scholarly journals Adaptive and maladaptive expression plasticity underlying herbicide resistance in an agricultural weed

2020 ◽  
Author(s):  
Emily B. Josephs ◽  
Megan L. Van Etten ◽  
Alex Harkess ◽  
Adrian Platts ◽  
Regina S. Baucom

AbstractPlastic phenotypic responses to environmental change are common, yet we lack a clear understanding of the fitness consequences of these plastic responses. Here, we use the evolution of herbicide resistance in the common morning glory (Ipomoea purpurea) as a model for understanding the relative importance of adaptive and maladaptive gene expression responses to herbicide. Specifically, we compare leaf gene expression changes caused by herbicide spray to the expression changes that evolve in response to artificial selection for herbicide resistance. We identify a number of genes that show plastic and evolved responses to herbicide and find that for the majority of genes with both plastic and evolved responses, plastic responses appear to be adaptive. We also find that selection for herbicide response increases gene expression plasticity. Overall, these results show the importance of adaptive plasticity for herbicide resistance in a common weed and that expression changes in response to strong environmental change can be adaptive.

2018 ◽  
Author(s):  
Alfredo Rago ◽  
Kostas Kouvaris ◽  
Tobias Uller ◽  
Richard Watson

AbstractAdaptive plasticity allows organisms to cope with environmental change, thereby increasing the population’s long-term fitness. However, individual selection can only compare the fitness of individuals within each generation: if the environment changes more slowly than the generation time (i.e., a coarse-grained environment) a population will not experience selection for plasticity even if it is adaptive in the long-term. How does adaptive plasticity then evolve? One explanation is that, if competing alleles conferring different degrees of plasticity persist across multiple environments, natural selection between lineages carrying those alleles could select for adaptive plasticity (lineage selection).We show that adaptive plasticity can evolve even in the absence of such lineage selection. Instead, we propose that adaptive plasticity in coarse-grained environments evolves as a by-product of inefficient short-term natural selection. In our simulations, populations that can efficiently respond to selective pressures follow short-term, local, optima and have lower long-term fitness. Conversely, populations that accumulate limited genetic change within each environment evolve long-term adaptive plasticity even when plasticity incurs short-term costs. These results remain qualitatively similar regardless of whether we decrease the efficiency of natural selection by increasing the rate of environmental change or decreasing mutation rate, demonstrating that both factors act via the same mechanism. We demonstrate how this mechanism can be understood through the concept of learning rate.Our work shows how plastic responses that are costly in the short term, yet adaptive in the long term, can evolve as a by-product of inefficient short-term selection, without selection for plasticity at either the individual or lineage level.


Author(s):  
Noëlle K. J. Bittner ◽  
Katya L. Mack ◽  
Michael W. Nachman

AbstractUnderstanding how organisms adapt to new environments is a key problem in evolution, yet it remains unclear whether phenotypic plasticity generally facilitates or hinders this process. Here we studied the evolved and plastic responses to water stress in lab-born descendants of wild house mice (Mus musculus domesticus) collected from desert and non-desert environments. Using a full sib design, we measured organismal phenotypes and gene expression under normal (hydrated) and water stressed (dehydrated) conditions. After many generations in the lab, mice from the desert consumed significantly less water than mice from other localities, indicating that this difference has a genetic basis. Under water stress, desert mice lost less weight than non-desert mice, and desert mice exhibited differences in blood chemistry related to osmoregulatory function. Gene expression in the kidney revealed evolved differences between mice from different environments as well as plastic responses between hydrated and dehydrated mice. Desert mice showed reduced gene expression plasticity under water stress compared to non-desert mice. Importantly, the non-desert mice generally showed shifts towards desert-like expression under water stress, consistent with adaptive plasticity. Finally, patterns of gene expression identified several candidate genes for adaptation to the desert, including Aqp1 and Apoe. These findings provide evidence for local adaptation in a recently introduced species and suggest that adaptive plasticity may have facilitated the colonization of the desert environment.


2021 ◽  
Author(s):  
Shinji Tanigaki ◽  
Akira Uchino ◽  
Shigenori Okawa ◽  
Chikako Miura ◽  
Kenshiro Hamamura ◽  
...  

2019 ◽  
Vol 374 (1768) ◽  
pp. 20180174 ◽  
Author(s):  
Rebecca J. Fox ◽  
Jennifer M. Donelson ◽  
Celia Schunter ◽  
Timothy Ravasi ◽  
Juan D. Gaitán-Espitia

How populations and species respond to modified environmental conditions is critical to their persistence both now and into the future, particularly given the increasing pace of environmental change. The process of adaptation to novel environmental conditions can occur via two mechanisms: (1) the expression of phenotypic plasticity (the ability of one genotype to express varying phenotypes when exposed to different environmental conditions), and (2) evolution via selection for particular phenotypes, resulting in the modification of genetic variation in the population. Plasticity, because it acts at the level of the individual, is often hailed as a rapid-response mechanism that will enable organisms to adapt and survive in our rapidly changing world. But plasticity can also retard adaptation by shifting the distribution of phenotypes in the population, shielding it from natural selection. In addition to which, not all plastic responses are adaptive—now well-documented in cases of ecological traps. In this theme issue, we aim to present a considered view of plasticity and the role it could play in facilitating or hindering adaption to environmental change. This introduction provides a re-examination of our current understanding of the role of phenotypic plasticity in adaptation and sets the theme issue's contributions in their broader context. Four key themes emerge: the need to measure plasticity across both space and time; the importance of the past in predicting the future; the importance of the link between plasticity and sexual selection; and the need to understand more about the nature of selection on plasticity itself. We conclude by advocating the need for cross-disciplinary collaborations to settle the question of whether plasticity will promote or retard species' rates of adaptation to ever-more stressful environmental conditions. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.


Author(s):  
Karen D. Williams ◽  
Marla B. Sokolowski

Why is there so much variation in insect behavior? This chapter will address the sources of behavioral variability, with a particular focus on phenotypic plasticity. Variation in social, nutritional, and seasonal environmental contexts during development and adulthood can give rise to phenotypic plasticity. To delve into mechanism underlying behavioral flexibility in insects, examples of polyphenisms, a type of phenotypic plasticity, will be discussed. Selected examples reveal that environmental change can affect gene expression, which in turn can affect behavioral plasticity. These changes in gene expression together with gene-by-environment interactions are discussed to illuminate our understanding of insect behavioral plasticity.


2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Chao Yan ◽  
Kate Hartcher ◽  
Wen Liu ◽  
Jinlong Xiao ◽  
Hai Xiang ◽  
...  

Abstract Conditions in early life play profound and long-lasting effects on the welfare and adaptability to stress of chickens. This study aimed to explore the hypothesis that the provision of environmental complexity in early life improves birds’ adaptive plasticity and ability to cope with a challenge later in life. It also tried to investigate the effect of the gut-brain axis by measuring behavior, stress hormone, gene expression, and gut microbiota. One-day-old chicks were split into 3 groups: (1) a barren environment (without enrichment items) group (BG, n = 40), (2) a litter materials group (LG, n = 40), and (3) a perches with litter materials group (PLG, n = 40). Then, enrichment items were removed and simulated as an environmental challenge at 31 to 53 d of age. Birds were subjected to a predator test at 42 d of age. In the environmental challenge, when compared with LG, PLG birds were characterized by decreased fearfulness, lower plasma corticosterone, improved gut microbial functions, lower relative mRNA expression of GR, and elevated mRNA expressions of stress-related genes CRH, BDNF, and NR2A in the hypothalamus (all P < 0.05). Unexpectedly, the opposite was true for the LG birds when compared with the BG (P < 0.05). Decreased plasma corticosterone and fearfulness were accompanied by altered hypothalamic gene mRNA expressions of BDNF, NR2A, GR, and CRH through the HPA axis in response to altered gut microbial compositions and functions. The findings suggest that gut microbiota may integrate fearfulness, plasma corticosterone, and gene expression in the hypothalamus to provide an insight into the gut-brain axis in chicks. In conclusion, having access to both perches and litter materials in early life allowed birds to cope better with a future challenge. Birds in perches and litter materials environment may have optimal development and adaptive plasticity through the gut-brain axis.


Genome ◽  
2020 ◽  
pp. 1-11
Author(s):  
Bahar Patlar ◽  
Alberto Civetta

It has long been acknowledged that changes in the regulation of gene expression may account for major organismal differences. However, we still do not fully understand how changes in gene expression evolve and how do such changes influence organisms’ differences. We are even less aware of the impact such changes might have in restricting gene flow between species. Here, we focus on studies of gene expression and speciation in the Drosophila model. We review studies that have identified gene interactions in post-mating reproductive isolation and speciation, particularly those that modulate male gene expression. We also address studies that have experimentally manipulated changes in gene expression to test their effect in post-mating reproductive isolation. We highlight the need for a more in-depth analysis of the role of selection causing disrupted gene expression of such candidate genes in sterile/inviable hybrids. Moreover, we discuss the relevance to incorporate more routinely assays that simultaneously evaluate the potential effects of environmental factors and genetic background in modulating plastic responses in male genes and their potential role in speciation.


2004 ◽  
Vol 06 (02) ◽  
pp. 189-211 ◽  
Author(s):  
MARK LEMON ◽  
PAUL JEFFREY ◽  
BRIAN S. MCINTOSH ◽  
TIM OXLEY

Participation has become part of the language of environmental management. While this move is positive there remains a danger that overly formalised and restricted participatory procedures, in terms of the information sought, may constrain and hinder dialogue and learning between the public and management agencies. Responses to specific issues are often sought from members of the public without a clear understanding about whether those issues are salient to them, where they are salient or how they fit into multiple and dynamic interpretations of environmental change. This paper uses case study material from the UK to demonstrate a novel Pathways Approach to the recording and analysis of individual perceptions about environmental change. The approach seeks to concentrate on experience and interpretation and is based on the conceptualisation of perceived cause–effect relationships and the pathways that support them. The links between time, space and community are considered within this analysis, as is the potential for improved participation through the provision of policy relevant information to planners and environmental managers operating in complex, multi-perspective situations.


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