087393

  7. Evolution of environmental cues for phenotypic plasticity.

    PubMed

    Chevin, Luis-Miguel; Lande, Russell

    2015-10-01

    Phenotypically plastic characters may respond to multiple variables in their environment, but the evolutionary consequences of this phenomenon have rarely been addressed theoretically. We model the evolution of linear reaction norms in response to several correlated environmental variables, in a population undergoing stationary environmental fluctuations. At evolutionary equilibrium, the linear combination of environmental variables that acts as a developmental cue for the plastic trait is the multivariate best linear predictor of changes in the optimum. However, the reaction norm with respect to any single environmental variable may exhibit nonintuitive patterns. Apparently maladaptive, or hyperadaptive plasticity can evolve with respect to single environmental variables, and costs of plasticity may increase, rather than reduce, plasticity in response to some variables. We also find conditions for the evolution of an indirect environmental indicator that affects expression of a plastic phenotype, despite not influencing natural selection on it. PMID:26292649

  8. Phenotypic plasticity with instantaneous but delayed switches.

    PubMed

    Utz, Margarete; Jeschke, Jonathan M; Loeschcke, Volker; Gabriel, Wilfried

    2014-01-01

    Phenotypic plasticity is a widespread phenomenon, allowing organisms to better adapt to changing environments. Most empirical and theoretical studies are restricted to irreversible plasticity where the expression of a specific phenotype is mostly determined during development. However, reversible plasticity is not uncommon; here, organisms are able to switch back and forth between phenotypes. We present two optimization models for the fitness of (i) non-plastic, (ii) irreversibly plastic, and (iii) reversibly plastic genotypes in a fluctuating environment. In one model, the fitness values of an organism during different life phases act together multiplicatively (so as to consider traits that are related to survival). The other model additionally considers additive effects (corresponding to traits related to fecundity). Both models yield qualitatively similar results. If the only costs of reversible plasticity are due to temporal maladaptation while switching between phenotypes, reversibility is virtually always advantageous over irreversibility, especially for slow environmental fluctuations. If reversibility implies an overall decreased fitness, then irreversibility is advantageous if the environment fluctuates quickly or if stress events last relatively short. Our results are supported by observations from different types of organisms and have implications for many basic and applied research questions, e.g., on invasive alien species. PMID:24041594

  9. Regulatory mechanisms link phenotypic plasticity to evolvability

    PubMed Central

    van Gestel, Jordi; Weissing, Franz J.

    2016-01-01

    Organisms have a remarkable capacity to respond to environmental change. They can either respond directly, by means of phenotypic plasticity, or they can slowly adapt through evolution. Yet, how phenotypic plasticity links to evolutionary adaptability is largely unknown. Current studies of plasticity tend to adopt a phenomenological reaction norm (RN) approach, which neglects the mechanisms underlying plasticity. Focusing on a concrete question – the optimal timing of bacterial sporulation – we here also consider a mechanistic approach, the evolution of a gene regulatory network (GRN) underlying plasticity. Using individual-based simulations, we compare the RN and GRN approach and find a number of striking differences. Most importantly, the GRN model results in a much higher diversity of responsive strategies than the RN model. We show that each of the evolved strategies is pre-adapted to a unique set of unseen environmental conditions. The regulatory mechanisms that control plasticity therefore critically link phenotypic plasticity to the adaptive potential of biological populations. PMID:27087393

  10. Sustainable harvest: managing plasticity for resilient crops

    PubMed Central

    Bloomfield, Justin A; Rose, Terry J; King, Graham J

    2014-01-01

    Maintaining crop production to feed a growing world population is a major challenge for this period of rapid global climate change. No consistent conceptual or experimental framework for crop plants integrates information at the levels of genome regulation, metabolism, physiology and response to growing environment. An important role for plasticity in plants is assisting in homeostasis in response to variable environmental conditions. Here, we outline how plant plasticity is facilitated by epigenetic processes that modulate chromatin through dynamic changes in DNA methylation, histone variants, small RNAs and transposable elements. We present examples of plant plasticity in the context of epigenetic regulation of developmental phases and transitions and map these onto the key stages of crop establishment, growth, floral initiation, pollination, seed set and maturation of harvestable product. In particular, we consider how feedback loops of environmental signals and plant nutrition affect plant ontogeny. Recent advances in understanding epigenetic processes enable us to take a fresh look at the crosstalk between regulatory systems that confer plasticity in the context of crop development. We propose that these insights into genotype × environment (G × E) interaction should underpin development of new crop management strategies, both in terms of information-led agronomy and in recognizing the role of epigenetic variation in crop breeding. PMID:24891039

  11. Endothelial Plasticity: Shifting Phenotypes through Force Feedback

    PubMed Central

    Krenning, Guido; Barauna, Valerio G.; Krieger, José E.; Harmsen, Martin C.; Moonen, Jan-Renier A. J.

    2016-01-01

    The endothelial lining of the vasculature is exposed to a large variety of biochemical and hemodynamic stimuli with different gradients throughout the vascular network. Adequate adaptation requires endothelial cells to be highly plastic, which is reflected by the remarkable heterogeneity of endothelial cells in tissues and organs. Hemodynamic forces such as fluid shear stress and cyclic strain are strong modulators of the endothelial phenotype and function. Although endothelial plasticity is essential during development and adult physiology, proatherogenic stimuli can induce adverse plasticity which contributes to disease. Endothelial-to-mesenchymal transition (EndMT), the hallmark of endothelial plasticity, was long thought to be restricted to embryonic development but has emerged as a pathologic process in a plethora of diseases. In this perspective we argue how shear stress and cyclic strain can modulate EndMT and discuss how this is reflected in atherosclerosis and pulmonary arterial hypertension. PMID:26904133

  12. Amphibious fishes: evolution and phenotypic plasticity.

    PubMed

    Wright, Patricia A; Turko, Andy J

    2016-08-01

    Amphibious fishes spend part of their life in terrestrial habitats. The ability to tolerate life on land has evolved independently many times, with more than 200 extant species of amphibious fishes spanning 17 orders now reported. Many adaptations for life out of water have been described in the literature, and adaptive phenotypic plasticity may play an equally important role in promoting favourable matches between the terrestrial habitat and behavioural, physiological, biochemical and morphological characteristics. Amphibious fishes living at the interface of two very different environments must respond to issues relating to buoyancy/gravity, hydration/desiccation, low/high O2 availability, low/high CO2 accumulation and high/low NH3 solubility each time they traverse the air-water interface. Here, we review the literature for examples of plastic traits associated with the response to each of these challenges. Because there is evidence that phenotypic plasticity can facilitate the evolution of fixed traits in general, we summarize the types of investigations needed to more fully determine whether plasticity in extant amphibious fishes can provide indications of the strategies used during the evolution of terrestriality in tetrapods. PMID:27489213

  13. Genetic Regulation of Phenotypic Plasticity and Canalisation in Yeast Growth.

    PubMed

    Yadav, Anupama; Dhole, Kaustubh; Sinha, Himanshu

    2016-01-01

    The ability of a genotype to show diverse phenotypes in different environments is called phenotypic plasticity. Phenotypic plasticity helps populations to evade extinctions in novel environments, facilitates adaptation and fuels evolution. However, most studies focus on understanding the genetic basis of phenotypic regulation in specific environments. As a result, while it's evolutionary relevance is well established, genetic mechanisms regulating phenotypic plasticity and their overlap with the environment specific regulators is not well understood. Saccharomyces cerevisiae is highly sensitive to the environment, which acts as not just external stimulus but also as signalling cue for this unicellular, sessile organism. We used a previously published dataset of a biparental yeast population grown in 34 diverse environments and mapped genetic loci regulating variation in phenotypic plasticity, plasticity QTL, and compared them with environment-specific QTL. Plasticity QTL is one whose one allele exhibits high plasticity whereas the other shows a relatively canalised behaviour. We mapped phenotypic plasticity using two parameters-environmental variance, an environmental order-independent parameter and reaction norm (slope), an environmental order-dependent parameter. Our results show a partial overlap between pleiotropic QTL and plasticity QTL such that while some plasticity QTL are also pleiotropic, others have a significant effect on phenotypic plasticity without being significant in any environment independently. Furthermore, while some plasticity QTL are revealed only in specific environmental orders, we identify large effect plasticity QTL, which are order-independent such that whatever the order of the environments, one allele is always plastic and the other is canalised. Finally, we show that the environments can be divided into two categories based on the phenotypic diversity of the population within them and the two categories have differential regulators of

  14. Cyanogenic glycosides: synthesis, physiology, and phenotypic plasticity.

    PubMed

    Gleadow, Roslyn M; Møller, Birger Lindberg

    2014-01-01

    Cyanogenic glycosides (CNglcs) are bioactive plant products derived from amino acids. Structurally, these specialized plant compounds are characterized as α-hydroxynitriles (cyanohydrins) that are stabilized by glucosylation. In recent years, improved tools within analytical chemistry have greatly increased the number of known CNglcs by enabling the discovery of less abundant CNglcs formed by additional hydroxylation, glycosylation, and acylation reactions. Cyanogenesis--the release of toxic hydrogen cyanide from endogenous CNglcs--is an effective defense against generalist herbivores but less effective against fungal pathogens. In the course of evolution, CNglcs have acquired additional roles to improve plant plasticity, i.e., establishment, robustness, and viability in response to environmental challenges. CNglc concentration is usually higher in young plants, when nitrogen is in ready supply, or when growth is constrained by nonoptimal growth conditions. Efforts are under way to engineer CNglcs into some crops as a pest control measure, whereas in other crops efforts are directed toward their removal to improve food safety. Given that many food crops are cyanogenic, it is important to understand the molecular mechanisms regulating cyanogenesis so that the impact of future environmental challenges can be anticipated. PMID:24579992

  15. Molecular mechanisms of phenotypic plasticity in social insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyphenism in insects, whereby a single genome expresses different phenotypes in response to environmental cues, is a fascinating biological phenomenon. Social insects are especially intriguing examples of phenotypic plasticity because division of labor results in the development of extreme morphol...

  16. Phenotypic plasticity in two marine snails: constraints superseding life history.

    PubMed

    Hollander, J; Collyer, M L; Adams, D C; Johannesson, K

    2006-11-01

    In organisms encountering predictable environments, fixed development is expected, whereas in organisms that cannot predict their future environment, phenotypic plasticity would be optimal to increase local adaptation. To test this prediction we experimentally compared phenotypic plasticity in two rocky-shore snail species; Littorina saxatilis releasing miniature snails on the shore, and Littorina littorea releasing drifting larvae settling on various shores, expecting L. littorea to show more phenotypic plasticity than L. saxatilis. We compared magnitude and direction of vectors of phenotypic difference in juvenile shell traits after 3 months exposure to different stimuli simulating sheltered and crab-rich shores, or wave-exposed and crab-free shores. Both species showed similar direction and magnitude of vectors of phenotypic difference with minor differences only between ecotypes of the nondispersing species, indicating that plasticity is an evolving trait in L. saxatilis. The lack of a strong plastic response in L. littorea might be explained by limits rather than costs to plasticity. PMID:17040383

  17. The ubiquity of phenotypic plasticity in plants: a synthesis

    PubMed Central

    Palacio-López, Kattia; Beckage, Brian; Scheiner, Samuel; Molofsky, Jane

    2015-01-01

    Adaptation to heterogeneous environments can occur via phenotypic plasticity, but how often this occurs is unknown. Reciprocal transplant studies provide a rich dataset to address this issue in plant populations because they allow for a determination of the prevalence of plastic versus canalized responses. From 31 reciprocal transplant studies, we quantified the frequency of five possible evolutionary patterns: (1) canalized response–no differentiation: no plasticity, the mean phenotypes of the populations are not different; (2) canalized response–population differentiation: no plasticity, the mean phenotypes of the populations are different; (3) perfect adaptive plasticity: plastic responses with similar reaction norms between populations; (4) adaptive plasticity: plastic responses with parallel, but not congruent reaction norms between populations; and (5) nonadaptive plasticity: plastic responses with differences in the slope of the reaction norms. The analysis included 362 records: 50.8% life-history traits, 43.6% morphological traits, and 5.5% physiological traits. Across all traits, 52% of the trait records were not plastic, and either showed no difference in means across sites (17%) or differed among sites (83%). Among the 48% of trait records that showed some sort of plasticity, 49.4% showed perfect adaptive plasticity, 19.5% adaptive plasticity, and 31% nonadaptive plasticity. These results suggest that canalized responses are more common than adaptive plasticity as an evolutionary response to environmental heterogeneity. PMID:26380672

  18. The role of phenotypic plasticity in driving genetic evolution.

    PubMed Central

    Price, Trevor D; Qvarnström, Anna; Irwin, Darren E

    2003-01-01

    Models of population divergence and speciation are often based on the assumption that differences between populations are due to genetic factors, and that phenotypic change is due to natural selection. It is equally plausible that some of the differences among populations are due to phenotypic plasticity. We use the metaphor of the adaptive landscape to review the role of phenotypic plasticity in driving genetic evolution. Moderate levels of phenotypic plasticity are optimal in permitting population survival in a new environment and in bringing populations into the realm of attraction of an adaptive peak. High levels of plasticity may increase the probability of population persistence but reduce the likelihood of genetic change, because the plastic response itself places the population close to a peak. Moderate levels of plasticity arise whenever multiple traits, some of which are plastic and others not, form a composite trait involved in the adaptive response. For example, altered behaviours may drive selection on morphology and physiology. Because there is likely to be a considerable element of chance in which behaviours become established, behavioural change followed by morphological and physiological evolution may be a potent force in driving evolution in novel directions. We assess the role of phenotypic plasticity in stimulating evolution by considering two examples from birds: (i) the evolution of red and yellow plumage coloration due to carotenoid consumption; and (ii) the evolution of foraging behaviours on islands. Phenotypic plasticity is widespread in nature and may speed up, slow down, or have little effect on evolutionary change. Moderate levels of plasticity may often facilitate genetic evolution but careful analyses of individual cases are needed to ascertain whether plasticity has been essential or merely incidental to population differentiation. PMID:12965006

  19. Endocrine regulation of predator-induced phenotypic plasticity.

    PubMed

    Dennis, Stuart R; LeBlanc, Gerald A; Beckerman, Andrew P

    2014-11-01

    Elucidating the developmental and genetic control of phenotypic plasticity remains a central agenda in evolutionary ecology. Here, we investigate the physiological regulation of phenotypic plasticity induced by another organism, specifically predator-induced phenotypic plasticity in the model ecological and evolutionary organism Daphnia pulex. Our research centres on using molecular tools to test among alternative mechanisms of developmental control tied to hormone titres, receptors and their timing in the life cycle. First, we synthesize detail about predator-induced defenses and the physiological regulation of arthropod somatic growth and morphology, leading to a clear prediction that morphological defences are regulated by juvenile hormone and life-history plasticity by ecdysone and juvenile hormone. We then show how a small network of genes can differentiate phenotype expression between the two primary developmental control pathways in arthropods: juvenoid and ecdysteroid hormone signalling. Then, by applying an experimental gradient of predation risk, we show dose-dependent gene expression linking predator-induced plasticity to the juvenoid hormone pathway. Our data support three conclusions: (1) the juvenoid signalling pathway regulates predator-induced phenotypic plasticity; (2) the hormone titre (ligand), rather than receptor, regulates predator-induced developmental plasticity; (3) evolution has favoured the harnessing of a major, highly conserved endocrine pathway in arthropod development to regulate the response to cues about changing environments (risk) from another organism (predator). PMID:25284611

  20. Phenotypic plasticity in prostate cancer: role of intrinsically disordered proteins

    PubMed Central

    Mooney, Steven M; Jolly, Mohit Kumar; Levine, Herbert; Kulkarni, Prakash

    2016-01-01

    A striking characteristic of cancer cells is their remarkable phenotypic plasticity, which is the ability to switch states or phenotypes in response to environmental fluctuations. Phenotypic changes such as a partial or complete epithelial to mesenchymal transition (EMT) that play important roles in their survival and proliferation, and development of resistance to therapeutic treatments, are widely believed to arise due to somatic mutations in the genome. However, there is a growing concern that such a deterministic view is not entirely consistent with multiple lines of evidence, which indicate that stochasticity may also play an important role in driving phenotypic plasticity. Here, we discuss how stochasticity in protein interaction networks (PINs) may play a key role in determining phenotypic plasticity in prostate cancer (PCa). Specifically, we point out that the key players driving transitions among different phenotypes (epithelial, mesenchymal, and hybrid epithelial/mesenchymal), including ZEB1, SNAI1, OVOL1, and OVOL2, are intrinsically disordered proteins (IDPs) and discuss how plasticity at the molecular level may contribute to stochasticity in phenotypic switching by rewiring PINs. We conclude by suggesting that targeting IDPs implicated in EMT in PCa may be a new strategy to gain additional insights and develop novel treatments for this disease, which is the most common form of cancer in adult men. PMID:27427552

  1. Phenotypic plasticity in prostate cancer: role of intrinsically disordered proteins.

    PubMed

    Mooney, Steven M; Jolly, Mohit Kumar; Levine, Herbert; Kulkarni, Prakash

    2016-01-01

    A striking characteristic of cancer cells is their remarkable phenotypic plasticity, which is the ability to switch states or phenotypes in response to environmental fluctuations. Phenotypic changes such as a partial or complete epithelial to mesenchymal transition (EMT) that play important roles in their survival and proliferation, and development of resistance to therapeutic treatments, are widely believed to arise due to somatic mutations in the genome. However, there is a growing concern that such a deterministic view is not entirely consistent with multiple lines of evidence, which indicate that stochasticity may also play an important role in driving phenotypic plasticity. Here, we discuss how stochasticity in protein interaction networks (PINs) may play a key role in determining phenotypic plasticity in prostate cancer (PCa). Specifically, we point out that the key players driving transitions among different phenotypes (epithelial, mesenchymal, and hybrid epithelial/mesenchymal), including ZEB1, SNAI1, OVOL1, and OVOL2, are intrinsically disordered proteins (IDPs) and discuss how plasticity at the molecular level may contribute to stochasticity in phenotypic switching by rewiring PINs. We conclude by suggesting that targeting IDPs implicated in EMT in PCa may be a new strategy to gain additional insights and develop novel treatments for this disease, which is the most common form of cancer in adult men. PMID:27427552

  2. Phenotypic Plasticity and Selection: Nonexclusive Mechanisms of Adaptation

    PubMed Central

    Grenier, S.; Barre, P.; Litrico, I.

    2016-01-01

    Selection and plasticity are two mechanisms that allow the adaptation of a population to a changing environment. Interaction between these nonexclusive mechanisms must be considered if we are to understand population survival. This review discusses the ways in which plasticity and selection can interact, based on a review of the literature on selection and phenotypic plasticity in the evolution of populations. The link between selection and phenotypic plasticity is analysed at the level of the individual. Plasticity can affect an individual's response to selection and so may modify the end result of genetic diversity evolution at population level. Genetic diversity increases the ability of populations or communities to adapt to new environmental conditions. Adaptive plasticity increases individual fitness. However this effect must be viewed from the perspective of the costs of plasticity, although these are not easy to estimate. It is becoming necessary to engage in new experimental research to demonstrate the combined effects of selection and plasticity for adaptation and their consequences on the evolution of genetic diversity. PMID:27313957

  3. Molecular mechanisms of phenotypic plasticity in social insects.

    PubMed

    Corona, Miguel; Libbrecht, Romain; Wheeler, Diana E

    2016-02-01

    Polyphenism in insects, whereby a single genome expresses different phenotypes in response to environmental cues, is a fascinating biological phenomenon. Social insects are especially intriguing examples of phenotypic plasticity because division of labor results in the development of extreme morphological phenotypes, such as the queen and worker castes. Although sociality evolved independently in ants, bees, wasps and termites, similar genetic pathways regulate phenotypic plasticity in these different groups of social insects. The insulin/insulin-like growth signaling (IIS) plays a key role in this process. Recent research reveals that IIS interacts with other pathways including target of rapamycin (TOR), epidermal growth factor receptor (Egfr), juvenile hormone (JH) and vitellogenin (Vg) to regulate caste differentiation. PMID:27436553

  4. Phenotyping for drought tolerance of crops in the genomics era

    PubMed Central

    Tuberosa, Roberto

    2012-01-01

    Improving crops yield under water-limited conditions is the most daunting challenge faced by breeders. To this end, accurate, relevant phenotyping plays an increasingly pivotal role for the selection of drought-resilient genotypes and, more in general, for a meaningful dissection of the quantitative genetic landscape that underscores the adaptive response of crops to drought. A major and universally recognized obstacle to a more effective translation of the results produced by drought-related studies into improved cultivars is the difficulty in properly phenotyping in a high-throughput fashion in order to identify the quantitative trait loci that govern yield and related traits across different water regimes. This review provides basic principles and a broad set of references useful for the management of phenotyping practices for the study and genetic dissection of drought tolerance and, ultimately, for the release of drought-tolerant cultivars. PMID:23049510

  5. Evolutionary adaptation of phenotypic plasticity in a synthetic microbial system

    NASA Astrophysics Data System (ADS)

    Tans, Sander

    2010-03-01

    While phenotypic plasticity -the capability to respond to the environment- is vital to organisms, tests of its adaptation have remained indecisive because constraints and selection in variable environments are unknown and entangled. We show that one can determine the phenotype-fitness landscape that specifies selection on plasticity, by uncoupling the environmental cue and stress in a genetically engineered microbial system. Evolutionary trajectories revealed genetic constraints in a regulatory protein, which imposed cross-environment trade-offs that favored specialization. However, depending on the synchronicity and amplitude of the applied cue and stress variations, adaptation could break constraints, resolve trade-offs, and evolve optimal phenotypes that exhibit qualitatively altered (inverse) responses to the cue. Our results provide a first step to explain the adaptive origins of complex behavior in heterogeneous environments.

  6. RNA Directed Modulation of Phenotypic Plasticity in Human Cells.

    PubMed

    Trakman, Laura; Hewson, Chris; Burdach, Jon; Morris, Kevin V

    2016-01-01

    Natural selective processes have been known to drive phenotypic plasticity, which is the emergence of different phenotypes from one genome following environmental stimulation. Long non-coding RNAs (lncRNAs) have been observed to modulate transcriptional and epigenetic states of genes in human cells. We surmised that lncRNAs are governors of phenotypic plasticity and drive natural selective processes through epigenetic modulation of gene expression. Using heat shocked human cells as a model we find several differentially expressed transcripts with the top candidates being lncRNAs derived from retro-elements. One particular retro-element derived transcripts, Retro-EIF2S2, was found to be abundantly over-expressed in heat shocked cells. Over-expression of Retro-EIF2S2 significantly enhanced cell viability and modulated a predisposition for an adherent cellular phenotype upon heat shock. Mechanistically, we find that this retro-element derived transcript interacts directly with a network of proteins including 40S ribosomal protein S30 (FAU), Eukaryotic translation initiation factor 5A (EIF5A), and Ubiquitin-60S ribosomal protein L40 (UBA52) to affect protein modulated cell adhesion pathways. We find one motif in Retro-EIF2S2 that exhibits binding to FAU and modulates phenotypic cell transitions from adherent to suspension states. The observations presented here suggest that retroviral derived transcripts actively modulate phenotypic plasticity in human cells in response to environmental selective pressures and suggest that natural selection may play out through the action of retro-elements in human cells. PMID:27082860

  7. RNA Directed Modulation of Phenotypic Plasticity in Human Cells

    PubMed Central

    Burdach, Jon; Morris, Kevin V.

    2016-01-01

    Natural selective processes have been known to drive phenotypic plasticity, which is the emergence of different phenotypes from one genome following environmental stimulation. Long non-coding RNAs (lncRNAs) have been observed to modulate transcriptional and epigenetic states of genes in human cells. We surmised that lncRNAs are governors of phenotypic plasticity and drive natural selective processes through epigenetic modulation of gene expression. Using heat shocked human cells as a model we find several differentially expressed transcripts with the top candidates being lncRNAs derived from retro-elements. One particular retro-element derived transcripts, Retro-EIF2S2, was found to be abundantly over-expressed in heat shocked cells. Over-expression of Retro-EIF2S2 significantly enhanced cell viability and modulated a predisposition for an adherent cellular phenotype upon heat shock. Mechanistically, we find that this retro-element derived transcript interacts directly with a network of proteins including 40S ribosomal protein S30 (FAU), Eukaryotic translation initiation factor 5A (EIF5A), and Ubiquitin-60S ribosomal protein L40 (UBA52) to affect protein modulated cell adhesion pathways. We find one motif in Retro-EIF2S2 that exhibits binding to FAU and modulates phenotypic cell transitions from adherent to suspension states. The observations presented here suggest that retroviral derived transcripts actively modulate phenotypic plasticity in human cells in response to environmental selective pressures and suggest that natural selection may play out through the action of retro-elements in human cells. PMID:27082860

  8. Plasticity, stability, and yield: the origins of Anthony David Bradshaw's model of adaptive phenotypic plasticity.

    PubMed

    Peirson, B R Erick

    2015-04-01

    Plant ecologist Anthony David Bradshaw's account of the evolution of adaptive phenotypic plasticity remains central to contemporary research aimed at understanding how organisms persist in heterogeneous environments. Bradshaw suggested that changes in particular traits in response to specific environmental factors could be under direct genetic control, and that natural selection could therefore act directly to shape those responses: plasticity was not "noise" obscuring a genetic signal, but could be specific and refined just as any other adaptive phenotypic trait. In this paper, I document the contexts and development of Bradshaw's investigation of phenotypic plasticity in plants, including a series of unreported experiments in the late 1950s and early 1960s. Contrary to the mythology that later emerged around Bradshaw's ideas, Bradshaw was engaged in a serious and sustained empirical research program concerning plasticity in the 1950s and 1960s that went far beyond a single review paper. Moreover, that work was not isolated, but was surrounded by an already rich theoretical discourse and a substantial body of empirical research concerning the evolution of developmental plasticity and stability. Bradshaw recast the problem of how to understand (and control) plasticity and stability within an epistemic framework focused on genetic differences and natural selection. PMID:25641217

  9. Invasion strategies in clonal aquatic plants: are phenotypic differences caused by phenotypic plasticity or local adaptation?

    PubMed Central

    Riis, Tenna; Lambertini, Carla; Olesen, Birgit; Clayton, John S.; Brix, Hans; Sorrell, Brian K.

    2010-01-01

    Background and Aims The successful spread of invasive plants in new environments is often linked to multiple introductions and a diverse gene pool that facilitates local adaptation to variable environmental conditions. For clonal plants, however, phenotypic plasticity may be equally important. Here the primary adaptive strategy in three non-native, clonally reproducing macrophytes (Egeria densa, Elodea canadensis and Lagarosiphon major) in New Zealand freshwaters were examined and an attempt was made to link observed differences in plant morphology to local variation in habitat conditions. Methods Field populations with a large phenotypic variety were sampled in a range of lakes and streams with different chemical and physical properties. The phenotypic plasticity of the species before and after cultivation was studied in a common garden growth experiment, and the genetic diversity of these same populations was also quantified. Key Results For all three species, greater variation in plant characteristics was found before they were grown in standardized conditions. Moreover, field populations displayed remarkably little genetic variation and there was little interaction between habitat conditions and plant morphological characteristics. Conclusions The results indicate that at the current stage of spread into New Zealand, the primary adaptive strategy of these three invasive macrophytes is phenotypic plasticity. However, while limited, the possibility that genetic diversity between populations may facilitate ecotypic differentiation in the future cannot be excluded. These results thus indicate that invasive clonal aquatic plants adapt to new introduced areas by phenotypic plasticity. Inorganic carbon, nitrogen and phosphorous were important in controlling plant size of E. canadensis and L. major, but no other relationships between plant characteristics and habitat conditions were apparent. This implies that within-species differences in plant size can be explained

  10. UAV-based high-throughput phenotyping in legume crops

    NASA Astrophysics Data System (ADS)

    Sankaran, Sindhuja; Khot, Lav R.; Quirós, Juan; Vandemark, George J.; McGee, Rebecca J.

    2016-05-01

    In plant breeding, one of the biggest obstacles in genetic improvement is the lack of proven rapid methods for measuring plant responses in field conditions. Therefore, the major objective of this research was to evaluate the feasibility of utilizing high-throughput remote sensing technology for rapid measurement of phenotyping traits in legume crops. The plant responses of several chickpea and peas varieties to the environment were assessed with an unmanned aerial vehicle (UAV) integrated with multispectral imaging sensors. Our preliminary assessment showed that the vegetation indices are strongly correlated (p<0.05) with seed yield of legume crops. Results endorse the potential of UAS-based sensing technology to rapidly measure those phenotyping traits.

  11. Analysis of Constituents for Phenotyping Drought Tolerance in Crop Improvement

    PubMed Central

    Setter, Tim L.

    2012-01-01

    Investigators now have a wide range of analytical tools to use in measuring metabolites, proteins and transcripts in plant tissues. These tools have the potential to assist genetic studies that seek to phenotype genetic lines for heritable traits that contribute to drought tolerance. To be useful for crop breeding, hundreds or thousands of genetic lines must be assessed. This review considers the utility of assaying certain constituents with roles in drought tolerance for phenotyping genotypes. Abscisic acid (ABA), organic and inorganic osmolytes, compatible solutes, and late embryogenesis abundant proteins, are considered. Confounding effects that require appropriate tissue and timing specificity, and the need for high-throughput and analytical cost efficiency are discussed. With future advances in analytical methods and the value of analyzing constituents that provide information on the underlying mechanisms of drought tolerance, these approaches are expected to contribute to development crops with improved drought tolerance. PMID:22675308

  12. Virus Infection Suppresses Nicotiana benthamiana Adaptive Phenotypic Plasticity

    PubMed Central

    Bedhomme, Stéphanie; Elena, Santiago F.

    2011-01-01

    Competition and parasitism are two important selective forces that shape life-histories, migration rates and population dynamics. Recently, it has been shown in various pathosystems that parasites can modify intraspecific competition, thus generating an indirect cost of parasitism. Here, we investigated if this phenomenon was present in a plant-potyvirus system using two viruses of different virulence (Tobacco etch virus and Turnip mosaic virus). Moreover, we asked if parasitism interacted with the shade avoidance syndrome, the plant-specific phenotypic plasticity in response to intraspecific competition. Our results indicate that the modification of intraspecific competition by parasitism is not present in the Nicotiana benthamiana – potyvirus system and suggests that this phenomenon is not universal but depends on the peculiarities of each pathosystem. However, whereas the healthy N. benthamiana presented a clear shade avoidance syndrome, this phenotypic plasticity totally disappeared when the plants were infected with TEV and TuMV, very likely resulting in a fitness loss and being another form of indirect cost of parasitism. This result suggests that the suppression or the alteration of adaptive phenotypic plasticity might be a component of virulence that is often overlooked. PMID:21359142

  13. Virus infection suppresses Nicotiana benthamiana adaptive phenotypic plasticity.

    PubMed

    Bedhomme, Stéphanie; Elena, Santiago F

    2011-01-01

    Competition and parasitism are two important selective forces that shape life-histories, migration rates and population dynamics. Recently, it has been shown in various pathosystems that parasites can modify intraspecific competition, thus generating an indirect cost of parasitism. Here, we investigated if this phenomenon was present in a plant-potyvirus system using two viruses of different virulence (Tobacco etch virus and Turnip mosaic virus). Moreover, we asked if parasitism interacted with the shade avoidance syndrome, the plant-specific phenotypic plasticity in response to intraspecific competition. Our results indicate that the modification of intraspecific competition by parasitism is not present in the Nicotiana benthamiana--potyvirus system and suggests that this phenomenon is not universal but depends on the peculiarities of each pathosystem. However, whereas the healthy N. benthamiana presented a clear shade avoidance syndrome, this phenotypic plasticity totally disappeared when the plants were infected with TEV and TuMV, very likely resulting in a fitness loss and being another form of indirect cost of parasitism. This result suggests that the suppression or the alteration of adaptive phenotypic plasticity might be a component of virulence that is often overlooked. PMID:21359142

  14. Relaxed selection is a precursor to the evolution of phenotypic plasticity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenotypic plasticity represents one of the most important ways that organisms adaptively respond to environmental variation. Alternate phenotypes produced through phenotypic plasiticity generally arise through conditional gene expression, which is predicted to result in relaxed selective constrain...

  15. A role for phenotypic plasticity in the evolution of aposematism.

    PubMed Central

    Sword, Gregory A

    2002-01-01

    The evolution of warning coloration (aposematism) has been difficult to explain because rare conspicuous mutants should suffer a higher cost of discovery by predators relative to the cryptic majority, while at frequencies too low to facilitate predator aversion learning. Traditional models for the evolution of aposematism have assumed conspicuous prey phenotypes to be genetically determined and constitutive. By contrast, we have recently come to understand that warning coloration can be environmentally determined and mediated by local prey density, thereby reducing the initial costs of conspicuousness. The expression of density-dependent colour polyphenism is widespread among the insects and may provide an alternative pathway for the evolution of constitutive aposematic phenotypes in unpalatable prey by providing a protected intermediate stage. If density-dependent aposematism can function as an adaptive intermediate stage for the evolution of constitutive aposematic phenotypes, differential reaction norm evolution is predicted among related palatable and unpalatable prey populations. Here, I present empirical evidence that indicates that (i) the expression of density-dependent colour polyphenism has differentially evolved between palatable and unpalatable populations of the grasshopper Schistocerca emarginata (= lineata) (Orthoptera: Acrididae), and (ii) variation in plasticity between these populations is commensurate with the expected costs of conspicuousness. PMID:12204123

  16. Does plasticity enhance or dampen phenotypic parallelism? A test with three lake-stream stickleback pairs.

    PubMed

    Oke, K B; Bukhari, M; Kaeuffer, R; Rolshausen, G; Räsänen, K; Bolnick, D I; Peichel, C L; Hendry, A P

    2016-01-01

    Parallel (and convergent) phenotypic variation is most often studied in the wild, where it is difficult to disentangle genetic vs. environmentally induced effects. As a result, the potential contributions of phenotypic plasticity to parallelism (and nonparallelism) are rarely evaluated in a formal sense. Phenotypic parallelism could be enhanced by plasticity that causes stronger parallelism across populations in the wild than would be expected from genetic differences alone. Phenotypic parallelism could be dampened if site-specific plasticity induced differences between otherwise genetically parallel populations. We used a common-garden study of three independent lake-stream stickleback population pairs to evaluate the extent to which adaptive divergence has a genetic or plastic basis, and to investigate the enhancing vs. dampening effects of plasticity on phenotypic parallelism. We found that lake-stream differences in most traits had a genetic basis, but that several traits also showed contributions from plasticity. Moreover, plasticity was much more prevalent in one watershed than in the other two. In most cases, plasticity enhanced phenotypic parallelism, whereas in a few cases, plasticity had a dampening effect. Genetic and plastic contributions to divergence seem to play a complimentary, likely adaptive, role in phenotypic parallelism of lake-stream stickleback. These findings highlight the value of formally comparing wild-caught and laboratory-reared individuals in the study of phenotypic parallelism. PMID:26411538

  17. Phenotypic plasticity in thermal tolerance in the Glanville fritillary butterfly.

    PubMed

    Luo, Shiqi; Chong Wong, Swee; Xu, Chongren; Hanski, Ilkka; Wang, Rongjiang; Lehtonen, Rainer

    2014-05-01

    Ambient temperature is an ubiquitous environmental factor affecting all organisms. Global climate change increases temperature variation and the frequency of extreme temperatures, which may pose challenges to ectotherms. Here, we examine phenotypic plasticity to temperature and genotypic effects on thermal tolerance in the Glanville fritillary butterfly (Melitaea cinxia). We found no significant difference in heat or cold tolerance in populations originating from a continental climate in China and from Finland with moderate temperature variation. Acclimation to large-amplitude temperature variation increased heat tolerance in both populations, but decreased cold tolerance and increased hsp70-2 expression in the Chinese population only. The latter result indicates a genotypic effect in the response to temperature variation. In the Finnish population, a non-synonymous SNP in the phosphoglucose isomerase (Pgi) gene was associated with heat knock-down time. PMID:24802146

  18. Phenotypic plasticity confers multiple fitness benefits to a mimic.

    PubMed

    Cortesi, Fabio; Feeney, William E; Ferrari, Maud C O; Waldie, Peter A; Phillips, Genevieve A C; McClure, Eva C; Sköld, Helen N; Salzburger, Walter; Marshall, N Justin; Cheney, Karen L

    2015-03-30

    Animal communication is often deceptive; however, such dishonesty can become ineffective if it is used too often, is used out of context, or is too easy to detect [1-3]. Mimicry is a common form of deception, and most mimics gain the greatest fitness benefits when they are rare compared to their models [3, 4]. If mimics are encountered too frequently or if their model is absent, avoidance learning of noxious models is disrupted (Batesian mimicry [3]), or receivers become more vigilant and learn to avoid perilous mimics (aggressive mimicry [4]). Mimics can moderate this selective constraint by imperfectly resembling multiple models [5], through polymorphisms [6], or by opportunistically deploying mimetic signals [1, 7]. Here we uncover a novel mechanism to escape the constraints of deceptive signaling: phenotypic plasticity allows mimics to deceive targets using multiple guises. Using a combination of behavioral, cell histological, and molecular methods, we show that a coral reef fish, the dusky dottyback (Pseudochromis fuscus), flexibly adapts its body coloration to mimic differently colored reef fishes and in doing so gains multiple fitness benefits. We find that by matching the color of other reef fish, dottybacks increase their success of predation upon juvenile fish prey and are therefore able to deceive their victims by resembling multiple models. Furthermore, we demonstrate that changing color also increases habitat-associated crypsis that decreases the risk of being detected by predators. Hence, when mimics and models share common selective pressures, flexible imitation of models might inherently confer secondary benefits to mimics. Our results show that phenotypic plasticity can act as a mechanism to ease constraints that are typically associated with deception. VIDEO ABSTRACT. PMID:25802153

  19. Toward a population genetic framework of developmental evolution: the costs, limits, and consequences of phenotypic plasticity

    PubMed Central

    Snell-Rood, Emilie C.; Van Dyken, James David; Cruickshank, Tami; Wade, Michael J.; Moczek, Armin P.

    2011-01-01

    Adaptive phenotypic plasticity allows organisms to cope with environmental variability, and yet, despite its adaptive significance, phenotypic plasticity is neither ubiquitous nor infinite. In this review, we merge developmental and population genetic perspectives to explore costs and limits on the evolution of plasticity. Specifically, we focus on the role of modularity in developmental genetic networks as a mechanism underlying phenotypic plasticity, and apply to it lessons learned from population genetic theory on the interplay between relaxed selection and mutation accumulation. We argue that the environmental specificity of gene expression and the associated reduction in pleiotropic constraints drive a fundamental tradeoff between the range of plasticity that can be accommodated and mutation accumulation in alternative developmental networks. This tradeoff has broad implications for understanding the origin and maintenance of plasticity and may contribute to a better understanding of the role of plasticity in the origin, diversification, and loss of phenotypic diversity. PMID:20020499

  20. Changes in Selection Regime Cause Loss of Phenotypic Plasticity in Planktonic Freshwater Copepods

    PubMed Central

    Sereda, Sergej Vital’evič; Wilke, Thomas; Schultheiß, Roland

    2014-01-01

    Rapid phenotypic adaptation is critical for populations facing environmental changes and can be facilitated by phenotypic plasticity in the selected traits. Whereas recurrent environmental fluctuations can favour the maintenance or de novo evolution of plasticity, strong selection is hypothesized to decrease plasticity or even fix the trait (genetic assimilation). Despite advances in the theoretical understanding of the impact of plasticity on diversification processes, comparatively little empirical data of populations undergoing diversification mediated by plasticity are available. Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions. Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality. We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure. PMID:24587186

  1. Phenotypically plastic neophobia: a response to variable predation risk

    PubMed Central

    Brown, Grant E.; Ferrari, Maud C. O.; Elvidge, Chris K.; Ramnarine, Indar; Chivers, Douglas P.

    2013-01-01

    Prey species possess a variety of morphological, life history and behavioural adaptations to evade predators. While specific evolutionary conditions have led to the expression of permanent, non-plastic anti-predator traits, the vast majority of prey species rely on experience to express adaptive anti-predator defences. While ecologists have identified highly sophisticated means through which naive prey can deal with predation threats, the potential for death upon the first encounter with a predator is still a remarkably important unresolved issue. Here, we used both laboratory and field studies to provide the first evidence for risk-induced neophobia in two taxa (fish and amphibians), and argue that phenotypically plastic neophobia acts as an adaptive anti-predator strategy for vulnerable prey dealing with spatial and temporal variation in predation risk. Our study also illustrates how risk-free maintenance conditions used in laboratory studies may blind researchers to adaptive anti-predator strategies that are only expressed in high-risk conditions. PMID:23390103

  2. Strong and parallel salinity-induced phenotypic plasticity in one generation of threespine stickleback.

    PubMed

    Mazzarella, A B; Voje, K L; Hansson, T H; Taugbøl, A; Fischer, B

    2015-03-01

    Phenotypic plasticity is a major factor contributing to variation of organisms in nature, yet its evolutionary significance is insufficiently understood. One example system where plasticity might have played an important role in an adaptive radiation is the threespine stickleback (Gasterosteus aculeatus), a fish that has diversified after invading freshwater lakes repeatedly from the marine habitat. The parallel phenotypic changes that occurred in this radiation were extremely rapid. This study evaluates phenotypic plasticity in stickleback body shape in response to salinity in fish stemming from a wild freshwater population. Using a split-clutch design, we detected surprisingly large phenotypically plastic changes in body shape after one generation. Fish raised in salt water developed shallower bodies and longer jaws, and these changes were consistent and parallel across families. Although this work highlights the effect of phenotypic plasticity, we also find indications that constraints may play a role in biasing the direction of possible phenotypic change. The slopes of the allometric relationship of individual linear traits did not change across treatments, indicating that plastic change does not affect the covariation of traits with overall size. We conclude that stickleback have a large capacity for plastic phenotypic change in response to salinity and that plasticity and evolutionary constraints have likely contributed to the phenotypic diversification of these fish. PMID:25656304

  3. Rethinking phenotypic plasticity and its consequences for individuals, populations and species

    PubMed Central

    Forsman, A

    2015-01-01

    Much research has been devoted to identify the conditions under which selection favours flexible individuals or genotypes that are able to modify their growth, development and behaviour in response to environmental cues, to unravel the mechanisms of plasticity and to explore its influence on patterns of diversity among individuals, populations and species. The consequences of developmental plasticity and phenotypic flexibility for the performance and ecological success of populations and species have attracted a comparatively limited but currently growing interest. Here, I re-emphasize that an increased understanding of the roles of plasticity in these contexts requires a ‘whole organism' (rather than ‘single trait') approach, taking into consideration that organisms are integrated complex phenotypes. I further argue that plasticity and genetic polymorphism should be analysed and discussed within a common framework. I summarize predictions from theory on how phenotypic variation stemming from developmental plasticity and phenotypic flexibility may affect different aspects of population-level performance. I argue that it is important to distinguish between effects associated with greater interindividual phenotypic variation resulting from plasticity, and effects mediated by variation among individuals in the capacity to express plasticity and flexibility as such. Finally, I claim that rigorous testing of predictions requires methods that allow for quantifying and comparing whole organism plasticity, as well as the ability to experimentally manipulate the level of and capacity for developmental plasticity and phenotypic flexibility independent of genetic variation. PMID:25293873

  4. Molecular signatures of plastic phenotypes in two eusocial insect species with simple societies.

    PubMed

    Patalano, Solenn; Vlasova, Anna; Wyatt, Chris; Ewels, Philip; Camara, Francisco; Ferreira, Pedro G; Asher, Claire L; Jurkowski, Tomasz P; Segonds-Pichon, Anne; Bachman, Martin; González-Navarrete, Irene; Minoche, André E; Krueger, Felix; Lowy, Ernesto; Marcet-Houben, Marina; Rodriguez-Ales, Jose Luis; Nascimento, Fabio S; Balasubramanian, Shankar; Gabaldon, Toni; Tarver, James E; Andrews, Simon; Himmelbauer, Heinz; Hughes, William O H; Guigó, Roderic; Reik, Wolf; Sumner, Seirian

    2015-11-10

    Phenotypic plasticity is important in adaptation and shapes the evolution of organisms. However, we understand little about what aspects of the genome are important in facilitating plasticity. Eusocial insect societies produce plastic phenotypes from the same genome, as reproductives (queens) and nonreproductives (workers). The greatest plasticity is found in the simple eusocial insect societies in which individuals retain the ability to switch between reproductive and nonreproductive phenotypes as adults. We lack comprehensive data on the molecular basis of plastic phenotypes. Here, we sequenced genomes, microRNAs (miRNAs), and multiple transcriptomes and methylomes from individual brains in a wasp (Polistes canadensis) and an ant (Dinoponera quadriceps) that live in simple eusocial societies. In both species, we found few differences between phenotypes at the transcriptional level, with little functional specialization, and no evidence that phenotype-specific gene expression is driven by DNA methylation or miRNAs. Instead, phenotypic differentiation was defined more subtly by nonrandom transcriptional network organization, with roles in these networks for both conserved and taxon-restricted genes. The general lack of highly methylated regions or methylome patterning in both species may be an important mechanism for achieving plasticity among phenotypes during adulthood. These findings define previously unidentified hypotheses on the genomic processes that facilitate plasticity and suggest that the molecular hallmarks of social behavior are likely to differ with the level of social complexity. PMID:26483466

  5. Molecular signatures of plastic phenotypes in two eusocial insect species with simple societies

    PubMed Central

    Patalano, Solenn; Vlasova, Anna; Wyatt, Chris; Ewels, Philip; Camara, Francisco; Ferreira, Pedro G.; Asher, Claire L.; Jurkowski, Tomasz P.; Segonds-Pichon, Anne; Bachman, Martin; González-Navarrete, Irene; Minoche, André E.; Krueger, Felix; Lowy, Ernesto; Marcet-Houben, Marina; Rodriguez-Ales, Jose Luis; Nascimento, Fabio S.; Balasubramanian, Shankar; Gabaldon, Toni; Tarver, James E.; Andrews, Simon; Himmelbauer, Heinz; Hughes, William O. H.; Guigó, Roderic; Reik, Wolf; Sumner, Seirian

    2015-01-01

    Phenotypic plasticity is important in adaptation and shapes the evolution of organisms. However, we understand little about what aspects of the genome are important in facilitating plasticity. Eusocial insect societies produce plastic phenotypes from the same genome, as reproductives (queens) and nonreproductives (workers). The greatest plasticity is found in the simple eusocial insect societies in which individuals retain the ability to switch between reproductive and nonreproductive phenotypes as adults. We lack comprehensive data on the molecular basis of plastic phenotypes. Here, we sequenced genomes, microRNAs (miRNAs), and multiple transcriptomes and methylomes from individual brains in a wasp (Polistes canadensis) and an ant (Dinoponera quadriceps) that live in simple eusocial societies. In both species, we found few differences between phenotypes at the transcriptional level, with little functional specialization, and no evidence that phenotype-specific gene expression is driven by DNA methylation or miRNAs. Instead, phenotypic differentiation was defined more subtly by nonrandom transcriptional network organization, with roles in these networks for both conserved and taxon-restricted genes. The general lack of highly methylated regions or methylome patterning in both species may be an important mechanism for achieving plasticity among phenotypes during adulthood. These findings define previously unidentified hypotheses on the genomic processes that facilitate plasticity and suggest that the molecular hallmarks of social behavior are likely to differ with the level of social complexity. PMID:26483466

  6. The evolution of phenotypic plasticity: genealogy of a debate in genetics.

    PubMed

    Nicoglou, Antonine

    2015-04-01

    The paper describes the context and the origin of a particular debate that concerns the evolution of phenotypic plasticity. In 1965, British biologist A. D. Bradshaw proposed a widely cited model intended to explain the evolution of norms of reaction, based on his studies of plant populations. Bradshaw's model went beyond the notion of the "adaptive norm of reaction" discussed before him by Dobzhansky and Schmalhausen by suggesting that "plasticity"--the ability of a phenotype to be modified by the environment--should be genetically determined. To prove Bradshaw's hypothesis, it became necessary for some authors to identify the pressures exerted by natural selection on phenotypic plasticity in particular traits, and thus to model its evolution. In this paper, I contrast two different views, based on quantitative genetic models, proposed in the mid-1980s: Russell Lande and Sara Via's conception of phenotypic plasticity, which assumes that the evolution of plasticity is linked to the evolution of the plastic trait itself, and Samuel Scheiner and Richard Lyman's view, which assumes that the evolution of plasticity is independent from the evolution of the trait. I show how the origin of this specific debate, and different assumptions about the evolution of phenotypic plasticity, depended on Bradshaw's definition of plasticity and the context of quantitative genetics. PMID:25636689

  7. Evolution of phenotypic plasticity and environmental tolerance of a labile quantitative character in a fluctuating environment.

    PubMed

    Lande, R

    2014-05-01

    Quantitative genetic models of evolution of phenotypic plasticity are used to derive environmental tolerance curves for a population in a changing environment, providing a theoretical foundation for integrating physiological and community ecology with evolutionary genetics of plasticity and norms of reaction. Plasticity is modelled for a labile quantitative character undergoing continuous reversible development and selection in a fluctuating environment. If there is no cost of plasticity, a labile character evolves expected plasticity equalling the slope of the optimal phenotype as a function of the environment. This contrasts with previous theory for plasticity influenced by the environment at a critical stage of early development determining a constant adult phenotype on which selection acts, for which the expected plasticity is reduced by the environmental predictability over the discrete time lag between development and selection. With a cost of plasticity in a labile character, the expected plasticity depends on the cost and on the environmental variance and predictability averaged over the continuous developmental time lag. Environmental tolerance curves derived from this model confirm traditional assumptions in physiological ecology and provide new insights. Tolerance curve width increases with larger environmental variance, but can only evolve within a limited range. The strength of the trade-off between tolerance curve height and width depends on the cost of plasticity. Asymmetric tolerance curves caused by male sterility at high temperature are illustrated. A simple condition is given for a large transient increase in plasticity and tolerance curve width following a sudden change in average environment. PMID:24724972

  8. Phenotypic and genomic plasticity of alternative male reproductive tactics in sailfin mollies

    PubMed Central

    Fraser, Bonnie A.; Janowitz, Ilana; Thairu, Margaret; Travis, Joseph; Hughes, Kimberly A.

    2014-01-01

    A major goal of modern evolutionary biology is to understand the causes and consequences of phenotypic plasticity, the ability of a single genotype to produce multiple phenotypes in response to variable environments. While ecological and quantitative genetic studies have evaluated models of the evolution of adaptive plasticity, some long-standing questions about plasticity require more mechanistic approaches. Here, we address two of those questions: does plasticity facilitate adaptive evolution? And do physiological costs place limits on plasticity? We examine these questions by comparing genetically and plastically regulated behavioural variation in sailfin mollies (Poecilia latipinna), which exhibit striking variation in plasticity for male mating behaviour. In this species, some genotypes respond plastically to a change in the social environment by switching between primarily courting and primarily sneaking behaviour. In contrast, other genotypes have fixed mating strategies (either courting or sneaking) and do not display plasticity. We found that genetic and plastic variation in behaviour were accompanied by partially, but not completely overlapping changes in brain gene expression, in partial support of models that predict that plasticity can facilitate adaptive evolution. We also found that behavioural plasticity was accompanied by broader and more robust changes in brain gene expression, suggesting a substantial physiological cost to plasticity. We also observed that sneaking behaviour, but not courting, was associated with upregulation of genes involved in learning and memory, suggesting that sneaking is more cognitively demanding than courtship. PMID:24573842

  9. Evidence of selection on phenotypic plasticity and cost of plasticity in response to host-feeding sources in the major Chagas disease vector Triatoma infestans.

    PubMed

    Nattero, Julieta; Leonhard, Gustavo; Gürtler, Ricardo E; Crocco, Liliana B

    2015-12-01

    Phenotypic plasticity is the ability of a genotype to display alternative phenotypes in different environments. Understanding how plasticity evolves and the factors that favor and constrain its evolution have attracted great interest. We investigated whether selection on phenotypic plasticity and costs of plasticity affect head and wing morphology in response to host-feeding sources in the major Chagas disease vector Triatoma infestans. Full-sib families were assigned to blood-feeding on either live pigeons or guinea pigs throughout their lives. We measured diet-induced phenotypic plasticity on wing and head size and shape; characterized selection on phenotypic plasticity for female and male fecundity rates, and evaluated costs of plasticity. Wing size and shape variables exhibited significant differences in phenotypic plasticity associated with host-feeding source in female and male bugs. Evidence of selection on phenotypic plasticity was detected in head size and shape for guinea pig-fed females. A lower female fecundity rate was detected in more plastic families for traits that showed selection on plasticity. These results provide insights into the morphological phenotypic plasticity of T. infestans, documenting fitness advantages of head size and shape for females fed on guinea pigs. This vector species showed measurable benefits of responding plastically to environmental variation rather than adopting a fixed development plan. The presence of cost of plasticity suggests constraints on the evolution of plasticity. Our study indicates that females fed on guinea pigs (and perhaps on other suitable mammalian hosts) have greater chances of evolving under selection on phenotypic plasticity subject to some constraints. PMID:26433077

  10. The alignment between phenotypic plasticity, the major axis of genetic variation and the response to selection

    PubMed Central

    Lind, Martin I.; Yarlett, Kylie; Reger, Julia; Carter, Mauricio J.; Beckerman, Andrew P.

    2015-01-01

    Phenotypic plasticity is the ability of a genotype to produce more than one phenotype in order to match the environment. Recent theory proposes that the major axis of genetic variation in a phenotypically plastic population can align with the direction of selection. Therefore, theory predicts that plasticity directly aids adaptation by increasing genetic variation in the direction favoured by selection and reflected in plasticity. We evaluated this theory in the freshwater crustacean Daphnia pulex, facing predation risk from two contrasting size-selective predators. We estimated plasticity in several life-history traits, the G matrix of these traits, the selection gradients on reproduction and survival, and the predicted responses to selection. Using these data, we tested whether the genetic lines of least resistance and the predicted response to selection aligned with plasticity. We found predator environment-specific G matrices, but shared genetic architecture across environments resulted in more constraint in the G matrix than in the plasticity of the traits, sometimes preventing alignment of the two. However, as the importance of survival selection increased, the difference between environments in their predicted response to selection increased and resulted in closer alignment between the plasticity and the predicted selection response. Therefore, plasticity may indeed aid adaptation to new environments. PMID:26423845

  11. The alignment between phenotypic plasticity, the major axis of genetic variation and the response to selection.

    PubMed

    Lind, Martin I; Yarlett, Kylie; Reger, Julia; Carter, Mauricio J; Beckerman, Andrew P

    2015-10-01

    Phenotypic plasticity is the ability of a genotype to produce more than one phenotype in order to match the environment. Recent theory proposes that the major axis of genetic variation in a phenotypically plastic population can align with the direction of selection. Therefore, theory predicts that plasticity directly aids adaptation by increasing genetic variation in the direction favoured by selection and reflected in plasticity. We evaluated this theory in the freshwater crustacean Daphnia pulex, facing predation risk from two contrasting size-selective predators. We estimated plasticity in several life-history traits, the G matrix of these traits, the selection gradients on reproduction and survival, and the predicted responses to selection. Using these data, we tested whether the genetic lines of least resistance and the predicted response to selection aligned with plasticity. We found predator environment-specific G matrices, but shared genetic architecture across environments resulted in more constraint in the G matrix than in the plasticity of the traits, sometimes preventing alignment of the two. However, as the importance of survival selection increased, the difference between environments in their predicted response to selection increased and resulted in closer alignment between the plasticity and the predicted selection response. Therefore, plasticity may indeed aid adaptation to new environments. PMID:26423845

  12. Relaxed Genetic Constraint is Ancestral to the Evolution of Phenotypic Plasticity

    PubMed Central

    Leichty, Aaron R.; Pfennig, David W.; Jones, Corbin D.; Pfennig, Karin S.

    2012-01-01

    Phenotypic plasticity––the capacity of a single genotype to produce different phenotypes in response to varying environmental conditions––is widespread. Yet, whether, and how, plasticity impacts evolutionary diversification is unclear. According to a widely discussed hypothesis, plasticity promotes rapid evolution because genes expressed differentially across different environments (i.e., genes with “biased” expression) experience relaxed genetic constraint and thereby accumulate variation faster than do genes with unbiased expression. Indeed, empirical studies confirm that biased genes evolve faster than unbiased genes in the same genome. An alternative hypothesis holds, however, that the relaxed constraint and faster evolutionary rates of biased genes may be a precondition for, rather than a consequence of, plasticity’s evolution. Here, we evaluated these alternative hypotheses by characterizing evolutionary rates of biased and unbiased genes in two species of frogs that exhibit a striking form of phenotypic plasticity. We also characterized orthologs of these genes in four species of frogs that had diverged from the two plastic species before the plasticity evolved. We found that the faster evolutionary rates of biased genes predated the evolution of the plasticity. Furthermore, biased genes showed greater expression variance than did unbiased genes, suggesting that they may be more dispensable. Phenotypic plasticity may therefore evolve when dispensable genes are co-opted for novel function in environmentally induced phenotypes. Thus, relaxed genetic constraint may be a cause––not a consequence––of the evolution of phenotypic plasticity, and thereby contribute to the evolution of novel traits. PMID:22526866

  13. What can aquatic gastropods tell us about phenotypic plasticity? A review and meta-analysis.

    PubMed

    Bourdeau, P E; Butlin, R K; Brönmark, C; Edgell, T C; Hoverman, J T; Hollander, J

    2015-10-01

    There have been few attempts to synthesise the growing body of literature on phenotypic plasticity to reveal patterns and generalities about the extent and magnitude of plastic responses. Here, we conduct a review and meta-analysis of published literature on phenotypic plasticity in aquatic (marine and freshwater) gastropods, a common system for studying plasticity. We identified 96 studies, using pre-determined search terms, published between 1985 and November 2013. The literature was dominated by studies of predator-induced shell form, snail growth rates and life history parameters of a few model taxa, accounting for 67% of all studies reviewed. Meta-analyses indicated average plastic responses in shell thickness, shell shape, and growth and fecundity of freshwater species was at least three times larger than in marine species. Within marine gastropods, species with planktonic development had similar average plastic responses to species with benthic development. We discuss these findings in the context of the role of costs and limits of phenotypic plasticity and environmental heterogeneity as important constraints on the evolution of plasticity. We also consider potential publication biases and discuss areas for future research, indicating well-studied areas and important knowledge gaps. PMID:26219231

  14. Phenotypic plasticity alone cannot explain climate-induced change in avian migration timing.

    PubMed

    Buskirk, Josh; Mulvihill, Robert S; Leberman, Robert C

    2012-10-01

    Recent climate change has been linked to shifts in the timing of life-cycle events in many organisms, but there is debate over the degree to which phenological changes are caused by evolved genetic responses of populations or by phenotypic plasticity of individuals. We estimated plasticity of spring arrival date in 27 species of bird that breed in the vicinity of an observatory in eastern North America. For 2441 individuals detected in multiple years, arrival occurred earlier during warm years, especially in species that migrate short distances. Phenotypic plasticity averaged -0.93 days °C(-1) ± 0.70 (95% CI). However, plasticity accounted for only 13-25% of the climate-induced trend in phenology observed over 46 years. Although our approach probably underestimates the full scope of plasticity, the data suggest that part of the response to environmental change has been caused by microevolution. The estimated evolutionary rates are plausible (0.016 haldanes). PMID:23145329

  15. Phenotypic plasticity of winter wheat heading date and grain yield across the U.S. Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenotypic plasticity describes the range of phenotypes produced by a single genotype under varying environmental conditions. We evaluated the extent of phenotypic variation and plasticity in thermal time to heading and grain yield in 299 hard winter wheat (Triticum aestivum L.) genotypes representa...

  16. Bio-based and biodegradable plastics for use in crop production.

    PubMed

    Riggi, Ezio; Santagata, Gabriella; Malinconico, Mario

    2011-01-01

    The production and management of crops uses plastics for many applications (e.g., low tunnels, high tunnels, greenhouses, mulching, silage bags, hay bales, pheromone traps, coatings of fertilizers or pesticides or hormones or seeds, and nursery pots and containers for growing transplants). All these applications have led some authors to adopt the term "plasticulture" when discussing the use of plastic materials in agriculture and related industries. Unfortunately, the sustainability of this use of plastics is low, and renewability and degradability have become key words in the debate over sustainable production and utilization of plastic. Recently, researchers and the plastics industry have made strong efforts (i) to identify new biopolymers and natural additives from renewable sources that can be used in plastics production and (ii) to enhance the degradability (biological or physical) of the new ecologically sustainable materials. In the present review, we describe the main research results, current applications, patents that have been applied for in the last two decades, and future perspectives on sustainable use of plastics to support crop production. The article presents some promising patents on bio-based and biodegradable plastics for use in crop production. PMID:21114467

  17. A Test for Pre-Adapted Phenotypic Plasticity in the Invasive Tree Acer negundo L.

    PubMed Central

    Lamarque, Laurent J.; Porté, Annabel J.; Eymeric, Camille; Lasnier, Jean-Baptiste; Lortie, Christopher J.; Delzon, Sylvain

    2013-01-01

    Phenotypic plasticity is a key mechanism associated with the spread of exotic plants and previous studies have found that invasive species are generally more plastic than co-occurring species. Comparatively, the evolution of phenotypic plasticity in plant invasion has received less attention, and in particular, the genetic basis of plasticity is largely unexamined. Native from North America, Acer negundo L. is aggressively impacting the riparian forests of southern and eastern Europe thanks to higher plasticity relative to co-occurring native species. We therefore tested here whether invasive populations have evolved increased plasticity since introduction. The performance of 1152 seedlings from 8 native and 8 invasive populations was compared in response to nutrient availability. Irrespective of nutrients, invasive populations had higher growth and greater allocation to above-ground biomass relative to their native conspecifics. More importantly, invasive genotypes did not show increased plasticity in any of the 20 traits examined. This result suggests that the high magnitude of plasticity to nutrient variation of invasive seedlings might be pre-adapted in the native range. Invasiveness of A. negundo could be explained by higher mean values of traits due to genetic differentiation rather than by evolution of increased plasticity. PMID:24040212

  18. The ecology and evolution of animal medication: genetically fixed response versus phenotypic plasticity.

    PubMed

    Choisy, Marc; de Roode, Jacobus C

    2014-08-01

    Animal medication against parasites can occur either as a genetically fixed (constitutive) or phenotypically plastic (induced) behavior. Taking the tritrophic interaction between the monarch butterfly Danaus plexippus, its protozoan parasite Ophryocystis elektroscirrha, and its food plant Asclepias spp. as a test case, we develop a game-theory model to identify the epidemiological (parasite prevalence and virulence) and environmental (plant toxicity and abundance) conditions that predict the evolution of genetically fixed versus phenotypically plastic forms of medication. Our model shows that the relative benefits (the antiparasitic properties of medicinal food) and costs (side effects of medicine, the costs of searching for medicine, and the costs of plasticity itself) crucially determine whether medication is genetically fixed or phenotypically plastic. Our model suggests that animals evolve phenotypic plasticity when parasite risk (a combination of virulence and prevalence and thus a measure of the strength of parasite-mediated selection) is relatively low to moderately high and genetically fixed medication when parasite risk becomes very high. The latter occurs because at high parasite risk, the costs of plasticity are outweighed by the benefits of medication. Our model provides a simple and general framework to study the conditions that drive the evolution of alternative forms of animal medication. PMID:25061676

  19. Speciation, phenotypic variation and plasticity: what can endocrine disruptors tell us?

    PubMed

    Ayala-García, Braulio; López-Santibáñez Guevara, Marta; Marcos-Camacho, Lluvia I; Fuentes-Farías, Alma L; Meléndez-Herrera, Esperanza; Gutiérrez-Ospina, Gabriel

    2013-01-01

    Phenotype variability, phenotypic plasticity, and the inheritance of phenotypic traits constitute the fundamental ground of processes such as individuation, individual and species adaptation and ultimately speciation. Even though traditional evolutionary thinking relies on genetic mutations as the main source of intra- and interspecies phenotypic variability, recent studies suggest that the epigenetic modulation of gene transcription and translation, epigenetic memory, and epigenetic inheritance are by far the most frequent reliable sources of transgenerational variability among viable individuals within and across organismal species. Therefore, individuation and speciation should be considered as nonmutational epigenetic phenomena. PMID:23762055

  20. Cooperation between phenotypic plasticity and genetic mutations can account for the cumulative selection in evolution

    PubMed Central

    Nishikawa, Ken; Kinjo, Akira R.

    2014-01-01

    We propose the cooperative model of phenotype-driven evolution, in which natural selection operates on a phenotype caused by both genetic and epigenetic factors. The conventional theory of evolutionary synthesis assumes that a phenotypic value (P) is the sum of genotypic value (G) and environmental deviation (E), P=G+E, where E is the fluctuations of the phenotype among individuals in the absence of environmental changes. In contrast, the cooperative model assumes that an evolution is triggered by an environmental change and individuals respond to the change by phenotypic plasticity (epigenetic changes). The phenotypic plasticity, while essentially qualitative, is denoted by a quantitative value F which is modeled as a normal random variable like E, but with a much larger variance. Thus, the fundamental equation of the cooperative model is given as P=G+F where F includes the effect of E. Computer simulations using a genetic algorithm demonstrated that the cooperative model realized much faster evolution than the evolutionary synthesis. This accelerated evolution was found to be due to the cumulative evolution made possible by a ratchet mechanism due to the epigenetic contribution to the phenotypic value. The cooperative model can well account for the phenomenon of genetic assimilation, which, in turn, suggests the mechanism of cumulative selection. The cooperative model may also serve as a theoretical basis to understand various ideas and phenomena of the phenotype-driven evolution such as genetic assimilation, the theory of facilitated phenotypic variation, and epigenetic inheritance over generations. PMID:27493504

  1. Diet-induced phenotypic plasticity in European eel (Anguilla anguilla).

    PubMed

    De Meyer, Jens; Christiaens, Joachim; Adriaens, Dominique

    2016-02-01

    Two phenotypes are present within the European eel population: broad-heads and narrow-heads. The expression of these phenotypes has been linked to several factors, such as diet and differential growth. The exact factors causing this dimorphism, however, are still unknown. In this study, we performed a feeding experiment on glass eels from the moment they start to feed. Eels were either fed a hard diet, which required biting and spinning behavior, or a soft diet, which required suction feeding. We found that the hard feeders develop a broader head and a larger adductor mandibulae region than eels that were fed a soft diet, implying that the hard feeders are capable of larger bite forces. Next to this, soft feeders develop a sharper and narrower head, which could reduce hydrodynamic drag, allowing more rapid strikes towards their prey. Both phenotypes were found in a control group, which were given a combination of both diets. These phenotypes were, however, not as extreme as the hard or the soft feeding group, indicating that some specimens are more likely to consume hard prey and others soft prey, but that they do not selectively eat one of both diets. In conclusion, we found that diet is a major factor influencing head shape in European eel and this ability to specialize in feeding on hard or soft prey could decrease intra-specific competition in European eel populations. PMID:26847560

  2. Phenotypic Plasticity of Southern Ocean Diatoms: Key to Success in the Sea Ice Habitat?

    PubMed Central

    Sackett, Olivia; Petrou, Katherina; Reedy, Brian; De Grazia, Adrian; Hill, Ross; Doblin, Martina; Beardall, John; Ralph, Peter; Heraud, Philip

    2013-01-01

    Diatoms are the primary source of nutrition and energy for the Southern Ocean ecosystem. Microalgae, including diatoms, synthesise biological macromolecules such as lipids, proteins and carbohydrates for growth, reproduction and acclimation to prevailing environmental conditions. Here we show that three key species of Southern Ocean diatom (Fragilariopsis cylindrus, Chaetoceros simplex and Pseudo-nitzschia subcurvata) exhibited phenotypic plasticity in response to salinity and temperature regimes experienced during the seasonal formation and decay of sea ice. The degree of phenotypic plasticity, in terms of changes in macromolecular composition, was highly species-specific and consistent with each species’ known distribution and abundance throughout sea ice, meltwater and pelagic habitats, suggesting that phenotypic plasticity may have been selected for by the extreme variability of the polar marine environment. We argue that changes in diatom macromolecular composition and shifts in species dominance in response to a changing climate have the potential to alter nutrient and energy fluxes throughout the Southern Ocean ecosystem. PMID:24363795

  3. Differential Expression of Ecdysone Receptor Leads to Variation in Phenotypic Plasticity across Serial Homologs

    PubMed Central

    Tong, Xiaoling; Bear, Ashley; Liew, Seng Fatt; Bhardwaj, Shivam; Wasik, Bethany R.; Dinwiddie, April; Bastianelli, Carole; Cheong, Wei Fun; Wenk, Markus R.; Cao, Hui

    2015-01-01

    Bodies are often made of repeated units, or serial homologs, that develop using the same core gene regulatory network. Local inputs and modifications to this network allow serial homologs to evolve different morphologies, but currently we do not understand which modifications allow these repeated traits to evolve different levels of phenotypic plasticity. Here we describe variation in phenotypic plasticity across serial homologous eyespots of the butterfly Bicyclus anynana, hypothesized to be under selection for similar or different functions in the wet and dry seasonal forms. Specifically, we document the presence of eyespot size and scale brightness plasticity in hindwing eyespots hypothesized to vary in function across seasons, and reduced size plasticity and absence of brightness plasticity in forewing eyespots hypothesized to have the same function across seasons. By exploring the molecular and physiological causes of this variation in plasticity across fore and hindwing serial homologs we discover that: 1) temperature experienced during the wandering stages of larval development alters titers of an ecdysteroid hormone, 20-hydroxyecdysone (20E), in the hemolymph of wet and dry seasonal forms at that stage; 2) the 20E receptor (EcR) is differentially expressed in the forewing and hindwing eyespot centers of both seasonal forms during this critical developmental stage; and 3) manipulations of EcR signaling disproportionately affected hindwing eyespots relative to forewing eyespots. We propose that differential EcR expression across forewing and hindwing eyespots at a critical stage of development explains the variation in levels of phenotypic plasticity across these serial homologues. This finding provides a novel signaling pathway, 20E, and a novel molecular candidate, EcR, for the regulation of levels of phenotypic plasticity across body parts or serial homologs. PMID:26405828

  4. Local adaptation and the evolution of phenotypic plasticity in Trinidadian guppies (Poecilia reticulata).

    PubMed

    Torres-Dowdall, Julián; Handelsman, Corey A; Reznick, David N; Ghalambor, Cameron K

    2012-11-01

    Divergent selection pressures across environments can result in phenotypic differentiation that is due to local adaptation, phenotypic plasticity, or both. Trinidadian guppies exhibit local adaptation to the presence or absence of predators, but the degree to which predator-induced plasticity contributes to population differentiation is less clear. We conducted common garden experiments on guppies obtained from two drainages containing populations adapted to high- and low-predation environments. We reared full-siblings from all populations in treatments simulating the presumed ancestral (predator cues present) and derived (predator cues absent) conditions and measured water column use, head morphology, and size at maturity. When reared in presence of predator cues, all populations had phenotypes that were typical of a high-predation ecotype. However, when reared in the absence of predator cues, guppies from high- and low-predation regimes differed in head morphology and size at maturity; the qualitative nature of these differences corresponded to those that characterize adaptive phenotypes in high- versus low-predation environments. Thus, divergence in plasticity is due to phenotypic differences between high- and low-predation populations when reared in the absence of predator cues. These results suggest that plasticity might initially play an important role during colonization of novel environments, and then evolve as a by-product of adaptation to the derived environment. PMID:23106708

  5. Depolarization Alters Phenotype, Maintains Plasticity of Predifferentiated Mesenchymal Stem Cells

    PubMed Central

    Sundelacruz, Sarah; Levin, Michael

    2013-01-01

    Although adult stem cell transplantation has been implemented as a therapy for tissue repair, it is limited by the availability of functional adult stem cells. A potential approach to generate stem and progenitor cells may be to modulate the differentiated status of somatic cells. Therefore, there is a need for a better understanding of how the differentiated phenotype of mature cells is regulated. We hypothesize that bioelectric signaling plays an important role in the maintenance of the differentiated state, as it is a functional regulator of the differentiation process in various cells and tissues. In this study, we asked whether the mature phenotype of osteoblasts and adipocytes derived from human mesenchymal stem cells (hMSCs) could be altered by modulation of their membrane potential. hMSC-derived osteoblasts and adipocytes were depolarized by treatment with ouabain, a Na+/K+ ATPase inhibitor, or by treatment with high concentrations of extracellular K+. To characterize the effect of voltage modulation on the differentiated state, the depolarized cells were evaluated for (1) the loss of differentiation markers; (2) the up-regulation of stemness markers and stem properties; and (3) differences in gene expression profiles in response to voltage modulation. hMSC-derived osteoblasts and adipocytes exhibited significant down-regulation of bone and fat tissue markers in response to depolarization, despite the presence of differentiation-inducing soluble factors, suggesting that bioelectric signaling overrides biochemical signaling in the maintenance of cell state. Suppression of the osteoblast or adipocyte phenotype was not accompanied by up-regulation of genes associated with the stem state. Thus, depolarization does not activate the stem cell genetic signature and, therefore, does not induce a full reprogramming event. However, after transdifferentiating the depolarized cells to evaluate for multi-lineage potential, depolarized osteoblasts demonstrated improved

  6. Phenotypic plasticity in Scenedesmus incrassatulus (Chlorophyceae) in response to heavy metals stress.

    PubMed

    Peña-Castro, Julián Mario; Martínez-Jerónimo, Fernando; Esparza-García, Fernando; Cañizares-Villanueva, Rosa Olivia

    2004-12-01

    The microalgae genus Scenedesmus is commonly found in freshwater bodies, wastewater facilities and water polluted with heavy metals. Phenotypic plasticity in Scenedesmus has been documented in response to a wide variety of conditions; however, heavy metals have not been comprehensively documented as phenotypic plasticity inducers. In this study, we report the phenotypic plasticity of Scenedesmus incrassatulus (a non-spiny, four-cell coenobium forming species) in response to EC(50) value of copper, cadmium and hexavalent chromium. S. incrassatulus was grown in batch cultures in the presence of each metal. Chlorophyll-a content, cell size, parameters derived from the schematic energy-flux model for photosystem II, and morphotype expressions were recorded. Divalent cation metals induced unicellular forms, and hexavalent chromium produced out-of-shape coenobia corresponding to various stages of autospore formation. The changes induced by divalent metals were interpreted as phenotypic plasticity, because they were always associated to population doublings and were reversible when toxicant pressure was removed (only for Cu). Copper was the best inductor of unicellular forms and also affected significantly all the photosynthetic parameters measured. The developed morphotypes could confer ecological advantages to S. incrassatulus in metal stressed environments. PMID:15519408

  7. Heritability, evolvability, phenotypic plasticity and temporal variation in sperm-competition success of Drosophila melanogaster.

    PubMed

    Dobler, R; Reinhardt, K

    2016-05-01

    Sperm-competition success (SCS) is seen as centrally important for evolutionary change: superior fathers sire superior sons and thereby inherit the traits that make them superior. Additional hypotheses, that phenotypic plasticity in SCS and sperm ageing explain variation in paternity, are less considered. Even though various alleles have individually been shown to be correlated with variation in SCS, few studies have addressed the heritability, or evolvability, of overall SCS. Those studies that have addressed found low or no heritability and have not examined evolvability. They have further not excluded phenotypic plasticity, and temporal effects on SCS, despite their known dramatic effects on sperm function. In Drosophila melanogaster, we found that both standard components of sperm competition, sperm defence and sperm offence, showed nonsignificant heritability across several offspring cohorts. Instead, our analysis revealed, for the first time, the existence of phenotypic plasticity in SCS across an extreme environment (5% CO2 ), and an influence of sperm ageing. Evolvability of SCS was substantial for sperm defence but weak for sperm offence. Our results suggest that the paradigm of explaining evolution by sperm competition is more complex and will benefit from further experimental work on the heritability or evolvability of SCS, measuring phenotypic plasticity, and separating the effects of sperm competition and sperm ageing. PMID:26990919

  8. Phenotypic Plasticity through Transcriptional Regulation of the Evolutionary Hotspot Gene tan in Drosophila melanogaster.

    PubMed

    Gibert, Jean-Michel; Mouchel-Vielh, Emmanuèle; De Castro, Sandra; Peronnet, Frédérique

    2016-08-01

    Phenotypic plasticity is the ability of a given genotype to produce different phenotypes in response to distinct environmental conditions. Phenotypic plasticity can be adaptive. Furthermore, it is thought to facilitate evolution. Although phenotypic plasticity is a widespread phenomenon, its molecular mechanisms are only beginning to be unravelled. Environmental conditions can affect gene expression through modification of chromatin structure, mainly via histone modifications, nucleosome remodelling or DNA methylation, suggesting that phenotypic plasticity might partly be due to chromatin plasticity. As a model of phenotypic plasticity, we study abdominal pigmentation of Drosophila melanogaster females, which is temperature sensitive. Abdominal pigmentation is indeed darker in females grown at 18°C than at 29°C. This phenomenon is thought to be adaptive as the dark pigmentation produced at lower temperature increases body temperature. We show here that temperature modulates the expression of tan (t), a pigmentation gene involved in melanin production. t is expressed 7 times more at 18°C than at 29°C in female abdominal epidermis. Genetic experiments show that modulation of t expression by temperature is essential for female abdominal pigmentation plasticity. Temperature modulates the activity of an enhancer of t without modifying compaction of its chromatin or level of the active histone mark H3K27ac. By contrast, the active mark H3K4me3 on the t promoter is strongly modulated by temperature. The H3K4 methyl-transferase involved in this process is likely Trithorax, as we show that it regulates t expression and the H3K4me3 level on the t promoter and also participates in female pigmentation and its plasticity. Interestingly, t was previously shown to be involved in inter-individual variation of female abdominal pigmentation in Drosophila melanogaster, and in abdominal pigmentation divergence between Drosophila species. Sensitivity of t expression to

  9. Phenotypic Plasticity through Transcriptional Regulation of the Evolutionary Hotspot Gene tan in Drosophila melanogaster

    PubMed Central

    Mouchel-Vielh, Emmanuèle; De Castro, Sandra; Peronnet, Frédérique

    2016-01-01

    Phenotypic plasticity is the ability of a given genotype to produce different phenotypes in response to distinct environmental conditions. Phenotypic plasticity can be adaptive. Furthermore, it is thought to facilitate evolution. Although phenotypic plasticity is a widespread phenomenon, its molecular mechanisms are only beginning to be unravelled. Environmental conditions can affect gene expression through modification of chromatin structure, mainly via histone modifications, nucleosome remodelling or DNA methylation, suggesting that phenotypic plasticity might partly be due to chromatin plasticity. As a model of phenotypic plasticity, we study abdominal pigmentation of Drosophila melanogaster females, which is temperature sensitive. Abdominal pigmentation is indeed darker in females grown at 18°C than at 29°C. This phenomenon is thought to be adaptive as the dark pigmentation produced at lower temperature increases body temperature. We show here that temperature modulates the expression of tan (t), a pigmentation gene involved in melanin production. t is expressed 7 times more at 18°C than at 29°C in female abdominal epidermis. Genetic experiments show that modulation of t expression by temperature is essential for female abdominal pigmentation plasticity. Temperature modulates the activity of an enhancer of t without modifying compaction of its chromatin or level of the active histone mark H3K27ac. By contrast, the active mark H3K4me3 on the t promoter is strongly modulated by temperature. The H3K4 methyl-transferase involved in this process is likely Trithorax, as we show that it regulates t expression and the H3K4me3 level on the t promoter and also participates in female pigmentation and its plasticity. Interestingly, t was previously shown to be involved in inter-individual variation of female abdominal pigmentation in Drosophila melanogaster, and in abdominal pigmentation divergence between Drosophila species. Sensitivity of t expression to

  10. Phenotypic plasticity in the range-margin population of the lycaenid butterfly Zizeeria maha

    PubMed Central

    2010-01-01

    Background Many butterfly species have been experiencing the northward range expansion and physiological adaptation, probably due to climate warming. Here, we document an extraordinary field case of a species of lycaenid butterfly, Zizeeria maha, for which plastic phenotypes of wing color-patterns were revealed at the population level in the course of range expansion. Furthermore, we examined whether this outbreak of phenotypic changes was able to be reproduced in a laboratory. Results In the recently expanded northern range margins of this species, more than 10% of the Z. maha population exhibited characteristic color-pattern modifications on the ventral wings for three years. We physiologically reproduced similar phenotypes by an artificial cold-shock treatment of a normal southern population, and furthermore, we genetically reproduced a similar phenotype after selective breeding of a normal population for ten generations, demonstrating that the cold-shock-induced phenotype was heritable and partially assimilated genetically in the breeding line. Similar genetic process might have occurred in the previous and recent range-margin populations as well. Relatively minor modifications expressed in the tenth generation of the breeding line together with other data suggest a role of founder effect in this field case. Conclusions Our results support the notion that the outbreak of the modified phenotypes in the recent range-margin population was primed by the revelation of plastic phenotypes in response to temperature stress and by the subsequent genetic process in the previous range-margin population, followed by migration and temporal establishment of genetically unstable founders in the recent range margins. This case presents not only an evolutionary role of phenotypic plasticity in the field but also a novel evolutionary aspect of range expansion at the species level. PMID:20718993

  11. Evidence of weaker phenotypic plasticity by prey to novel cues from non-native predators.

    PubMed

    Hollander, Johan; Bourdeau, Paul E

    2016-08-01

    A central question in evolutionary biology is how coevolutionary history between predator and prey influences their interactions. Contemporary global change and range expansion of exotic organisms impose a great challenge for prey species, which are increasingly exposed to invading non-native predators, with which they share no evolutionary history. Here, we complete a comprehensive survey of empirical studies of coevolved and naive predator-prey interactions to assess whether a shared evolutionary history with predators influences the magnitude of predator-induced defenses mounted by prey. Using marine bivalves and gastropods as model prey, we found that coevolved prey and predator-naive prey showed large discrepancies in magnitude of predator-induced phenotypic plasticity. Although naive prey, predominantly among bivalve species, did exhibit some level of plasticity - prey exposed to native predators showed significantly larger amounts of phenotypic plasticity. We discuss these results and the implications they may have for native communities and ecosystems. PMID:27551388

  12. Jack-of-all-trades: phenotypic plasticity facilitates the invasion of an alien slug species

    PubMed Central

    Knop, Eva; Reusser, Nik

    2012-01-01

    Invasive alien species might benefit from phenotypic plasticity by being able to (i) maintain fitness in stressful environments (‘robust’), (ii) increase fitness in favourable environments (‘opportunistic’), or (iii) combine both abilities (‘robust and opportunistic’). Here, we applied this framework, for the first time, to an animal, the invasive slug, Arion lusitanicus, and tested (i) whether it has a more adaptive phenotypic plasticity compared with a congeneric native slug, Arion fuscus, and (ii) whether it is robust, opportunistic or both. During one year, we exposed specimens of both species to a range of temperatures along an altitudinal gradient (700–2400 m a.s.l.) and to high and low food levels, and we compared the responsiveness of two fitness traits: survival and egg production. During summer, the invasive species had a more adaptive phenotypic plasticity, and at high temperatures and low food levels, it survived better and produced more eggs than A. fuscus, representing the robust phenotype. During winter, A. lusitanicus displayed a less adaptive phenotype than A. fuscus. We show that the framework developed for plants is also very useful for a better mechanistic understanding of animal invasions. Warmer summers and milder winters might lead to an expansion of this invasive species to higher altitudes and enhance its spread in the lowlands, supporting the concern that global climate change will increase biological invasions. PMID:23015630

  13. Distinct subspecies or phenotypic plasticity? Genetic and morphological differentiation of mountain honey bees in East Africa

    PubMed Central

    Gruber, Karl; Schöning, Caspar; Otte, Marianne; Kinuthia, Wanja; Hasselmann, Martin

    2013-01-01

    Identifying the forces shaping intraspecific phenotypic and genotypic divergence are of key importance in evolutionary biology. Phenotypic divergence may result from local adaptation or, especially in species with strong gene flow, from pronounced phenotypic plasticity. Here, we examine morphological and genetic divergence among populations of the western honey bee Apis mellifera in the topographically heterogeneous East African region. The currently accepted “mountain refugia hypothesis” states that populations living in disjunct montane forests belong to a different lineage than those in savanna habitats surrounding these forests. We obtained microsatellite data, mitochondrial sequences, and morphometric data from worker honey bees collected from feral colonies in three montane forests and corresponding neighboring savanna regions in Kenya. Honey bee colonies from montane forests showed distinct worker morphology compared with colonies in savanna areas. Mitochondrial sequence data did not support the existence of the two currently accepted subspecies. Furthermore, analyses of the microsatellite data with a Bayesian clustering method did not support the existence of two source populations as it would be expected under the mountain refugia scenario. Our findings suggest that phenotypic plasticity rather than distinct ancestry is the leading cause behind the phenotypic divergence observed between montane forest and savanna honey bees. Our study thus corroborates the idea that high gene flow may select for increased plasticity. PMID:24223262

  14. Use of Hay, Green, and Plastic Mulches to Suppress Nutsedge in Horticultural Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple and yellow nutsedges (Cyperus rotundus and C. esculentus, respectively) are among the most serious weed problems in Florida, Caribbean, and other parts of the world. They have been reported to cause yield losses of 20-89% in various horticultural crops. Production systems based on plastic mul...

  15. Williams' paradox and the role of phenotypic plasticity in sexual systems.

    PubMed

    Leonard, Janet L

    2013-10-01

    As George Williams pointed out in 1975, although evolutionary explanations, based on selection acting on individuals, have been developed for the advantages of simultaneous hermaphroditism, sequential hermaphroditism and gonochorism, none of these evolutionary explanations adequately explains the current distribution of these sexual systems within the Metazoa (Williams' Paradox). As Williams further pointed out, the current distribution of sexual systems is explained largely by phylogeny. Since 1975, we have made a great deal of empirical and theoretical progress in understanding sexual systems. However, we still lack a theory that explains the current distribution of sexual systems in animals and we do not understand the evolutionary transitions between hermaphroditism and gonochorism. Empirical data, collected over the past 40 years, demonstrate that gender may have more phenotypic plasticity than was previously realized. We know that not only sequential hermaphrodites, but also simultaneous hermaphrodites have phenotypic plasticity that alters sex allocation in response to social and environmental conditions. A focus on phenotypic plasticity suggests that one sees a continuum in animals between genetically determined gonochorism on the one hand and simultaneous hermaphroditism on the other, with various types of sequential hermaphroditism and environmental sex determination as points along the spectrum. Here I suggest that perhaps the reason we have been unable to resolve Williams' Paradox is because the problem was not correctly framed. First, because, for example, simultaneous hermaphroditism provides reproductive assurance or dioecy ensures outcrossing does not mean that there are no other evolutionary paths that can provide adaptive responses to those selective pressures. Second, perhaps the question we need to ask is: What selective forces favor increased versus reduced phenotypic plasticity in gender expression? It is time to begin to look at the question

  16. Adaptive phenotypic plasticity and local adaptation for temperature tolerance in freshwater zooplankton

    PubMed Central

    Yampolsky, Lev Y.; Schaer, Tobias M. M.; Ebert, Dieter

    2014-01-01

    Many organisms have geographical distributions extending from the tropics to near polar regions or can experience up to 30°C temperature variation within the lifespan of an individual. Two forms of evolutionary adaptation to such wide ranges in ambient temperatures are frequently discussed: local adaptation and phenotypic plasticity. The freshwater planktonic crustacean Daphnia magna, whose range extends from South Africa to near arctic sites, shows strong phenotypic and genotypic variation in response to temperature. In this study, we use D. magna clones from 22 populations (one clone per population) ranging from latitude 0° (Kenya) to 66° North (White Sea) to explore the contributions of phenotypic plasticity and local adaptation to high temperature tolerance. Temperature tolerance was studied as knockout time (time until immobilization, Timm) at 37°C in clones acclimatized to either 20°C or 28°C. Acclimatization to 28°C strongly increased Timm, testifying to adaptive phenotypic plasticity. At the same time, Timm significantly correlated with average high temperature at the clones’ sites of origin, suggesting local adaptation. As earlier studies have found that haemoglobin expression contributes to temperature tolerance, we also quantified haemoglobin concentration in experimental animals and found that both acclimatization temperature (AccT) and temperature at the site of origin are positively correlated with haemoglobin concentration. Furthermore, Daphnia from warmer climates upregulate haemoglobin much more strongly in response to AccT, suggesting local adaptation for plasticity in haemoglobin expression. Our results show that both local adaptation and phenotypic plasticity contribute to temperature tolerance, and elucidate a possible role of haemoglobin in mediating these effects that differs along a cold–warm gradient. PMID:24352948

  17. Phenotypic Plasticity Influences the Size, Shape and Dynamics of the Geographic Distribution of an Invasive Plant

    PubMed Central

    Pichancourt, Jean-Baptiste; van Klinken, Rieks D.

    2012-01-01

    Phenotypic plasticity has long been suspected to allow invasive species to expand their geographic range across large-scale environmental gradients. We tested this possibility in Australia using a continental scale survey of the invasive tree Parkinsonia aculeata (Fabaceae) in twenty-three sites distributed across four climate regions and three habitat types. Using tree-level responses, we detected a trade-off between seed mass and seed number across the moisture gradient. Individual trees plastically and reversibly produced many small seeds at dry sites or years, and few big seeds at wet sites and years. Bigger seeds were positively correlated with higher seed and seedling survival rates. The trade-off, the relation between seed mass, seed and seedling survival, and other fitness components of the plant life-cycle were integrated within a matrix population model. The model confirms that the plastic response resulted in average fitness benefits across the life-cycle. Plasticity resulted in average fitness being positively maintained at the wet and dry range margins where extinction risks would otherwise have been high (“Jack-of-all-Trades” strategy JT), and fitness being maximized at the species range centre where extinction risks were already low (“Master-of-Some” strategy MS). The resulting hybrid “Jack-and-Master” strategy (JM) broadened the geographic range and amplified average fitness in the range centre. Our study provides the first empirical evidence for a JM species. It also confirms mechanistically the importance of phenotypic plasticity in determining the size, the shape and the dynamic of a species distribution. The JM allows rapid and reversible phenotypic responses to new or changing moisture conditions at different scales, providing the species with definite advantages over genetic adaptation when invading diverse and variable environments. Furthermore, natural selection pressure acting on phenotypic plasticity is predicted to result in

  18. Flood induced phenotypic plasticity in amphibious genus Elatine (Elatinaceae)

    PubMed Central

    Sramkó, Gábor; Horváth, Orsolya; Popiela, Agnieszka; Mesterházy, Attila; Lukács, Balázs András

    2015-01-01

    Vegetative characters are widely used in the taxonomy of the amphibious genus Elatine L. However, these usually show great variation not just between species but between their aquatic and terrestrial forms. In the present study we examine the variation of seed and vegetative characters in nine Elatine species (E. brachysperma, E. californica, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma and E. triandra) to reveal the extension of plasticity induced by the amphibious environment, and to test character reliability for species identification. Cultivated plant clones were kept under controlled conditions exposed to either aquatic or terrestrial environmental conditions. Six vegetative characters (length of stem, length of internodium, length of lamina, width of lamina, length of petioles, length of pedicel) and four seed characters (curvature, number of pits / lateral row, 1st and 2nd dimension) were measured on 50 fruiting stems of the aquatic and on 50 stems of the terrestrial form of the same clone. MDA, NPMANOVA Random Forest classification and cluster analysis were used to unravel the morphological differences between aquatic and terrestrial forms. The results of MDA cross-validated and Random Forest classification clearly indicated that only seed traits are stable within species (i.e., different forms of the same species keep similar morphology). Consequently, only seed morphology is valuable for taxonomic purposes since vegetative traits are highly influenced by environmental factors. PMID:26713235

  19. Functional and Phenotypic Plasticity of CD4+ T Cell Subsets

    PubMed Central

    Caza, Tiffany; Landas, Steve

    2015-01-01

    The remarkable plasticity of CD4+ T cells allows individuals to respond to environmental stimuli in a context-dependent manner. A balance of CD4+ T cell subsets is critical to mount responses against pathogen challenges to prevent inappropriate activation, to maintain tolerance, and to participate in antitumor immune responses. Specification of subsets is a process beginning in intrathymic development and continuing within the circulation. It is highly flexible to adapt to differences in nutrient availability and the tissue microenvironment. CD4+ T cell subsets have significant cross talk, with the ability to “dedifferentiate” given appropriate environmental signals. This ability is dependent on the metabolic status of the cell, with mTOR acting as the rheostat. Autoimmune and antitumor immune responses are regulated by the balance between regulatory T cells and Th17 cells. When a homeostatic balance of subsets is not maintained, immunopathology can result. CD4+ T cells carry complex roles within tumor microenvironments, with context-dependent immune responses influenced by oncogenic drivers and the presence of inflammation. Here, we examine the signals involved in CD4+ T cell specification towards each subset, interconnectedness of cytokine networks, impact of mTOR signaling, and cellular metabolism in lineage specification and provide a supplement describing techniques to study these processes. PMID:26583116

  20. Contributions of phenotypic plasticity to differences in thermogenic performance between highland and lowland deer mice.

    PubMed

    Cheviron, Zachary A; Bachman, Gwendolyn C; Storz, Jay F

    2013-04-01

    Small mammals face especially severe thermoregulatory challenges at high altitude because the reduced O2 availability constrains the capacity for aerobic thermogenesis. Adaptive enhancement of thermogenic performance under hypoxic conditions may be achieved via physiological adjustments that occur within the lifetime of individuals (phenotypic plasticity) and/or genetically based changes that occur across generations, but their relative contributions to performance differences between highland and lowland natives are unclear. Here, we examined potentially evolved differences in thermogenic performance between populations of deer mice (Peromyscus maniculatus) that are native to different altitudes. The purpose of the study was to assess the contribution of phenotypic plasticity to population differences in thermogenic performance under hypoxia. We used a common-garden deacclimation experiment to demonstrate that highland deer mice have enhanced thermogenic capacities under hypoxia, and that performance differences between highland and lowland mice persist when individuals are born and reared under common-garden conditions, suggesting that differences in thermogenic capacity have a genetic basis. Conversely, population differences in thermogenic endurance appear to be entirely attributable to physiological plasticity during adulthood. These combined results reveal distinct sources of phenotypic plasticity for different aspects of thermogenic performance, and suggest that thermogenic capacity and endurance may have different mechanistic underpinnings. PMID:23197099

  1. Climate change in the oceans: evolutionary versus phenotypically plastic responses of marine animals and plants

    PubMed Central

    Reusch, Thorsten B H

    2014-01-01

    I summarize marine studies on plastic versus adaptive responses to global change. Due to the lack of time series, this review focuses largely on the potential for adaptive evolution in marine animals and plants. The approaches were mainly synchronic comparisons of phenotypically divergent populations, substituting spatial contrasts in temperature or CO2 environments for temporal changes, or in assessments of adaptive genetic diversity within populations for traits important under global change. The available literature is biased towards gastropods, crustaceans, cnidarians and macroalgae. Focal traits were mostly environmental tolerances, which correspond to phenotypic buffering, a plasticity type that maintains a functional phenotype despite external disturbance. Almost all studies address coastal species that are already today exposed to fluctuations in temperature, pH and oxygen levels. Recommendations for future research include (i) initiation and analyses of observational and experimental temporal studies encompassing diverse phenotypic traits (including diapausing cues, dispersal traits, reproductive timing, morphology) (ii) quantification of nongenetic trans-generational effects along with components of additive genetic variance (iii) adaptive changes in microbe–host associations under the holobiont model in response to global change (iv) evolution of plasticity patterns under increasingly fluctuating environments and extreme conditions and (v) joint consideration of demography and evolutionary adaptation in evolutionary rescue approaches. PMID:24454551

  2. Role of phenotypic plasticity and population differentiation in adaptation to novel environmental conditions

    PubMed Central

    Volis, Sergei; Ormanbekova, Danara; Yermekbayev, Kanat

    2015-01-01

    Species can adapt to new environmental conditions either through individual phenotypic plasticity, intraspecific genetic differentiation in adaptive traits, or both. Wild emmer wheat, Triticum dicoccoides, an annual grass with major distribution in Eastern Mediterranean region, is predicted to experience in the near future, as a result of global climate change, conditions more arid than in any part of the current species distribution. To understand the role of the above two means of adaptation, and the effect of population range position, we analyzed reaction norms, extent of plasticity, and phenotypic selection across two experimental environments of high and low water availability in two core and two peripheral populations of this species. We studied 12 quantitative traits, but focused primarily on the onset of reproduction and maternal investment, which are traits that are closely related to fitness and presumably involved in local adaptation in the studied species. We hypothesized that the population showing superior performance under novel environmental conditions will either be genetically differentiated in quantitative traits or exhibit higher phenotypic plasticity than the less successful populations. We found the core population K to be the most plastic in all three trait categories (phenology, reproductive traits, and fitness) and most successful among populations studied, in both experimental environments; at the same time, the core K population was clearly genetically differentiated from the two edge populations. Our results suggest that (1) two means of successful adaptation to new environmental conditions, phenotypic plasticity and adaptive genetic differentiation, are not mutually exclusive ways of achieving high adaptive ability; and (2) colonists from some core populations can be more successful in establishing beyond the current species range than colonists from the range extreme periphery with conditions seemingly closest to those in the new

  3. Stem cell plasticity revisited: The continuum marrow model and phenotypic changes mediated by microvesicles

    PubMed Central

    Quesenberry, Peter J.; Dooner, Mark S.; Aliotta, Jason M.

    2010-01-01

    The phenotype of marrow hematopoietic stem cells is determined by cell cycle state and microvesicle entry into the stem cells. The stem cell population is continually changing based on cell cycle transit and thus can only be defined on a population basis. Purification of marrow stem cells only addresses the heterogeneity of these populations. When whole marrow is studied, the long-term repopulating stem cells are in active cell cycle. However, with some variability, when highly purified stem cells are studied, the cells appear to be dormant. Thus, the study of purified stem cells is intrinsically misleading. Tissue-derived microvesicles enhanced by injury effect the phenotype of different cell classes. We propose that previously described stem cell plasticity is due to microvesicle modulation. We further propose a stem cell population model in which the individual cell phenotypes continually changes, but the population phenotype is relatively stable. This, in turn, is modulated by microvesicle and microenvironmental influences. PMID:20382199

  4. Environmental alteration and phenotypic regulation of Candida albicans adhesion to plastic.

    PubMed Central

    Kennedy, M J; Rogers, A L; Yancey, R J

    1989-01-01

    The adhesion of Candida albicans to plastic was examined after growth in two chemically defined media, Lee-Buckley-Campbell (LBC) and yeast nitrogen base (YNB), by binding isotherms, Langmuir isotherms, and Scatchard plots, and the number of binding sites (N) and the affinity constants (K) were calculated. K and N were twofold and fourfold higher, respectively, after growth in LBC compared with that in YNB. A comparison of adhesion in different assay solutions gave similar results, with the solution given to dehydrated patients (5% glucose in 0.45% NaCl [D5.45]) allowing for the highest K and the largest N. Scatchard curves for both LBC- and YNB-grown cells had negative slopes, which is supportive evidence for the view that negative cooperativity is involved in the binding process. Additional experiments to examine the role of cell surface hydrophobicity in adhesion to plastic were conducted with the white and opaque phenotypes of C. albicans. There was no significant difference in the adhesion of these phenotypes to plastic, although the opaque phenotype was significantly more hydrophobic. Adhesion, but not cell surface hydrophobicity, of both phenotypes was significantly greater in D5.45. Moreover, relatively hydrophilic mycelial forms of C. albicans were found to attach only when D5.45 was used as the assay medium and, in contrast to yeast-phase cells, were insensitive to reduced adhesion by nonionic detergents. These results suggest that the adhesion of C. albicans to plastic is regulated by environmental circumstances and the phenotypic state of the organism. PMID:2680985

  5. The effects of phenotypic plasticity on photosynthetic performance in winter rye, winter wheat and Brassica napus.

    PubMed

    Dahal, Keshav; Kane, Khalil; Gadapati, Winona; Webb, Elizabeth; Savitch, Leonid V; Singh, Jasbir; Sharma, Pooja; Sarhan, Fathey; Longstaffe, Fred J; Grodzinski, Bernard; Hüner, Norman P A

    2012-02-01

    The contributions of phenotypic plasticity to photosynthetic performance in winter (cv Musketeer, cv Norstar) and spring (cv SR4A, cv Katepwa) rye (Secale cereale) and wheat (Triticum aestivum) cultivars grown at either 20°C [non-acclimated (NA)] or 5°C [cold acclimated (CA)] were assessed. The 22-40% increase in light-saturated rates of CO₂ assimilation in CA vs NA winter cereals were accounted for by phenotypic plasticity as indicated by the dwarf phenotype and increased specific leaf weight. However, phenotypic plasticity could not account for (1) the differential temperature sensitivity of CO₂ assimilation and photosynthetic electron transport, (2) the increased efficiency and light-saturated rates of photosynthetic electron transport or (3) the decreased light sensitivity of excitation pressure and non-photochemical quenching between NA and NA winter cultivars. Cold acclimation decreased photosynthetic performance of spring relative to winter cultivars. However, the differences in photosynthetic performances between CA winter and spring cultivars were dependent upon the basis on which photosynthetic performance was expressed. Overexpression of BNCBF17 in Brassica napus generally decreased the low temperature sensitivity (Q₁₀) of CO₂ assimilation and photosynthetic electron transport even though the latter had not been exposed to low temperature. Photosynthetic performance in wild type compared to the BNCBF17-overexpressing transgenic B. napus indicated that CBFs/DREBs regulate not only freezing tolerance but also govern plant architecture, leaf anatomy and photosynthetic performance. The apparent positive and negative effects of cold acclimation on photosynthetic performance are discussed in terms of the apparent costs and benefits of phenotypic plasticity, winter survival and reproductive fitness. PMID:21883254

  6. A conceptual review of mate choice: stochastic demography, within-sex phenotypic plasticity, and individual flexibility.

    PubMed

    Ah-King, Malin; Gowaty, Patricia Adair

    2016-07-01

    Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell 2009). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that "choosiness" of potential mates is environmentally and socially labile, that is, induced - not fixed - in "the choosy sex" with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent

  7. Phenotypic plasticity alone cannot explain climate-induced change in avian migration timing

    PubMed Central

    Buskirk, Josh; Mulvihill, Robert S; Leberman, Robert C

    2012-01-01

    Recent climate change has been linked to shifts in the timing of life-cycle events in many organisms, but there is debate over the degree to which phenological changes are caused by evolved genetic responses of populations or by phenotypic plasticity of individuals. We estimated plasticity of spring arrival date in 27 species of bird that breed in the vicinity of an observatory in eastern North America. For 2441 individuals detected in multiple years, arrival occurred earlier during warm years, especially in species that migrate short distances. Phenotypic plasticity averaged −0.93 days °C−1 ± 0.70 (95% CI). However, plasticity accounted for only 13–25% of the climate-induced trend in phenology observed over 46 years. Although our approach probably underestimates the full scope of plasticity, the data suggest that part of the response to environmental change has been caused by microevolution. The estimated evolutionary rates are plausible (0.016 haldanes). PMID:23145329

  8. Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation

    PubMed Central

    2011-01-01

    Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp.) in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among other traits - between

  9. Eco-evolutionary dynamics of plant-herbivore communities: incorporating plant phenotypic plasticity.

    PubMed

    Ohgushi, Takayuki

    2016-04-01

    The interplay between evolution and ecological communities is critical for the integration of different levels of biological organization. Recent work has begun to unveil the importance of plant phenotypic plasticity and plant-herbivore (co)evolution to link plant evolution and associated insect communities. Specifically, herbivore-induced plant traits (i.e., plastic phenotypes) have significant effects on the structure and diversity of herbivore communities, which can in turn promote the evolution of not only the focal plant but also insect community members. Here, I will provide a conceptual framework on the eco-evolutionary dynamics of plant-herbivore communities to understand how biological organizations are integrated in plant-insect interactions. Research on eco-evolutionary dynamics of plant-herbivore communities will undoubtedly enrich understanding of a wide range of plant-insect interactions. PMID:27436645

  10. Plasticity as Phenotype: G x E Interaction in a Freshwater Snail

    NASA Astrophysics Data System (ADS)

    Brunkow, P. E.; Calloway, S. A.

    2005-05-01

    Plasticity in morphological development allows species to accommodate environmental variation experienced during growth; however, genetic variation for phenotypic plasticity per se has been relatively under-studied. We utilized the well-documented plastic response of shell development to predator cues in a freshwater snail to quantify genetic variation for plasticity in growth rate and shell shape. Field-caught pairs of snails reproduced in the laboratory to create families of full siblings, which were then divided and allowed to grow in control and predator cue treatments. Predator (crayfish) cues had significant effects on both size-corrected growth rate and shell shape; family identity also significantly affected both final shell shape and growth rate. The interaction between predator treatment and family identity significantly affected snail growth rate but not final shell shape, suggesting genetic variation in the plastic response to predator cues for a physiological variable (growth rate) but not for a variable known to mechanically reduce the risk of predation (shell shape), at least in this population of snails. The possibility that risk of multiple modes of predation (i.e., both fish and crayfish) in some populations might maintain genetic variation in morphological plasticity is discussed.

  11. High phenotypic plasticity of Suaeda maritima observed under hypoxic conditions in relation to its physiological basis

    PubMed Central

    Wetson, Anne M.; Zörb, Christian; John, Elizabeth A.; Flowers, Timothy J.

    2012-01-01

    Background and Aims Phenotypic plasticity, the potential of specific traits of a genotype to respond to different environmental conditions, is an important adaptive mechanism for minimizing potentially adverse effects of environmental fluctuations in space and time. Suaeda maritima shows morphologically different forms on high and low areas of the same salt marsh. Our aims were to examine whether these phenotypic differences occurred as a result of plastic responses to the environment. Soil redox state, indicative of oxygen supply, was examined as a factor causing the observed morphological and physiological differences. Methods Reciprocal transplantation of seedlings was carried out between high and low marsh sites on a salt marsh and in simulated tidal-flow tanks in a glasshouse. Plants from the same seed source were grown in aerated or hypoxic solution, and roots were assayed for lactate dehydrogenase (LDH) and alcohol dehydrogenase, and changes in their proteome. Key Results Transplanted (away) seedlings and those that remained in their home position developed the morphology characteristic of the home or away site. Shoot Na+, Cl− and K+ concentrations were significantly different in plants in the high and low marsh sites, but with no significant difference between home and away plants at each site. High LDH activity in roots of plants grown in aeration and in hypoxia indicated pre-adaptation to fluctuating root aeration and could be a factor in the phenotypic plasticity and growth of S. maritima over the full tidal range of the salt marsh environment. Twenty-six proteins were upregulated under hypoxic conditions. Conclusions Plasticity of morphological traits for growth form at extremes of the soil oxygenation spectrum of the tidal salt marsh did not correlate with the lack of physiological plasticity in the constitutively high LDH found in the roots. PMID:22316572

  12. Rapid Evolution of Phenotypic Plasticity and Shifting Thresholds of Genetic Assimilation in the Nematode Caenorhabditis remanei

    PubMed Central

    Sikkink, Kristin L.; Reynolds, Rose M.; Ituarte, Catherine M.; Cresko, William A.; Phillips, Patrick C.

    2014-01-01

    Many organisms can acclimate to new environments through phenotypic plasticity, a complex trait that can be heritable, subject to selection, and evolve. However, the rate and genetic basis of plasticity evolution remain largely unknown. We experimentally evolved outbred populations of the nematode Caenorhabditis remanei under an acute heat shock during early larval development. When raised in a nonstressful environment, ancestral populations were highly sensitive to a 36.8° heat shock and exhibited high mortality. However, initial exposure to a nonlethal high temperature environment resulted in significantly reduced mortality during heat shock (hormesis). Lines selected for heat shock resistance rapidly evolved the capacity to withstand heat shock in the native environment without any initial exposure to high temperatures, and early exposure to high temperatures did not lead to further increases in heat resistance. This loss of plasticity would appear to have resulted from the genetic assimilation of the heat induction response in the noninducing environment. However, analyses of transcriptional variation via RNA-sequencing from the selected populations revealed no global changes in gene regulation correlated with the observed changes in heat stress resistance. Instead, assays of the phenotypic response across a broader range of temperatures revealed that the induced plasticity was not fixed across environments, but rather the threshold for the response was shifted to higher temperatures over evolutionary time. These results demonstrate that apparent genetic assimilation can result from shifting thresholds of induction across environments and that analysis of the broader environmental context is critically important for understanding the evolution of phenotypic plasticity. PMID:24727288

  13. Phenotypic plasticity in reproductive traits: Evidence from a viviparous snake. [Thamnophis marcianus

    SciTech Connect

    Ford, N.B.; Seigel, R.A. )

    1989-12-01

    A number of recent studies have indicated that life history characteristics (e.g., number of offspring, offspring size, age at sexual maturity) are strongly affected by proximate environmental factors such as prey availability. Evaluating this phenotypic plasticity will be crucial to a complete understanding of the evolution of life history traits, because the occurrence of such variability casts doubt on the common assumption that the values of life history characteristics expressed in nature are the outcome of long-term natural selection. In this study, the authors manipulated the diets of a captive-bred colony of the viviparous snake Thamnophis marcianus to determine to what degree the reproductive characteristics of this species were determined by food intake. They found that both number of offspring and clutch mass were significantly affected by prey availability, but that relative clutch mass and offspring size were fixed relative to diet. The data suggest that like other organisms, T. marcianus shows a gradient in phenotypic plasticity, with some traits more canalized than others. Therefore, intraspecific comparisons of life history characteristics should not be made without information on which traits are subject to phenotypic plasticity.

  14. When to rely on maternal effects and when on phenotypic plasticity?

    PubMed Central

    Kuijper, Bram; Hoyle, Rebecca B.

    2015-01-01

    Existing insight suggests that maternal effects have a substantial impact on evolution, yet these predictions assume that maternal effects themselves are evolutionarily constant. Hence, it is poorly understood how natural selection shapes maternal effects in different ecological circumstances. To overcome this, the current study derives an evolutionary model of maternal effects in a quantitative genetics context. In constant environments, we show that maternal effects evolve to slight negative values that result in a reduction of the phenotypic variance (canalization). By contrast, in populations experiencing abrupt change, maternal effects transiently evolve to positive values for many generations, facilitating the transmission of beneficial maternal phenotypes to offspring. In periodically fluctuating environments, maternal effects evolve according to the autocorrelation between maternal and offspring environments, favoring positive maternal effects when change is slow, and negative maternal effects when change is rapid. Generally, the strongest maternal effects occur for traits that experience very strong selection and for which plasticity is severely constrained. By contrast, for traits experiencing weak selection, phenotypic plasticity enhances the evolutionary scope of maternal effects, although maternal effects attain much smaller values throughout. As weak selection is common, finding substantial maternal influences on offspring phenotypes may be more challenging than anticipated. PMID:25809121

  15. Environmental quality, developmental plasticity and the thrifty phenotype: a review of evolutionary models.

    PubMed

    Wells, Jonathan C K

    2007-01-01

    The concept of the thrifty phenotype, first proposed by Hales and Barker, is now widely used in medical research, often in contrast to the thrifty genotype model, to interpret associations between early-life experience and adult health status. Several evolutionary models of the thrifty phenotype, which refers to developmental plasticity, have been presented. These include (A) the weather forecast model of Bateson, (B) the maternal fitness model of Wells, (C) the intergenerational phenotypic inertia model of Kuzawa, and (D) the predictive adaptive response model of Gluckman and Hanson. These models are compared and contrasted, in order to assess their relative utility for understanding human ontogenetic development. The most broadly applicable model is model A, which proposes that developing organisms respond to cues of environmental quality, and that mismatches between this forecast and subsequent reality generate significant adverse effects in adult phenotype. The remaining models all address in greater detail what kind of information is provided by such a forecast. Whereas both models B and C emphasise the adaptive benefits of exploiting information about the past, encapsulated in maternal phenotype, model D assumes that the fetus uses cues about the present external environment to predict its probable adult environment. I argue that for humans, with a disproportionately long period between the closing of sensitive windows of plasticity and the attainment of reproductive maturity, backward-looking models B and C represent a better approach, and indicate that the developing offspring aligns itself with stable cues of maternal phenotype so as to match its energy demand with maternal capacity to supply. In contrast, the predictive adaptive response model D over-estimates the capacity of the offspring to predict the future, and also fails to address the long-term parent-offspring dynamics of human development. Differences between models have implications for the

  16. Phenotypic plasticity of early and late successional forbs in response to shifts in resources.

    PubMed

    Huang, Yingxin; Zhao, Xueyong; Zhou, Daowei; Zhang, Hongxiang; Zheng, Wei

    2012-01-01

    We compared the phenotypic plasticity of two early successional forbs of nutrient-poor mobile dunes (Agriophyllum squarrosum and Corispermum macrocarpum) and two later successional forbs (weeds) of stabilized, higher nutrient dunes and cropland (Chenopodium acuminatum and Salsola collina) to variations in environmental factors. A controlled (including soil nutrients, water, and population density) greenhouse experiment was conducted in Horqin sandy land, China. Late successional species had high plasticity in growth response to nutrients and water or high performance in high soil nutrients and water, reflecting their higher nutrient habitat. In contrast, the early successional species have low plasticity, reflecting their adaptation to resource-poor early successional soil. Late successional species did not always have higher reproductive effort than early successional species. Plants did not have a uniform strategy of increasing reproductive effort with any environmental stressors. Reproductive effort increased with increasing water availability and decreasing nutrient levels, while density had no effect. Patterns of plasticity traits for late successional species exhibited a complex of Master-of-some and Jack-of-all-trades. Late successional species had higher performance or higher plasticity than early successional species. PMID:23185600

  17. Phenotypic Plasticity of Early and Late Successional Forbs in Response to Shifts in Resources

    PubMed Central

    Huang, Yingxin; Zhao, Xueyong; Zhou, Daowei; Zhang, Hongxiang; Zheng, Wei

    2012-01-01

    We compared the phenotypic plasticity of two early successional forbs of nutrient-poor mobile dunes (Agriophyllum squarrosum and Corispermum macrocarpum) and two later successional forbs (weeds) of stabilized, higher nutrient dunes and cropland (Chenopodium acuminatum and Salsola collina) to variations in environmental factors. A controlled (including soil nutrients, water, and population density) greenhouse experiment was conducted in Horqin sandy land, China. Late successional species had high plasticity in growth response to nutrients and water or high performance in high soil nutrients and water, reflecting their higher nutrient habitat. In contrast, the early successional species have low plasticity, reflecting their adaptation to resource-poor early successional soil. Late successional species did not always have higher reproductive effort than early successional species. Plants did not have a uniform strategy of increasing reproductive effort with any environmental stressors. Reproductive effort increased with increasing water availability and decreasing nutrient levels, while density had no effect. Patterns of plasticity traits for late successional species exhibited a complex of Master-of-some and Jack-of-all-trades. Late successional species had higher performance or higher plasticity than early successional species. PMID:23185600

  18. Phenotypic Plasticity of the Introduced New Zealand Mud Snail, Potamopyrgus antipodarum, Compared to Sympatric Native Snails

    PubMed Central

    Levri, Edward P.; Krist, Amy C.; Bilka, Rachel; Dybdahl, Mark F.

    2014-01-01

    Phenotypic plasticity is likely to be important in determining the invasive potential of a species, especially if invasive species show greater plasticity or tolerance compared to sympatric native species. Here in two separate experiments we compare reaction norms in response to two environmental variables of two clones of the New Zealand mud snail, Potamopyrgus antipodarum, isolated from the United States, (one invasive and one not yet invasive) with those of two species of native snails that are sympatric with the invader, Fossaria bulimoides group and Physella gyrina group. We placed juvenile snails in environments with high and low conductivity (300 and 800 mS) in one experiment, and raised them at two different temperatures (16°C and 22°C) in a second experiment. Growth rate and mortality were measured over the course of 8 weeks. Mortality rates were higher in the native snails compared to P. antipodarum across all treatments, and variation in conductivity influenced mortality. In both experiments, reaction norms did not vary significantly between species. There was little evidence that the success of the introduced species is a result of greater phenotypic plasticity to these variables compared to the sympatric native species. PMID:24699685

  19. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma

    PubMed Central

    Biddle, Adrian; Gammon, Luke; Liang, Xiao; Costea, Daniela Elena; Mackenzie, Ian C.

    2016-01-01

    Cancer stem cells (CSCs) drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC), we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44highEpCAMlow/− CD24+ cell surface marker profile. Treatment with TGFβ and retinoic acid (RA) enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER) stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs. PMID:26981578

  20. The Baldwin effect and genetic assimilation: revisiting two mechanisms of evolutionary change mediated by phenotypic plasticity.

    PubMed

    Crispo, Erika

    2007-11-01

    Two different, but related, evolutionary theories pertaining to phenotypic plasticity were proposed by James Mark Baldwin and Conrad Hal Waddington. Unfortunately, these theories are often confused with one another. Baldwin's notion of organic selection posits that plasticity influences whether an individual will survive in a new environment, thus dictating the course of future evolution. Heritable variations can then be selected upon to direct phenotypic evolution (i.e., "orthoplasy"). The combination of these two processes (organic selection and orthoplasy) is now commonly referred to as the "Baldwin effect." Alternately, Waddington's genetic assimilation is a process whereby an environmentally induced phenotype, or "acquired character," becomes canalized through selection acting upon the developmental system. Genetic accommodation is a modern term used to describe the process of heritable changes that occur in response to a novel induction. Genetic accommodation is a key component of the Baldwin effect, and genetic assimilation is a type of genetic accommodation. I here define both the Baldwin effect and genetic assimilation in terms of genetic accommodation, describe cases in which either should occur in nature, and propose that each could play a role in evolutionary diversification. PMID:17714500

  1. Snowshoe hares display limited phenotypic plasticity to mismatch in seasonal camouflage

    USGS Publications Warehouse

    Zimova, Marketa; Mills, L. Scott; Lukacs, Paul M.; Mitchell, Michael S.

    2014-01-01

    As duration of snow cover decreases owing to climate change, species undergoing seasonal colour moults can become colour mismatched with their background. The immediate adaptive solution to this mismatch is phenotypic plasticity, either in phenology of seasonal colour moults or in behaviours that reduce mismatch or its consequences. We observed nearly 200 snowshoe hares across a wide range of snow conditions and two study sites in Montana, USA, and found minimal plasticity in response to mismatch between coat colour and background. We found that moult phenology varied between study sites, likely due to differences in photoperiod and climate, but was largely fixed within study sites with only minimal plasticity to snow conditions during the spring white-to-brown moult. We also found no evidence that hares modify their behaviour in response to colour mismatch. Hiding and fleeing behaviours and resting spot preference of hares were more affected by variables related to season, site and concealment by vegetation, than by colour mismatch. We conclude that plasticity in moult phenology and behaviours in snowshoe hares is insufficient for adaptation to camouflage mismatch, suggesting that any future adaptation to climate change will require natural selection on moult phenology or behaviour.

  2. Snowshoe hares display limited phenotypic plasticity to mismatch in seasonal camouflage

    PubMed Central

    Zimova, Marketa; Mills, L. Scott; Lukacs, Paul M.; Mitchell, Michael S.

    2014-01-01

    As duration of snow cover decreases owing to climate change, species undergoing seasonal colour moults can become colour mismatched with their background. The immediate adaptive solution to this mismatch is phenotypic plasticity, either in phenology of seasonal colour moults or in behaviours that reduce mismatch or its consequences. We observed nearly 200 snowshoe hares across a wide range of snow conditions and two study sites in Montana, USA, and found minimal plasticity in response to mismatch between coat colour and background. We found that moult phenology varied between study sites, likely due to differences in photoperiod and climate, but was largely fixed within study sites with only minimal plasticity to snow conditions during the spring white-to-brown moult. We also found no evidence that hares modify their behaviour in response to colour mismatch. Hiding and fleeing behaviours and resting spot preference of hares were more affected by variables related to season, site and concealment by vegetation, than by colour mismatch. We conclude that plasticity in moult phenology and behaviours in snowshoe hares is insufficient for adaptation to camouflage mismatch, suggesting that any future adaptation to climate change will require natural selection on moult phenology or behaviour. PMID:24619446

  3. RU24722 induces spatially organized phenotypic plasticity in the locus coeruleus.

    PubMed

    Debure, L I; Bezin, L; Ginovart, N; Rousset, C; Pujol, J F; Weissmann, D

    1994-09-01

    The plasticity of tyrosine hydroxylase (TH) expression in rat locus coeruleus (LC) was evaluated after RU24722 TH induction using, as a new parameter of characterization, the quantitative topology of LC defined by TH-positive cells. This new phenotype was spatially organized into cell subpopulations in the medial LC, dorsal and ventro-lateral to the initial perikaryal space. Reserpine and parachlorophenylalanine, which elicited a similar increase in the TH content, failed to induce a significant change in the number of TH-expressing cells. Activation of TH expression is not sufficient to reveal the existence of such a plasticity and some original but still unknown mechanism(s) of control of TH expression is affected by RU24722. PMID:7827334

  4. Phenotypic plasticity in age at first reproduction of female northern sea otters (Enhydra lutris kenyoni)

    USGS Publications Warehouse

    Von Biela, V.R.; Gill, V.A.; Bodkin, J.L.; Burns, Jennifer M.

    2009-01-01

    Life-history theory predicts that within a species, reproduction and survival rates will differ among populations that differ in resource availability or predation rates through phenotypic plasticity. When populations are near carrying capacity (K) or when they are declining due to reduced prey resources, the average age at 1st reproduction (average AFR) is predicted to be older than in populations below K. Differences between the trajectories of northern sea otter (Enhydra lutris kenyoni) populations in Alaska provides an opportunity to examine phenotypic plasticity. Using premolar teeth or reproductive tracts, we estimated average AFR from demographically distinct populations of sea otters in Alaska. We obtained samples from 2 populations near K, Prince William Sound (PWS) and the Aleutian Archipelago (archived samples), and from 2populations below K, the Kodiak Archipelago and Sitka. The average AFR was lower in populations below K (3.60 years ??0.16 SD)compared to those near K (4.21 ?? 0.13 years, P <0.001), and differed among all populations, with the Aleutian population possessing the oldest average AFR (4.29 ?? 0.09 years) followed by PWS (4.05 ?? 0.24 years), Sitka (3.80 ?? 0.21 years), and Kodiak (3.19 ?? 0.37 years). The difference in average AFR among populations supports life-history theory and provides evidence of phenotypic plasticity in sea otters. Our findings highlight the value of using average AFR as a tool for monitoring mammalian populations. ?? 2009 American Society of Mammalogists.

  5. Recent advances in ecological genomics: from phenotypic plasticity to convergent and adaptive evolution and speciation.

    PubMed

    Landry, Christian R; Aubin-Horth, Nadia

    2014-01-01

    Biological diversity emerges from the interaction between genomes and their environment. Recent conceptual and technological developments allow dissecting these interactions over short and long time-scales. The 16 contributions to this book by leaders in the field cover major recent progresses in the field of Ecological Genomics. Altogether, they illustrate the interplay between the life-history and genomic architecture of organisms, how the interaction of the environment and the genome is shaping phenotypic variation through phenotypic plasticity, how the process of adaptation may be constrained and fueled by internal and external features of organisms and finally, how species formation is the result of intricate interactions between genomes and the ecological conditions. These contributions also show how fundamental questions in biology transcend the boundaries of kingdoms, species and environments and illustrate how integrative approaches are powerful means to answer the most important and challenging questions in ecology and evolution. PMID:24277292

  6. Non-swarming grasshoppers exhibit density-dependent phenotypic plasticity reminiscent of swarming locusts.

    PubMed

    Gotham, Steven; Song, Hojun

    2013-11-01

    Locusts are well known for exhibiting an extreme form of density-dependent phenotypic plasticity known as locust phase polyphenism. At low density, locust nymphs are cryptically colored and shy, but at high density they transform into conspicuously colored and gregarious individuals. Most of what we know about locust phase polyphenism come from the study of the desert locust Schistocerca gregaria (Forskål), which is a devastating pest species affecting many countries in North Africa and the Middle East. The desert locust belongs to the grasshopper genus Schistocerca Stål, which includes mostly non-swarming, sedentary species. Recent phylogenetic studies suggest that the desert locust is the earliest branching lineage within Schistocerca, which raises a possibility that the presence of density-dependent phenotypic plasticity may be a plesiomorphic trait for the whole genus. In order to test this idea, we have quantified the effect of rearing density in terms of the resulting behavior, color, and morphology in two non-swarming Schistocerca species native to Florida. When reared in both isolated and crowded conditions, the two non-swarming species, Schistocerca americana (Drury) and Schistocerca serialis cubense (Saussure) clearly exhibited plastic reaction norms in all traits measured, which were reminiscent of the desert locust. Specifically, we found that both species were more active and more attracted to each other when reared in a crowded condition than in isolation. They were mainly bright green in color when isolated, but developed strong black patterns and conspicuous background colors when crowded. We found a strong effect of rearing density in terms of size. There were also more mechanoreceptor hairs on the outer face of the hind femora in the crowded nymphs in both species. Although both species responded similarly, there were some clear species-specific differences in terms of color and behavior. Furthermore, we compare and contrast our findings with

  7. Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to sustained water velocities.

    PubMed

    Yavno, S; Fox, M G

    2013-11-01

    Phenotypic plasticity can contribute to the proliferation and invasion success of nonindigenous species by promoting phenotypic changes that increase fitness, facilitate range expansion and improve survival. In this study, differences in phenotypic plasticity were investigated using young-of-year pumpkinseed sunfish from colonies established with lentic and lotic populations originating in Canada (native) and Spain (non-native). Individuals were subjected to static and flowing water treatments for 80 days. Inter- and intra-population differences were tested using ancova and discriminant function analysis, and differences in phenotypic plasticity were tested through a manova of discriminant function scores. Differences between Iberian and North American populations were observed in dorsal fin length, pectoral fin position and caudal peduncle length. Phenotypic plasticity had less influence on morphology than genetic factors, regardless of population origin. Contrary to predictions, Iberian pumpkinseed exhibited lower levels of phenotypic plasticity than native populations, suggesting that canalization may have occurred in the non-native populations during the processes of introduction and range expansion. PMID:24070018

  8. Leaf damage decreases fitness and constrains phenotypic plasticity to drought of a perennial herb

    NASA Astrophysics Data System (ADS)

    Gianoli, Ernesto; Quezada, Iván M.; Suárez, Lorena H.

    2009-09-01

    Mediterranean-type ecosystems are increasingly prone to drought stress. Herbivory might limit plant functional responses to water shortage. This may occur as a result of plant resource depletion or due to the fact that leaf damage and drought may elicit opposite phenotypic responses. We evaluated the impact of herbivory on plant fitness in the field, and the effects of leaf damage on phenotypic plasticity to reduced soil moisture in a greenhouse. The study species was Convolvulus demissus, a perennial herb endemic to central Chile, which has a Mediterranean-type climate. Controlled herbivory by chrysomelid beetles (natural herbivores) in the field had a negative impact on plant fitness, estimated as number of fruits. Whereas reduced soil moisture alone did not affect seedling survival, damaged seedlings (simulated herbivory) had greater mortality when growing under water shortage. The hypothesis that herbivory would constrain phenotypic plasticity was supported by significant statistical interactions between leaf damage and soil moisture, followed by inspections of reaction norms. This was verified both overall (all phenotypic traits taken together, MANOVA) and in four of the six traits evaluated (ANOVAs). When plants were damaged, the reaction norms in response to low soil moisture of water use efficiency, root:shoot ratio and xylem water potential showed reduced slopes. While undamaged plants increased root biomass in response to low moisture, the opposite trend was found for damaged plants. The simultaneous occurrence of herbivory and drought events might curtail recruitment in plant populations of central Chile and other Mediterranean-type ecosystems due to the inability of damaged seedlings to show functional responses to low soil moisture. This finding is of ecological significance in view of current and projected trends of increased aridity in these ecosystems.

  9. Phenotypic Plasticity and Integration in the Mangrove Rivulus (Kryptolebias marmoratus): A Prospectus

    PubMed Central

    Earley, Ryan L.; Hanninen, Amanda F.; Fuller, Adam; Garcia, Mark J.; Lee, Elizabeth A.

    2012-01-01

    The mangrove rivulus (Kryptolebias marmoratus) is a small fish native to mangrove ecosystems in Florida, the Caribbean, Central America, and South America. This species is one of only two self-fertilizing, hermaphroditic vertebrates capable of producing offspring that are genetically identical to both the parent and all siblings. Long bouts of selfing result in individuals with completely homozygous genotypes, effectively allowing for the production of “clones.” Rivulus is also extremely sensitive to environmental change, both during development and adulthood. Life-history traits, behavior, physiology, morphology, and even sexual phenotype are shaped to a large extent by the interaction of genes with the environment, and many of these traits appear to co-vary. True reaction norms can be generated for this species in much the same way as has been done for clonally reproducing invertebrates and plants that have contributed immensely to our understanding of the evolution of phenotypic plasticity. That is, rivulus provides the opportunity to place individuals with identical genotypes in many different environments at any point during ontogeny or adulthood. In addition, rivulus populations are characterized by high genotypic diversity, a luxury not afforded by many clonal vertebrates, which allows us to evaluate variation among genotypes in the shape of reaction norms and in patterns of covariance among traits. We provide background information on phenotypic plasticity and phenotypic integration, coupled with a description of characteristics that we feel qualify rivulus as a potentially powerful model in which to study the evolution of reaction norms and covariance among traits. PMID:22990587

  10. Phenotypic clines, plasticity, and morphological trade-offs in an intertidal snail.

    PubMed

    Trussell, G C

    2000-02-01

    Understanding the genetic and environmental bases of phenotypic variation and how they covary on local and broad geographic scales is an important goal of evolutionary ecology. Such information can shed light on how organisms adapt to different and changing environments and how life-history trade-offs arise. Surveys of phenotypic variation in 25 Littorina obtusata populations across an approximately 400-km latitudinal gradient in the Gulf of Maine revealed pronounced clines. The shells of snails from northern habitats weighed less and were thinner and weaker in compression than those of conspecifics from southern habitats. In contrast, body size (as measured by soft tissue mass) followed an opposite pattern; northern snails weighed more than southern snails. A reciprocal transplant between a northern and southern habitat revealed substantial plasticity in shell form and body mass and their respective measures of growth. Southern snails transplanted to the northern habitat produced lighter, thinner shells and more body mass than controls raised in their native habitat. In contrast, northern snails transplanted to the southern site produced heavier, thicker shells and less body mass than controls raised in their native habitat. Patterns of final phenotypic variation for all traits were consistent with cogradient variation (i.e., a positive covariance between genetic and environmental influences). However, growth in shell traits followed a countergradient pattern (i.e., a negative covariance between genetic and environmental influences). Interestingly, body growth followed a cogradient pattern, which may reflect constraints imposed by cogradient variation in final shell size and thickness. This result suggests the existence of potential life-history trade-offs associated with increased shell production. Differences in L. obtusata shell form, body mass, and their respective measures of growth are likely induced by geographic differences in both water temperature and

  11. Differential gene expression and phenotypic plasticity in behavioural castes of the primitively eusocial wasp, Polistes canadensis

    PubMed Central

    Sumner, Seirian; Pereboom, Jeffrey J.M; Jordan, William C

    2005-01-01

    Understanding how a single genome can produce a variety of different phenotypes is of fundamental importance in evolutionary and developmental biology. One of the most striking examples of phenotypic plasticity is the female caste system found in eusocial insects, where variation in reproductive (queens) and non-reproductive (workers) phenotypes results in a broad spectrum of caste types, ranging from behavioural through to morphological castes. Recent advances in genomic techniques allow novel comparisons on the nature of caste phenotypes to be made at the level of the genes in organisms for which there is little genome information, facilitating new approaches in studying social evolution and behaviour. Using the paper wasp Polistes canadensis as a model system, we investigated for the first time how behavioural castes in primitively eusocial insect societies are associated with differential expression of shared genes. We found that queens and newly emerged females express gene expression patterns that are distinct from each other whilst workers generally expressed intermediate patterns, as predicted by Polistes biology. We compared caste-associated genes in P. canadensis with those expressed in adult queens and workers of more advanced eusocial societies, which represent four independent origins of eusociality. Nine genes were conserved across the four taxa, although their patterns of expression and putative functions varied. Thus, we identify several genes that are putatively of evolutionary importance in the molecular biology that underlies a number of caste systems of independent evolutionary origin. PMID:16519229

  12. Simulated herbivory does not constrain phenotypic plasticity to shade through ontogeny in a relict tree.

    PubMed

    Pardo, A; García, F M; Valladares, F; Pulido, F

    2016-07-01

    Ecological limits to phenotypic plasticity (PP), induced by simultaneous biotic and abiotic factors, can prevent organisms from exhibiting optimal plasticity, and in turn lead to decreased fitness. Herbivory is an important biotic stressor and may limit plant functional responses to challenging environmental conditions such as shading. In this study we investigated whether plant functional responses and PP to shade are constrained by herbivory, and whether such constraints are due to direct effects based on resource limitation by considering ontogeny. We used as a model system the relict tree Prunus lusitanica and implemented an indoor experiment to quantify the response of saplings of different ages to shade and herbivory. We measured five functional traits and quantitatively calculated PP. Results showed that herbivory did not constrain functional responses or PP to shade except for shoot:root ratio (SR), which, despite showing a high PP in damaged saplings, decreased under shade instead of increasing. Damaged saplings of older age did not exhibit reduced constraints on functional responses to shade and generally presented a lower PP than damaged saplings of younger age. Our findings suggest that herbivory-mediated constraints on plant plasticity to shade may not be as widespread as previously thought. Nonetheless, the negative effect of herbivory on SR plastic expression to shade could be detrimental for plant fitness. Finally, our results suggest a secondary role of direct effects (resource-based) on P. lusitanica plasticity limitation. Further studies should quantify plant resources in order to gain a better understanding of this seldom-explored subject. PMID:26991208

  13. Evidence for phenotypic plasticity in the Antarctic extremophile Chlamydomonas raudensis Ettl. UWO 241

    PubMed Central

    Pocock, Tessa; Vetterli, Adrien; Falk, Stefan

    2011-01-01

    Life in extreme environments poses unique challenges to photosynthetic organisms. The ability for an extremophilic green alga and its genetic and mesophilic equivalent to acclimate to changes in their environment was examined to determine the extent of their phenotypic plasticities. The Antarctic extremophile Chlamydomonas raudensis Ettl. UWO 241 (UWO) was isolated from an ice-covered lake in Antarctica, whereas its mesophilic counterpart C. raudensis Ettl. SAG 49.72 (SAG) was isolated from a meadow pool in the Czech Republic. The effects of changes in temperature and salinity on growth, morphology, and photochemistry were examined in the two strains. Differential acclimative responses were observed in UWO which include a wider salinity range for growth, and broader temperature- and salt-induced fluctuations in Fv/Fm, relative to SAG. Furthermore, the redox state of the photosynthetic electron transport chain, measured as 1–qP, was modulated in the extremophile whereas this was not observed in the mesophile. Interestingly, it is shown for the first time that SAG is similar to UWO in that it is unable to undergo state transitions. The different natural histories of these two strains exert different evolutionary pressures and, consequently, different abilities for acclimation, an important component of phenotypic plasticity. In contrast to SAG, UWO relied on a redox sensing and signalling system under the growth conditions used in this study. It is proposed that growth and adaptation of UWO under a stressful and extreme environment poises this extremophile for better success under changing environmental conditions. PMID:21041369

  14. Evidence for phenotypic plasticity in the Antarctic extremophile Chlamydomonas raudensis Ettl. UWO 241.

    PubMed

    Pocock, Tessa; Vetterli, Adrien; Falk, Stefan

    2011-01-01

    Life in extreme environments poses unique challenges to photosynthetic organisms. The ability for an extremophilic green alga and its genetic and mesophilic equivalent to acclimate to changes in their environment was examined to determine the extent of their phenotypic plasticities. The Antarctic extremophile Chlamydomonas raudensis Ettl. UWO 241 (UWO) was isolated from an ice-covered lake in Antarctica, whereas its mesophilic counterpart C. raudensis Ettl. SAG 49.72 (SAG) was isolated from a meadow pool in the Czech Republic. The effects of changes in temperature and salinity on growth, morphology, and photochemistry were examined in the two strains. Differential acclimative responses were observed in UWO which include a wider salinity range for growth, and broader temperature- and salt-induced fluctuations in F(v)/F(m), relative to SAG. Furthermore, the redox state of the photosynthetic electron transport chain, measured as 1-q(P), was modulated in the extremophile whereas this was not observed in the mesophile. Interestingly, it is shown for the first time that SAG is similar to UWO in that it is unable to undergo state transitions. The different natural histories of these two strains exert different evolutionary pressures and, consequently, different abilities for acclimation, an important component of phenotypic plasticity. In contrast to SAG, UWO relied on a redox sensing and signalling system under the growth conditions used in this study. It is proposed that growth and adaptation of UWO under a stressful and extreme environment poises this extremophile for better success under changing environmental conditions. PMID:21041369

  15. The nuclear phenotypic plasticity observed in fish during rRNA regulation entails Cajal bodies dynamics

    SciTech Connect

    Alvarez, Marco; Nardocci, Gino; Thiry, Marc; Alvarez, Rodrigo; Reyes, Mauricio; Molina, Alfredo; Vera, M. Ines . E-mail: mvera@unab.cl

    2007-08-17

    Cajal bodies (CBs) are small mobile organelles found throughout the nucleoplasm of animal and plant cells. The dynamics of these organelles involves interactions with the nucleolus. The later has been found to play a substantial role in the compensatory response that evolved in eurythermal fish to adapt to the cyclic seasonal habitat changes, i.e., temperature and photoperiod. Contrary to being constitutive, rRNA synthesis is dramatically regulated between summer and winter, thus affecting ribosomal biogenesis which plays a central role in the acclimatization process. To examine whether CBs, up to now, never described in fish, were also sustaining the phenotypic plasticity observed in nuclei of fish undergoing seasonal acclimatization, we identified these organelles both, by transmission electronic microscopy and immunodetection with the marker protein p80-coilin. We found transcripts in all tissues analyzed. Furthermore we assessed that p80-coilin gene expression was always higher in summer-acclimatized fish when compared to that adapted to the cold season, indicating that p80-coilin expression is modulated upon seasonal acclimatization. Concurrently, CBs were more frequently found in summer-acclimatized carp which suggests that the organization of CBs is involved in adaptive processes and contribute to the phenotypic plasticity of fish cell nuclei observed concomitantly with profound reprogramming of nucleolar components and regulation of ribosomal rRNAs.

  16. Optimizing experimental procedures for quantitative evaluation of crop plant performance in high throughput phenotyping systems

    PubMed Central

    Junker, Astrid; Muraya, Moses M.; Weigelt-Fischer, Kathleen; Arana-Ceballos, Fernando; Klukas, Christian; Melchinger, Albrecht E.; Meyer, Rhonda C.; Riewe, David; Altmann, Thomas

    2015-01-01

    Detailed and standardized protocols for plant cultivation in environmentally controlled conditions are an essential prerequisite to conduct reproducible experiments with precisely defined treatments. Setting up appropriate and well defined experimental procedures is thus crucial for the generation of solid evidence and indispensable for successful plant research. Non-invasive and high throughput (HT) phenotyping technologies offer the opportunity to monitor and quantify performance dynamics of several hundreds of plants at a time. Compared to small scale plant cultivations, HT systems have much higher demands, from a conceptual and a logistic point of view, on experimental design, as well as the actual plant cultivation conditions, and the image analysis and statistical methods for data evaluation. Furthermore, cultivation conditions need to be designed that elicit plant performance characteristics corresponding to those under natural conditions. This manuscript describes critical steps in the optimization of procedures for HT plant phenotyping systems. Starting with the model plant Arabidopsis, HT-compatible methods were tested, and optimized with regard to growth substrate, soil coverage, watering regime, experimental design (considering environmental inhomogeneities) in automated plant cultivation and imaging systems. As revealed by metabolite profiling, plant movement did not affect the plants' physiological status. Based on these results, procedures for maize HT cultivation and monitoring were established. Variation of maize vegetative growth in the HT phenotyping system did match well with that observed in the field. The presented results outline important issues to be considered in the design of HT phenotyping experiments for model and crop plants. It thereby provides guidelines for the setup of HT experimental procedures, which are required for the generation of reliable and reproducible data of phenotypic variation for a broad range of applications. PMID

  17. Species-specific differences in adaptive phenotypic plasticity in an ecologically relevant trophic trait: hypertrophic lips in Midas cichlid fishes.

    PubMed

    Machado-Schiaffino, Gonzalo; Henning, Frederico; Meyer, Axel

    2014-07-01

    The spectacular species richness of cichlids and their diversity in morphology, coloration, and behavior have made them an ideal model for the study of speciation and adaptive evolution. Hypertrophic lips evolved repeatedly and independently in African and Neotropical cichlid radiations. Cichlids with hypertrophic lips forage predominantly in rocky crevices and it has been hypothesized that mechanical stress caused by friction could result in larger lips through phenotypic plasticity. To test the influence of the environment on the size and development of lips, we conducted a series of breeding and feeding experiments on Midas cichlids. Full-sibs of Amphilophus labiatus (thick-lipped) and Amphilophus citrinellus (thin-lipped) each were split into a control group which was fed food from the water column and a treatment group whose food was fixed to substrates. We found strong evidence for phenotypic plasticity on lip area in the thick-lipped species, but not in the thin-lipped species. Intermediate phenotypic values were observed in hybrids from thick- and thin-lipped species reared under "control" conditions. Thus, both a genetic, but also a phenotypic plastic component is involved in the development of hypertrophic lips in Neotropical cichlids. Moreover, species-specific adaptive phenotypic plasticity was found, suggesting that plasticity is selected for in recent thick-lipped species. PMID:24475874

  18. Quantitative assessment of the importance of phenotypic plasticity in adaptation to climate change in wild bird populations.

    PubMed

    Vedder, Oscar; Bouwhuis, Sandra; Sheldon, Ben C

    2013-07-01

    Predictions about the fate of species or populations under climate change scenarios typically neglect adaptive evolution and phenotypic plasticity, the two major mechanisms by which organisms can adapt to changing local conditions. As a consequence, we have little understanding of the scope for organisms to track changing environments by in situ adaptation. Here, we use a detailed individual-specific long-term population study of great tits (Parus major) breeding in Wytham Woods, Oxford, UK to parameterise a mechanistic model and thus directly estimate the rate of environmental change to which in situ adaptation is possible. Using the effect of changes in early spring temperature on temporal synchrony between birds and a critical food resource, we focus in particular on the contribution of phenotypic plasticity to population persistence. Despite using conservative estimates for evolutionary and reproductive potential, our results suggest little risk of population extinction under projected local temperature change; however, this conclusion relies heavily on the extent to which phenotypic plasticity tracks the changing environment. Extrapolating the model to a broad range of life histories in birds suggests that the importance of phenotypic plasticity for adjustment to projected rates of temperature change increases with slower life histories, owing to lower evolutionary potential. Understanding the determinants and constraints on phenotypic plasticity in natural populations is thus crucial for characterising the risks that rapidly changing environments pose for the persistence of such populations. PMID:23874152

  19. Antarctic climate change: extreme events disrupt plastic phenotypic response in Adélie penguins.

    PubMed

    Lescroël, Amélie; Ballard, Grant; Grémillet, David; Authier, Matthieu; Ainley, David G

    2014-01-01

    In the context of predicted alteration of sea ice cover and increased frequency of extreme events, it is especially timely to investigate plasticity within Antarctic species responding to a key environmental aspect of their ecology: sea ice variability. Using 13 years of longitudinal data, we investigated the effect of sea ice concentration (SIC) on the foraging efficiency of Adélie penguins (Pygoscelis adeliae) breeding in the Ross Sea. A 'natural experiment' brought by the exceptional presence of giant icebergs during 5 consecutive years provided unprecedented habitat variation for testing the effects of extreme events on the relationship between SIC and foraging efficiency in this sea-ice dependent species. Significant levels of phenotypic plasticity were evident in response to changes in SIC in normal environmental conditions. Maximum foraging efficiency occurred at relatively low SIC, peaking at 6.1% and decreasing with higher SIC. The 'natural experiment' uncoupled efficiency levels from SIC variations. Our study suggests that lower summer SIC than currently observed would benefit the foraging performance of Adélie penguins in their southernmost breeding area. Importantly, it also provides evidence that extreme climatic events can disrupt response plasticity in a wild seabird population. This questions the predictive power of relationships built on past observations, when not only the average climatic conditions are changing but the frequency of extreme climatic anomalies is also on the rise. PMID:24489657

  20. Phenotypic plasticity in the spawning traits of bigheaded carp (Hypophthalmichthys spp.) in novel ecosystems

    USGS Publications Warehouse

    Coulter, Alison A.; Keller, Doug; Amberg, Jon J.; Bailey, Elizabeth J.; Goforth, Reuben R.

    2013-01-01

    1. Bigheaded carp, including both silver (Hypophthalmichthys molitrix) and bighead (H. nobilis) carp, are successful invasive fishes that threaten global freshwater biodiversity. High phenotypic plasticity probably contributes to their success in novel ecosystems, although evidence of plasticity in several spawning traits has hitherto been largely anecdotal or speculative. 2. We collected drifting eggs from a Midwestern U.S.A. river from June to September 2011 and from April to June 2012 to investigate the spawning traits of bigheaded carp in novel ecosystems. 3. Unlike reports from the native range, the presence of drifting bigheaded carp eggs was not related to changes in hydrological regime or mean daily water temperature. Bigheaded carp also exhibited protracted spawning, since we found drifting eggs throughout the summer and as late as 1 September 2011. Finally, we detected bigheaded carp eggs in a river reach where the channel is c. 30 m wide with a catchment area of 4579 km2, the smallest stream in which spawning has yet been documented. 4. Taken with previous observations of spawning traits that depart from those observed within the native ranges of both bighead and silver carp, our findings provide direct evidence that bigheaded carp exhibit plastic spawning traits in novel ecosystems that may facilitate invasion and establishment in a wider range of river conditions than previously envisaged.

  1. Antarctic Climate Change: Extreme Events Disrupt Plastic Phenotypic Response in Adélie Penguins

    PubMed Central

    Lescroël, Amélie; Ballard, Grant; Grémillet, David; Authier, Matthieu; Ainley, David G.

    2014-01-01

    In the context of predicted alteration of sea ice cover and increased frequency of extreme events, it is especially timely to investigate plasticity within Antarctic species responding to a key environmental aspect of their ecology: sea ice variability. Using 13 years of longitudinal data, we investigated the effect of sea ice concentration (SIC) on the foraging efficiency of Adélie penguins (Pygoscelis adeliae) breeding in the Ross Sea. A ‘natural experiment’ brought by the exceptional presence of giant icebergs during 5 consecutive years provided unprecedented habitat variation for testing the effects of extreme events on the relationship between SIC and foraging efficiency in this sea-ice dependent species. Significant levels of phenotypic plasticity were evident in response to changes in SIC in normal environmental conditions. Maximum foraging efficiency occurred at relatively low SIC, peaking at 6.1% and decreasing with higher SIC. The ‘natural experiment’ uncoupled efficiency levels from SIC variations. Our study suggests that lower summer SIC than currently observed would benefit the foraging performance of Adélie penguins in their southernmost breeding area. Importantly, it also provides evidence that extreme climatic events can disrupt response plasticity in a wild seabird population. This questions the predictive power of relationships built on past observations, when not only the average climatic conditions are changing but the frequency of extreme climatic anomalies is also on the rise. PMID:24489657

  2. Climate change, adaptation, and phenotypic plasticity: the problem and the evidence

    PubMed Central

    Merilä, Juha; Hendry, Andrew P

    2014-01-01

    Many studies have recorded phenotypic changes in natural populations and attributed them to climate change. However, controversy and uncertainty has arisen around three levels of inference in such studies. First, it has proven difficult to conclusively distinguish whether phenotypic changes are genetically based or the result of phenotypic plasticity. Second, whether or not the change is adaptive is usually assumed rather than tested. Third, inferences that climate change is the specific causal agent have rarely involved the testing – and exclusion – of other potential drivers. We here review the various ways in which the above inferences have been attempted, and evaluate the strength of support that each approach can provide. This methodological assessment sets the stage for 11 accompanying review articles that attempt comprehensive syntheses of what is currently known – and not known – about responses to climate change in a variety of taxa and in theory. Summarizing and relying on the results of these reviews, we arrive at the conclusion that evidence for genetic adaptation to climate change has been found in some systems, but is still relatively scarce. Most importantly, it is clear that more studies are needed – and these must employ better inferential methods – before general conclusions can be drawn. Overall, we hope that the present paper and special issue provide inspiration for future research and guidelines on best practices for its execution. PMID:24454544

  3. Phenotypic Plasticity and Integration in Response to Flooded Conditions in Natural Accessions of Arabidopsis thaliana (L.) Heynh (Brassicaceae)

    PubMed Central

    PIGLIUCCI, MASSIMO; KOLODYNSKA, ANNA

    2002-01-01

    Flood response is a crucial component of the life strategy of many plants, but it is seldom studied in non‐flooded tolerant species, even though they may be subjected to stressful environmental conditions. Phenotypic plasticity in reaction to environmental stress affects the whole plant phenotype and can alter the character correlations that constitute the phenotypic architecture of the individual, yet few studies have investigated the lability of phenotypic integration to water regime. Moreover, little has been done to date to quantify the sort of selective pressures that different components of a plant’s phenotype may be experiencing under contrasting water regimes. Genetic differentiation and phenotypic plasticity at the single‐trait and multivariate levels were investigated in 47 accessions of the weedy plant Arabidopsis thaliana, and the relationship of plastic characters to reproductive fitness was quantified. Results indicate that these plants tend to be highly genetically differentiated for all traits, in agreement with predictions made on the basis of environmental variation and mating system. Varied patterns of apparent selection under flooded and non‐flooded conditions were also uncovered, suggesting trade‐offs in allocation between roots and above‐ground biomass, as well as between leaves and reproductive structures. While the major components of the plants’ multivariate phenotypic architecture were not significantly affected by environmental changes, many of the details were different under flooded and non‐flooded conditions. PMID:12197517

  4. Inherent phenotypic plasticity facilitates progression of head and neck cancer: Endotheliod characteristics enable angiogenesis and invasion

    SciTech Connect

    Tong, Meng; Han, Byungdo B.; Holpuch, Andrew S.; Pei, Ping; He, Lingli; Mallery, Susan R.

    2013-04-15

    The presence of the EMT (epithelial-mesenchymal transition), EndMT (endothelial-mesenchymal transition) and VM (vasculogenic mimicry) demonstrates the multidirectional extent of phenotypic plasticity in cancers. Previous findings demonstrating the crosstalk between head and neck squamous cell carcinoma (HNSCC) and vascular endothelial growth factor (VEGF) imply that HNSCC cells share some functional commonalities with endothelial cells. Our current results reveal that cultured HNSCC cells not only possess endothelial-specific markers, but also display endotheliod functional features including low density lipoprotein uptake, formation of tube-like structures on Matrigel and growth state responsiveness to VEGF and endostatin. HNSCC cell subpopulations are also highly responsive to transforming growth factor-β1 and express its auxiliary receptor, endoglin. Furthermore, the endotheliod characteristics observed in vitro recapitulate phenotypic features observed in human HNSCC tumors. Conversely, cultured normal human oral keratinocytes and intact or ulcerated human oral epithelia do not express comparable endotheliod characteristics, which imply that assumption of endotheliod features is restricted to transformed keratinocytes. In addition, this phenotypic state reciprocity facilitates HNSCC progression by increasing production of factors that are concurrently pro-proliferative and pro-angiogenic, conserving cell energy stores by LDL internalization and enhancing cell mobility. Finally, recognition of this endotheliod phenotypic transition provides a solid rationale to evaluate the antitumorigenic potential of therapeutic agents formerly regarded as exclusively angiostatic in scope. - Highlights: ► HNSCC tumor cells express endothelial specific markers VE-cadherin, CD31 and vimentin. ► Similarly, cultured HNSCC cells retain expression of these markers. ► HNSCC cells demonstrate functional endotheliod characteristics i.e. AcLDL uptake. ► HNSCC cell

  5. Ecotypic differentiation and phenotypic plasticity in reproductive traits of Armadillidium vulgare (Isopoda: Oniscidea).

    PubMed

    Hassall, Mark; Helden, Alvin; Goldson, Andrew; Grant, Alastair

    2005-03-01

    Armadillidium vulgare differed in growth and survivorship on two field sites. Growth rates were higher at a site with consistently higher quality food than at the other site where less high-quality food was produced and which was less predictably accessible. Survivorship was higher at the second site where temperature fluctuations were consistently smaller. Individuals from the two populations were kept for 6 months under the same food and temperature conditions and patterns of resource allocation to reproductive traits analysed. Members of the population from the site with good growth conditions had significantly higher reproductive allocation, by 13.5%, and larger broods, by 9.1%, than those from the site with poor growth conditions. Contrary to theoretical predictions, they also had significantly larger offspring, by 7.5% dry mass. Larger offspring survived better than small ones. This differential survivorship, by 20% for a 3.4% difference in live mass, was much more pronounced under conditions of moisture stress and under fluctuating temperature regimes. Larger offspring would therefore be at a selective advantage on the site with more severe temperature fluctuations. Phenotypic plasticity in reproductive traits in response to experimental changes in food quality, temperature and crowding were monitored. Reproductive allocation was increased by 20.8% under conditions of higher food quality, by 14.7% at higher temperatures, and by 12.5% under less crowded conditions. Brood size, but not offspring dry mass, increased when food quality increased. When crowding increased by 25.0%, the size of broods remained the same but the dry mass of individual offspring decreased by 11.2%. Members of the population from the site with more variable access to high-quality food showed more plasticity in reproductive traits in response to changes in food supply than members of the population from the site with the more predictable food supply. Members of the population from the

  6. Phenotypic plasticity of invasive Alternanthera philoxeroides in relation to different water availability, compared to its native congener

    NASA Astrophysics Data System (ADS)

    Geng, Yu-Peng; Pan, Xiao-Yun; Xu, Cheng-Yuan; Zhang, Wen-Ju; Li, Bo; Chen, Jia-Kuan

    2006-11-01

    Phenotypic plasticity and genetic differentiation are two possible mechanisms that plants use to cope with varying environments. Although alligator weed ( Alternanthera philoxeroides) possesses very low genetic diversity, this alien weed has successfully invaded diverse habitats with considerably varying water availability (from swamps to dry lands) in China. In contrast, its native congener ( Alternanthera sessilis) has a much narrower ecological breadth, and is usually found in moist habitats. To understand the mechanisms underlying the contrasting pattern, we performed a greenhouse experiment to compare the reaction norms of alligator weed with those of its native congener, in which water availability was manipulated. Our results revealed that the two congeners had similar direction of phenotypic plasticity. However, A. philoxeroides showed greater plasticity in amount than did A. sessilis in many traits examined during the switch from wet to drought treatment. Nearly all of the phenotypic variance in A. philoxeroides could be ascribed to plasticity, while A. sessilis had a much higher fraction of phenotypic variance that could be explained by genotypic variation. These interspecific differences in plastic responses to variable water availability partially explained the difference in spatial distribution of the two congeners.

  7. Is There a Relationship between DNA Methylation and Phenotypic Plasticity in Invertebrates?

    PubMed Central

    Roberts, Steven B.; Gavery, Mackenzie R.

    2011-01-01

    There is a significant amount of variation in DNA methylation characteristics across organisms. Likewise, the biological role of DNA methylation varies across taxonomic lineages. The complexity of DNA methylation patterns in invertebrates has only recently begun to be characterized in-depth. In some invertebrate species that have been examined to date, methylated DNA is found primarily within coding regions and patterning is closely associated with gene function. Here we provide a perspective on the potential role of DNA methylation in these invertebrates with a focus on how limited methylation may contribute to increased phenotypic plasticity in highly fluctuating environments. Specifically, limited methylation could facilitate a variety of transcriptional opportunities including access to alternative transcription start sites, increasing sequence mutations, exon skipping, and transient methylation. PMID:22232607

  8. Phenotypic plasticity in sex allocation for a simultaneously hermaphroditic coral reef fish

    NASA Astrophysics Data System (ADS)

    Hart, M. K.; Svoboda, A.; Mancilla Cortez, D.

    2011-06-01

    Phenotypic plasticity can facilitate reproductive strategies that maximize mating success in variable environments and lead to differences in sex allocation among populations. For simultaneous hermaphrodites with sperm competition, including Serranus tortugarum a small coral reef fish, proportional male allocation (testis in total gonad) is often greater where local density or mating group size is higher. We tested whether S. tortugarum reduced male allocation when transplanted from a higher density site to a lower density site. After 4 months, transplants mirrored the sex-allocation patterns of the resident population on their new reef. Transplants had significantly lower male allocation than representatives from their source population, largely as a result of reduced testis mass relative to body size.

  9. Short-term phenotypic plasticity in long-chain cuticular hydrocarbons.

    PubMed

    Thomas, Melissa L; Simmons, Leigh W

    2011-10-22

    Cuticular hydrocarbons provide arthropods with the chemical equivalent of the visually extravagant plumage of birds. Their long chain length, together with the number and variety of positions in which methyl branches and double bonds occur, provide cuticular hydrocarbons with an extraordinary level of information content. Here, we demonstrate phenotypic plasticity in an individual's cuticular hydrocarbon profile. Using solid-phase microextraction, a chemical technique that enables multiple sampling of the same individual, we monitor short-term changes in cuticular hydrocarbon profiles of individual crickets, Teleogryllus oceanicus, in response to a social challenge. We experimentally manipulate the dominance status of males and find that dominant males, on losing fights with other dominant males, change their hydrocarbon profile to more closely resemble that of a subordinate. This result demonstrates that cuticular hydrocarbons can be far more responsive to changes in social dominance than previously realized. PMID:21367785

  10. Neonatal EEG/sleep state analyses: a complex phenotype of developmental neural plasticity.

    PubMed

    Scher, Mark S; Loparo, Kenneth A

    2009-01-01

    Computer analyses of EEG/sleep states can be used as physiologic biomarkers of developmental neural plasticity. Frequency- and time-dependent signal processing strategies of cerebral and noncerebral measures can help test current theories of neuronal network maturation in terms of segregation and integration of short-distance versus long-distance neuronal connections throughout the neuroaxis. Specific phenotypic expressions of adaptive or maladaptive neuronal connectivity are proposed based on comparisons of whole-brain EEG/sleep resting states between preterm and full-term cohorts when developmental outcome measures are applied. Combined use of neurophysiological datasets with neuroimaging and genetic methodologies define endophenotypes that will more accurately diagnose children at risk for developmental disorders, as well as design appropriate neuroprotective interventions for the individual's age and disease progress. PMID:19546563

  11. Affecting Pseudomonas aeruginosa Phenotypic Plasticity by Quorum Sensing Dysregulation Hampers Pathogenicity in Murine Chronic Lung Infection

    PubMed Central

    Bondí, Roslen; Messina, Marco; De Fino, Ida; Bragonzi, Alessandra; Rampioni, Giordano; Leoni, Livia

    2014-01-01

    In Pseudomonas aeruginosa quorum sensing (QS) activates the production of virulence factors, playing a critical role in pathogenesis. Multiple negative regulators modulate the timing and the extent of the QS response either in the pre-quorum or post-quorum phases of growth. This regulation likely increases P. aeruginosa phenotypic plasticity and population fitness, facilitating colonization of challenging environments such as higher organisms. Accordingly, in addition to the factors required for QS signals synthesis and response, also QS regulators have been proposed as targets for anti-virulence therapies. However, while it is known that P. aeruginosa mutants impaired in QS are attenuated in their pathogenic potential, the effect of mutations causing a dysregulated timing and/or magnitude of the QS response has been poorly investigated so far in animal models of infection. In order to investigate the impact of QS dysregulation on P. aeruginosa pathogenesis in a murine model of lung infection, the QteE and RsaL proteins have been selected as representatives of negative regulators controlling P. aeruginosa QS in the pre- and post-quorum periods, respectively. Results showed that the qteE mutation does not affect P. aeruginosa lethality and ability to establish chronic infection in mice, despite causing a premature QS response and enhanced virulence factors production in test tube cultures compared to the wild type. Conversely, the post-quorum dysregulation caused by the rsaL mutation hampers the establishment of P. aeruginosa chronic lung infection in mice without affecting the mortality rate. On the whole, this study contributes to a better understanding of the impact of QS regulation on P. aeruginosa phenotypic plasticity during the infection process. Possible fallouts of these findings in the anti-virulence therapy field are also discussed. PMID:25420086

  12. Life history traits and phenotypic selection among sunflower crop-wild hybrids and their wild counterpart: implications for crop allele introgression.

    PubMed

    Kost, Matthew A; Alexander, Helen M; Jason Emry, D; Mercer, Kristin L

    2015-06-01

    Hybridization produces strong evolutionary forces. In hybrid zones, selection can differentially occur on traits and selection intensities may differ among hybrid generations. Understanding these dynamics in crop-wild hybrid zones can clarify crop-like traits likely to introgress into wild populations and the particular hybrid generations through which introgression proceeds. In a field experiment with four crop-wild hybrid Helianthus annuus (sunflower) cross types, we measured growth and life history traits and performed phenotypic selection analysis on early season traits to ascertain the likelihood, and routes, of crop allele introgression into wild sunflower populations. All cross types overwintered, emerged in the spring, and survived until flowering, indicating no early life history barriers to crop allele introgression. While selection indirectly favored earlier seedling emergence and taller early season seedlings, direct selection only favored greater early season leaf length. Further, there was cross type variation in the intensity of selection operating on leaf length. Thus, introgression of multiple early season crop-like traits, due to direct selection for greater early season leaf length, should not be impeded by any cross type and may proceed at different rates among generations. In sum, alleles underlying early season sunflower crop-like traits are likely to introgress into wild sunflower populations. PMID:26029263

  13. Stress hormones mediate predator-induced phenotypic plasticity in amphibian tadpoles.

    PubMed

    Middlemis Maher, Jessica; Werner, Earl E; Denver, Robert J

    2013-05-01

    Amphibian tadpoles display extensive anti-predator phenotypic plasticity, reducing locomotory activity and, with chronic predator exposure, developing relatively smaller trunks and larger tails. In many vertebrates, predator exposure alters activity of the neuroendocrine stress axis. We investigated predator-induced effects on stress hormone production and the mechanistic link to anti-predator defences in Rana sylvatica tadpoles. Whole-body corticosterone (CORT) content was positively correlated with predator biomass in natural ponds. Exposure to caged predators in mesocosms caused a reduction in CORT by 4 hours, but increased CORT after 4 days. Tadpoles chronically exposed to exogenous CORT developed larger tails relative to their trunks, matching morphological changes induced by predator chemical cue; this predator effect was blocked by the corticosteroid biosynthesis inhibitor metyrapone. Tadpole tail explants treated in vitro with CORT increased tissue weight, suggesting that CORT acts directly on the tail. Short-term treatment of tadpoles with CORT increased predation mortality, likely due to increased locomotory activity. However, long-term CORT treatment enhanced survivorship, likely due to induced morphology. Our findings support the hypothesis that tadpole physiological and behavioural/morphological responses to predation are causally interrelated. Tadpoles initially suppress CORT and behaviour to avoid capture, but increase CORT with longer exposure, inducing adaptive phenotypic changes. PMID:23466985

  14. Phenotypic plasticity of the basidiomata of Thelephora sp. (Thelephoraceae) in tropical forest habitats.

    PubMed

    Ramirez-Lópezl, Itzel; Ríos, Margarita Villegas; Cano-Santana, Zenón

    2013-03-01

    Phenotypic plasticity in macroscopic fungi has been poorly studied in comparison to plants or animals and only general aspects of these changes have been described. In this work, the phenotypic variation in the basidiomata of Thelephora sp. (Thelephoraceae) was examined, as well as some aspects of its ecology and habitat, using 24 specimens collected in the tropical forests of the Chamela Biological Station, Jalisco, Mexico. Our observations showed that this taxon has clavarioid basidiomata that can become resupinate during development and growth if they are in contact with rocks, litter or live plants, establishing in the latter only an epiphytic relationship. This tropical species may form groups of up to 139 basidiomata over an area of 32.2m2, and in both types of vegetation (tropical sub-evergreen and deciduous forest) were primarily located on steep (>20 degree) South-facing slopes. It is found under closed canopy in both tropical forests, but its presence in sub-evergreen forests is greater than expected. PMID:23894987

  15. Phenotypic plasticity or speciation? A case from a clonal marine organism

    PubMed Central

    2008-01-01

    Background Clonal marine organisms exhibit high levels of morphological variation. Morphological differences may be a response to environmental factors but also they can be attributed to accumulated genetic differences due to disruption of gene flow among populations. In this study, we examined the extensive morphological variation (of 14 characters) in natural populations observed in the gorgonian Eunicea flexuosa, a widely distributed Caribbean octocoral. Eco-phenotypic and genetic effects were evaluated by reciprocal transplants of colonies inhabiting opposite ends of the depth gradient and analysis of population genetics of mitochondrial and nuclear genes, respectively. Results Significant differences (P < 0.001) in 14 morphological traits were found among colonies inhabiting 12 locations distributed in seven reefs in southwest Puerto Rico. Results from principal component analysis indicated the presence of two groups based on depth distribution, suggesting the presence of two discrete morphotypes (i.e. shallow type < 5 m and deep type > 17 m). A discriminant function analysis based on a priori univariate and multivariate analyses (which separated the colonies in morphotypes) correctly classified 93% of the colonies for each environment. Light, water motion and sediment transport might influence the distribution of the two morphotypes. Reaction norms of morphological characters of colonies reciprocally transplanted showed gradual significant changes through the 15 months of transplantation. Sclerites of shallow water colonies became larger when transplanted to deeper environments and vice versa, but neither of the two transplanted groups overlapped with the residents' morphology. Genetic analysis of mitochondrial and nuclear genes suggested that such discrete morphology and non-overlapping phenotypic plasticity is correlated with the presence of two independent evolutionary lineages. The distribution of the lineages is non-random and may be related to

  16. Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to competition.

    PubMed

    Yavno, Stan; Rooke, Anna C; Fox, Michael G

    2014-06-01

    Non-indigenous species are oftentimes exposed to ecosystems with unfamiliar species, and organisms that exhibit a high degree of phenotypic plasticity may be better able to contend with the novel competitors that they may encounter during range expansion. In this study, differences in morphological plasticity were investigated using young-of-year pumpkinseed sunfish (Lepomis gibbosus) from native North American and non-native European populations. Two Canadian populations, isolated from bluegill sunfish (L. macrochirus) since the last glaciation, and two Spanish populations, isolated from bluegill since their introduction in Europe, were reared in a common environment using artificial enclosures. Fish were subjected to allopatric (without bluegill) or sympatric (with bluegill) conditions, and differences in plasticity were tested through a MANOVA of discriminant function scores. All pumpkinseed populations exhibited dietary shifts towards more benthivorous prey when held with bluegill. Differences between North American and European populations were observed in body dimensions, gill raker length and pelvic fin position. Sympatric treatments induced an increase in body width and a decrease in caudal peduncle length in native fish; non-native fish exhibited longer caudal peduncle lengths when held in sympatry with bluegill. Overall, phenotypic plasticity influenced morphological divergence less than genetic factors, regardless of population. Contrary to predictions, pumpkinseeds from Europe exhibited lower levels of phenotypic plasticity than Canadian populations, suggesting that European pumpkinseeds are more canalized than their North American counterparts. PMID:24771040

  17. Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to competition

    NASA Astrophysics Data System (ADS)

    Yavno, Stan; Rooke, Anna C.; Fox, Michael G.

    2014-06-01

    Non-indigenous species are oftentimes exposed to ecosystems with unfamiliar species, and organisms that exhibit a high degree of phenotypic plasticity may be better able to contend with the novel competitors that they may encounter during range expansion. In this study, differences in morphological plasticity were investigated using young-of-year pumpkinseed sunfish ( Lepomis gibbosus) from native North American and non-native European populations. Two Canadian populations, isolated from bluegill sunfish ( L. macrochirus) since the last glaciation, and two Spanish populations, isolated from bluegill since their introduction in Europe, were reared in a common environment using artificial enclosures. Fish were subjected to allopatric (without bluegill) or sympatric (with bluegill) conditions, and differences in plasticity were tested through a MANOVA of discriminant function scores. All pumpkinseed populations exhibited dietary shifts towards more benthivorous prey when held with bluegill. Differences between North American and European populations were observed in body dimensions, gill raker length and pelvic fin position. Sympatric treatments induced an increase in body width and a decrease in caudal peduncle length in native fish; non-native fish exhibited longer caudal peduncle lengths when held in sympatry with bluegill. Overall, phenotypic plasticity influenced morphological divergence less than genetic factors, regardless of population. Contrary to predictions, pumpkinseeds from Europe exhibited lower levels of phenotypic plasticity than Canadian populations, suggesting that European pumpkinseeds are more canalized than their North American counterparts.

  18. Morphological divergence and flow-induced phenotypic plasticity in a native fish from anthropogenically altered stream habitats.

    PubMed

    Franssen, Nathan R; Stewart, Laura K; Schaefer, Jacob F

    2013-11-01

    Understanding population-level responses to human-induced changes to habitats can elucidate the evolutionary consequences of rapid habitat alteration. Reservoirs constructed on streams expose stream fishes to novel selective pressures in these habitats. Assessing the drivers of trait divergence facilitated by these habitats will help identify evolutionary and ecological consequences of reservoir habitats. We tested for morphological divergence in a stream fish that occupies both stream and reservoir habitats. To assess contributions of genetic-level differences and phenotypic plasticity induced by flow variation, we spawned and reared individuals from both habitats types in flow and no flow conditions. Body shape significantly and consistently diverged in reservoir habitats compared with streams; individuals from reservoirs were shallower bodied with smaller heads compared with individuals from streams. Significant population-level differences in morphology persisted in offspring but morphological variation compared with field-collected individuals was limited to the head region. Populations demonstrated dissimilar flow-induced phenotypic plasticity when reared under flow, but phenotypic plasticity in response to flow variation was an unlikely explanation for observed phenotypic divergence in the field. Our results, together with previous investigations, suggest the environmental conditions currently thought to drive morphological change in reservoirs (i.e., predation and flow regimes) may not be the sole drivers of phenotypic change. PMID:24363894

  19. Effect of plastic mulching on mycotoxin occurrence and mycobiome abundance in soil samples from asparagus crops.

    PubMed

    Muñoz, K; Schmidt-Heydt, M; Stoll, D; Diehl, D; Ziegler, J; Geisen, R; Schaumann, G E

    2015-11-01

    Plastic mulching (PM) is widely used in modern agriculture because of its advantageous effects on soil temperature and water conservation, factors which strongly influence the microbiology of the soil. The aim of this study was to assess the effect of PM on mycotoxin occurrence in relation with mycobiome abundance/diversity and soil physicochemical properties. Soil samples were collected from green (GA) and white asparagus (WA) crops, the last under PM. Both crops were cultivated in a ridge-furrow-ridge system without irrigation. Samples were analyzed for mycotoxin occurrence via liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Total colony-forming unit was indicative of mycobiome abundance, and analysis of mycobiome diversity was performed by internal transcribed spacer (ITS) sequencing. PM avoided the drop of soil temperature in winter and allowed higher soil temperature in early spring compared to non-covered soil. Moreover, the use of PM provided controlled conditions for water content in soil. This was enough to generate a dissimilar mycotoxin occurrence and mycobiome diversity/abundance in covered and non-covered soil. Mycotoxin soil contamination was confirmed for deoxynivalenol (DON), range LOD to 32.1 ng/g (LOD = 1.1 ng/g). The DON values were higher under PM (average 16.9 ± 10.1 ng/g) than in non-covered soil (9.1 ± 7.9 ng/g); however, this difference was not statically significant (p = 0.09). Mycobiome analysis showed a fungal compartment up to fivefold higher in soil under PM compared to GA. The diversity of the mycobiome varied between crops and also along the soil column, with an important dominance of Fusarium species at the root zone in covered soils. PMID:26412448

  20. Next-generation phenotyping: requirements and strategies for enhancing our understanding of genotype-phenotype relationships and its relevance to crop improvement.

    PubMed

    Cobb, Joshua N; Declerck, Genevieve; Greenberg, Anthony; Clark, Randy; McCouch, Susan

    2013-04-01

    More accurate and precise phenotyping strategies are necessary to empower high-resolution linkage mapping and genome-wide association studies and for training genomic selection models in plant improvement. Within this framework, the objective of modern phenotyping is to increase the accuracy, precision and throughput of phenotypic estimation at all levels of biological organization while reducing costs and minimizing labor through automation, remote sensing, improved data integration and experimental design. Much like the efforts to optimize genotyping during the 1980s and 1990s, designing effective phenotyping initiatives today requires multi-faceted collaborations between biologists, computer scientists, statisticians and engineers. Robust phenotyping systems are needed to characterize the full suite of genetic factors that contribute to quantitative phenotypic variation across cells, organs and tissues, developmental stages, years, environments, species and research programs. Next-generation phenotyping generates significantly more data than previously and requires novel data management, access and storage systems, increased use of ontologies to facilitate data integration, and new statistical tools for enhancing experimental design and extracting biologically meaningful signal from environmental and experimental noise. To ensure relevance, the implementation of efficient and informative phenotyping experiments also requires familiarity with diverse germplasm resources, population structures, and target populations of environments. Today, phenotyping is quickly emerging as the major operational bottleneck limiting the power of genetic analysis and genomic prediction. The challenge for the next generation of quantitative geneticists and plant breeders is not only to understand the genetic basis of complex trait variation, but also to use that knowledge to efficiently synthesize twenty-first century crop varieties. PMID:23471459

  1. Phenotypic plasticity and water flux rates of Citrus root orders under salinity

    PubMed Central

    Rewald, Boris; Raveh, Eran; Gendler, Tanya; Ephrath, Jhonathan E.; Rachmilevitch, Shimon

    2012-01-01

    Knowledge about the root system structure and the uptake efficiency of root orders is critical to understand the adaptive plasticity of plants towards salt stress. Thus, this study describes the phenological and physiological plasticity of Citrus volkameriana rootstocks under severe NaCl stress on the level of root orders. Phenotypic root traits known to influence uptake processes, for example frequency of root orders, specific root area, cortical thickness, and xylem traits, did not change homogeneously throughout the root system, but changes after 6 months under 90 mM NaCl stress were root order specific. Chloride accumulation significantly increased with decreasing root order, and the Cl− concentration in lower root orders exceeded those in leaves. Water flux densities of first-order roots decreased to <20% under salinity and did not recover after stress release. The water flux densities of higher root orders changed marginally under salinity and increased 2- to 6-fold in second and third root orders after short-term stress release. Changes in root order frequency, morphology, and anatomy indicate rapid and major modification of C. volkameriana root systems under salt stress. Reduced water uptake under salinity was related to changes of water flux densities among root orders and to reduced root surface areas. The importance of root orders for water uptake changed under salinity from root tips towards higher root orders. The root order-specific changes reflect differences in vulnerability (indicated by the salt accumulation) and ontogenetic status, and point to functional differences among root orders under high salinity. PMID:22268156

  2. Endocrine mechanisms, behavioral phenotypes and plasticity: known relationships and open questions

    PubMed Central

    2015-01-01

    Behavior of wild vertebrate individuals can vary in response to environmental or social factors. Such within-individual behavioral variation is often mediated by hormonal mechanisms. Hormones also serve as a basis for among-individual variations in behavior including animal personalities and the degree of responsiveness to environmental and social stimuli. How do relationships between hormones and behavioral traits evolve to produce such behavioral diversity within and among individuals? Answering questions about evolutionary processes generating among-individual variation requires characterizing how specific hormones are related to variation in specific behavioral traits, whether observed hormonal variation is related to individual fitness and, whether hormonal traits are consistent (repeatable) aspects of an individual's phenotype. With respect to within-individual variation, we need to improve our insight into the nature of the quantitative relationships between hormones and the traits they regulate, which in turn will determine how they may mediate behavioral plasticity of individuals. To address these questions, we review the actions of two steroid hormones, corticosterone and testosterone, in mediating changes in vertebrate behavior, focusing primarily on birds. In the first part, we concentrate on among-individual variation and present examples for how variation in corticosterone concentrations can relate to behaviors such as exploration of novel environments and parental care. We then review studies on correlations between corticosterone variation and fitness, and on the repeatability over time of corticosterone concentrations. At the end of this section, we suggest that further progress in our understanding of evolutionary patterns in the hormonal regulation of behavior may require, as one major tool, reaction norm approaches to characterize hormonal phenotypes as well as their responses to environments. In the second part, we discuss types of quantitative

  3. Assessment of the genetic and phenotypic diversity among rhizogenic Agrobacterium biovar 1 strains infecting solanaceous and cucurbit crops.

    PubMed

    Bosmans, Lien; Álvarez-Pérez, Sergio; Moerkens, Rob; Wittemans, Lieve; Van Calenberge, Bart; Kerckhove, Stefan Van; Paeleman, Anneleen; De Mot, René; Rediers, Hans; Lievens, Bart

    2015-08-01

    Rhizogenic Agrobacterium biovar 1 strains have been found to cause extensive root proliferation on hydroponically grown Cucurbitaceae and Solanaceae crops, resulting in substantial economic losses. As these agrobacteria live under similar ecological conditions, infecting a limited number of crops, it may be hypothesized that genetic and phenotypic variation among such strains is relatively low. In this study we assessed the phenotypic diversity as well as the phylogenetic and evolutionary relationships of several rhizogenic Agrobacterium biovar 1 strains from cucurbit and solanaceous crops. A collection of 41 isolates was subjected to a number of phenotypic assays and characterized by MLSA targeting four housekeeping genes (16S rRNA gene, recA, rpoB and trpE) and two loci from the root-inducing Ri-plasmid (part of rolB and virD2). Besides phenotypic variation, remarkable genotypic diversity was observed, especially for some chromosomal loci such as trpE. In contrast, genetic diversity was lower for the plasmid-borne loci, indicating that the studied chromosomal housekeeping genes and Ri-plasmid-borne loci might not exhibit the same evolutionary history. Furthermore, phylogenetic and network analyses and several recombination tests suggested that recombination could be contributing in some extent to the evolutionary dynamics of rhizogenic Agrobacterium populations. Finally, a genomospecies-level identification analysis revealed that at least four genomospecies may occur on cucurbit and tomato crops (G1, G3, G8 and G9). Together, this study gives a first glimpse at the genetic and phenotypic diversity within this economically important plant pathogenic bacterium. PMID:26187479

  4. Phenotypic and molecular characterization of native Azospirillum strains from rice fields to improve crop productivity.

    PubMed

    Sahoo, Ranjan K; Ansari, Mohammad W; Pradhan, Madhusmita; Dangar, Tushar K; Mohanty, Santanu; Tuteja, Narendra

    2014-07-01

    Beneficial microorganisms have been considered as an important tool for crop improvement. Native isolates of Azospirillum spp. were obtained from the rhizospheres of different rice fields. Phenotypic, biochemical and molecular characterizations of these isolates led to the identification of six efficient strain of Azospirillum. PCR amplification of the nif genes (nifH, nifD and nifK) and protein profile of Azospirillum strains revealed inter-generic and inter-specific diversity among the strains. In vitro nitrogen fixation performance and the plant growth promotion activities, viz. siderophore, HCN, salicylic acid, IAA, GA, zeatin, ABA, NH3, phosphorus metabolism, ACC deaminase and iron tolerance were found to vary among the Azospirillum strains. The effect of Azospirillum formulations on growth of rice var. Khandagiri under field condition was evaluated, which revealed that the native formulation of Azospirillum of CRRI field (As6) was most effective to elevate endogenous nutrient content, and improved growth and better yield are the result. The 16S rRNA sequence revealed novelty of native Azospirillum lipoferum (As6) (JQ796078) in the NCBI database. PMID:24414168

  5. Impact of Interspecific Hybridization between Crops and Weedy Relatives on the Evolution of Flowering Time in Weedy Phenotypes

    PubMed Central

    Vacher, Corinne; Kossler, Tanya M.; Hochberg, Michael E.; Weis, Arthur E.

    2011-01-01

    Background Like conventional crops, some GM cultivars may readily hybridize with their wild or weedy relatives. The progressive introgression of transgenes into wild or weedy populations thus appears inevitable, and we are now faced with the challenge of determining the possible evolutionary effects of these transgenes. The aim of this study was to gain insight into the impact of interspecific hybridization between transgenic plants and weedy relatives on the evolution of the weedy phenotype. Methodology/Principal Findings Experimental populations of weedy birdseed rape (Brassica rapa) and transgenic rapeseed (B. napus) were grown under glasshouse conditions. Hybridization opportunities with transgenic plants and phenotypic traits (including phenological, morphological and reproductive traits) were measured for each weedy individual. We show that weedy individuals that flowered later and for longer periods were more likely to receive transgenic pollen from crops and weed×crop hybrids. Because stem diameter is correlated with flowering time, plants with wider stems were also more likely to be pollinated by transgenic plants. We also show that the weedy plants with the highest probability of hybridization had the lowest fecundity. Conclusion/Significance Our results suggest that weeds flowering late and for long periods are less fit because they have a higher probability of hybridizing with crops or weed×crop hybrids. This may result in counter-selection against this subset of weed phenotypes, and a shorter earlier flowering period. It is noteworthy that this potential evolution in flowering time does not depend on the presence of the transgene in the crop. Evolution in flowering time may even be counter-balanced by positive selection acting on the transgene if the latter was positively associated with maternal genes promoting late flowering and long flowering periods. Unfortunately, we could not verify this association in the present experiment. PMID:21304909

  6. Does the white clover response to sulphur availability correspond to phenotypic or ontogenetic plasticity?

    NASA Astrophysics Data System (ADS)

    Varin, Sébastien; Leveel, Benjamen; Lemauviel-Lavenant, Servane; Cliquet, Jean-Bernard

    2009-05-01

    White clover ( Trifolium repens L.) is a key species in grasslands. Its performance in grassland communities is strongly linked to nitrogen (N) availability. A decrease in soil sulphur (S) content has appeared in the last few decades in grasslands in Northern Europe and this could change the behaviour of white clover. S is essential for plants and particularly for legumes through its effect upon nitrogen fixation. The aim of this study was to determine the effects of S deficiency on white clover fitness, analysing its plasticity in a time course of growth. Three concentrations of SO 42-, "Low S" (0.009 mM), "Medium S" (0.384 mM) and "High S" (1.509 mM), were used to grow plants in a hydroponic system. S availability modified biomasses significantly only at the end of the experiment (11 weeks). Medium S appeared optimal while Low S induced a lower aboveground dry mass. An appropriate S availability (Medium S) not only increased S content but also increased N content by stimulating N 2 fixation. Plant growth analysis using growth fitted curves and the calculation of RGR revealed that S effects on biomass corresponded to the production of different phenotypes and not to a growth delay. This work shows that the acceleration growth phase (49-56 days) is a key period for the nutritional needs of white clover and should be the best period for a sulphur fertilisation regime that aims to enhance white clover fitness.

  7. Phenotypic and Functional Plasticity of Murine Intestinal NKp46+ Group 3 Innate Lymphoid Cells.

    PubMed

    Verrier, Thomas; Satoh-Takayama, Naoko; Serafini, Nicolas; Marie, Solenne; Di Santo, James P; Vosshenrich, Christian A J

    2016-06-01

    Group 3 innate lymphoid cells (ILC3) actively participate in mucosal defense and homeostasis through prompt secretion of IL-17A, IL-22, and IFN-γ. Reports identify two ILC3 lineages: a CCR6(+)T-bet(-) subset that appears early in embryonic development and promotes lymphoid organogenesis and a CCR6(-)T-bet(+) subset that emerges after microbial colonization and harbors NKp46(+) ILC3. We demonstrate that NKp46 expression in the ILC3 subset is highly unstable. Cell fate mapping using Ncr1(CreGFP) × Rosa26(RFP) mice revealed the existence of an intestinal RFP(+) ILC3 subset (Ncr1(FM)) lacking NKp46 expression at the transcript and protein levels. Ncr1(FM) ILC3 produced more IL-22 and were distinguishable from NKp46(+) ILC3 by differential CD117, CD49a, DNAX accessory molecule-1, and, surprisingly, CCR6 expression. Ncr1(FM) ILC3 emerged after birth and persisted in adult mice following broad-spectrum antibiotic treatment. These results identify an unexpected phenotypic instability within NKp46(+) ILC3 that suggests a major role for environmental signals in tuning ILC3 functional plasticity. PMID:27183613

  8. Flagellar phenotypic plasticity in volvocalean algae correlates with Péclet number.

    PubMed

    Solari, Cristian A; Drescher, Knut; Ganguly, Sujoy; Kessler, John O; Michod, Richard E; Goldstein, Raymond E

    2011-10-01

    Flagella-generated fluid stirring has been suggested to enhance nutrient uptake for sufficiently large micro-organisms, and to have played a role in evolutionary transitions to multicellularity. A corollary to this predicted size-dependent benefit is a propensity for phenotypic plasticity in the flow-generating mechanism to appear in large species under nutrient deprivation. We examined four species of volvocalean algae whose radii and flow speeds differ greatly, with Péclet numbers (Pe) separated by several orders of magnitude. Populations of unicellular Chlamydomonas reinhardtii and one- to eight-celled Gonium pectorale (Pe ∼ 0.1-1) and multicellular Volvox carteri and Volvox barberi (Pe ∼ 100) were grown in diluted and undiluted media. For C. reinhardtii and G. pectorale, decreasing the nutrient concentration resulted in smaller cells, but had no effect on flagellar length and propulsion force. In contrast, these conditions induced Volvox colonies to grow larger and increase their flagellar length, separating the somatic cells further. Detailed studies on V. carteri found that the opposing effects of increasing beating force and flagellar spacing balance, so the fluid speed across the colony surface remains unchanged between nutrient conditions. These results lend further support to the hypothesized link between the Péclet number, nutrient uptake and the evolution of biological complexity in the Volvocales. PMID:21367778

  9. Phenotypic plasticity in juvenile jellyfish medusae facilitates effective animal-fluid interaction.

    PubMed

    Nawroth, J C; Feitl, K E; Colin, S P; Costello, J H; Dabiri, J O

    2010-06-23

    Locomotion and feeding in marine animals are intimately linked to the flow dynamics created by specialized body parts. This interaction is of particular importance during ontogeny, when changes in behaviour and scale challenge the organism with shifts in fluid regimes and altered functionality. Previous studies have indicated that Scyphozoan jellyfish ontogeny accommodates the changes in fluid dynamics associated with increasing body dimensions and velocities during development. However, in addition to scale and behaviour that-to a certain degree-underlie the control of the animal, flow dynamics are also dependent on external factors such as temperature. Here, we show phenotypic plasticity in juvenile Aurelia aurita medusae, where morphogenesis is adapted to altered fluid regimes imposed by changes in ambient temperature. In particular, differential proportional growth was found to compensate for temperature-dependent changes in viscous effects, enabling the animal to use adhering water boundary layers as 'paddles'-and thus economize tissue-at low temperatures, while switching to tissue-dominated propulsion at higher temperatures where the boundary layer thickness is insufficient to serve for paddling. This effect was predicted by a model of animal-fluid interaction and confirmed empirically by flow-field visualization and assays of propulsion efficiency. PMID:20335200

  10. The contribution of phenotypic plasticity to the evolution of insecticide tolerance in amphibian populations

    PubMed Central

    Hua, Jessica; Jones, Devin K; Mattes, Brian M; Cothran, Rickey D; Relyea, Rick A; Hoverman, Jason T

    2015-01-01

    Understanding population responses to rapid environmental changes caused by anthropogenic activities, such as pesticides, is a research frontier. Genetic assimilation (GA), a process initiated by phenotypic plasticity, is one mechanism potentially influencing evolutionary responses to novel environments. While theoretical and laboratory research suggests that GA has the potential to influence evolutionary trajectories, few studies have assessed its role in the evolution of wild populations experiencing novel environments. Using the insecticide, carbaryl, and 15 wood frog populations distributed across an agricultural gradient, we tested whether GA contributed to the evolution of pesticide tolerance. First, we investigated the evidence for evolved tolerance to carbaryl and discovered that population-level patterns of tolerance were consistent with evolutionary responses to pesticides; wood frog populations living closer to agriculture were more tolerant than populations living far from agriculture. Next, we tested the potential role of GA in the evolution of pesticide tolerance by assessing whether patterns of tolerance were consistent with theoretical predictions. We found that populations close to agriculture displayed constitutive tolerance to carbaryl whereas populations far from agriculture had low naïve tolerance but high magnitudes of induced tolerance. These results suggest GA could play a role in evolutionary responses to novel environments in nature. PMID:26136824

  11. Extrafloral nectary phenotypic plasticity is damage- and resource-dependent in Vicia faba

    PubMed Central

    Mondor, Edward B; Tremblay, Michelle N; Messing, Russell H

    2006-01-01

    Phenotypic plasticity enables many damaged plants to increase nectar secretion rates from extrafloral nectaries (EFNs), or in the case of broad bean, Vicia faba L., to produce additional EFNs, to attract natural enemies of herbivores. While plants benefit greatly from these defensive mutualisms, the costs of producing EFNs are largely unknown. We hypothesized that if EFN production is costly, then damaged plants with high resource levels would be able to produce more EFNs than plants that are resource-limited. Here, we show that this indirect inducible defence does follow this general pattern. Vicia faba enriched with 6 or 12 g of 14 : 14 : 14 NPK fertilizer increased EFN numbers after leaf damage by 46 and 60%, respectively, compared with nutrient-poor plants. Thus, EFN production is both damage- and resource-dependent. Analogous to direct defences, production of EFNs may limit the overall loss of leaf tissue when risk of herbivory increases. PMID:17148294

  12. Ontogenetic loss of phenotypic plasticity of age at metamorphosis in tadpoles

    SciTech Connect

    Hensley, F.R. )

    1993-12-01

    Amphibian larvae exhibit phenotypic plasticity in size at metamorphosis and duration of the larval period. I used Pseudacris crucifer tadpoles to test two models for predicting tadpole age and size at metamorphosis under changing environmental conditions. The Wilbur-Collins model states that metamorphosis is initiated as a function of a tadpole's size and relative growth rate, and predicts that changes in growth rate throughout the larval period affect age and size at metamorphosis. An alternative model, the fixed-rate model, states that age at metamorphosis is fixed early in larval life, and subsequent changes in growth rate will have no effect on the length of the larval period. My results confirm that food supplies affect both age and size at metamorphosis, but developmental rates became fixed at approximately Gosner (1960) stages 35-37. Neither model completely predicted these results. I suggest that the generally accepted Wilbur-Collins model is improved by incorporating a point of fixed developmental timing. Growth trajectories predicted from this modified model fit the results of this study better than trajectories based on either of the original models. The results of this study suggests a constraint that limits the simultaneous optimization of age and size at metamorphosis. 32 refs., 5 figs., 1 tab.

  13. Chloroplast redox imbalance governs phenotypic plasticity: the "grand design of photosynthesis" revisited.

    PubMed

    Hüner, Norman P A; Bode, Rainer; Dahal, Keshav; Hollis, Lauren; Rosso, Dominic; Krol, Marianna; Ivanov, Alexander G

    2012-01-01

    Sunlight, the ultimate energy source for life on our planet, enters the biosphere as a direct consequence of the evolution of photoautotrophy. Photoautotrophs must balance the light energy absorbed and trapped through extremely fast, temperature-insensitive photochemistry with energy consumed through much slower, temperature-dependent biochemistry and metabolism. The attainment of such a balance in cellular energy flow between chloroplasts, mitochondria and the cytosol is called photostasis. Photoautotrophs sense cellular energy imbalances through modulation of excitation pressure which is a measure of the relative redox state of Q(A), the first stable quinone electron acceptor of photosystem II reaction centers. High excitation pressure constitutes a potential stress condition that can be caused either by exposure to an irradiance that exceeds the capacity of C, N, and S assimilation to utilize the electrons generated from the absorbed energy or by low temperature or any stress that decreases the capacity of the metabolic pathways downstream of photochemistry to utilize photosynthetically generated reductants. The similarities and differences in the phenotypic responses between cyanobacteria, green algae, crop plants, and variegation mutants of Arabidopsis thaliana as a function of cold acclimation and photoacclimation are reconciled in terms of differential responses to excitation pressure and the predisposition of photoautotrophs to maintain photostasis. The various acclimation strategies associated with green algae and cyanobacteria versus winter cereals and A. thaliana are discussed in terms of retrograde regulation and the "grand design of photosynthesis" originally proposed by Arnon (1982). PMID:23230444

  14. Chloroplast redox imbalance governs phenotypic plasticity: the “grand design of photosynthesis” revisited

    PubMed Central

    Hüner, Norman P. A.; Bode, Rainer; Dahal, Keshav; Hollis, Lauren; Rosso, Dominic; Krol, Marianna; Ivanov, Alexander G.

    2012-01-01

    Sunlight, the ultimate energy source for life on our planet, enters the biosphere as a direct consequence of the evolution of photoautotrophy. Photoautotrophs must balance the light energy absorbed and trapped through extremely fast, temperature-insensitive photochemistry with energy consumed through much slower, temperature-dependent biochemistry and metabolism. The attainment of such a balance in cellular energy flow between chloroplasts, mitochondria and the cytosol is called photostasis. Photoautotrophs sense cellular energy imbalances through modulation of excitation pressure which is a measure of the relative redox state of QA, the first stable quinone electron acceptor of photosystem II reaction centers. High excitation pressure constitutes a potential stress condition that can be caused either by exposure to an irradiance that exceeds the capacity of C, N, and S assimilation to utilize the electrons generated from the absorbed energy or by low temperature or any stress that decreases the capacity of the metabolic pathways downstream of photochemistry to utilize photosynthetically generated reductants. The similarities and differences in the phenotypic responses between cyanobacteria, green algae, crop plants, and variegation mutants of Arabidopsis thaliana as a function of cold acclimation and photoacclimation are reconciled in terms of differential responses to excitation pressure and the predisposition of photoautotrophs to maintain photostasis. The various acclimation strategies associated with green algae and cyanobacteria versus winter cereals and A. thaliana are discussed in terms of retrograde regulation and the “grand design of photosynthesis” originally proposed by Arnon (1982). PMID:23230444

  15. Bridging the phenotypic and genetic data useful for integrated breeding through a data annotation using the Crop Ontology developed by the crop communities of practice

    PubMed Central

    Shrestha, Rosemary; Matteis, Luca; Skofic, Milko; Portugal, Arllet; McLaren, Graham; Hyman, Glenn; Arnaud, Elizabeth

    2012-01-01

    The Crop Ontology (CO) of the Generation Challenge Program (GCP) (http://cropontology.org/) is developed for the Integrated Breeding Platform (IBP) (http://www.integratedbreeding.net/) by several centers of The Consultative Group on International Agricultural Research (CGIAR): bioversity, CIMMYT, CIP, ICRISAT, IITA, and IRRI. Integrated breeding necessitates that breeders access genotypic and phenotypic data related to a given trait. The CO provides validated trait names used by the crop communities of practice (CoP) for harmonizing the annotation of phenotypic and genotypic data and thus supporting data accessibility and discovery through web queries. The trait information is completed by the description of the measurement methods and scales, and images. The trait dictionaries used to produce the Integrated Breeding (IB) fieldbooks are synchronized with the CO terms for an automatic annotation of the phenotypic data measured in the field. The IB fieldbook provides breeders with direct access to the CO to get additional descriptive information on the traits. Ontologies and trait dictionaries are online for cassava, chickpea, common bean, groundnut, maize, Musa, potato, rice, sorghum, and wheat. Online curation and annotation tools facilitate (http://cropontology.org) direct maintenance of the trait information and production of trait dictionaries by the crop communities. An important feature is the cross referencing of CO terms with the Crop database trait ID and with their synonyms in Plant Ontology (PO) and Trait Ontology (TO). Web links between cross referenced terms in CO provide online access to data annotated with similar ontological terms, particularly the genetic data in Gramene (University of Cornell) or the evaluation and climatic data in the Global Repository of evaluation trials of the Climate Change, Agriculture and Food Security programme (CCAFS). Cross-referencing and annotation will be further applied in the IBP. PMID:22934074

  16. Bridging the phenotypic and genetic data useful for integrated breeding through a data annotation using the Crop Ontology developed by the crop communities of practice.

    PubMed

    Shrestha, Rosemary; Matteis, Luca; Skofic, Milko; Portugal, Arllet; McLaren, Graham; Hyman, Glenn; Arnaud, Elizabeth

    2012-01-01

    The Crop Ontology (CO) of the Generation Challenge Program (GCP) (http://cropontology.org/) is developed for the Integrated Breeding Platform (IBP) (http://www.integratedbreeding.net/) by several centers of The Consultative Group on International Agricultural Research (CGIAR): bioversity, CIMMYT, CIP, ICRISAT, IITA, and IRRI. Integrated breeding necessitates that breeders access genotypic and phenotypic data related to a given trait. The CO provides validated trait names used by the crop communities of practice (CoP) for harmonizing the annotation of phenotypic and genotypic data and thus supporting data accessibility and discovery through web queries. The trait information is completed by the description of the measurement methods and scales, and images. The trait dictionaries used to produce the Integrated Breeding (IB) fieldbooks are synchronized with the CO terms for an automatic annotation of the phenotypic data measured in the field. The IB fieldbook provides breeders with direct access to the CO to get additional descriptive information on the traits. Ontologies and trait dictionaries are online for cassava, chickpea, common bean, groundnut, maize, Musa, potato, rice, sorghum, and wheat. Online curation and annotation tools facilitate (http://cropontology.org) direct maintenance of the trait information and production of trait dictionaries by the crop communities. An important feature is the cross referencing of CO terms with the Crop database trait ID and with their synonyms in Plant Ontology (PO) and Trait Ontology (TO). Web links between cross referenced terms in CO provide online access to data annotated with similar ontological terms, particularly the genetic data in Gramene (University of Cornell) or the evaluation and climatic data in the Global Repository of evaluation trials of the Climate Change, Agriculture and Food Security programme (CCAFS). Cross-referencing and annotation will be further applied in the IBP. PMID:22934074

  17. The Relative Importance of Genetic Diversity and Phenotypic Plasticity in Determining Invasion Success of a Clonal Weed in the USA and China

    PubMed Central

    Geng, Yupeng; van Klinken, Rieks D.; Sosa, Alejandro; Li, Bo; Chen, Jiakuan; Xu, Cheng-Yuan

    2016-01-01

    Phenotypic plasticity has been proposed as an important adaptive strategy for clonal plants in heterogeneous habitats. Increased phenotypic plasticity can be especially beneficial for invasive clonal plants, allowing them to colonize new environments even when genetic diversity is low. However, the relative importance of genetic diversity and phenotypic plasticity for invasion success remains largely unknown. Here, we performed molecular marker analyses and a common garden experiment to investigate the genetic diversity and phenotypic plasticity of the globally important weed Alternanthera philoxeroides in response to different water availability (terrestrial vs. aquatic habitats). This species relies predominantly on clonal propagation in introduced ranges. We therefore expected genetic diversity to be restricted in the two sampled introduced ranges (the USA and China) when compared to the native range (Argentina), but that phenotypic plasticity may allow the species' full niche range to nonetheless be exploited. We found clones from China had very low genetic diversity in terms of both marker diversity and quantitative variation when compared with those from the USA and Argentina, probably reflecting different introduction histories. In contrast, similar patterns of phenotypic plasticity were found for clones from all three regions. Furthermore, despite the different levels of genetic diversity, bioclimatic modeling suggested that the full potential bioclimatic distribution had been invaded in both China and USA. Phenotypic plasticity, not genetic diversity, was therefore critical in allowing A. philoxeroides to invade diverse habitats across broad geographic areas. PMID:26941769

  18. The Relative Importance of Genetic Diversity and Phenotypic Plasticity in Determining Invasion Success of a Clonal Weed in the USA and China.

    PubMed

    Geng, Yupeng; van Klinken, Rieks D; Sosa, Alejandro; Li, Bo; Chen, Jiakuan; Xu, Cheng-Yuan

    2016-01-01

    Phenotypic plasticity has been proposed as an important adaptive strategy for clonal plants in heterogeneous habitats. Increased phenotypic plasticity can be especially beneficial for invasive clonal plants, allowing them to colonize new environments even when genetic diversity is low. However, the relative importance of genetic diversity and phenotypic plasticity for invasion success remains largely unknown. Here, we performed molecular marker analyses and a common garden experiment to investigate the genetic diversity and phenotypic plasticity of the globally important weed Alternanthera philoxeroides in response to different water availability (terrestrial vs. aquatic habitats). This species relies predominantly on clonal propagation in introduced ranges. We therefore expected genetic diversity to be restricted in the two sampled introduced ranges (the USA and China) when compared to the native range (Argentina), but that phenotypic plasticity may allow the species' full niche range to nonetheless be exploited. We found clones from China had very low genetic diversity in terms of both marker diversity and quantitative variation when compared with those from the USA and Argentina, probably reflecting different introduction histories. In contrast, similar patterns of phenotypic plasticity were found for clones from all three regions. Furthermore, despite the different levels of genetic diversity, bioclimatic modeling suggested that the full potential bioclimatic distribution had been invaded in both China and USA. Phenotypic plasticity, not genetic diversity, was therefore critical in allowing A. philoxeroides to invade diverse habitats across broad geographic areas. PMID:26941769

  19. Stress relief may promote the evolution of greater phenotypic plasticity in exotic invasive species: a hypothesis

    PubMed Central

    Huang, Qiao Q; Pan, Xiao Y; Fan, Zhi W; Peng, Shao L

    2015-01-01

    Invasion ecologists have often found that exotic invaders evolve to be more plastic than conspecific populations from their native range. However, an open question is why some exotic invaders can even evolve to be more plastic given that there may be costs to being plastic. Investigation into the benefits and costs of plasticity suggests that stress may constrain the expression of plasticity (thereby reducing the benefits of plasticity) and exacerbate the costs of plasticity (although this possibility might not be generally applicable). Therefore, evolution of adaptive plasticity is more likely to be constrained in stressful environments. Upon introduction to a new range, exotic species may experience more favorable growth conditions (e.g., because of release from natural enemies). Therefore, we hypothesize that any factors mitigating stress in the introduced range may promote exotic invaders to evolve increased adaptive plasticity by reducing the costs and increasing the benefits of plasticity. Empirical evidence is largely consistent with this hypothesis. This hypothesis contributes to our understanding of why invasive species are often found to be more competitive in a subset of environments. Tests of this hypothesis may not only help us understand what caused increased plasticity in some exotic invaders, but could also tell us if costs (unless very small) are more likely to inhibit the evolution of adaptive plasticity in stressful environments in general. PMID:25859323

  20. Phenotypic plasticity to light of two congeneric trees from contrasting habitats: Brazilian Atlantic Forest versus cerrado (savanna).

    PubMed

    Barros, F de V; Goulart, M F; Telles, S B Sá; Lovato, M B; Valladares, F; de Lemos-Filho, J P

    2012-01-01

    The Brazilian Atlantic Forest is a typically multi-layer tropical forest, while cerrado (savanna) is a patchy habitat with different physiognomy. Despite these differences, both habitats have high light heterogeneity. Functional traits of Dalbergia nigra and D. miscolobium from the Atlantic Forest and cerrado, respectively, were evaluated under shade (25% of full sunlight) and full sunlight in a nursery experiment. We hypothesised that both species should benefit from high phenotypic plasticity in relation to light. Plasticity was estimated using the relative distance phenotypic index (RDPI). D. miscolobium had lower shoot growth under both light conditions, suggesting it has low competitive capacity in the forest environment, which could explain its limited ability to expand over areas of Atlantic Forest. The studied species exhibited photoprotection strategies under high light and improved light capture under low light. Stomatal conductance, ETR(max) (maximum electron transport rate), PPFD(sat) (saturating photosynthetically active photon flux density), chlorophyll and carotenoid content had higher RDPI than stem morphological traits. Although both species showed considerable phenotypic plasticity, D. miscolobium had higher RDPI for eight of 11 evaluated traits. This high plasticity could be one of the factors that explain the occurrence of this species in a wide range of environmental conditions, from open grassland to dense woodlands, and it could also reflect its adaptation to high light. D. nigra also had considerable plasticity and good growth performance in both shade and full sunlight, but its absence in areas of cerrado suggests that factors other than light limit its occurrence in these habitats. PMID:21972934

  1. Phenotypic plasticity and interpopulation differences in life history traits of Armadillidium vulgare (Isopoda:Oniscidae).

    PubMed

    Hassall, Mark; Helden, Alvin; Benton, Timothy

    2003-09-01

    The hypothesis that the balance of trade-offs between survivorship, growth and reproductive allocation in the terrestrial isopod Armadillidium vulgare will change when resource input is increased has been investigated experimentally. When the quality of food available was increased, by adding a mixture of litter from herbaceous dicotyledonous plants to a background low-quality food of dead grasses, survivorship was found to be the most phenotypically plastic trait, increasing by 168%. Growth rates increased by 99% but reproductive allocation by only 21%. In the field, members of a population from a site with more high-quality food grew more than twice as fast as those from a site where less high-quality food was available. The population from the site with higher food availability, contrary to predictions from the laboratory study, did not survive as well as that from the site with less available high-quality food. This may be because the site that is more favourable for growth has a more stressful physical environment due to much bigger temperature fluctuations, which are known to be an important cause of mortality in this species. When individuals from both populations were reared under controlled laboratory conditions, both the parental and F1 generations from the poor growth environment survived better than those from the good growth habitat. However, even when given an excess of high-quality food those from the poor growth environment continued to grow more slowly and had a lower reproductive allocation than those from the site with higher food availability. We conclude that microevolutionary changes may have occurred in the balance of resource allocation between survivorship, growth and reproductive allocation, to favour higher survivorship during the longer prereproductive period at the site where growth to the threshold size for reproduction takes longer. PMID:12827489

  2. Norway maple displays greater seasonal growth and phenotypic plasticity to light than native sugar maple.

    PubMed

    Paquette, Alain; Fontaine, Bastien; Berninger, Frank; Dubois, Karine; Lechowicz, Martin J; Messier, Christian; Posada, Juan M; Valladares, Fernando; Brisson, Jacques

    2012-11-01

    Norway maple (Acer platanoides L), which is among the most invasive tree species in forests of eastern North America, is associated with reduced regeneration of the related native species, sugar maple (Acer saccharum Marsh) and other native flora. To identify traits conferring an advantage to Norway maple, we grew both species through an entire growing season under simulated light regimes mimicking a closed forest understorey vs. a canopy disturbance (gap). Dynamic shade-houses providing a succession of high-intensity direct-light events between longer periods of low, diffuse light were used to simulate the light regimes. We assessed seedling height growth three times in the season, as well as stem diameter, maximum photosynthetic capacity, biomass allocation above- and below-ground, seasonal phenology and phenotypic plasticity. Given the north European provenance of Norway maple, we also investigated the possibility that its growth in North America might be increased by delayed fall senescence. We found that Norway maple had significantly greater photosynthetic capacity in both light regimes and grew larger in stem diameter than sugar maple. The differences in below- and above-ground biomass, stem diameter, height and maximum photosynthesis were especially important in the simulated gap where Norway maple continued extension growth during the late fall. In the gap regime sugar maple had a significantly higher root : shoot ratio that could confer an advantage in the deepest shade of closed understorey and under water stress or browsing pressure. Norway maple is especially invasive following canopy disturbance where the opposite (low root : shoot ratio) could confer a competitive advantage. Considering the effects of global change in extending the potential growing season, we anticipate that the invasiveness of Norway maple will increase in the future. PMID:23076822

  3. Urbanization and its effects on personality traits: a result of microevolution or phenotypic plasticity?

    PubMed

    Miranda, Ana Catarina; Schielzeth, Holger; Sonntag, Tanja; Partecke, Jesko

    2013-09-01

    Human-altered environmental conditions affect many species at the global scale. An extreme form of anthropogenic alteration is the existence and rapid increase of urban areas. A key question, then, is how species cope with urbanization. It has been suggested that rural and urban conspecifics show differences in behaviour and personality. However, (i) a generalization of this phenomenon has never been made; and (ii) it is still unclear whether differences in personality traits between rural and urban conspecifics are the result of phenotypic plasticity or of intrinsic differences. In a literature review, we show that behavioural differences between rural and urban conspecifics are common and taxonomically widespread among animals, suggesting a significant ecological impact of urbanization on animal behaviour. In order to gain insight into the mechanisms leading to behavioural differences in urban individuals, we hand-raised and kept European blackbirds (Turdus merula) from a rural and a nearby urban area under common-garden conditions. Using these birds, we investigated individual variation in two behavioural responses to the presence of novel objects: approach to an object in a familiar area (here defined as neophilia), and avoidance of an object in a familiar foraging context (defined as neophobia). Neophilic and neophobic behaviours were mildly correlated and repeatable even across a time period of one year, indicating stable individual behavioural strategies. Blackbirds from the urban population were more neophobic and seasonally less neophilic than blackbirds from the nearby rural area. These intrinsic differences in personality traits are likely the result of microevolutionary changes, although we cannot fully exclude early developmental influences. PMID:23681984

  4. Dynamic precision phenotyping reveals mechanism of crop tolerance to herbivory by the western corn rootworm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The western corn rootworm, Diabrotica virgifera virgifera (LeConte) is a major pest of maize, Zea mays L. Over the years, this pest has repeatedly shown its resilience and adaptability not only to traditional crop management strategies including chemical pesticides and crop rotation, but also to de...

  5. Limited plasticity in the phenotypic variance-covariance matrix for male advertisement calls in the black field cricket, Teleogryllus commodus

    PubMed Central

    Pitchers, W. R.; Brooks, R.; Jennions, M. D.; Tregenza, T.; Dworkin, I.; Hunt, J.

    2013-01-01

    Phenotypic integration and plasticity are central to our understanding of how complex phenotypic traits evolve. Evolutionary change in complex quantitative traits can be predicted using the multivariate breeders’ equation, but such predictions are only accurate if the matrices involved are stable over evolutionary time. Recent work, however, suggests that these matrices are temporally plastic, spatially variable and themselves evolvable. The data available on phenotypic variance-covariance matrix (P) stability is sparse, and largely focused on morphological traits. Here we compared P for the structure of the complex sexual advertisement call of six divergent allopatric populations of the Australian black field cricket, Teleogryllus commodus. We measured a subset of calls from wild-caught crickets from each of the populations and then a second subset after rearing crickets under common-garden conditions for three generations. In a second experiment, crickets from each population were reared in the laboratory on high- and low-nutrient diets and their calls recorded. In both experiments, we estimated P for call traits and used multiple methods to compare them statistically (Flury hierarchy, geometric subspace comparisons and random skewers). Despite considerable variation in means and variances of individual call traits, the structure of P was largely conserved among populations, across generations and between our rearing diets. Our finding that P remains largely stable, among populations and between environmental conditions, suggests that selection has preserved the structure of call traits in order that they can function as an integrated unit. PMID:23530814

  6. Limited plasticity in the phenotypic variance-covariance matrix for male advertisement calls in the black field cricket, Teleogryllus commodus.

    PubMed

    Pitchers, W R; Brooks, R; Jennions, M D; Tregenza, T; Dworkin, I; Hunt, J

    2013-05-01

    Phenotypic integration and plasticity are central to our understanding of how complex phenotypic traits evolve. Evolutionary change in complex quantitative traits can be predicted using the multivariate breeders' equation, but such predictions are only accurate if the matrices involved are stable over evolutionary time. Recent study, however, suggests that these matrices are temporally plastic, spatially variable and themselves evolvable. The data available on phenotypic variance-covariance matrix (P) stability are sparse, and largely focused on morphological traits. Here, we compared P for the structure of the complex sexual advertisement call of six divergent allopatric populations of the Australian black field cricket, Teleogryllus commodus. We measured a subset of calls from wild-caught crickets from each of the populations and then a second subset after rearing crickets under common-garden conditions for three generations. In a second experiment, crickets from each population were reared in the laboratory on high- and low-nutrient diets and their calls recorded. In both experiments, we estimated P for call traits and used multiple methods to compare them statistically (Flury hierarchy, geometric subspace comparisons and random skewers). Despite considerable variation in means and variances of individual call traits, the structure of P was largely conserved among populations, across generations and between our rearing diets. Our finding that P remains largely stable, among populations and between environmental conditions, suggests that selection has preserved the structure of call traits in order that they can function as an integrated unit. PMID:23530814

  7. New Insights on the Maternal Diet Induced-Hypertension: Potential Role of the Phenotypic Plasticity and Sympathetic-Respiratory Overactivity

    PubMed Central

    Costa-Silva, João H.; de Brito-Alves, José L.; Barros, Monique Assis de V.; Nogueira, Viviane Oliveira; Paulino-Silva, Kássya M.; de Oliveira-Lira, Allan; Nobre, Isabele G.; Fragoso, Jéssica; Leandro, Carol G.

    2015-01-01

    Systemic arterial hypertension (SAH) is an important risk factor for cardiovascular disease and affects worldwide population. Current environment including life style coupled with genetic programming have been attributed to the rising incidence of hypertension. Besides, environmental conditions during perinatal development such as maternal malnutrition can program changes in the integration among renal, neural, and endocrine system leading to hypertension. This phenomenon is termed phenotypic plasticity and refers to the adjustment of a phenotype in response to environmental stimuli without genetic change, following a novel or unusual input during development. Human and animal studies indicate that fetal exposure to an adverse maternal environment may alter the renal morphology and physiology that contribute to the development of hypertension. Recently, it has been shown that the maternal protein restriction alter the central control of SAH by a mechanism that include respiratory dysfunction and enhanced sympathetic-respiratory coupling at early life, which may contribute to adult hypertension. This review will address the new insights on the maternal diet induced-hypertension that include the potential role of the phenotypic plasticity, specifically the perinatal protein malnutrition, and sympathetic-respiratory overactivity. PMID:26635631

  8. Habitat Choice and Temporal Variation Alter the Balance between Adaptation by Genetic Differentiation, a Jack-of-All-Trades Strategy, and Phenotypic Plasticity.

    PubMed

    Scheiner, Samuel M

    2016-05-01

    Confronted with variable environments, species adapt in several ways, including genetic differentiation, a jack-of-all-trades strategy, or phenotypic plasticity. Adaptive habitat choice favors genetic differentiation and local adaptation over a generalist, jack-of-all-trades strategy. Models predict that, absent plasticity costs, variable environments generally favor phenotypic plasticity over genetic differentiation and being a jack-of-all-trades generalist. It is unknown how habitat choice might affect the evolution of plasticity. Using an individual-based simulation model, I explored the interaction of choice and plasticity. With only spatial variation, habitat choice promotes genetic differentiation over a jack-of-all-trades strategy or phenotypic plasticity. In the absence of plasticity, temporal variation favors a jack-of-all-trades strategy over choice-mediated genetic differentiation; when plasticity is an option, it is favored. This occurs because habitat choice creates a feedback between genetic differentiation and dispersal rates. As demes become better adapted to their local environments, the effective dispersal rate decreases, because more individuals have very high fitness and so choose not to disperse, reinforcing local stabilizing selection and negating selection for plasticity. Temporal variation breaks that feedback. These results point to a potential data paradox: systems with habitat choice may have the lowest actual movement rates. The potential for adaptive habitat choice may be very common, but its existence may reduce observed dispersal rates enough that we do not recognize systems where it may be present, warranting further exploration of likely systems. PMID:27104995

  9. Phenotypic plasticity as an index of drought tolerance in three Patagonian steppe grasses

    PubMed Central

    Couso, L. L.; Fernández, R. J.

    2012-01-01

    Background and Aims Despite general agreement regarding the adaptive importance of plasticity, evidence for the role of environmental resource availability in plants is scarce. In arid and semi-arid environments, the persistence and dominance of perennial species depends on their capacity to tolerate drought: tolerance could be given on one extreme by fixed traits and, on the other, by plastic traits. To understand drought tolerance of species it is necessary to know the plasticity of their water economy-related traits, i.e. the position in the fixed–plastic continuum. Methods Three conspicuous co-existing perennial grasses from a Patagonian steppe were grown under controlled conditions with four levels of steady-state water availability. Evaluated traits were divided into two groups. The first was associated with potential plant performance and correlated with fitness, and included above-ground biomass, total biomass, tillering and tiller density at harvest. The second group consisted of traits associated with mechanisms of plant adjustment to environmental changes and included root biomass, shoot/root ratio, tiller biomass, length of total elongated leaf, length of yellow tissue divided by time and final length divided by the time taken to reach final length. Key Results and Conclusions The most plastic species along this drought gradient was the most sensitive to drought, whereas the least plastic and slowest growing was the most tolerant. This negative relationship between tolerance and plasticity was true for fitness-related traits but was trait-dependent for underlying traits. Remarkably, the most tolerant species had the highest positive plasticity (i.e. opposite to the default response to stress) in an underlying trait, directly explaining its drought resistance: it increased absolute root biomass. The niche differentiation axis that allows the coexistence of species in this group of perennial dryland grasses, all limited by soil surface moisture, would

  10. Biotic and abiotic drivers of phenotypic plasticity of wing dimorphism in Sclerodermus pupariae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wing phenotype polymorphism is commonly observed in insects, yet little is known about the influence of environmental cues on the development or expression of the alternative phenotypes. Here, we examined the effects of biotic and abiotic factors including temperature, photoperiod, light intensity,...

  11. Mechanism of a plastic phenotypic response: predator-induced shell thickening in the intertidal gastropod Littorina obtusata.

    PubMed

    Brookes, J I; Rochette, Rémy

    2007-05-01

    Phenotypic plasticity has been the object of considerable interest over the past several decades, but in few cases are mechanisms underlying plastic responses well understood. For example, it is unclear whether predator-induced changes in gastropod shell morphology represent an active physiological response or a by-product of reduced feeding. We address this question by manipulating feeding and growth of intertidal snails, Littorina obtusata, using two approaches: (i) exposure to predation cues from green crabs Carcinus maenas and (ii) reduced food availability, and quantifying growth in shell length, shell mass, and body mass, as well as production of faecal material and shell micro-structural characteristics (mineralogy and organic fraction) after 96 days. We demonstrate that L. obtusata actively increases calcification rate in response to predation threat, and that this response entails energetic and developmental costs. That this induced response is not strictly tied to the animal's behaviour should enhance its evolutionary potential. PMID:17465912

  12. Light and Nutrient Dependent Responses in Secondary Metabolites of Plantago lanceolata Offspring Are Due to Phenotypic Plasticity in Experimental Grasslands

    PubMed Central

    Miehe-Steier, Annegret; Roscher, Christiane; Reichelt, Michael; Gershenzon, Jonathan; Unsicker, Sybille B.

    2015-01-01

    A few studies in the past have shown that plant diversity in terms of species richness and functional composition can modify plant defense chemistry. However, it is not yet clear to what extent genetic differentiation of plant chemotypes or phenotypic plasticity in response to diversity-induced variation in growth conditions or a combination of both is responsible for this pattern. We collected seed families of ribwort plantain (Plantago lanceolata) from six-year old experimental grasslands of varying plant diversity (Jena Experiment). The offspring of these seed families was grown under standardized conditions with two levels of light and nutrients. The iridoid glycosides, catalpol and aucubin, and verbascoside, a caffeoyl phenylethanoid glycoside, were measured in roots and shoots. Although offspring of different seed families differed in the tissue concentrations of defensive metabolites, plant diversity in the mothers' environment did not explain the variation in the measured defensive metabolites of P. lanceolata offspring. However secondary metabolite levels in roots and shoots were strongly affected by light and nutrient availability. Highest concentrations of iridoid glycosides and verbascoside were found under high light conditions, and nutrient availability had positive effects on iridoid glycoside concentrations in plants grown under high light conditions. However, verbascoside concentrations decreased under high levels of nutrients irrespective of light. The data from our greenhouse study show that phenotypic plasticity in response to environmental variation rather than genetic differentiation in response to plant community diversity is responsible for variation in secondary metabolite concentrations of P. lanceolata in the six-year old communities of the grassland biodiversity experiment. Due to its large phenotypic plasticity P. lanceolata has the potential for a fast and efficient adjustment to varying environmental conditions in plant communities of

  13. Phenotypic plasticity in growth and fecundity induced by strong population fluctuations affects reproductive traits of female fish.

    PubMed

    Karjalainen, Juha; Urpanen, Olli; Keskinen, Tapio; Huuskonen, Hannu; Sarvala, Jouko; Valkeajärvi, Pentti; Marjomäki, Timo J

    2016-02-01

    Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populations with markedly different densities, and hence naturally induced differences in their growth and fecundity. The energy allocation to somatic tissues and eggs prior to spawning served as a proxy for total resource availability to individual females, and its effects on offspring survival and growth were analyzed. Vendace females allocated a rather constant proportion of available energy to eggs (per body mass) despite different growth patterns depending on the total resources in the different lakes; investment into eggs thus dictated the share remaining for growth. The energy allocation to eggs per mass was higher in young than in old spawners and the egg size and the relative fecundity differed between them: Young females produced more and smaller eggs and larvae than old spawners. In contrast to earlier observations of salmonids, a shortage of maternal food resources did not increase offspring size and survival. Vendace females in sparse populations with ample resources and high growth produced larger eggs and larvae. Vendace accommodate strong population fluctuations by their high plasticity in growth and fecundity, which affect their offspring size and consequently their recruitment and productivity, and account for their persistence and resilience in the face of high

  14. MUTZ-3 derived Langerhans cells in human skin equivalents show differential migration and phenotypic plasticity after allergen or irritant exposure.

    PubMed

    Kosten, Ilona J; Spiekstra, Sander W; de Gruijl, Tanja D; Gibbs, Susan

    2015-08-15

    After allergen or irritant exposure, Langerhans cells (LC) undergo phenotypic changes and exit the epidermis. In this study we describe the unique ability of MUTZ-3 derived Langerhans cells (MUTZ-LC) to display similar phenotypic plasticity as their primary counterparts when incorporated into a physiologically relevant full-thickness skin equivalent model (SE-LC). We describe differences and similarities in the mechanisms regulating LC migration and plasticity upon allergen or irritant exposure. The skin equivalent consisted of a reconstructed epidermis containing primary differentiated keratinocytes and CD1a(+) MUTZ-LC on a primary fibroblast-populated dermis. Skin equivalents were exposed to a panel of allergens and irritants. Topical exposure to sub-toxic concentrations of allergens (nickel sulfate, resorcinol, cinnamaldehyde) and irritants (Triton X-100, SDS, Tween 80) resulted in LC migration out of the epidermis and into the dermis. Neutralizing antibody to CXCL12 blocked allergen-induced migration, whereas anti-CCL5 blocked irritant-induced migration. In contrast to allergen exposure, irritant exposure resulted in cells within the dermis becoming CD1a(-)/CD14(+)/CD68(+) which is characteristic of a phenotypic switch of MUTZ-LC to a macrophage-like cell in the dermis. This phenotypic switch was blocked with anti-IL-10. Mechanisms previously identified as being involved in LC activation and migration in native human skin could thus be reproduced in the in vitro constructed skin equivalent model containing functional LC. This model therefore provides a unique and relevant research tool to study human LC biology in situ under controlled in vitro conditions, and will provide a powerful tool for hazard identification, testing novel therapeutics and identifying new drug targets. PMID:26028481

  15. Control of phenotypic plasticity of smooth muscle cells by bone morphogenetic protein signaling through the myocardin-related transcription factors.

    PubMed

    Lagna, Giorgio; Ku, Manching M; Nguyen, Peter H; Neuman, Nicole A; Davis, Brandi N; Hata, Akiko

    2007-12-21

    Vascular smooth muscle cells (VSMCs), unlike other muscle cells, do not terminally differentiate. In response to injury, VSMCs change phenotype, proliferate, and migrate as part of the repair process. Dysregulation of this plasticity program contributes to the pathogenesis of several vascular disorders, such as atherosclerosis, restenosis, and hypertension. The discovery of mutations in the gene encoding BMPRII, the type II subunit of the receptor for bone morphogenetic proteins (BMPs), in patients with pulmonary arterial hypertension (PAH) provided an indication that BMP signaling may affect the homeostasis of VSMCs and their phenotype modulation. Here we report that BMP signaling potently induces SMC-specific genes in pluripotent cells and prevents dedifferentiation of arterial SMCs. The BMP-induced phenotype switch requires intact RhoA/ROCK signaling but is not blocked by inhibitors of the TGFbeta and PI3K/Akt pathways. Furthermore, nuclear localization and recruitment of the myocardin-related transcription factors (MRTF-A and MRTF-B) to a smooth muscle alpha-actin promoter is observed in response to BMP treatment. Thus, BMP signaling modulates VSMC phenotype via cross-talk with the RhoA/MRTFs pathway, and may contribute to the development of the pathological characteristics observed in patients with PAH and other obliterative vascular diseases. PMID:17947237

  16. Phenotypic and phylogenetic analysis of lactic acid bacteria isolated from forage crops and grasses in the Tibetan Plateau.

    PubMed

    Pang, Huili; Tan, Zhongfang; Qin, Guangyong; Wang, Yanping; Li, Zongwei; Jin, Qingsheng; Cai, Yimin

    2012-02-01

    A total of 140 lactic acid bacteria (LAB) strains were isolated from corn, alfalfa, clover, sainfoin, and Indian goosegrass in the Tibetan Plateau. According to phenotypic and chemotaxonomic characteristics, 16S rDNA sequence, and recA gene PCR amplification, these LAB isolates were identified as belonging to five genera and nine species. Corn contained more LAB species than other forage crops. Leuconostoc pseudomesenteroides, Lactococcus lactis subsp. lactis, Lactobacillus brevis, and Weissella paramesenteroides were dominant members of the LAB population on alfalfa, clover, sainfoin, and Indian goosegrass, respectively. The comprehensive 16S rDNA and recA-based approach effectively described the LAB community structure of the relatively abundant LAB species distributed on different forage crops. This is the first report describing the diversity and natural populations of LAB associated with Tibetan forage crops, and most isolates grow well at or below 10°C. The results will be valuable for the future design of appropriate inoculants for silage fermentation in this very cold area. PMID:22367939

  17. [Responses of Agriophyllum squarrosum phenotypic plasticity to the changes of soil nutrient and moisture contents and population density].

    PubMed

    Huang, Ying-xin; Zhao, Xue-yong; Zhang, Hong-xuan; Luo, Ya-yong; Mao, Wei

    2008-12-01

    This paper studied the phenotypic plasticity of Agriophyllum squarrosum under effects of soil nutrient and moisture contents and population density. The results showed that with the increase of soil nutrient content, the root/shoot ratio of A. squarrosum was decreased from 0.135 to 0.073. However, soil moisture content and population density had less effect on the root/shoot ratio. The plasticity of reproductive allocation of A. squarrosum as responding to the changes of soil nutrient and moisture contents was a "real plasticity", and the allocation was negatively correlated with soil nutrient content but positively correlated with soil moisture content. When soil nutrient content was high or moisture content was low, the reproductive allocation of A. squarrosum changed larger with plant size. Population density had no effects on the reproductive allocation, while plant size conditioned the allocation. Among the three test affecting factors, soil nutrient content had the greatest effects on the morphological characters and biomass of A. squarrosum. PMID:19288709

  18. Plastic and Heritable Components of Phenotypic Variation in Nucella lapillus: An Assessment Using Reciprocal Transplant and Common Garden Experiments

    PubMed Central

    Pascoal, Sonia; Carvalho, Gary; Creer, Simon; Rock, Jenny; Kawaii, Kei; Mendo, Sonia; Hughes, Roger

    2012-01-01

    Assessment of plastic and heritable components of phenotypic variation is crucial for understanding the evolution of adaptive character traits in heterogeneous environments. We assessed the above in relation to adaptive shell morphology of the rocky intertidal snail Nucella lapillus by reciprocal transplantation of snails between two shores differing in wave action and rearing snails of the same provenance in a common garden. Results were compared with those reported for similar experiments conducted elsewhere. Microsatellite variation indicated limited gene flow between the populations. Intrinsic growth rate was greater in exposed-site than sheltered-site snails, but the reverse was true of absolute growth rate, suggesting heritable compensation for reduced foraging opportunity at the exposed site. Shell morphology of reciprocal transplants partially converged through plasticity toward that of native snails. Shell morphology of F2s in the common garden partially retained characteristics of the P-generation, suggesting genetic control. A maternal effect was revealed by greater resemblance of F1s than F2s to the P-generation. The observed synergistic effects of plastic, maternal and genetic control of shell-shape may be expected to maximise fitness when environmental characteristics become unpredictable through dispersal. PMID:22299035

  19. Comparing differences in species sensitivity to toxicants: Phenotypic plasticity versus concentration-response relationships

    SciTech Connect

    Kammenga, J.E.; Riksen, J.A.G.

    1996-09-01

    The comparison of species sensitivity to toxicants is classically derived from differences in the concentration-response relationships of a sensitive trait such as reproduction. The authors tested this general concept by conceiving the concentration-response relationship as a plastic response to a range of discrete environments. Using a demographic model based on life-cycle experiments for two nematode species (Plectus acuminatus and Heterocephalobus pauciannulatus) they related copper-induced plasticity in reproduction to changes in fitness, which was defined as the population growth rate. Daily reproduction (n{sub t}) in P. acuminatus was more sensitive to copper (EC20 = 48 {micro}M) than in H. pauciannulatus (EC20 = 138 {micro}M). However, the relationship between plasticity in n{sub t} and fitness showed that for both species, fitness was reduced with 5%. These findings imply that P. acuminatus and H. pauciannulatus are equally susceptible to toxicant-induced changes in n{sub t} despite their differences in EC20 values for reproduction. It may be concluded that differences in susceptibility of species to toxicants are not only determined by the effect on sensitive traits but also by the relationship between plasticity in this trait and fitness.

  20. Quantifying Phenotypic Plasticity Using Genetic Information for Simulating Plant Height in Winter Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A challenge for crop simulation modeling is to incorporate existing and rapidly emerging genomic information into models to develop new and improved algorithms. The objective of this effort was to simulate plant height in winter wheat (Triticum aestivum L.) across a range of environments in Nebraska...

  1. Proteomics to assess the role of phenotypic plasticity in aquatic organisms exposed to pollution and global warming.

    PubMed

    Silvestre, Frédéric; Gillardin, Virginie; Dorts, Jennifer

    2012-11-01

    Nowadays, the unprecedented rates of anthropogenic changes in ecosystems suggest that organisms have to migrate to new distributional ranges or to adapt commensurately quickly to new conditions to avoid becoming extinct. Pollution and global warming are two of the most important threats aquatic organisms will have to face in the near future. If genetic changes in a population in response to natural selection are extensively studied, the role of acclimation through phenotypic plasticity (the property of a given genotype to produce different phenotypes in response to particular environmental conditions) in a species to deal with new environmental conditions remains largely unknown. Proteomics is the extensive study of the protein complement of a genome. It is dynamic and depends on the specific tissue, developmental stage, and environmental conditions. As the final product of gene expression, it is subjected to several regulatory steps from gene transcription to the functional protein. Consequently, there is a discrepancy between the abundance of mRNA and the abundance of the corresponding protein. Moreover, proteomics is closer to physiology and gives a more functional knowledge of the regulation of gene expression than does transcriptomics. The study of protein-expression profiles, however, gives a better portrayal of the cellular phenotype and is considered as a key link between the genotype and the organismal phenotype. Under new environmental conditions, we can observe a shift of the protein-expression pattern defining a new cellular phenotype that can possibly improve the fitness of the organism. It is now necessary to define a proteomic norm of reaction for organisms acclimating to environmental stressors. Its link to fitness will give new insights into how organisms can evolve in a changing environment. The proteomic literature bearing on chronic exposure to pollutants and on acclimation to heat stress in aquatic organisms, as well as potential application of

  2. Dissecting the Phenotypic Components of Crop Plant Growth and Drought Responses Based on High-Throughput Image Analysis[W][OPEN

    PubMed Central

    Chen, Dijun; Neumann, Kerstin; Friedel, Swetlana; Kilian, Benjamin; Chen, Ming; Altmann, Thomas; Klukas, Christian

    2014-01-01

    Significantly improved crop varieties are urgently needed to feed the rapidly growing human population under changing climates. While genome sequence information and excellent genomic tools are in place for major crop species, the systematic quantification of phenotypic traits or components thereof in a high-throughput fashion remains an enormous challenge. In order to help bridge the genotype to phenotype gap, we developed a comprehensive framework for high-throughput phenotype data analysis in plants, which enables the extraction of an extensive list of phenotypic traits from nondestructive plant imaging over time. As a proof of concept, we investigated the phenotypic components of the drought responses of 18 different barley (Hordeum vulgare) cultivars during vegetative growth. We analyzed dynamic properties of trait expression over growth time based on 54 representative phenotypic features. The data are highly valuable to understand plant development and to further quantify growth and crop performance features. We tested various growth models to predict plant biomass accumulation and identified several relevant parameters that support biological interpretation of plant growth and stress tolerance. These image-based traits and model-derived parameters are promising for subsequent genetic mapping to uncover the genetic basis of complex agronomic traits. Taken together, we anticipate that the analytical framework and analysis results presented here will be useful to advance our views of phenotypic trait components underlying plant development and their responses to environmental cues. PMID:25501589

  3. Phenotypic, functional, and plasticity features of classical and alternatively activated human macrophages.

    PubMed

    Tarique, Abdullah A; Logan, Jayden; Thomas, Emma; Holt, Patrick G; Sly, Peter D; Fantino, Emmanuelle

    2015-11-01

    Macrophages are dynamic cells that mature under the influence of signals from the local microenvironment into either classically (M1) or alternatively (M2) activated macrophages with specific functional and phenotypic properties. Although the phenotypic identification of M1 and M2 macrophages is well established in mice, this is less clear for human macrophages. In addition, the persistence and reversibility of polarized human phenotypes is not well established. Human peripheral blood monocytes were differentiated into uncommitted macrophages (M0) and then polarized to M1 and M2 phenotypes using LPS/IFN-γ and IL-4/IL-13, respectively. M1 and M2 were identified as CD64(+)CD80(+) and CD11b(+)CD209(+), respectively, by flow cytometry. Polarized M1 cells secreted IP-10, IFN-γ, IL-8, TNF-α, IL-1β, and RANTES, whereas M2 cells secreted IL-13, CCL17, and CCL18. Functionally, M2 cells were highly endocytic. In cytokine-deficient medium, the polarized macrophages reverted back to the M0 state within 12 days. If previously polarized macrophages were given the alternative polarizing stimulus after 6 days of resting in cytokine-deficient medium, a switch in polarization was seen (i.e., M1 macrophages switched to M2 and expressed CD11b(+)CD209(+) and vice versa). In summary, we report phenotypic identification of human M1 and M2 macrophages, their functional characteristics, and their ability to be reprogrammed given the appropriate stimuli. PMID:25870903

  4. MUTZ-3 derived Langerhans cells in human skin equivalents show differential migration and phenotypic plasticity after allergen or irritant exposure

    SciTech Connect

    Kosten, Ilona J.; Spiekstra, Sander W.; Gruijl, Tanja D. de; Gibbs, Susan

    2015-08-15

    After allergen or irritant exposure, Langerhans cells (LC) undergo phenotypic changes and exit the epidermis. In this study we describe the unique ability of MUTZ-3 derived Langerhans cells (MUTZ-LC) to display similar phenotypic plasticity as their primary counterparts when incorporated into a physiologically relevant full-thickness skin equivalent model (SE-LC). We describe differences and similarities in the mechanisms regulating LC migration and plasticity upon allergen or irritant exposure. The skin equivalent consisted of a reconstructed epidermis containing primary differentiated keratinocytes and CD1a{sup +} MUTZ-LC on a primary fibroblast-populated dermis. Skin equivalents were exposed to a panel of allergens and irritants. Topical exposure to sub-toxic concentrations of allergens (nickel sulfate, resorcinol, cinnamaldehyde) and irritants (Triton X-100, SDS, Tween 80) resulted in LC migration out of the epidermis and into the dermis. Neutralizing antibody to CXCL12 blocked allergen-induced migration, whereas anti-CCL5 blocked irritant-induced migration. In contrast to allergen exposure, irritant exposure resulted in cells within the dermis becoming CD1a{sup −}/CD14{sup +}/CD68{sup +} which is characteristic of a phenotypic switch of MUTZ-LC to a macrophage-like cell in the dermis. This phenotypic switch was blocked with anti-IL-10. Mechanisms previously identified as being involved in LC activation and migration in native human skin could thus be reproduced in the in vitro constructed skin equivalent model containing functional LC. This model therefore provides a unique and relevant research tool to study human LC biology in situ under controlled in vitro conditions, and will provide a powerful tool for hazard identification, testing novel therapeutics and identifying new drug targets. - Highlights: • MUTZ-3 derived Langerhans cells integrated into skin equivalents are fully functional. • Anti-CXCL12 blocks allergen-induced MUTZ-LC migration.

  5. Gene Expression Reaction Norms Unravel the Molecular and Cellular Processes Underpinning the Plastic Phenotypes of Alternanthera Philoxeroides in Contrasting Hydrological Conditions

    PubMed Central

    Gao, Lexuan; Geng, Yupeng; Yang, Hongxing; Hu, Yonghong; Yang, Ji

    2015-01-01

    Alternanthera philoxeroides is an amphibious invasive weed that can colonize both aquatic and terrestrial habitats. Individuals growing in different habitats exhibit extensive phenotypic variation but little genetic differentiation. Little is known about the molecular basis underlying environment-induced phenotypic changes. Variation in transcript abundance in A. philoxeroides was characterized throughout the time-courses of pond and upland treatments using RNA-Sequencing. Seven thousand eight hundred and five genes demonstrated variable expression in response to different treatments, forming 11 transcriptionally coordinated gene groups. Functional enrichment analysis of plastically expressed genes revealed pathway changes in hormone-mediated signaling, osmotic adjustment, cell wall remodeling, and programmed cell death, providing a mechanistic understanding of the biological processes underlying the phenotypic changes in A. philoxeroides. Both transcriptional modulation of environmentally sensitive loci and environmentally dependent control of regulatory loci influenced the plastic responses to the environment. Phenotypic responses and gene expression patterns to contrasting hydrological conditions were compared between A. philoxeroides and its alien congener Alternanthera pungens. The terricolous A. pungens displayed limited phenotypic plasticity to different treatments. It was postulated based on gene expression comparison that the interspecific variation in plasticity between A. philoxeroides and A. pungens was not due to environmentally-mediated changes in hormone levels but to variations in the type and relative abundance of different signal transducers and receptors expressed in the target tissue. PMID:26617628

  6. Phenotypic Plasticity Regulates Candida albicans Interactions and Virulence in the Vertebrate Host

    PubMed Central

    Mallick, Emily M.; Bergeron, Audrey C.; Jones, Stephen K.; Newman, Zachary R.; Brothers, Kimberly M.; Creton, Robbert; Wheeler, Robert T.; Bennett, Richard J.

    2016-01-01

    Phenotypic diversity is critical to the lifestyles of many microbial species, enabling rapid responses to changes in environmental conditions. In the human fungal pathogen Candida albicans, cells exhibit heritable switching between two phenotypic states, white and opaque, which yield differences in mating, filamentous growth, and interactions with immune cells in vitro. Here, we address the in vivo virulence properties of the two cell states in a zebrafish model of infection. Multiple attributes were compared including the stability of phenotypic states, filamentation, virulence, dissemination, and phagocytosis by immune cells, and phenotypes equated across three different host temperatures. Importantly, we found that both white and opaque cells could establish a lethal systemic infection. The relative virulence of the two cell types was temperature dependent; virulence was similar at 25°C, but at higher temperatures (30 and 33°C) white cells were significantly more virulent than opaque cells. Despite the difference in virulence, fungal burden, and dissemination were similar between cells in the two states. Additionally, both white and opaque cells exhibited robust filamentation during infection and blocking filamentation resulted in decreased virulence, establishing that this program is critical for pathogenesis in both cell states. Interactions between C. albicans cells and immune cells differed between white and opaque states. Macrophages and neutrophils preferentially phagocytosed white cells over opaque cells in vitro, and neutrophils showed preferential phagocytosis of white cells in vivo. Together, these studies distinguish the properties of white and opaque cells in a vertebrate host, and establish that the two cell types demonstrate both important similarities and key differences during infection. PMID:27303374

  7. Cortical plasticity within and across lifetimes: how can development inform us about phenotypic transformations?

    PubMed Central

    Krubitzer, Leah; Dooley, James C.

    2013-01-01

    The neocortex is the part of the mammalian brain that is involved in perception, cognition, and volitional motor control. It is a highly dynamic structure that is dramatically altered within the lifetime of an animal and in different lineages throughout the course of evolution. These alterations account for the remarkable variations in behavior that species exhibit. Of particular interest is how these cortical phenotypes change within the lifetime of the individual and eventually evolve in species over time. Because we cannot study the evolution of the neocortex directly we use comparative analysis to appreciate the types of changes that have been made to the neocortex and the similarities that exist across taxa. Developmental studies inform us about how these phenotypic transitions may arise by alterations in developmental cascades or changes in the physical environment in which the brain develops. Both genes and the sensory environment contribute to aspects of the phenotype and similar features, such as the size of a cortical field, can be altered in a variety of ways. Although both genes and the laws of physics place constraints on the evolution of the neocortex, mammals have evolved a number of mechanisms that allow them to loosen these constraints and often alter the course of their own evolution. PMID:24130524

  8. Proctophantastes nettastomatis (Digenea: Zoogonidae) from Vanuatu deep-sea fish: new morphological features, allometric growth, and phenotypic plasticity aspects.

    PubMed

    Mouahid, Gabriel; Faliex, Elisabeth; Allienne, Jean-François; Cribb, Thomas H; Bray, Rodney A

    2012-05-01

    The present paper deals with Proctophantastes nettastomatis (Digenea: Zoogonidae; Lepidophyllinae) found in the intestine of three species of deep-sea fish, Dicrolene longimana (Ophidiidae, Ophidiiformes), Bathyuroconger sp. (Congridae, Anguilliformes), and Venefica tentaculata (Nettastomatidae, Anguilliformes). The fish were collected near the islands of Espiritu Santo, Erromango, and Epi, respectively, in the archipelago of Vanuatu (Southern Pacific Ocean) at depths ranging from 561 to 990 m. Morphological and histological analyses showed that the Vanuatu specimens differ from Proctophantastes abyssorum, Proctophantastes gillissi, Proctophantastes glandulosum, Proctophantastes infundibulum, and Proctophantastes brayi but are close to P. nettastomatis discovered in Suruga Bay, Japan. P. nettastomatis is redescribed based both on the observations of our specimens and of the Japanese holotype and paratype. The morphological variability of the species is described. Morphometric data allowed the identification of positive allometric growth for the hindbody, negative allometric growth for the ventral sucker, and a growth phenotypic plasticity between Ophidiiformes and Anguilliformes definitive hosts. PMID:22089085

  9. Soil Fate of Agricultural Fumigants in Raised-Bed, Plastic-Mulch Crop Production Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil concentrations and degradation rates of methyl isothiocyanate (MITC), chloropicrin (CP), 1,3-dichloropropene (1,3-D), and dimethyl disulfide (DMDS) in the vapor and nonvapor phase were determined under fumigant application scenarios representative of commercial raised bed, plastic mulched veget...

  10. Evidence for phenotypic plasticity in response to photic cues and the connection with genes of risk in schizophrenia

    PubMed Central

    Miller, Christine L.

    2013-01-01

    Numerous environmental factors have been identified as influential in the development of schizophrenia. Some are byproducts of modern life, yet others were present in our evolutionary past and persist to a lesser degree in the current era. The present study brings together published epidemiological data for schizophrenia and data on variables related to photic input for places of residence across geographical regions, using rainfall as an inverse, proxy measure for light levels. Data were gathered from the literature for two countries, the former Yugoslavia and Ireland, during a time in the early 20th century when mobility was relatively limited. The data for Yugoslavia showed a strong correlation between hospital census rates for schizophrenia (by place of birth) and annual rain (r = 0.96, p = 0.008). In Ireland, the hospital census rates and first admissions for schizophrenia (by place of permanent residence) showed a trend for correlation with annual rain, reaching significance for 1st admissions when the rainfall data was weighted by the underlying population distribution (r = 0.71, p = 0.047). In addition, across the years 1921–1945, birth-year variations in a spring quarter season-of-birth effect for schizophrenia in Ireland showed a trend for correlation with January-March rainfall (r = 0.80, p ≤ 0.10). The data are discussed in terms of the effect of photoperiod on the gestation and behavior of offspring in animals, and the premise is put forth that vestigial phenotypic plasticity for such photic cues still exists in humans. Moreover, genetic polymorphisms of risk identified for psychotic disorders include genes modulated by photoperiod and sunlight intensity. Such a relationship between phenotypic plasticity in response to a particular environmental regime and subsequent natural selection for fixed changes in the environmentally responsive genes, has been well studied in animals and should not be discounted when considering human disease. PMID:23847488

  11. Phenotypic plasticity in skull and dental morphology in the prairie deer mouse (Peromyscus maniculatus bairdii).

    PubMed

    Myers, P; Lundrigan, B L; Gillespie, B W; Zelditch, M L

    1996-08-01

    Morphologists and systematists have long suspected that dietary consistency can affect skull and dental form in mammals. We examined plasticity of skull shape and tooth morphology in prairie deer mice (Peromyscus maniculatus bairdii) by feeding mice diets that differed in consistency but not nutritional quality. Shape differences were analyzed qualitatively and quantitatively, using both landmark-based morphometrics and traditional distance measurements. Mice fed a gruel made of laboratory chow soaked in water differed from those fed hard blocks of chow by a slight anterior shift in the incisor tips, a narrowed zygomatic plate, a reduction in size of the masseteric tubercles, an overall decrease in skull size in lateral view, and an increase in overall size in ventral view. Disparities between our results and previous studies may be due to the differences in behavior between the inbred, relatively inactive laboratory strains commonly used in experimental studies and the outbred, constantly active species used here. Also, in contrast to previous studies, the statistical analysis employed here took into account both family relationships of the animals and the large number of statistical comparisons performed. Failure to consider these factors would have resulted in an exaggerated estimate of the effects of diet on skull form and may taint other studies that have explored the same aspects of plasticity. PMID:8755340

  12. Mathematical modelling of phenotypic plasticity and conversion to a stem-cell state under hypoxia

    NASA Astrophysics Data System (ADS)

    Dhawan, Andrew; Madani Tonekaboni, Seyed Ali; Taube, Joseph H.; Hu, Stephen; Sphyris, Nathalie; Mani, Sendurai A.; Kohandel, Mohammad

    2016-02-01

    Hypoxia, or oxygen deficiency, is known to be associated with breast tumour progression, resistance to conventional therapies and poor clinical prognosis. The epithelial-mesenchymal transition (EMT) is a process that confers invasive and migratory capabilities as well as stem cell properties to carcinoma cells thus promoting metastatic progression. In this work, we examined the impact of hypoxia on EMT-associated cancer stem cell (CSC) properties, by culturing transformed human mammary epithelial cells under normoxic and hypoxic conditions, and applying in silico mathematical modelling to simulate the impact of hypoxia on the acquisition of CSC attributes and the transitions between differentiated and stem-like states. Our results indicate that both the heterogeneity and the plasticity of the transformed cell population are enhanced by exposure to hypoxia, resulting in a shift towards a more stem-like population with increased EMT features. Our findings are further reinforced by gene expression analyses demonstrating the upregulation of EMT-related genes, as well as genes associated with therapy resistance, in hypoxic cells compared to normoxic counterparts. In conclusion, we demonstrate that mathematical modelling can be used to simulate the role of hypoxia as a key contributor to the plasticity and heterogeneity of transformed human mammary epithelial cells.

  13. The influence of abiotic stress and phenotypic plasticity on the distribution of invasive Alternanthera philoxeroides along a riparian zone

    NASA Astrophysics Data System (ADS)

    Pan, Xiaoyun; Geng, Yupeng; Zhang, Wenju; Li, Bo; Chen, Jiakuan

    2006-11-01

    Relatively few studies have compared invasibility and species invasiveness among microhabitats within communities, synchronously. We surveyed the abundance and performance of non-native Alternanthera philoxeroides (Mart.) Griseb. (alligator weed), its co-occurring native congener, Alternanthera sessilis (L.) DC. (sessile joyweed), and other species in a wetland community along a riparian zone in southeast China to test the hypotheses that: i) degree of invasion differs between different types of microhabitats within the community; and ii) microhabitat types that differ in invasibility also differ in soil resource availability or in sediment characteristics likely to affect resource availability; iii) phenotypic plasticity of A. philoxeroides may play a key role in its adaptation to diverse habitats as can be concluded from its extremely low genetic diversity in China. The study riparian zone comprises different types of microhabitats including wet abandoned field, swamp, marsh dunes and gravel dunes. Consistent with these hypotheses, cover of A. philoxeroides was high in abandoned fields (73 ± 2.9%) and swamps (94 ± 1.3%), which had high soil nutrients and water availability. On the contrary, cover of native A. sessilis was relatively high in marsh dunes and grave dunes, which had coarse gravel surfaces, low soil nutrients and low water availability. A. philoxeroides showed greater morphological plasticity in response to habitat variation. In abiotically harsh habitats, stems had limited growth, and were prostrate with weak adventitious roots at nodes, forming thin, scattered patches. In the two richer habitats, the highly branched plants spread over the water or soil surface, supporting dense stronger leaf-bearing stems which grew vertically. The growth pattern of A. sessilis among microhabitats did not exhibit significant variations. These results suggest that morphological plasticity and microhabitat types with high soil resources may facilitate invasions of A

  14. Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity

    PubMed Central

    2011-01-01

    Background To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Results Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. Conclusions The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree species, contributes to its spread

  15. Obesity/hyperleptinemic phenotype adversely affects hippocampal plasticity: effects of dietary restriction.

    PubMed

    Grillo, Claudia A; Piroli, Gerardo G; Evans, Ashlie N; Macht, Victoria A; Wilson, Steven P; Scott, Karen A; Sakai, Randall R; Mott, David D; Reagan, Lawrence P

    2011-08-01

    Epidemiological studies estimate that greater than 60% of the adult US population may be categorized as either overweight or obese and there is a growing appreciation that obesity affects the functional integrity of the central nervous system (CNS). We recently developed a lentivirus (LV) vector that produces an insulin receptor (IR) antisense RNA sequence (IRAS) that when injected into the hypothalamus selectively decreases IR signaling in hypothalamus, resulting in increased body weight, peripheral adiposity and plasma leptin levels. To test the hypothesis that this obesity/hyperleptinemic phenotype would impair hippocampal synaptic transmission, we examined short term potentiation (STP) and long term potentiation (LTP) in the hippocampus of rats that received the LV-IRAS construct or the LV-Control construct in the hypothalamus (hypo-IRAS and hypo-Con, respectively). Stimulation of the Schaffer collaterals elicits STP that develops into LTP in the CA1 region of hypo-Con rats; conversely, hypo-IRAS rats exhibit STP that fails to develop into LTP. To more closely examine the potential role of hyperleptinemia in these electrophysiological deficits, hypo-IRAS were subjected to mild food restriction paradigms that would either: 1) prevent the development of the obesity phenotype; or 2) reverse an established obesity phenotype in hypo-IRAS rats. Both of these paradigms restored LTP in the CA1 region and reversed the decreases in the phosphorylated/total ratio of GluA1 Ser845 AMPA receptor subunit expression observed in the hippocampus of hypo-IRAS rats. Collectively, these data support the hypothesis that obesity impairs hippocampal synaptic transmission and support the hypothesis that these deficits are mediated through the impairment of hippocampal leptin activity. PMID:21036186

  16. MYC/PGC-1α Balance Determines the Metabolic Phenotype and Plasticity of Pancreatic Cancer Stem Cells.

    PubMed

    Sancho, Patricia; Burgos-Ramos, Emma; Tavera, Alejandra; Bou Kheir, Tony; Jagust, Petra; Schoenhals, Matthieu; Barneda, David; Sellers, Katherine; Campos-Olivas, Ramon; Graña, Osvaldo; Viera, Catarina R; Yuneva, Mariia; Sainz, Bruno; Heeschen, Christopher

    2015-10-01

    The anti-diabetic drug metformin targets pancreatic cancer stem cells (CSCs), but not their differentiated progenies (non-CSCs), which may be related to distinct metabolic phenotypes. Here we conclusively demonstrate that while non-CSCs were highly glycolytic, CSCs were dependent on oxidative metabolism (OXPHOS) with very limited metabolic plasticity. Thus, mitochondrial inhibition, e.g., by metformin, translated into energy crisis and apoptosis. However, resistant CSC clones eventually emerged during treatment with metformin due to their intermediate glycolytic/respiratory phenotype. Mechanistically, suppression of MYC and subsequent increase of PGC-1α were identified as key determinants for the OXPHOS dependency of CSCs, which was abolished in resistant CSC clones. Intriguingly, no resistance was observed for the mitochondrial ROS inducer menadione and resistance could also be prevented/reversed for metformin by genetic/pharmacological inhibition of MYC. Thus, the specific metabolic features of pancreatic CSCs are amendable to therapeutic intervention and could provide the basis for developing more effective therapies to combat this lethal cancer. PMID:26365176

  17. Genetic connectivity and phenotypic plasticity in the cyprinodont Aphanius farsicus from the Maharlu Basin, south-western Iran.

    PubMed

    Gholami, Z; Esmaeili, H R; Erpenbeck, D; Reichenbacher, B

    2015-03-01

    Meristic and morphometric characteristics, including otolith data, of the Farsi tooth-carp Aphanius farsicus, which is endemic to the endorheic Maharlu Basin in south-western Iran, were analysed for a sample of 92 individuals from four spring-streams; DNA sequence data (cytochrome b gene) are presented for 29 specimens. Some phenotypic variation was detected but the genetic data clearly indicate connectivity between the populations. Possible links between phenotypic variation and environmental variables such as water temperature, habitat size and absence or presence of predators and competitors are discussed. Based on a literature survey and the new data, it is concluded that population connectivity is maintained during times of droughts via large aquifers that formed during the late Pliocene to early Pleistocene, when the extant endorheic Maharlu Basin was created. Based on new data presented here and previous work, it is apparent that plastic and constant characteristics are present in Aphanius species, and that, if a population becomes isolated, a given trend of evolution may give rise to a taxonomically useful characteristic. PMID:25644025

  18. Current Concept and Update of the Macrophage Plasticity Concept: Intracellular Mechanisms of Reprogramming and M3 Macrophage “Switch” Phenotype

    PubMed Central

    Malyshev, Igor; Malyshev, Yuri

    2015-01-01

    Macrophages play a key role in immunity. In this review, we consider the traditional notion of macrophage plasticity, data that do not fit into existing concepts, and a hypothesis for existence of a new switch macrophage phenotype. Depending on the microenvironment, macrophages can reprogram their phenotype toward the proinflammatory M1 phenotype or toward the anti-inflammatory M2 phenotype. Macrophage reprogramming involves well-coordinated changes in activities of signalling and posttranslational mechanisms. Macrophage reprogramming is provided by JNK-, PI3K/Akt-, Notch-, JAK/STAT-, TGF-β-, TLR/NF-κB-, and hypoxia-dependent pathways. Posttranscriptional regulation is based on micro-mRNA. We have hypothesized that, in addition to the M1 and M2 phenotypes, an M3 switch phenotype exists. This switch phenotype responds to proinflammatory stimuli with reprogramming towards the anti-inflammatory M2 phenotype or, contrarily, it responds to anti-inflammatory stimuli with reprogramming towards the proinflammatory M1 phenotype. We have found signs of such a switch phenotype in lung diseases. Understanding the mechanisms of macrophage reprogramming will assist in the selection of new therapeutic targets for correction of impaired immunity. PMID:26366410

  19. Image-Based High-Throughput Field Phenotyping of Crop Roots1[W][OPEN

    PubMed Central

    Bucksch, Alexander; Burridge, James; York, Larry M.; Das, Abhiram; Nord, Eric; Weitz, Joshua S.; Lynch, Jonathan P.

    2014-01-01

    Current plant phenotyping technologies to characterize agriculturally relevant traits have been primarily developed for use in laboratory and/or greenhouse conditions. In the case of root architectural traits, this limits phenotyping efforts, largely, to young plants grown in specialized containers and growth media. Hence, novel approaches are required to characterize mature root systems of older plants grown under actual soil conditions in the field. Imaging methods able to address the challenges associated with characterizing mature root systems are rare due, in part, to the greater complexity of mature root systems, including the larger size, overlap, and diversity of root components. Our imaging solution combines a field-imaging protocol and algorithmic approach to analyze mature root systems grown in the field. Via two case studies, we demonstrate how image analysis can be utilized to estimate localized root traits that reliably capture heritable architectural diversity as well as environmentally induced architectural variation of both monocot and dicot plants. In the first study, we show that our algorithms and traits (including 13 novel traits inaccessible to manual estimation) can differentiate nine maize (Zea mays) genotypes 8 weeks after planting. The second study focuses on a diversity panel of 188 cowpea (Vigna unguiculata) genotypes to identify which traits are sufficient to differentiate genotypes even when comparing plants whose harvesting date differs up to 14 d. Overall, we find that automatically derived traits can increase both the speed and reproducibility of the trait estimation pipeline under field conditions. PMID:25187526

  20. Image-based high-throughput field phenotyping of crop roots.

    PubMed

    Bucksch, Alexander; Burridge, James; York, Larry M; Das, Abhiram; Nord, Eric; Weitz, Joshua S; Lynch, Jonathan P

    2014-10-01

    Current plant phenotyping technologies to characterize agriculturally relevant traits have been primarily developed for use in laboratory and/or greenhouse conditions. In the case of root architectural traits, this limits phenotyping efforts, largely, to young plants grown in specialized containers and growth media. Hence, novel approaches are required to characterize mature root systems of older plants grown under actual soil conditions in the field. Imaging methods able to address the challenges associated with characterizing mature root systems are rare due, in part, to the greater complexity of mature root systems, including the larger size, overlap, and diversity of root components. Our imaging solution combines a field-imaging protocol and algorithmic approach to analyze mature root systems grown in the field. Via two case studies, we demonstrate how image analysis can be utilized to estimate localized root traits that reliably capture heritable architectural diversity as well as environmentally induced architectural variation of both monocot and dicot plants. In the first study, we show that our algorithms and traits (including 13 novel traits inaccessible to manual estimation) can differentiate nine maize (Zea mays) genotypes 8 weeks after planting. The second study focuses on a diversity panel of 188 cowpea (Vigna unguiculata) genotypes to identify which traits are sufficient to differentiate genotypes even when comparing plants whose harvesting date differs up to 14 d. Overall, we find that automatically derived traits can increase both the speed and reproducibility of the trait estimation pipeline under field conditions. PMID:25187526

  1. Photosynthetic consequences of phenotypic plasticity in response to submergence: Rumex palustris as a case study.

    PubMed

    Mommer, Liesje; Pons, Thÿs L; Visser, Eric J W

    2006-01-01

    Survival and growth of terrestrial plants is negatively affected by complete submergence. This is mainly the result of hampered gas exchange between plants and their environment, since gas diffusion is severely reduced in water compared with air, resulting in O2 deficits which limit aerobic respiration. The continuation of photosynthesis could probably alleviate submergence-stress in terrestrial plants, but its potential under water will be limited as the availability of CO2 is hampered. Several submerged terrestrial plant species, however, express plastic responses of the shoot which may reduce gas diffusion resistance and enhance benefits from underwater photosynthesis. In particular, the plasticity of the flooding-tolerant terrestrial species Rumex palustris turned out to be remarkable, making it a model species suitable for the study of these responses. During submergence, the morphology and anatomy of newly developed leaves changed: 'aquatic' leaves were thinner and had thinner cuticles. As a consequence, internal O2 concentrations and underwater CO2 assimilation rates were higher at the prevailing low CO2 concentrations in water. Compared with heterophyllous amphibious plant species, underwater photosynthesis rates of terrestrial plants may be very limited, but the effects of underwater photosynthesis on underwater survival are impressive. A combination of recently published data allowed quantification of the magnitude of the acclimation response in this species. Gas diffusion resistance in terrestrial leaves underwater was about 15,000 times higher than in air. Strikingly, acclimation to submergence reduced this factor to 400, indicating that acclimated leaves of R. palustris had an approximately 40 times lower gas diffusion resistance than non-acclimated ones. PMID:16291797

  2. Physiological plasticity to water flow habitat in the damselfish, Acanthochromis polyacanthus: linking phenotype to performance.

    PubMed

    Binning, Sandra A; Ros, Albert F H; Nusbaumer, David; Roche, Dominique G

    2015-01-01

    The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1) whether aspects of swimming physiology and morphology show plastic responses to water flow, 2) whether trait divergence correlates with swimming performance and 3) whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology. PMID:25807560

  3. Physiological Plasticity to Water Flow Habitat in the Damselfish, Acanthochromis polyacanthus: Linking Phenotype to Performance

    PubMed Central

    Binning, Sandra A.; Ros, Albert F. H.; Nusbaumer, David; Roche, Dominique G.

    2015-01-01

    The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1) whether aspects of swimming physiology and morphology show plastic responses to water flow, 2) whether trait divergence correlates with swimming performance and 3) whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology. PMID:25807560

  4. Phenotypic plasticity of coralline algae in a High CO2 world.

    PubMed

    Ragazzola, Federica; Foster, Laura C; Form, Armin U; Büscher, Janina; Hansteen, Thor H; Fietzke, Jan

    2013-09-01

    It is important to understand how marine calcifying organisms may acclimatize to ocean acidification to assess their survival over the coming century. We cultured the cold water coralline algae, Lithothamnion glaciale, under elevated pCO2 (408, 566, 770, and 1024 μatm) for 10 months. The results show that the cell (inter and intra) wall thickness is maintained, but there is a reduction in growth rate (linear extension) at all elevated pCO2. Furthermore a decrease in Mg content at the two highest CO2 treatments was observed. Comparison between our data and that at 3 months from the same long-term experiment shows that the acclimation differs over time since at 3 months, the samples cultured under high pCO2 showed a reduction in the cell (inter and intra) wall thickness but a maintained growth rate. This suggests a reallocation of the energy budget between 3 and 10 months and highlights the high degree plasticity that is present. This might provide a selective advantage in future high CO2 world. PMID:24223280

  5. Phenotypic plasticity of Neonotonia wightii and Pueraria phaseoloides grown under different light intensities.

    PubMed

    Santos, Leonardo D T; Da Cruz, Leandro R; Dos Santos, Samuel A; Sant'anna-Santos, Bruno F; Dos Santos, Izabela T; De Oliveira, Ariane M; Barros, Rodrigo E; Santos, Márcia V; Faria, Rodrigo M

    2015-03-01

    Plants have the ability to undergo morphophysiological changes based on availability of light. The present study evaluated biomass accumulation, leaf morphoanatomy and physiology of Neonotonia wightii and Pueraria phaseoloides grown in full sunlight, as well as in 30% and 50% shade. Two assays were performed, one for each species, using a randomized block design with 10 replicates. A higher accumulation of fresh mass in the shoot of the plants was observed for both species under cultivation in 50% shade, while no differences were detected between the full sunlight and 30% shade. N. wightii and P. phaseoloides showed increase in area and reduction in thickness leaf when cultivated in 50% shade. There were no changes in photosynthetic rate, stomatal conductance, water use efficiency and evapotranspiration of P. phaseoloides plants because growth environment. However, the shade treatments caused alterations in physiological parameters of N. wightii. In both species, structural changes in the mesophyll occurred depending on the availability of light; however, the amount of leaf blade tissue remained unaltered. Despite the influence of light intensity variation on the morphophysiological plasticity of N. wightii and P. phaseoloides, no effects on biomass accumulation were observed in response to light. PMID:25714076

  6. Phenotypic plasticity of coralline algae in a High CO2 world

    PubMed Central

    Ragazzola, Federica; Foster, Laura C; Form, Armin U; Büscher, Janina; Hansteen, Thor H; Fietzke, Jan

    2013-01-01

    It is important to understand how marine calcifying organisms may acclimatize to ocean acidification to assess their survival over the coming century. We cultured the cold water coralline algae, Lithothamnion glaciale, under elevated pCO2 (408, 566, 770, and 1024 μatm) for 10 months. The results show that the cell (inter and intra) wall thickness is maintained, but there is a reduction in growth rate (linear extension) at all elevated pCO2. Furthermore a decrease in Mg content at the two highest CO2 treatments was observed. Comparison between our data and that at 3 months from the same long-term experiment shows that the acclimation differs over time since at 3 months, the samples cultured under high pCO2 showed a reduction in the cell (inter and intra) wall thickness but a maintained growth rate. This suggests a reallocation of the energy budget between 3 and 10 months and highlights the high degree plasticity that is present. This might provide a selective advantage in future high CO2 world. PMID:24223280

  7. Life History Variation in an Alpine Caddisfly: Local Adaptation or Phenotypic Plasticity?

    NASA Astrophysics Data System (ADS)

    Shama, L. N.; Robinson, C. T.

    2005-05-01

    Facultative species that inhabit permanent and temporary streams can be locally adapted to their stream of origin or exhibit life history plasticity. Temporary stream populations should respond to environmental cues signalling stream drying, whereas permanent stream populations may not. We used a common garden experiment to test whether males and females of an alpine caddisfly from six populations (3 permanent/3 temporary streams) differed in their life history responses to combined changes in photoperiod (ambient/late) and hydroperiod (constant/drying). Responses varied by sex, time-constraint cue and population. Both sexes shortened development time in the late photoperiod, and males emerged before females in all treatments. Growth rates were higher in the late photoperiod for both sexes, and females had higher growth rates and mass at emergence than males. Growth rate compensation in the late photoperiod resulted in similar masses at emergence for both photoperiods. Population-level differences in responses varied according to microgeographic co-gradient variation. Our results suggest that while stream drying cues may not exert sufficient selection pressure to promote faster development in temporary streams, populations may be locally adapted to differences in growing season length associated with stream-specific environmental characteristics.

  8. Phenotypic plasticity and function of the hard palate in growing rabbits.

    PubMed

    Menegaz, Rachel A; Sublett, Samantha V; Figueroa, Said D; Hoffman, Timothy J; Ravosa, Matthew J

    2009-02-01

    Morphological variation related to differential loading is well known for many craniomandibular elements. Yet, the function of the hard palate, and in particular the manner in which cortical and trabecular bone of the palate respond to masticatory loads, remains more ambiguous. Here, experimental data are presented that address the naturalistic influence of biomechanical loading on the postweaning development and structure of the hard palate. A rabbit model was used to test the hypothesis that variation in the morphology of the hard palate is linked to variation in masticatory stresses. Rabbit siblings were divided as weanlings into soft and hard/tough dietary treatment groups of 10 subjects each and were raised for 15 weeks until subadulthood. MicroCT analyses indicate that rabbits subjected to elevated masticatory loading developed hard palates with significantly greater bone area, greater cortical bone thickness along the oral lamina, and thicker anterior palates. Such diet-induced levels of palatal plasticity are comparable to those for other masticatory elements, which likely reflect osteogenic responses for maintaining the functional integrity of the palate vis-à-vis elevated stresses during unilateral mastication. These data support a role for mechanical loading in the determination of palatal morphology, especially its internal structure, in living and fossil mammals such as the hominin Paranthropus. Furthermore, these findings have potential implications for the evolution of the mammalian secondary hard palate as well as for clinical considerations of human oral pathologies. PMID:19089904

  9. Covariance of phenotypically plastic traits induces an adaptive shift in host selection behaviour

    PubMed Central

    Henry, Lee M; Roitberg, Bernard D; Gillespie, David R

    2006-01-01

    Flexibility in adult body size allows generalist parasitoids to use many host species at a cost of producing a range of adult sizes. Consequently, host selection behaviour must also maintain a level of flexibility as adult size is related to capture efficiency. In the present study, we investigated covariance of two plastic traits—size at pupation and host size selection behaviour—using Aphidius ervi reared on either Acyrthosiphon pisum or Aulacorthum solani, generating females of disparate sizes. Natal host was shown to change the ranking of perceived host quality with relation to host size. Parasitoids preferentially attacked hosts that corresponded to the size of the second instar of their natal host species. This resulted in optimal host selection behaviour when parasitoids were exposed to the same host species from which they emerged. Parasitoid size was positively correlated with host size preference, indicating that females use relative measurements when selecting suitable hosts. These coadapted gene complexes allow generalist parasitoids to effectively use multiple host species over several generations. However, the fixed nature of the behavioural response, within a parasitoid's lifetime, suggests that these traits may have evolved in a patchy host species environment. PMID:17015365

  10. Phenotypic differences between the sexes in the sexually plastic mangrove rivulus fish (Kryptolebias marmoratus).

    PubMed

    Garcia, Mark J; Ferro, Jack M; Mattox, Tyler; Kopelic, Sydney; Marson, Kristine; Jones, Ryan; Svendsen, Jon C; Earley, Ryan L

    2016-04-01

    To maximize reproductive success, many animal species have evolved functional sex change. Theory predicts that transitions between sexes should occur when the fitness payoff of the current sex is exceeded by the fitness payoff of the opposite sex. We examined phenotypic differences between the sexes in a sex-changing vertebrate, the mangrove rivulus fish (Kryptolebias marmoratus), to elucidate potential factors that might drive the 'decision' to switch sex. Rivulus populations consist of self-fertilizing hermaphrodites and males. Hermaphrodites transition into males under certain environmental conditions, affording us the opportunity to generate 40 hermaphrodite-male pairs where, within a pair, individuals possessed identical genotypes despite being different sexes. We quantified steroid hormone levels, behavior (aggression and risk taking), metabolism and morphology (organ masses). We found that hermaphrodites were more aggressive and risk averse, and had higher maximum metabolic rates and larger gonadosomatic indices. Males had higher steroid hormone levels and showed correlations among hormones that hermaphrodites lacked. Males also had greater total mass and somatic body mass and possessed considerable fat stores. Our findings suggest that there are major differences between the sexes in energy allocation, with hermaphrodites exhibiting elevated maximum metabolic rates, and showing evidence of favoring investments in reproductive tissues over somatic growth. Our study serves as the foundation for future research investigating how environmental challenges affect both physiology and reproductive investment and, ultimately, how these changes dictate the transition between sexes. PMID:27030777

  11. Of plasticity and specificity: dialectics of the micro- and macro-environment and the organ phenotype

    PubMed Central

    Bhat, Ramray; Bissell, Mina J.

    2013-01-01

    The study of biological form and how it arises is the domain of the developmental biologists; but once the form is achieved, the organ poses a fascinating conundrum for all the life scientists: how are form and function maintained in adult organs throughout most of the life of the organism? That they do appears to contradict the inherently plastic nature of organogenesis during development. How do cells with the same genetic information arrive at, and maintain such different architectures and functions, and how do they keep remembering that they are different from each other? It is now clear that narratives based solely on genes and an irreversible regulatory dynamics cannot answer these questions satisfactorily, and the concept of microenvironmental signaling needs to be added to the equation. During development, cells rearrange and differentiate in response to diffusive morphogens, juxtacrine signals and the extracellular matrix (ECM). These components, which constitute the modular microenvironment, are sensitive to cues from other tissues and organs of the developing embryo as well as from the external macroenvironment. On the other hand, once the organ is formed, these modular constituents integrate and constrain the organ architecture, which ensures structural and functional homeostasis and therefore, organ specificity. We argue here that a corollary of the above is that once the organ architecture is compromised in adults by mutations or by changes in the microenvironment such as aging or inflammation, that organ becomes subjected to the developmental and embryonic circuits in search of a new identity. But since the microenvironment is no longer embryonic, the confusion leads to cancer: hence as we have argued, tumors become new evolutionary organs perhaps in search of an elusive homeostasis. PMID:24678448

  12. Unisexual reproduction drives meiotic recombination and phenotypic and karyotypic plasticity in Cryptococcus neoformans.

    PubMed

    Sun, Sheng; Billmyre, R Blake; Mieczkowski, Piotr A; Heitman, Joseph

    2014-12-01

    In fungi, unisexual reproduction, where sexual development is initiated without the presence of two compatible mating type alleles, has been observed in several species that can also undergo traditional bisexual reproduction, including the important human fungal pathogens Cryptococcus neoformans and Candida albicans. While unisexual reproduction has been well characterized qualitatively, detailed quantifications are still lacking for aspects of this process, such as the frequency of recombination during unisexual reproduction, and how this compares with bisexual reproduction. Here, we analyzed meiotic recombination during α-α unisexual and a-α bisexual reproduction of C. neoformans. We found that meiotic recombination operates in a similar fashion during both modes of sexual reproduction. Specifically, we observed that in α-α unisexual reproduction, the numbers of crossovers along the chromosomes during meiosis, recombination frequencies at specific chromosomal regions, as well as meiotic recombination hot and cold spots, are all similar to those observed during a-α bisexual reproduction. The similarity in meiosis is also reflected by the fact that phenotypic segregation among progeny collected from the two modes of sexual reproduction is also similar, with transgressive segregation being observed in both. Additionally, we found diploid meiotic progeny were also produced at similar frequencies in the two modes of sexual reproduction, and transient chromosomal loss and duplication likely occurs frequently and results in aneuploidy and loss of heterozygosity that can span entire chromosomes. Furthermore, in both α-α unisexual and a-α bisexual reproduction, we observed biased allele inheritance in regions on chromosome 4, suggesting the presence of fragile chromosomal regions that might be vulnerable to mitotic recombination. Interestingly, we also observed a crossover event that occurred within the MAT locus during α-α unisexual reproduction. Our results

  13. Phenotypic developmental plasticity induced by preincubation egg storage in chicken embryos (Gallus gallus domesticus).

    PubMed

    Branum, Sylvia R; Tazawa, Hiroshi; Burggren, Warren W

    2016-02-01

    The developing chicken blastoderm can be temporarily maintained in dormancy below physiological zero temperature. However, prolonged preincubation egg storage impairs normal morphological and physiological development of embryos in a potential example of fetal programming (in this case, "embryonic programming"). We investigated how preincubation egg storage conditions (temperature, duration, hypoxia, and hypercapnia) affects viability, body mass, and physiological variables and functions in day 15 chicken embryos. Embryo viability was impaired in eggs stored for 2 and 3 weeks, with the effects greater at 22°C compared to 15°C. However, embryo size was reduced in eggs stored at 15°C compared with 22°C. Phenotypic change resulting from embryonic programming was evident in the fact that preincubation storage at 15°C diminished hematocrit (Hct), red blood cell concentration ([RBC]), and hemoglobin concentration ([Hb]). Storage duration at 15°C more severely affected the time course (2, 6, and 24 h) responses of Hct, [RBC], and [Hb] to progressive hypoxia and hypercapnia induced by submersion compared with storage duration at 22°C. The time-specific regulation of acid-base balance was changed progressively with storage duration at both 22 and 15°C preincubation storages. Consequently, preincubation egg storage at 22°C resulted in poor viability compared with eggs stored at 15°C, but size and physiological functions of embryos in eggs stored for 1-2 weeks were worse in eggs stored in the cooler than stored under room conditions. Avian eggs thus prove to be useful for examining developmental consequences to physiology of altered preincubation thermal environment in very early stages of development (embryonic programming). PMID:26908714

  14. Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming

    NASA Astrophysics Data System (ADS)

    Sawall, Yvonne; Al-Sofyani, Abdulmoshin; Hohn, Sönke; Banguera-Hinestroza, Eulalia; Voolstra, Christian R.; Wahl, Martin

    2015-03-01

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12° latitudes featuring a steep temperature gradient between the northern (28.5°N, 21-27°C) and southern (16.5°N, 28-33°C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29°C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals.

  15. Will Temperature Effects or Phenotypic Plasticity Determine the Thermal Response of a Heterothermic Tropical Bat to Climate Change?

    PubMed Central

    Stawski, Clare; Geiser, Fritz

    2012-01-01

    The proportion of organisms exposed to warm conditions is predicted to increase during global warming. To better understand how bats might respond to climate change, we aimed to obtain the first data on how use of torpor, a crucial survival strategy of small bats, is affected by temperature in the tropics. Over two mild winters, tropical free-ranging bats (Nyctophilus bifax, 10 g, n = 13) used torpor on 95% of study days and were torpid for 33.5±18.8% of 113 days measured. Torpor duration was temperature-dependent and an increase in ambient temperature by the predicted 2°C for the 21st century would decrease the time in torpor to 21.8%. However, comparisons among Nyctophilus populations show that regional phenotypic plasticity attenuates temperature effects on torpor patterns. Our data suggest that heterothermy is important for energy budgeting of bats even under warm conditions and that flexible torpor use will enhance bats’ chance of survival during climate change. PMID:22802959

  16. Meristem maintenance, auxin, jasmonic and abscisic acid pathways as a mechanism for phenotypic plasticity in Antirrhinum majus

    PubMed Central

    Weiss, Julia; Alcantud-Rodriguez, Raquel; Toksöz, Tugba; Egea-Cortines, Marcos

    2016-01-01

    Plants grow under climatic changing conditions that cause modifications in vegetative and reproductive development. The degree of changes in organ development i.e. its phenotypic plasticity seems to be determined by the organ identity and the type of environmental cue. We used intraspecific competition and found that Antirrhinum majus behaves as a decoupled species for lateral organ size and number. Crowding causes decreases in leaf size and increased leaf number whereas floral size is robust and floral number is reduced. Genes involved in shoot apical meristem maintenance like ROA and HIRZ, cell cycle (CYCD3a; CYCD3b, HISTONE H4) or organ polarity (GRAM) were not significantly downregulated under crowding conditions. A transcriptomic analysis of inflorescence meristems showed Gene Ontology enriched pathways upregulated including Jasmonic and Abscisic acid synthesis and or signalling. Genes involved in auxin synthesis such as AmTAR2 and signalling AmANT were not affected by crowding. In contrast, AmJAZ1, AmMYB21, AmOPCL1 and AmABA2 were significantly upregulated. Our work provides a mechanistic working hypothesis where a robust SAM and stable auxin signalling enables a homogeneous floral size while changes in JA and ABA signalling maybe responsible for the decreased leaf size and floral number. PMID:26804132

  17. Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming.

    PubMed

    Sawall, Yvonne; Al-Sofyani, Abdulmoshin; Hohn, Sönke; Banguera-Hinestroza, Eulalia; Voolstra, Christian R; Wahl, Martin

    2015-01-01

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12° latitudes featuring a steep temperature gradient between the northern (28.5°N, 21-27°C) and southern (16.5°N, 28-33°C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29°C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals. PMID:25754672

  18. Meristem maintenance, auxin, jasmonic and abscisic acid pathways as a mechanism for phenotypic plasticity in Antirrhinum majus.

    PubMed

    Weiss, Julia; Alcantud-Rodriguez, Raquel; Toksöz, Tugba; Egea-Cortines, Marcos

    2016-01-01

    Plants grow under climatic changing conditions that cause modifications in vegetative and reproductive development. The degree of changes in organ development i.e. its phenotypic plasticity seems to be determined by the organ identity and the type of environmental cue. We used intraspecific competition and found that Antirrhinum majus behaves as a decoupled species for lateral organ size and number. Crowding causes decreases in leaf size and increased leaf number whereas floral size is robust and floral number is reduced. Genes involved in shoot apical meristem maintenance like ROA and HIRZ, cell cycle (CYCD3a; CYCD3b, HISTONE H4) or organ polarity (GRAM) were not significantly downregulated under crowding conditions. A transcriptomic analysis of inflorescence meristems showed Gene Ontology enriched pathways upregulated including Jasmonic and Abscisic acid synthesis and or signalling. Genes involved in auxin synthesis such as AmTAR2 and signalling AmANT were not affected by crowding. In contrast, AmJAZ1, AmMYB21, AmOPCL1 and AmABA2 were significantly upregulated. Our work provides a mechanistic working hypothesis where a robust SAM and stable auxin signalling enables a homogeneous floral size while changes in JA and ABA signalling maybe responsible for the decreased leaf size and floral number. PMID:26804132

  19. Phenotypic plasticity of post-fire activity and thermal biology of a free-ranging small mammal.

    PubMed

    Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

    2016-05-15

    Ecosystems can change rapidly and sometimes irreversibly due to a number of anthropogenic and natural factors, such as deforestation and fire. How individual animals exposed to such changes respond behaviourally and physiologically is poorly understood. We quantified the phenotypic plasticity of activity patterns and torpor use - a highly efficient energy conservation mechanism - in brown antechinus (Antechinus stuartii), a small Australian marsupial mammal. We compared groups in densely vegetated forest areas (pre-fire and control) with a group in a burned, open habitat (post-fire). Activity and torpor patterns differed among groups and sexes. Females in the post-fire group spent significantly less time active than the other groups, both during the day and night. However, in males only daytime activity declined in the post-fire group, although overall activity was also reduced on cold days in males for all groups. The reduction in total or diurnal activity in the post-fire group was made energetically possible by a ~3.4-fold and ~2.2-fold increase in the proportion of time females and males, respectively, used torpor in comparison to that in the pre-fire and control groups. Overall, likely due to reproductive needs, torpor was more pronounced in females than in males, but low ambient temperatures increased torpor bout duration in both sexes. Importantly, for both male and female antechinus and likely other small mammals, predator avoidance and energy conservation - achieved by reduced activity and increased torpor use - appear to be vital for post-fire survival where ground cover and refuges have been obliterated. PMID:27001165

  20. Correlated responses to artificial body size selection in growth, development, phenotypic plasticity and juvenile viability in yellow dung flies.

    PubMed

    Teuschl, Y; Reim, C; Blanckenhorn, W U

    2007-01-01

    Most life history traits are positively influenced by body size, whereas disadvantages of large body size are poorly documented. To investigate presumed intrinsic costs of large size in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae), we established two replicates each of three body size laboratory selection lines (small, control and large; selection on males only), and subjected flies of the resulting extended body size range to various abiotic stresses. Response to selection was symmetrical in the small and large lines (realized h(2) = 0.16-0.18). After 24 generations of selection body size had changed by roughly 10%. Female size showed a correlated response to selection on male size, whereas sexual size dimorphism did not change. Development time also showed a correlated response as, similar to food limited flies, small line flies emerged earlier at smaller body size. At the lowest larval food limit possible, flies of all lines emerged at the same small body size after roughly the same development time; so overall phenotypic plasticity in body size and development time strongly increased following selection. Juvenile mortality increased markedly when food was extremely limited, large line flies showing highest mortality. Winter frost disproportionately killed large (line) flies because of their longer development times. Mortality at high temperatures was high but size-selective effects were inconsistent. In all environments the larger males suffered more. Initial growth rate was higher for males and at unlimited food. Small line individuals of both sexes grew slowest at unlimited larval food but fastest at limited larval food, suggesting a physiological cost of fast growth. Overall, extension of the natural body size range by artificial selection revealed some otherwise cryptic intrinsic juvenile viability costs of large size, mediated by longer development or faster growth, but only in stressful environments. PMID:17210003

  1. Life history traits and phenotypic selection among sunflower crop–wild hybrids and their wild counterpart: implications for crop allele introgression

    PubMed Central

    Kost, Matthew A; Alexander, Helen M; Jason Emry, D; Mercer, Kristin L

    2015-01-01

    Hybridization produces strong evolutionary forces. In hybrid zones, selection can differentially occur on traits and selection intensities may differ among hybrid generations. Understanding these dynamics in crop–wild hybrid zones can clarify crop-like traits likely to introgress into wild populations and the particular hybrid generations through which introgression proceeds. In a field experiment with four crop–wild hybrid Helianthus annuus (sunflower) cross types, we measured growth and life history traits and performed phenotypic selection analysis on early season traits to ascertain the likelihood, and routes, of crop allele introgression into wild sunflower populations. All cross types overwintered, emerged in the spring, and survived until flowering, indicating no early life history barriers to crop allele introgression. While selection indirectly favored earlier seedling emergence and taller early season seedlings, direct selection only favored greater early season leaf length. Further, there was cross type variation in the intensity of selection operating on leaf length. Thus, introgression of multiple early season crop-like traits, due to direct selection for greater early season leaf length, should not be impeded by any cross type and may proceed at different rates among generations. In sum, alleles underlying early season sunflower crop-like traits are likely to introgress into wild sunflower populations. PMID:26029263

  2. Evolution and ecology meet molecular genetics: adaptive phenotypic plasticity in two isolated Negev desert populations of Acacia raddiana at either end of a rainfall gradient

    PubMed Central

    Ward, David; Shrestha, Madan K.; Golan-Goldhirsh, Avi

    2012-01-01

    Background and Aims The ecological, evolutionary and genetic bases of population differentiation in a variable environment are often related to the selection pressures that plants experience. We compared differences in several growth- and defence-related traits in two isolated populations of Acacia raddiana trees from sites at either end of an extreme environmental gradient in the Negev desert. Methods We used random amplified polymorphic DNA (RAPD) to determine the molecular differences between populations. We grew plants under two levels of water, three levels of nutrients and three levels of herbivory to test for phenotypic plasticity and adaptive phenotypic plasticity. Key Results The RAPD analyses showed that these populations are highly genetically differentiated. Phenotypic plasticity in various morphological traits in A. raddiana was related to patterns of population genetic differentiation between the two study sites. Although we did not test for maternal effects in these long-lived trees, significant genotype × environment (G × E) interactions in some of these traits indicated that such plasticity may be adaptive. Conclusions The main selection pressure in this desert environment, perhaps unsurprisingly, is water. Increased water availability resulted in greater growth in the southern population, which normally receives far less rain than the northern population. Even under the conditions that we defined as low water and/or nutrients, the performance of the seedlings from the southern population was significantly better, perhaps reflecting selection for these traits. Consistent with previous studies of this genus, there was no evidence of trade-offs between physical and chemical defences and plant growth parameters in this study. Rather, there appeared to be positive correlations between plant size and defence parameters. The great variation in several traits in both populations may result in a diverse potential for responding to selection pressures in

  3. Transcriptomic and metabolomic analysis of Yukon Thellungiella plants grown in cabinets and their natural habitat show phenotypic plasticity

    PubMed Central

    2012-01-01

    Thellungiella shows metabolic plasticity in response to environmental stress and that resource availability can influence the expression of stress tolerance traits under field conditions. Conclusion Comparisons between Thellungiella plants responding to stress in cabinets and in their natural habitats showed differences but also overlap between transcript and metabolite profiles. The traits in common offer potential targets for improving crops that must respond appropriately to multiple, concurrent stresses. PMID:23025749

  4. The Antarctic hemoglobinless icefish, fifty five years later: a unique cardiocirculatory interplay of disaptation and phenotypic plasticity.

    PubMed

    Garofalo, F; Pellegrino, D; Amelio, D; Tota, B

    2009-09-01

    The teleostean Channichthyidae (icefish), endemic stenotherms of the Antarctic waters, perennially at or near freezing, represent a unique example of disaptation among adult vertebrates for their loss of functional traits, particularly hemoglobin (Hb) and, in some species, cardiac myoglobin (Mb), once considered to be essential-life oxygen-binding chromoproteins. Conceivably, this stably frigid, oxygen-rich habitat has permitted high tolerance of disaptation, followed by subsequent adaptive recovery based on gene expression reprogramming and compensatory responses, including an alternative cardio-circulatory design, Hb-free blood and Mb-free cardiac muscle. This review revisits the functional significance of the multilevel cardio-circulatory compensations (hypervolemia, near-zero hematocrit and low blood viscosity, large bore capillaries, increased vascularity with great capacitance, cardiomegaly with very large cardiac output, high blood flow with low systemic pressure and systemic resistance) that counteract the challenge of hypoxemic hypoxia by increasing peripheral oxygen transcellular movement for aerobic tissues, including the myocardium. Reconsidered in the context of recent knowledge on both polar cold adaptation and the new questions related to the advent of nitric oxide (NO) biology, these compensations can be interpreted either according to the "loss-without-penalty" alternative, or in the context of an excessive environmental oxygen supply at low cellular cost and oxygen requirement in the cold. Therefore, rather than reflecting oxygen limitation, several traits may indicate structural overcompensation of oxygen supply reductions at cell/tissue levels. At the multilevel cardio-circulatory adjustments, NO is revealing itself as a major integrator, compensating disaptation with functional phenotypic plasticity, as illustrated by the heart paradigm. Beside NOS-dependent NO generation, recent knowledge concerning Hb/Mb interplay with NO and nitrite has

  5. Phenotypic Plasticity in Reproductive Traits of the Perennial Shrub Ulex europaeus in Response to Shading: A Multi-Year Monitoring of Cultivated Clones

    PubMed Central

    Atlan, Anne; Hornoy, Benjamin; Delerue, Florian; Gonzalez, Maya; Pierre, Jean-Sébastien; Tarayre, Michèle

    2015-01-01

    Phenotypic plasticity may be advantageous for plants to be able to rapidly cope with new and changing environments associated with climate change or during biological invasions. This is especially true for perennial plants, as they may need a longer period to respond genetically to selective pressures than annuals, and also because they are more likely to experience environmental changes during their lifespan. However, few studies have explored the plasticity of the reproductive life history traits of woody perennial species. This study focuses on a woody shrub, Ulex europaeus (common gorse), and on the response of its reproductive traits to one important environmental factor, shading. The study was performed on clones originating from western France (within the native range of this invasive species) and grown for seven years. We compared traits of plants grown in a shade treatment (with two successive shade levels) vs. full natural light. The traits monitored included flowering onset, pod production and seed predation. All traits studied responded to shading, exhibiting various levels of plasticity. In particular, dense shade induced a radical but reversible decrease in flower and pod production, while moderate shade had little effect on reproductive traits. The magnitude of the response to dense shade depended on the genotype, showing a genetically based polymorphism of plasticity. The level of plasticity also showed substantial variations between years, and the effect of environmental variations was cumulative over time. This suggests that plasticity can influence the lifetime fitness of U. Europaeus and is involved in the capacity of the species to grow under contrasting environmental conditions. PMID:26383627

  6. Phenotypic Plasticity in Reproductive Traits of the Perennial Shrub Ulex europaeus in Response to Shading: A Multi-Year Monitoring of Cultivated Clones.

    PubMed

    Atlan, Anne; Hornoy, Benjamin; Delerue, Florian; Gonzalez, Maya; Pierre, Jean-Sébastien; Tarayre, Michèle

    2015-01-01

    Phenotypic plasticity may be advantageous for plants to be able to rapidly cope with new and changing environments associated with climate change or during biological invasions. This is especially true for perennial plants, as they may need a longer period to respond genetically to selective pressures than annuals, and also because they are more likely to experience environmental changes during their lifespan. However, few studies have explored the plasticity of the reproductive life history traits of woody perennial species. This study focuses on a woody shrub, Ulex europaeus (common gorse), and on the response of its reproductive traits to one important environmental factor, shading. The study was performed on clones originating from western France (within the native range of this invasive species) and grown for seven years. We compared traits of plants grown in a shade treatment (with two successive shade levels) vs. full natural light. The traits monitored included flowering onset, pod production and seed predation. All traits studied responded to shading, exhibiting various levels of plasticity. In particular, dense shade induced a radical but reversible decrease in flower and pod production, while moderate shade had little effect on reproductive traits. The magnitude of the response to dense shade depended on the genotype, showing a genetically based polymorphism of plasticity. The level of plasticity also showed substantial variations between years, and the effect of environmental variations was cumulative over time. This suggests that plasticity can influence the lifetime fitness of U. Europaeus and is involved in the capacity of the species to grow under contrasting environmental conditions. PMID:26383627

  7. PHENOTYPIC PLASTICITY AND GEOGRAPHIC VARIATION IN THERMAL TOLERANCE AND WATER LOSS OF THE TSETSE GLOSSINA PALLIDIPES (DIPTERA: GLOSSINIDAE): IMPLICATIONS FOR DISTRIBUTION MODELLING

    PubMed Central

    TERBLANCHE, JOHN S.; KLOK, C. JACO; KRAFSUR, ELLIOT S.; CHOWN, STEVEN L.

    2006-01-01

    Using the tsetse, Glossina pallidipes, we demonstrate that physiological plasticity (resulting from temperature acclimation) accounts for among-population variation in thermal tolerance and water loss rates. Critical thermal minimum (CTMin) was highly variable among populations, seasons and acclimation treatments, and the full range of variation was 9.3 °C (maximum value = 3.1 × minimum). Water loss rate showed similar variation (max = 3.7 × min). By contrast, critical thermal maxima (CTMax) varied least among populations, seasons and acclimation treatments, and the full range of variation was only c.1 °C. Most of the variation amongst the four field populations could be accounted for by phenotypic plasticity, which in the case of CTMin develops within five days of temperature exposure, and is lost rapidly on return to the original conditions. Limited variation in CTMax supports bioclimatic models that suggest tsetse are likely to show range contraction with warming from climate change. PMID:16687681

  8. Androgen deprivation induces phenotypic plasticity and promotes resistance to molecular targeted therapy in a PTEN-deficient mouse model of prostate cancer.

    PubMed

    De Velasco, Marco A; Tanaka, Motoyoshi; Yamamoto, Yutaka; Hatanaka, Yuji; Koike, Hiroyuki; Nishio, Kazuto; Yoshikawa, Kazuhiro; Uemura, Hirotsugu

    2014-09-01

    Castration-resistant prostate cancer is an incurable heterogeneous disease that is characterized by a complex multistep process involving different cellular and biochemical changes brought on by genetic and epigenetic alterations. These changes lead to the activation or overexpression of key survival pathways that also serve as potential therapeutic targets. Despite promising preclinical results, molecular targeted therapies aimed at such signaling pathways have so far been dismal. In the present study, we used a PTEN-deficient mouse model of prostate cancer to show that plasticity in castration-resistant tumors promotes therapeutic escape. Unlike castration-naïve tumors which depend on androgen receptor and PI3K/AKT signal activation for growth and survival, castration-resistant tumors undergo phenotypic plasticity leading to increased intratumoral heterogeneity. These tumors attain highly heterogeneous phenotypes that are characterized by cancer cells relying on alternate signal transduction pathways for growth and survival, such as mitogen-activated protein kinase and janus kinase/signal transducer and activator of transcription, and losing their dependence on PI3K signaling. These features thus enabled castration-resistant tumors to become insensitive to the therapeutic effects of PI3K/AKT targeted therapy. Overall, our findings provide evidence that androgen deprivation drives phenotypic plasticity in prostate cancer cells and implicate it as a crucial contributor to therapeutic resistance in castration-resistant prostate cancer. Therefore, incorporating intratumoral heterogeneity in a dynamic tumor model as a part of preclinical efficacy determination could improve prediction for response and provide better rationale for the development of more effective therapies. PMID:24986896

  9. Carry-over effects of conditions at the wintering grounds on breeding plumage signals in a migratory bird: roles of phenotypic plasticity and selection.

    PubMed

    Järvistö, P E; Calhim, S; Schuett, W; Sirkiä, P M; Velmala, W; Laaksonen, T

    2016-08-01

    To understand the consequences of ever-changing environment on the dynamics of phenotypic traits, distinguishing between selection processes and individual plasticity is crucial. We examined individual consistency/plasticity in several male secondary sexual traits expressed during the breeding season (white wing and forehead patch size, UV reflectance of white wing patch and dorsal melanin coloration) in a migratory pied flycatcher (Ficedula hypoleuca) population over an 11-year period. Furthermore, we studied carry-over effects of three environmental variables (NAO, a climatic index; NDVI, a vegetation index; and rainfall) at the wintering grounds (during prebreeding moult) on the expression of these breeding plumage traits of pied flycatcher males at individual and population levels. Whereas NAO correlates negatively with moisture in West Africa, NDVI correlates positively with primary production. Forehead patch size and melanin coloration were highly consistent within individuals among years, whereas the consistency of the other two traits was moderate. Wing patch size decreased with higher NAO and increased with higher rainfall and NDVI at the individual level. Interestingly, small-patched males suffered lower survival during high NAO winters than large-patched males, and vice versa during low NAO winters. These counteracting processes meant that the individual-level change was masked at the population level where no relationship was found. Our results provide a good example of how variation in the phenotypic composition of a natural population can be a result of both environment-dependent individual plasticity and short-term microevolution. Moreover, when plasticity and viability selection operate simultaneously, their impacts on population composition may not be evident. PMID:27159261

  10. Not all Laminaria digitata are the same! Phenotypic plasticity and the selection of appropriate surrogate macroalgae for ecohydraulic experimentation

    NASA Astrophysics Data System (ADS)

    Thomas, Robert E.; McLelland, Stuart J.; Henry, Pierre-Yves T.; Paul, Maike; Eiff, Olivier; Evertsen, Antti-Jussi O.; Aberle, Jochen; Teacă, Adrian

    2015-04-01

    not be transported from Norway to the UK, so we used the same species of live macroalgae harvested from a wave-dominated coast in the UK. These algae exhibited longer, narrower and more flexible blades. The same surrogate plants were used in both the field and flume experiments. In all cases, a profiling ADV was used to collect 45 velocity profiles composed of up to seven 35 mm-high profiles collected for 240 s at 100 Hz, at a streamwise spacing of 0.25 m and cross-stream spacing of 0.20 m. The results show that the live macroalgae in the flume simulation exerted less influence on the flow field than the live macroalgae at the field site. In contrast, the "optimized" surrogate macroalgae behaved similarly to the live algae at the field site and yielded similar mean and turbulent velocity fields as our prototype live macroalgae. This emphasizes both the importance of phenotypic plasticity and the importance of selecting surrogates that adequately represent the mean characteristics of the species of interest.

  11. Quantifying genetic variations and phenotypic plasticity of leaf phenology and growth for two temperate Fagaceae species (sessile oak and european beech)

    NASA Astrophysics Data System (ADS)

    Delzon, Sylvain; Vitasse, Yann; Alberto, Florian; Bresson, Caroline; Kremer, Antoine

    2010-05-01

    Under current climate change, research on inherent adaptive capacities of organisms is crucial to assess future evolutionary changes of natural populations. Genetic diversity and phenotypic plasticity constitute adaptative capacities that could allow populations to respond to new environmental conditions. The aim of the present study was (i) to determine whether there are genetic variations among populations from altitudinal gradients using a lowland common garden experiment and (ii) to assess the magnitude of phenotypic plasticity using a reciprocal transplant experiment (5 elevations from 100 to 1600 m asl.) for leaf phenology (flushing and senescence) and growth of two fagaceae species (Fagus sylvatica and Quercus petraea). We found significant differences in phenology among provenances for most species, and evidenced that these among-population differences in phenology were related to annual temperature of the provenance sites for both species. It's noteworthy that, along the same climatic gradient, the species exhibited opposite genetic clines: beech populations from high elevation flushed earlier than those of low elevation, whereas we observed an opposite trend for oak. Finally, we highlighted that both phenology timing and growth rate were highly consistent year to year. The results demonstrated that in spite of the proximity of the populations in their natural area, altitude led to genetic differentiations in their phenology and growth. Moreover, a high phenological plasticity was found for both species. We evidenced that reaction norms of flushing timing to temperature followed linear clinal trends for both species with an average shift of 5.7 days per degree increase. Timing of leaf senescence exhibited hyperbolic trends for beech and no or slight trends for oak. Furthermore, within species, there was no difference in magnitude of phenological plasticity among populations neither for flushing, nor for senescence. Consequently, for both species, the

  12. Foliar δ13C response patterns along a moisture gradient arising from genetic variation and phenotypic plasticity in grassland species of Inner Mongolia

    PubMed Central

    Liu, Yanjie; Niu, Haishan; Xu, Xingliang

    2013-01-01

    Plants depend upon both genetic differences and phenotypic plasticity to cope with environmental variation over different timescales. The spatial variation in foliar δ13C levels along a moisture gradient represents an overlay of genetic and plastic responses. We hypothesized that such a spatial variation would be more obvious than the variation arising purely from a plastic response to moisture change. Leymus chinensis and Stipa spp. were sampled from Inner Mongolia along a dry-wet transect, and some of these species were transplanted to an area with a moisture gradient. For Stipa spp., the slope of foliar δ13C and mean annual precipitation along the transect was significantly steeper than that of foliar δ13C and mean annual precipitation after the watering treatment. For L. chinensis, there was a general decreasing trend in foliar δ13C under the different (increasing) watering levels; however, its populations showed an irregular relationship between foliar δ13C and moisture origin. Therefore, support for our hypothesis was obtained from Stipa spp., but not from L. chinensis. PMID:23467429

  13. Low-altitude, high-resolution aerial imaging systems for row and field crop phenotyping: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Global plant genetics research efforts have focused on developing high yielding, stress tolerant and disease resistant row and field crop varieties that are more efficient in their use of agronomic inputs (water, nutrients, pesticides, etc.). Until recently, a key bottleneck in such research was the...

  14. Phenotypic Plasticity of Growth Trajectory and Ontogenic Allometry in Response to Density for Eucalyptus Hybrid Clones and Families

    PubMed Central

    BOUVET, JEAN-MARC; VIGNERON, PHILIPPE; SAYA, AUBIN

    2005-01-01

    • Background and Aims Response to density is a crucial aspect of the ecology of trees in forests and plantations. Few studies have investigated the genetics of plasticity in response to density for growth traits such as height and circumference through development. • Methods Two experiments were carried out in the field, the first with full-sib families of Eucalyptus urophylla × E. grandis hybrids, and the second with clones of E. tereticornis × E. grandis hybrids planted across a range of densities (625, 1111 and 2500 trees ha−1). Height, circumference and stem taper were measured through development in both experiments. Variance components were estimated and a repeated measure approach for plasticity and three different methods were used to compare the variance–covariance matrix across densities. • Key Results Genetic variance was significantly different from zero but the density × genotype interaction was significant only for clone experiments at the adult stage. Significant plasticity for three traits in both experiments was found. In the clone experiments, a significant clone × time × density interaction was found, suggesting that plasticity for growth and stem form is under genetic control. In both experiments, density did not affect environmental correlation, which remained high throughout tree development. The impact of density on genetic correlation was marked in the clone experiment, with a reduced value at lower density, but was not observed in the family trial. The differences between clones and family are mainly explained by the distribution of genetic variation within and among genotypes. • Conclusions The results suggest that plasticity for growth traits and form of tropical Eucalyptus species is under genetic control and that the environment changes genetic co-variation through ontogeny. The findings confirm that a tree population with a narrow genetic basis (represented by clones) is sensitive to a changing environment, whereas a

  15. Environmental influences on the Indo–Pacific octocoral Isis hippuris Linnaeus 1758 (Alcyonacea: Isididae): genetic fixation or phenotypic plasticity?

    PubMed Central

    Pochon, Xavier; Watling, Les

    2015-01-01

    As conspicuous modular components of benthic marine habitats, gorgonian (sea fan) octocorals have perplexed taxonomists for centuries through their shear diversity, particularly throughout the Indo–Pacific. Phenotypic incongruence within and between seemingly unitary lineages across contrasting environments can provide the raw material to investigate processes of disruptive selection. Two distinct phenotypes of the Isidid Isis hippuris Linnaeus, 1758 partition between differing reef environments: long-branched bushy colonies on degraded reefs, and short-branched multi/planar colonies on healthy reefs within the Wakatobi Marine National Park (WMNP), Indonesia. Multivariate analyses reveal phenotypic traits between morphotypes were likely integrated primarily at the colony level with increased polyp density and consistently smaller sclerite dimensions at the degraded site. Sediment load and turbidity, hence light availability, primarily influenced phenotypic differences between the two sites. This distinct morphological dissimilarity between the two sites is a reliable indicator of reef health; selection primarily acting on colony morphology, porosity through branching structure, as well as sclerite diversity and size. ITS2 sequence and predicted RNA secondary structure further revealed intraspecific variation between I. hippuris morphotypes relative to such environments (ΦST = 0.7683, P < 0.001). This evidence suggests—but does not confirm—that I. hippuris morphotypes within the WMNP are two separate species; however, to what extent and taxonomic assignment requires further investigation across its full geographic distribution. Incongruence between colonies present in the WMNP with tenuously described Isis alternatives (Isis reticulata Nutting, 1910, Isis minorbrachyblasta Zou, Huang & Wang, 1991), questions the validity of such assignments. Furthermore, phylogenetic analyses confirm early taxonomic suggestion that the characteristic jointed axis of the

  16. Effects of reduced-rate methyl bromide applications under conventional and virtually impermeable plastic film in perennial crop field nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Producers of perennial crop nursery stock in California use preplant soil fumigation to meet state phytosanitary requirements. Although methyl bromide (MB) has been phased out in many agricultural industries, it is still the preferred treatment in the perennial nursery industry and is u...

  17. Specific Preferences in Lineage Choice and Phenotypic Plasticity of Glioma Stem Cells Under BMP4 and Noggin Influence.

    PubMed

    Videla Richardson, Guillermo Agustín; Garcia, Carolina Paola; Roisman, Alejandro; Slavutsky, Irma; Fernandez Espinosa, Damián Darío; Romorini, Leonardo; Miriuka, Santiago Gabriel; Arakaki, Naomi; Martinetto, Horacio; Scassa, María Elida; Sevlever, Gustavo Emilio

    2016-01-01

    Although BMP4-induced differentiation of glioma stem cells (GSCs) is well recognized, details of the cellular responses triggered by this morphogen are still poorly defined. In this study, we established several GSC-enriched cell lines (GSC-ECLs) from high-grade gliomas. The expansion of these cells as adherent monolayers, and not as floating neurospheres, enabled a thorough study of the phenotypic changes that occurred during their differentiation. Herein, we evaluated GSC-ECLs' behavior toward differentiating conditions by depriving them of growth factors and/or by adding BMP4 at different concentrations. After analyzing cellular morphology, proliferation and lineage marker expression, we determined that GSC-ECLs have distinct preferences in lineage choice, where some of them showed an astrocyte fate commitment and others a neuronal one. We found that this election seems to be dictated by the expression pattern of BMP signaling components present in each GSC-ECL. Additionally, treatment of GSC-ECLs with the BMP antagonist, Noggin, also led to evident phenotypic changes. Interestingly, under certain conditions, some GSC-ECLs adopted an unexpected smooth muscle-like phenotype. As a whole, our findings illustrate the wide differentiation potential of GSCs, highlighting their molecular complexity and paving a way to facilitate personalized differentiating therapies. PMID:25808628

  18. Effects of ultraviolet-B irradiance on intraspecific competition and facilitation of plants: self-thinning, size inequality, and phenotypic plasticity.

    PubMed

    Zhang, Rui-Chang; Lin, Yue; Yue, Ming; Li, Qian; Zhang, Xiao-Fei; Liu, Xiao; Chi, Hong; Chai, Yong-Fu; Wang, Mao

    2012-01-01

    (1) The effects of facilitation on the structure and dynamics of plant populations have not been studied so widely as competition. The UV-B radiation, as a typical environmental factor causing stress, may result in direct stress and facilitation. (2) The effects of UV-B radiation on intraspecific competition and facilitation were investigated based on the following three predictions on self-thinning, size inequality, and phenotypic plasticity: i) Self-thinning is the reduction in density that results from the increase in the mean biomass of individuals in crowded populations, and is driven by competition. In this study, the mortality rate of the population is predicted to decrease from UV-B irradiance. ii) The size inequality of a population increases with competition intensity because larger individuals receive a disproportionate share of resources, thereby leaving limited resources for smaller individuals. The second hypothesis assumes that direct stress decreases the size inequality of the population. iii) Phenotypic plasticity is the ability to alter one's morphology in response to environmental changes. The third hypothesis assumes that certain morphological indices can change among the trade-offs between competition, facilitation, and stress. These predictions were tested by conducting a field pot experiment using mung beans, and were supported by the following results: (3) UV-B radiation increased the survival rate of the population at the end of self-thinning. However, this result was mainly due to direct stress rather than facilitation. (4) Just as competitor, facilitation was also asymmetric. It increased the size inequality of populations during self-thinning, whereas stress decreased the size inequality. (5) Direct stress and facilitation influence plants differently on various scales. Stress inhibited plant growth, whereas facilitation showed the opposite on an individual scale. Stress increased survival rate, whereas facilitation increased individual

  19. The Evolutionary Fate of Phenotypic Plasticity and Functional Traits under Domestication in Manioc: Changes in Stem Biomechanics and the Appearance of Stem Brittleness

    PubMed Central

    Ménard, Léa; McKey, Doyle; Mühlen, Gilda S.; Clair, Bruno; Rowe, Nick P.

    2013-01-01

    Domestication can influence many functional traits in plants, from overall life-history and growth form to wood density and cell wall ultrastructure. Such changes can increase fitness of the domesticate in agricultural environments but may negatively affect survival in the wild. We studied effects of domestication on stem biomechanics in manioc by comparing domesticated and ancestral wild taxa from two different regions of greater Amazonia. We compared mechanical properties, tissue organisation and wood characteristics including microfibril angles in both wild and domesticated plants, each growing in two different habitats (forest or savannah) and varying in growth form (shrub or liana). Wild taxa grew as shrubs in open savannah but as lianas in overgrown and forested habitats. Growth form plasticity was retained in domesticated manioc. However, stems of the domesticate showed brittle failure. Wild plants differed in mechanical architecture between shrub and liana phenotypes, a difference that diminished between shrubs and lianas of the domesticate. Stems of wild plants were generally stiffer, failed at higher bending stresses and were less prone to brittle fracture compared with shrub and liana phenotypes of the domesticate. Biomechanical differences between stems of wild and domesticated plants were mainly due to changes in wood density and cellulose microfibril angle rather than changes in secondary growth or tissue geometry. Domestication did not significantly modify “large-scale” trait development or growth form plasticity, since both wild and domesticated manioc can develop as shrubs or lianas. However, “finer-scale” developmental traits crucial to mechanical stability and thus ecological success of the plant were significantly modified. This profoundly influenced the likelihood of brittle failure, particularly in long climbing stems, thereby also influencing the survival of the domesticate in natural situations vulnerable to mechanical perturbation

  20. Impact of global warming at the range margins: phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian

    PubMed Central

    Ruiz-Aravena, Manuel; Gonzalez-Mendez, Avia; Estay, Sergio A; Gaitán-Espitia, Juan D; Barria-Oyarzo, Ismael; Bartheld, José L; Bacigalupe, Leonardo D

    2014-01-01

    When dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. In this work, we evaluated whether there is physiological plasticity in the thermal performance curve (TPC) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population of the endemic frog Pleurodema thaul. Our results indicate that individuals acclimated to 20°C and 25°C increased the breath of their TPCs by shifting their upper limits with respect to when they were acclimated at 10°C. In addition, even when dispersal is not possible for this population, the landscape is heterogeneous enough to offer opportunities for behavioral thermoregulation. In particular, under current climatic conditions, behavioral thermoregulation is not compulsory as available operative temperatures are encompassed within the population TPC limits. However, for severe projected temperatures under climate change, behavioral thermoregulation will be required in the sunny patches. In overall, our results suggest that this population of Pleurodema thaul will be able to endure the worst projected scenario of climate warming as it has not only the physiological capacities but also the environmental opportunities to regulate its body temperature behaviorally. PMID:25512843

  1. Impact of global warming at the range margins: phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian.

    PubMed

    Ruiz-Aravena, Manuel; Gonzalez-Mendez, Avia; Estay, Sergio A; Gaitán-Espitia, Juan D; Barria-Oyarzo, Ismael; Bartheld, José L; Bacigalupe, Leonardo D

    2014-12-01

    When dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. In this work, we evaluated whether there is physiological plasticity in the thermal performance curve (TPC) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population of the endemic frog Pleurodema thaul. Our results indicate that individuals acclimated to 20°C and 25°C increased the breath of their TPCs by shifting their upper limits with respect to when they were acclimated at 10°C. In addition, even when dispersal is not possible for this population, the landscape is heterogeneous enough to offer opportunities for behavioral thermoregulation. In particular, under current climatic conditions, behavioral thermoregulation is not compulsory as available operative temperatures are encompassed within the population TPC limits. However, for severe projected temperatures under climate change, behavioral thermoregulation will be required in the sunny patches. In overall, our results suggest that this population of Pleurodema thaul will be able to endure the worst projected scenario of climate warming as it has not only the physiological capacities but also the environmental opportunities to regulate its body temperature behaviorally. PMID:25512843

  2. Effects of Sowing Date on Phenotypic Plasticity of Fitness-Related Traits in Two Annual Weeds on the Songnen Plain of China

    PubMed Central

    Li, Haiyan; Lindquist, John L.; Yang, Yunfei

    2015-01-01

    Background Phenotypic plasticity of fitness-related traits is vital for plant species to adapt to variable environments. Chenopodium glaucum L. and Amaranthus retroflexus L. are two common weed species globally. Understanding the plasticity in life-history traits, especially in reproductive allocation, within and among these species is important for predicting their success and for managing them in different environments. Methodology/Principal Findings Seeds of the two plant species were sown every 10 days from 26 Jun to 15 Aug. Life-history and fitness-related traits of both phenology and morphology were measured, and dry biomass of roots, stems, leaves, and reproductive tissues was determined at physiological maturity. Length of reproductive and total life period of the two species differed among six sowing-date treatments. Later germinating plants led to relatively reduced total life period, size, and earlier reproduction than earlier germinating plants. The ratio of reproductive biomass to total plant biomass increased with later planting dates in C. glaucum but declined in A. retroflexus. Mature plant height, crown diameter, and reproductive tissue biomass, and seed production of C. glaucum and A. retroflexus increased with delayed reproductive period. Both species displayed true plasticity in reproductive allocation. However, the sowing date had a far greater effect on rate of vegetative growth than on allocation to reproduction. Conclusions/Significance The fitness of both C. glaucum and A. retroflexus populations have an apparent increase when the period between germination and seed production is much longer. However, C. glaucum appears better adapted to later sowing than A. retroflexus. Controlling seedlings prior to reproduction will alleviate the negative effect not only in the present year but also in future years. PMID:26023915

  3. Individual Consistency and Phenotypic Plasticity in Rockhopper Penguins: Female but Not Male Body Mass Links Environmental Conditions to Reproductive Investment

    PubMed Central

    Dehnhard, Nina; Eens, Marcel; Demongin, Laurent; Quillfeldt, Petra; Poisbleau, Maud

    2015-01-01

    In marine habitats, increasing ocean temperatures due to global climate change may distinctly reduce nutrient and consequently food availability for seabirds. Food availability is a known driver of body mass and reproductive investment in birds, but these traits may also depend on individual effects. Penguins show extreme intra-annual body mass variation and rely on accumulated body reserves for successful breeding. However, no study so far has tested individual consistency and phenotypic responses in body mass and reproductive investment in this taxon. Using a unique dataset on individually marked female and male southern rockhopper penguins (Eudyptes chrysocome chrysocome) across six years, we investigated 1) the individual consistency in body mass (measured at egg laying), body condition and reproductive investment across years, subsequently 2) identified the best-explanatory temperature-related environmental variables for female and male body mass, and 3) tested the effect of female and male body mass on reproductive investment. Body mass, body condition and reproductive investment were all highly repeatable. As body condition should control for the structural size of the birds, the similarly high repeatability estimates for body mass and body condition suggested that the consistent between-individual body mass differences were independent of structural size. This supported the use of body mass for the subsequent analyses. Body mass was higher under colder environmental conditions (positive Southern Annular Mode), but the overall phenotypic response appeared limited. Reproductive investment increased with female but not male body mass. While environmental effects on body mass in our study period were rather small, one can expect that ongoing global climate change will lead to a deterioration of food availability and we might therefore in the long-term expect a phenotypical decline in body mass and reproductive investment. PMID:26030824

  4. Tyrosine hydroxylase expression within Balb/C and C57black/6 mouse locus coeruleus. I. Topological organization and phenotypic plasticity of the enzyme-containing cell population.

    PubMed

    Ginovart, N; Marcel, D; Bezin, L; Garcia, C; Gagne, C; Pujol, J F; Weissmann, D

    1996-05-20

    Tyrosine hydroxylase phenotype expression was investigated in the catecholaminergic population of the locus coeruleus neurons of two pure inbred mouse strains, Balb/C and C57Black/6. Therefore, we have characterized the precise organization of tyrosine hydroxylase-expressing perikarya population, in control animals and following RU24722 treatment, which is known to induce tyrosine hydroxylase expression. Serial coronal sections were selected along the caudo-rostral extent of the structure and were processed for tyrosine hydroxylase immunocytochemistry. Three days after the treatment, an increase in the number of cells which expressed tyrosine hydroxylase was observed all along the locus coeruleus in the Balb/C strain only. This increase equalized the catecholaminergic neuron populations of the two strains. In the caudal subdivision of the structure, these newly detected perikarya were intermingled with the perikarya which expressed tyrosine hydroxylase in control conditions. In the rostral half, the additional immunoreactive perikarya enlarged the mean coerulean space, defined as the area delimited by the tyrosine hydroxylase-containing perikarya. These results demonstrate a plasticity of the tyrosine hydroxylase phenotype expression, topologically organized and specific to the Balb/C strain. PMID:8793080

  5. Reproductive allocation and nutrient relationships in Cuphea: A semi-domesticated oilseed crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    No information is available on allometric variations in C, N, and P in structural, reproductive and metabolic tissues and their ratios in Cuphea germplasm line PSR23, a semi-domesticated indeterminate and phenotypically plastic oilseed crop. The objectives of this study were to quantify the impact o...

  6. Phenotypic plasticity in the common snapping turtle (Chelydra serpentina): long-term physiological effects of chronic hypoxia during embryonic development.

    PubMed

    Wearing, Oliver H; Eme, John; Rhen, Turk; Crossley, Dane A

    2016-01-15

    Studies of embryonic and hatchling reptiles have revealed marked plasticity in morphology, metabolism, and cardiovascular function following chronic hypoxic incubation. However, the long-term effects of chronic hypoxia have not yet been investigated in these animals. The aim of this study was to determine growth and postprandial O2 consumption (V̇o2), heart rate (fH), and mean arterial pressure (Pm, in kPa) of common snapping turtles (Chelydra serpentina) that were incubated as embryos in chronic hypoxia (10% O2, H10) or normoxia (21% O2, N21). We hypothesized that hypoxic development would modify posthatching body mass, metabolic rate, and cardiovascular physiology in juvenile snapping turtles. Yearling H10 turtles were significantly smaller than yearling N21 turtles, both of which were raised posthatching in normoxic, common garden conditions. Measurement of postprandial cardiovascular parameters and O2 consumption were conducted in size-matched three-year-old H10 and N21 turtles. Both before and 12 h after feeding, H10 turtles had a significantly lower fH compared with N21 turtles. In addition, V̇o2 was significantly elevated in H10 animals compared with N21 animals 12 h after feeding, and peak postprandial V̇o2 occurred earlier in H10 animals. Pm of three-year-old turtles was not affected by feeding or hypoxic embryonic incubation. Our findings demonstrate that physiological impacts of developmental hypoxia on embryonic reptiles continue into juvenile life. PMID:26608655

  7. Phenotypic characteristics of expressed tyrosine hydroxylase protein in the adult rat nucleus tractus solitarius: plasticity revealed by RU24722 treatment.

    PubMed

    Garcia, C; Marcel, D; Le Cavorsin, M; Pujol, J F; Weissmann, D

    1994-10-01

    The phenotypic characteristics of expressed tyrosine hydroxylase protein have been precisely analysed in the rat nucleus tractus solitarius, which contains the majority of A2 noradrenergic and C2 adrenergic neurons of the medulla oblongata. This study was based upon quantitative analysis of immunohistochemical and immunoradioautographic staining of tyrosine hydroxylase protein in serial coronal sections. In control rats, there were few tyrosine hydroxylase-expressing cell bodies which express less than 2% of the immunoradiolabeled tyrosine hydroxylase protein measured in the structure. These cell bodies were scattered throughout an extensive immunopositive neuropile, which precisely delimited the topological space of the nucleus tractus solitarius quantiatively reconstructed using a polar coordinate system. The quantification of tyrosine hydroxylase tissue concentration from immunoradioautograms allowed us to subdivide the structure into two distinct regions. The posterior region of the nucleus tractus solitarius, which mainly corresponds to the A2 cell group, contains a relatively high tissue concentration of tyrosine hydroxylase protein (18.56 +/- 0.154 units per mg of tissue). The anterior region, which mainly corresponds to the C2 cell group, exhibits a relatively low concentration (12.09 +/- 0.81) of this protein. Three days after an intraperitoneal injection of RU24722, there was a strong increase (90 +/- 17%) in tyrosine hydroxylase protein content only in the anterior region of the nucleus tractus solitarius. This increase was associated with a dramatic elevation (142 +/- 20%) in the number of tyrosine hydroxylase-expressing cell bodies. The additional cell bodies were mainly located inside the initial perikarya-containing area.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7845594

  8. Morphological variability and molecular identification of Uncinaria spp. (Nematoda: Ancylostomatidae) from grizzly and black bears: new species or phenotypic plasticity?

    PubMed

    Catalano, Stefano; Lejeune, Manigandan; van Paridon, Bradley; Pagan, Christopher A; Wasmuth, James D; Tizzani, Paolo; Duignan, Pádraig J; Nadler, Steven A

    2015-04-01

    The hookworms Uncinaria rauschi Olsen, 1968 and Uncinaria yukonensis ( Wolfgang, 1956 ) were formally described from grizzly ( Ursus arctos horribilis) and black bears ( Ursus americanus ) of North America. We analyzed the intestinal tracts of 4 grizzly and 9 black bears from Alberta and British Columbia, Canada and isolated Uncinaria specimens with anatomical traits never previously documented. We applied morphological and molecular techniques to investigate the taxonomy and phylogeny of these Uncinaria parasites. The morphological analysis supported polymorphism at the vulvar region for females of both U. rauschi and U. yukonensis. The hypothesis of morphological plasticity for U. rauschi and U. yukonensis was confirmed by genetic analysis of the internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. Two distinct genotypes were identified, differing at 5 fixed sites for ITS-1 (432 base pairs [bp]) and 7 for ITS-2 (274 bp). Morphometric data for U. rauschi revealed host-related size differences: adult U. rauschi were significantly larger in black bears than in grizzly bears. Interpretation of these results, considering the historical biogeography of North American bears, suggests a relatively recent host-switching event of U. rauschi from black bears to grizzly bears which likely occurred after the end of the Wisconsin glaciation. Phylogenetic maximum parsimony (MP) and maximum likelihood (ML) analyses of the concatenated ITS-1 and ITS-2 datasets strongly supported monophyly of U. rauschi and U. yukonensis and their close relationship with Uncinaria stenocephala (Railliet, 1884), the latter a parasite primarily of canids and felids. Relationships among species within this group, although resolved by ML, were unsupported by MP and bootstrap resampling. The clade of U. rauschi, U. yukonensis, and U. stenocephala was recovered as sister to the clade represented by Uncinaria spp. from otariid pinnipeds. These results support the absence of strict

  9. Transient Shifts of Incubation Temperature Reveal Immediate and Long-Term Transcriptional Response in Chicken Breast Muscle Underpinning Resilience and Phenotypic Plasticity.

    PubMed

    Naraballobh, Watcharapong; Trakooljul, Nares; Murani, Eduard; Brunner, Ronald; Krischek, Carsten; Janisch, Sabine; Wicke, Michael; Ponsuksili, Siriluck; Wimmers, Klaus

    2016-01-01

    transiently decreased incubation temperature, which did not affect the phenotypes, prompts compensatory effects reflecting resilience. In contrast, higher incubation temperature triggers gene expression and has long-term effects on the phenotype. These mechanisms of considerable phenotypic plasticity contribute to the biodiversity and broaden the basis for managing poultry populations. PMID:27611643

  10. Growth in Turface® clay permits root hair phenotyping along the entire crown root in cereal crops and demonstrates that root hair growth can extend well beyond the root hair zone.

    PubMed

    Goron, Travis L; Watts, Sophia; Shearer, Charles; Raizada, Manish N

    2015-01-01

    In cereal crops, root hairs are reported to function within the root hair zone to carry out important roles in nutrient and water absorption. Nevertheless, these single cells remain understudied due to the practical challenges of phenotyping these delicate structures in large cereal crops growing on soil or other growth systems. Here we present an alternative growth system for examining the root hairs of cereal crops: the use of coarse Turface® clay alongside fertigation. This system allowed for root hairs to be easily visualized along the entire lengths of crown roots in three different cereal crops (maize, wheat, and finger millet). Surprisingly, we observed that the root hairs in these crops continued to grow beyond the canonical root hair zone, with the most root hair growth occurring on older crown root segments. We suggest that the Turface® fertigation system may permit a better understanding of the changing dynamics of root hairs as they age in large plants, and may facilitate new avenues for crop improvement below ground. However, the relevance of this system to field conditions must be further evaluated in other crops. PMID:25889276