Evolution of developmental plasticity by opposing dosage of signalling-modifying enzymes

AbstractPolyphenism, the extreme form of developmental plasticity, is the ability of a genotype to produce discrete morphologies matched to alternative environments. Because polyphenism is likely to be under switch-like molecular control, a comparative genetic approach could reveal the molecular targets of plasticity evolution. In the nematode Pristionchus pacificus, which form two alternative feeding-morphs, the polyphenism threshold is set by relative dosage of two lineage-specific enzymes that respond to morph-inducing cues. One enzyme, the sulfotransferase SEUD-1, integrates an intercellular signalling mechanism at its ultimate target, the cells producing dimorphic mouthparts. Additionally, multiple alterations of seud-1 support it as a potential target for plasticity evolution. First, a recent duplication of seud-1 in a sister species reveals a direct correlation between genomic dosage and the polyphenism threshold. Second, laboratory selection on the polyphenism threshold resulted in changes in relative transcriptional dosage. Our study thus offers a genetic explanation for how plastic responses evolve.

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Developmental plasticity: re-conceiving the genotype

Interface Focus ◽

10.1098/rsfs.2017.0009 ◽

2017 ◽

Vol 7 (5) ◽

pp. 20170009 ◽

Cited By ~ 22

Author(s):

Sonia E. Sultan

Keyword(s):

Environmental Conditions ◽

Developmental Plasticity ◽

Environmental Response ◽

Norm Of Reaction ◽

Individual Level ◽

Sorting Process ◽

Nuanced Understanding ◽

Developmental Programme ◽

Plastic Responses ◽

Synthesis Approach

In recent decades, the phenotype of an organism (i.e. its traits and behaviour) has been studied as the outcome of a developmental ‘programme’ coded in its genotype. This deterministic view is implicit in the Modern Synthesis approach to adaptive evolution as a sorting process among genetic variants. Studies of developmental pathways have revealed that genotypes are in fact differently expressed depending on environmental conditions. Accordingly, the genotype can be understood as a repertoire of potential developmental outcomes or norm of reaction. Reconceiving the genotype as an environmental response repertoire rather than a fixed developmental programme leads to three critical evolutionary insights. First, plastic responses to specific conditions often comprise functionally appropriate trait adjustments, resulting in an individual-level, developmental mode of adaptive variation. Second, because genotypes are differently expressed depending on the environment, the genetic diversity available to natural selection is itself environmentally contingent. Finally, environmental influences on development can extend across multiple generations via cytoplasmic and epigenetic factors transmitted to progeny individuals, altering their responses to their own, immediate environmental conditions and, in some cases, leading to inherited but non-genetic adaptations. Together, these insights suggest a more nuanced understanding of the genotype and its evolutionary role, as well as a shift in research focus to investigating the complex developmental interactions among genotypes, environments and previous environments.

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Frequent fires prime plant developmental responses to burning

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.1315 ◽

2019 ◽

Vol 286 (1909) ◽

pp. 20191315 ◽

Cited By ~ 3

Author(s):

Kimberley J. Simpson ◽

Jill K. Olofsson ◽

Brad S. Ripley ◽

Colin P. Osborne

Keyword(s):

Developmental Plasticity ◽

Fire Regime ◽

Fire Regimes ◽

Fire Frequency ◽

Fire Exposure ◽

Regime Changes ◽

Below Ground ◽

Developmental Responses ◽

In Fire ◽

Plastic Responses

Coping with temporal variation in fire requires plants to have plasticity in traits that promote persistence, but how plastic responses to current conditions are affected by past fire exposure remains unknown. We investigate phenotypic divergence between populations of four resprouting grasses exposed to differing experimental fire regimes (annually burnt or unburnt for greater than 35 years) and test whether divergence persists after plants are grown in a common environment for 1 year. Traits relating to flowering and biomass allocation were measured before plants were experimentally burnt, and their regrowth was tracked. Genetic differentiation between populations was investigated for a subset of individuals. Historic fire frequency influenced traits relating to flowering and below-ground investment. Previously burnt plants produced more inflorescences and invested proportionally more biomass below ground, suggesting a greater capacity for recruitment and resprouting than unburnt individuals. Tiller-scale regrowth rate did not differ between treatments, but prior fire exposure enhanced total regrown biomass in two species. We found no consistent genetic differences between populations suggesting trait differences arose from developmental plasticity. Grass development is influenced by prior fire exposure, independent of current environmental conditions. This priming response to fire, resulting in adaptive trait changes, may produce communities more resistant to future fire regime changes.

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Sex or cannibalism: Polyphenism and kin recognition control social action strategies in nematodes

Science Advances ◽

10.1126/sciadv.abg8042 ◽

2021 ◽

Vol 7 (35) ◽

pp. eabg8042

Author(s):

James W. Lightfoot ◽

Mohannad Dardiry ◽

Ata Kalirad ◽

Stefano Giaimo ◽

Gabi Eberhardt ◽

...

Keyword(s):

Social Action ◽

Developmental Plasticity ◽

Kin Recognition ◽

Reproductive Mode ◽

Feeding Strategies ◽

Action Strategies ◽

Major Factors ◽

And Behavior ◽

Alternative Feeding ◽

Genomic Relatedness

Resource polyphenisms, where single genotypes produce alternative feeding strategies in response to changing environments, are thought to be facilitators of evolutionary novelty. However, understanding the interplay between environment, morphology, and behavior and its significance is complex. We explore a radiation of Pristionchus nematodes with discrete polyphenic mouth forms and associated microbivorous versus cannibalistic traits. Notably, comparing 29 Pristionchus species reveals that reproductive mode strongly correlates with mouth-form plasticity. Male-female species exhibit the microbivorous morph and avoid parent-offspring conflict as indicated by genetic hybrids. In contrast, hermaphroditic species display cannibalistic morphs encouraging competition. Testing predation between 36 co-occurring strains of the hermaphrodite P. pacificus showed that killing inversely correlates with genomic relatedness. These empirical data together with theory reveal that polyphenism (plasticity), kin recognition, and relatedness are three major factors that shape cannibalistic behaviors. Thus, developmental plasticity influences cooperative versus competitive social action strategies in diverse animals.

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Plasticity and evolutionary convergence in the locomotor skeleton of Greater Antillean Anolis lizards

eLife ◽

10.7554/elife.57468 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 1

Author(s):

Nathalie Feiner ◽

Illiam SC Jackson ◽

Kirke L Munch ◽

Reinder Radersma ◽

Tobias Uller

Keyword(s):

Developmental Plasticity ◽

Morphological Plasticity ◽

Genetic Change ◽

Evolutionary Divergence ◽

Locomotor Performance ◽

Evolutionary Convergence ◽

Plastic Responses

Plasticity can put evolution on repeat if development causes species to generate similar morphologies in similar environments. Anolis lizards offer the opportunity to put this role of developmental plasticity to the test. Following colonization of the four Greater Antillean islands, Anolis lizards independently and repeatedly evolved six ecomorphs adapted to manoeuvring different microhabitats. By quantifying the morphology of the locomotor skeleton of 95 species, we demonstrate that ecomorphs on different islands have diverged along similar trajectories. However, microhabitat-induced morphological plasticity differed between species and did not consistently improve individual locomotor performance. Consistent with this decoupling between morphological plasticity and locomotor performance, highly plastic features did not show greater evolvability, and plastic responses to microhabitat were poorly aligned with evolutionary divergence between ecomorphs. The locomotor skeleton of Anolis may have evolved within a subset of possible morphologies that are highly accessible through genetic change, enabling adaptive convergence independently of plasticity.

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Nothing as it seems: behavioural plasticity appears correlated with morphology and colour, but is not in a Neotropical tadpole

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.0246 ◽

2021 ◽

Vol 288 (1948) ◽

Author(s):

Phoebe L. Reuben ◽

Justin C. Touchon

Keyword(s):

Life History ◽

Developmental Plasticity ◽

Adaptive Significance ◽

Species Level ◽

Environmental Stressors ◽

Behavioural Plasticity ◽

Level Variation ◽

Family Level ◽

Dendropsophus Ebraccatus ◽

Plastic Responses

In response to environmental stressors, organisms often demonstrate flexible responses in morphology, life history or behaviour. However, it is currently unclear if such plastic responses are coordinated or operate independently of one another. In vertebrates, this may partly result from studies examining population- or species-level mean responses, as opposed to finer grained analyses of individuals or families. We measured predator-specific morphological and coloration plasticity in 42 families of tadpoles of the treefrog Dendropsophus ebraccatus and behavioural plasticity from 18 of these families, allowing us to examine the correlation between three predator-induced plastic responses. For all three plastic responses, tadpoles showed strong opposing responses to each of two predators, providing the appearance of covariation in plasticity. However, the examination of individual families revealed a strong correlation between morphological and coloration plasticity, but no correlations between either morphology or colour and behavioural plasticity. Thus, our analysis shows that some aspects of the plastic phenotype develop together while others function independently. This highlights the importance of examining individual- and family-level variation for understanding the adaptive significance of developmental plasticity, which is crucial for a holistic appreciation of phenotypic plasticity and its importance in ecology and evolution.

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Molecular control of stomatal development

Biochemical Journal ◽

10.1042/bcj20170413 ◽

2018 ◽

Vol 475 (2) ◽

pp. 441-454 ◽

Cited By ~ 36

Author(s):

Nicholas Zoulias ◽

Emily L. Harrison ◽

Stuart A. Casson ◽

Julie E. Gray

Keyword(s):

Gas Exchange ◽

Cell Fate ◽

Developmental Plasticity ◽

Stomatal Density ◽

Bhlh Transcription Factor ◽

Stomatal Development ◽

Molecular Control ◽

Cell Fate Decisions ◽

Receptor Interactions ◽

Kinase Cascade

Plants have evolved developmental plasticity which allows the up- or down-regulation of photosynthetic and water loss capacities as new leaves emerge. This developmental plasticity enables plants to maximise fitness and to survive under differing environments. Stomata play a pivotal role in this adaptive process. These microscopic pores in the epidermis of leaves control gas exchange between the plant and its surrounding environment. Stomatal development involves regulated cell fate decisions that ensure optimal stomatal density and spacing, enabling efficient gas exchange. The cellular patterning process is regulated by a complex signalling pathway involving extracellular ligand–receptor interactions, which, in turn, modulate the activity of three master transcription factors essential for the formation of stomata. Here, we review the current understanding of the biochemical interactions between the epidermal patterning factor ligands and the ERECTA family of leucine-rich repeat receptor kinases. We discuss how this leads to activation of a kinase cascade, regulation of the bHLH transcription factor SPEECHLESS and its relatives, and ultimately alters stomatal production.

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Inflammageing in the cardiovascular system: mechanisms, emerging targets, and novel therapeutic strategies

Clinical Science ◽

10.1042/cs20191213 ◽

2020 ◽

Vol 134 (17) ◽

pp. 2243-2262

Author(s):

Danlin Liu ◽

Gavin Richardson ◽

Fehmi M. Benli ◽

Catherine Park ◽

João V. de Souza ◽

...

Keyword(s):

Cardiovascular Diseases ◽

Cardiovascular System ◽

Nlrp3 Inflammasome ◽

Molecular Mechanisms ◽

Molecular Targets ◽

Therapeutic Interventions ◽

Low Grade ◽

Cardiovascular Research ◽

Inflammatory Processes ◽

Ach Receptors

Abstract In the elderly population, pathological inflammation has been associated with ageing-associated diseases. The term ‘inflammageing’, which was used for the first time by Franceschi and co-workers in 2000, is associated with the chronic, low-grade, subclinical inflammatory processes coupled to biological ageing. The source of these inflammatory processes is debated. The senescence-associated secretory phenotype (SASP) has been proposed as the main origin of inflammageing. The SASP is characterised by the release of inflammatory cytokines, elevated activation of the NLRP3 inflammasome, altered regulation of acetylcholine (ACh) nicotinic receptors, and abnormal NAD+ metabolism. Therefore, SASP may be ‘druggable’ by small molecule therapeutics targeting those emerging molecular targets. It has been shown that inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and adverse cardiac remodelling. Therefore, the pathomechanism involving SASP activation via the NLRP3 inflammasome; modulation of NLRP3 via α7 nicotinic ACh receptors; and modulation by senolytics targeting other proteins have gained a lot of interest within cardiovascular research and drug development communities. In this review, which offers a unique view from both clinical and preclinical target-based drug discovery perspectives, we have focused on cardiovascular inflammageing and its molecular mechanisms. We have outlined the mechanistic links between inflammageing, SASP, interleukin (IL)-1β, NLRP3 inflammasome, nicotinic ACh receptors, and molecular targets of senolytic drugs in the context of cardiovascular diseases. We have addressed the ‘druggability’ of NLRP3 and nicotinic α7 receptors by small molecules, as these proteins represent novel and exciting targets for therapeutic interventions targeting inflammageing in the cardiovascular system and beyond.

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