scholarly journals Low Transcriptomic Plasticity of Antarctic Giant Isopod Glyptonotus antarcticus Juveniles Exposed to Acute Thermal Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Marcelo González-Aravena ◽  
Rodolfo Rondon ◽  
Alejandro Font ◽  
César A. Cárdenas ◽  
Jean-Yves Toullec ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Phenotypic Plasticity ◽  
Experimental Treatment ◽  
Population Level ◽  
Mitochondrial Respiratory Chain ◽  
Common Species ◽  
Physiological Capacity ◽  
Short Period ◽  
Individual Ability ◽  
Increasing Temperature

The Western Antarctic Peninsula (WAP) is among the areas of the planet showing some of the most significant increases in air and water temperature. It is projected that increasing temperature will modulate coastal ecosystems at species ecological performance and molecular composition. The main way that the organisms can cope with large thermal variation is by having a reversible phenotypic plasticity, which provides the organisms with a compensatory physiological response when facing challenging conditions. The giant Antarctic isopod Glyptonotus antarcticus is one of most common species in Antarctic waters. This species has a larval development inside of the maternal marsupium, where juveniles have a short period to acclimate to environmental conditions after birth. In this sense, we hypothesize that juveniles exposed to unusual temperature increases even for short periods, would not respond adequately showing a narrow phenotypic plasticity. We experimentally assessed if early juveniles of G. antarcticus have the molecular plasticity when exposed to increased temperature at 5°C during 1, 6, 12 and 24 h. Sequenced libraries were compared between control (0°C) and each experimental treatment to detect differentially expressed transcripts. The main molecular pathways affected by thermal stress were antioxidant, proteases, endopeptidases and ubiquination transcripts which were up-regulated and mitochondrial respiratory chain, cuticle, cytoskeleton and a molt transcript which were down-regulated. Regarding the HSP transcript, only 3 were up-regulated at least in two points of the stress kinetic, without classical Hsp70 and Hsp90 transcripts. This study shows that juveniles of G. antarcticus do not show molecular phenotypic plasticity to cope with acute short-term heat stress, even for one or few hours of exposure with an absence of an eco-physiological capacity to respond. This may have consequences at the ecological population level, showing a reduced individual ability to survive decreasing population recruitment.

scholarly journals Phenotypic plasticity of labile traits in the wild

2013 ◽  
Vol 59 (4) ◽  
pp. 485-505 ◽  
Author(s):  
Jon E. Brommer
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Statistical Approach ◽  
Scale Up ◽  
Population Level ◽  
Wild Populations ◽  
Quantitative Genetic ◽  
In The Wild ◽  
The Individual ◽  
Quantitative Genetic Parameters

Abstract Individual-based studies allow quantification of phenotypic plasticity in behavioural, life-history and other labile traits. The study of phenotypic plasticity in the wild can shed new light on the ultimate objectives (1) whether plasticity itself can evolve or is constrained by its genetic architecture, and (2) whether plasticity is associated to other traits, including fitness (selection). I describe the main statistical approach for how repeated records of individuals and a description of the environment (E) allow quantification of variation in plasticity across individuals (IxE) and genotypes (GxE) in wild populations. Based on a literature review of life-history and behavioural studies on plasticity in the wild, I discuss the present state of the two objectives listed above. Few studies have quantified GxE of labile traits in wild populations, and it is likely that power to detect statistically significant GxE is lacking. Apart from the issue of whether it is heritable, plasticity tends to correlate with average trait expression (not fully supported by the few genetic estimates available) and may thus be evolutionary constrained in this way. Individual-specific estimates of plasticity tend to be related to other traits of the individual (including fitness), but these analyses may be anti-conservative because they predominantly concern stats-on-stats. Despite the increased interest in plasticity in wild populations, the putative lack of power to detect GxE in such populations hinders achieving general insights. I discuss possible steps to invigorate the field by moving away from simply testing for presence of GxE to analyses that ‘scale up’ to population level processes and by the development of new behavioural theory to identify quantitative genetic parameters which can be estimated.

Photoluminescence Studies of [(CdSe)1(ZnSe)2]9-ZnSeTe Multiple Quantum Wells Under High Pressure

1994 ◽  
Vol 358 ◽  
Author(s):  
Z.P. Wang ◽  
Z.X. Liu ◽  
H.X. Han ◽  
J.Q. Zhang ◽  
G.H. Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Quantum Wells ◽  
Liquid Nitrogen Temperature ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type I ◽  
Short Period ◽  
Heavy Hole Subband ◽  
Photoluminescence Studies ◽  
Increasing Temperature

ABSTRACTWe have performed photoluminescence (PL) measurements at liquid nitrogen temperature under high pressure up to 5.5 GPa and in the temperature range 10-300 K at atmospheric pressure on {(ZnSe)30(ZnSe0.92Te0.08)30(ZnSe)30[(CdSe)1(ZnSe)2]9}x5 multiple quantum wells. The PL peaks, EB, E1 and Ew corresponding to the band edge luminescence in ZnSe barrier layer, the transitions from the first conduction subband to the heavy-hole subband in ZnSe0.92Te0.08 layers and [(CdSe)1(ZnSe)2]9 ultra short period superlattice quantum well (SPSLQW) layers have been observed. Experimental results show that ZnSe0.92Te0.08/ZnSe forms a type-I superlattice (SL) in contrast to the type-II ZnSe/ZnTe SL. The pressure coefficients of the EB, E1 and Ew exciton peaks have been determined as 67, 63 and 56 meV/GPa, respectively. With increasing temperature (or pressure), the E1 peak-intensity drastically decreases which is attributed to the thermal effect (or the appearance of many defects in ZnSe0.92Te0.08 under higher pressure).

scholarly journals Climate change enhances disease processes in crustaceans: case studies in lobsters, crabs, and shrimps

2019 ◽  
Author(s):  
Jeffrey D Shields
Keyword(s):  
Climate Change ◽  
Multiple Stressors ◽  
Population Level ◽  
Microbial Pathogens ◽  
Important Species ◽  
Immunological Responses ◽  
Developmental Rates ◽  
Commercially Important ◽  
Physiological Demands ◽  
Increasing Temperature

Abstract Climate change has resulted in increasing temperature and acidification in marine systems. Rising temperature and acidification act as stressors that negatively affect host barriers to infection, thus enhancing disease processes and influencing the emergence of pathogens in ecologically and commercially important species. Given that crustaceans are ectotherms, changes in temperature dominate their physiological and immunological responses to microbial pathogens and parasites. Because of this, the thermal ranges of several crustacean hosts and their pathogens can be used to project the outcomes of infections. Host factors such as molting, maturation, respiration, and immune function are strongly influenced by temperature, which in turn alter the host’s susceptibility to pathogens, further amplifying morbidity and mortality. Microbial pathogens are also strongly influenced by temperature, arguably more so than their crustacean hosts. Microbial pathogens, with higher thermal optima than their hosts, grow rapidly and overcome host immune defenses, which have been weakened by increased temperatures. Pathogen factors such as metabolic rates, growth rates, virulence factors, and developmental rates are often enhanced by rising temperature, which translates into increased transmission, dispersal, and proliferation at the population level, and ultimately emergence of outbreaks in host populations. Less well known are the effects of acidification and salinity intrusion on host-pathogen processes, but they operate alongside temperature, as multiple stressors, that impose significant metabolic and physiological demands on host homeostasis.

scholarly journals High differentiation in functional traits but similar phenotypic plasticity in populations of a soil specialist along a climatic gradient

2020 ◽  
Vol 125 (6) ◽  
pp. 969-980 ◽  
Author(s):  
Silvia Matesanz ◽  
Marina Ramos-Muñoz ◽  
Mario Blanco-Sánchez ◽  
Adrián Escudero
Keyword(s):  
Genetic Variation ◽  
Phenotypic Plasticity ◽  
Functional Traits ◽  
Common Garden ◽  
Population Level ◽  
General Purpose ◽  
Climatic Conditions ◽  
Environment Interaction ◽  
Moisture Variation ◽  
Neutral Genetic Variation

Abstract Background and Aims Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. Methods We created an outdoor common garden with rain exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life history and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. Key Results In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these probably adaptive responses were common to all populations, as shown by the lack of population × environment interaction for almost all functional traits. This generally common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. Conclusions Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site of origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.

scholarly journals Behavioural Phenotypic Plasticity of Submerged Oviposition in Damselflies (Insecta: Odonata)

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 124
Author(s):  
Jana Branwen Helebrandová ◽  
Petr Pyszko ◽  
Aleš Dolný
Keyword(s):  
Phenotypic Plasticity ◽  
Common Species ◽  
Temperate Zone ◽  
Learning Potential ◽  
Males And Females ◽  
Lestes Sponsa ◽  
The Difference ◽  
Submerged Oviposition

Emerald damselfly Lestes sponsa is a common species within the temperate zone, with no special need for protection. The tactic of submerged oviposition is well known from other Odonata species, but has rarely been noticed or described in Lestes sponsa. Our study investigated the tactics of oviposition in this species, and shows that submerged oviposition indeed occurs frequently in Lestes sponsa. We experimentally tested the difference in the roles of males and females during the submerged ovipositional behaviour by combining males/females from submerging populations with males/females from non-submerging populations. We discovered that, whereas submerging males coupling with non-submerging females did not lead to submersion, the opposite combination of pairs submerged. Other patterns of submersions are discussed further in this paper. Our research led to the conclusion that damselflies have the ability to learn and react to different situations in keeping with the learning potential of insects in general.

Patterns of metamorphic age and length in marine fishes, from individuals to taxa

2000 ◽  
Vol 57 (4) ◽  
pp. 856-869 ◽  
Author(s):  
Hugues P Benoît ◽  
Pierre Pepin ◽  
Joseph A Brown
Keyword(s):  
Growth Rate ◽  
Population Level ◽  
Individual Variability ◽  
Marine Fishes ◽  
Exponential Relationship ◽  
Factors Affecting ◽  
The Mean ◽  
Time Required ◽  
Increasing Temperature ◽  
Dominant Influence

We present a summary of variability in age and length at metamorphosis for marine fishes. Data from the literature were partitioned into taxonomic, population, and individual levels of resolution to examine the factors affecting the timing of metamorphosis. Temperature appears to be a dominant influence on timing, likely due to its effect on growth rate. Interspecifically, length at metamorphosis correlated poorly with that at hatching but was significantly related to temperature. This pattern was inconsistent for population-level comparisons. Metamorphic age decreased exponentially with increasing temperature in interspecific and population-level comparisons but did not covary with length for either level of resolution. This suggests that age at metamorphosis largely reflects the time required to grow to a given metamorphic length. Within populations, the correlation between metamorphic age and length increases with growth rate, a reflection of variance in age and length. A strong exponential relationship between mean metamorphic age and length and their associated variability (SD) exists, with a slope greater than unity in both cases (i.e., variability increases relative to the mean). With these relationships, we can infer the manner in which individual variability in metamorphic traits is generated throughout ontogeny. These results are considered in light of recruitment variability in marine fishes.

scholarly journals Individual heterogeneity influences the effects of translocation on urban dispersal of an invasive reptile

2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Abigail B. Feuka ◽  
Melia G. Nafus ◽  
Amy A. Yackel Adams ◽  
Larissa L. Bailey ◽  
Mevin B. Hooten
Keyword(s):  
Urban Areas ◽  
Experimental Treatment ◽  
Population Level ◽  
Step Length ◽  
Individual Heterogeneity ◽  
Small Scale ◽  
Boiga Irregularis ◽  
Bayesian Hierarchical ◽  
Treatment Groups ◽  
Movement Parameters

Abstract Background Invasive reptiles pose a serious threat to global biodiversity, but early detection of individuals in an incipient population is often hindered by their cryptic nature, sporadic movements, and variation among individuals. Little is known about the mechanisms that affect the movement of these species, which limits our understanding of their dispersal. Our aim was to determine whether translocation or small-scale landscape features affect movement patterns of brown treesnakes (Boiga irregularis), a destructive invasive predator on the island of Guam. Methods We conducted a field experiment to compare the movements of resident (control) snakes to those of snakes translocated from forests and urban areas into new urban habitats. We developed a Bayesian hierarchical model to analyze snake movement mechanisms and account for attributes unique to invasive reptiles by incorporating multiple behavioral states and individual heterogeneity in movement parameters. Results We did not observe strong differences in mechanistic movement parameters (turning angle or step length) among experimental treatment groups. We found some evidence that translocated snakes from both forests and urban areas made longer movements than resident snakes, but variation among individuals within treatment groups weakened this effect. Snakes translocated from forests moved more frequently from pavement than those translocated from urban areas. Snakes translocated from urban areas moved less frequently from buildings than resident snakes. Resident snakes had high individual heterogeneity in movement probability. Conclusions Our approach to modeling movement improved our understanding of invasive reptile dispersal by allowing us to examine the mechanisms that influence their movement. We also demonstrated the importance of accounting for individual heterogeneity in population-level analyses, especially when management goals involve eradication of an invasive species.

scholarly journals Inter- and intraspecific phenotypic plasticity of three phytoplankton species in response to ocean acidification

2017 ◽  
Vol 13 (2) ◽  
pp. 20160774 ◽  
Author(s):  
Giannina S. I. Hattich ◽  
Luisa Listmann ◽  
Julia Raab ◽  
Dorthe Ozod-Seradj ◽  
Thorsten B. H. Reusch ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Ocean Acidification ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Population Level ◽  
Reaction Norms ◽  
Short Time Scale ◽  
Sampling Effort ◽  
Phytoplankton Species ◽  
Species Response

Phenotypic plasticity describes the phenotypic adjustment of the same genotype to different environmental conditions and is best described by a reaction norm. We focus on the effect of ocean acidification on inter- and intraspecific reaction norms of three globally important phytoplankton species ( Emiliania huxleyi, Gephyrocapsa oceanica and Chaetoceros affinis ). Despite significant differences in growth rates between the species, they all showed a high potential for phenotypic buffering (similar growth rates between ambient and high CO 2 conditions). Only three coccolithophore genotypes showed a reduced growth in high CO 2 . Diverging responses to high CO 2 of single coccolithophore genotypes compared with the respective mean species responses, however, raise the question of whether an extrapolation to the population level is possible from single-genotype experiments. We therefore compared the mean response of all tested genotypes with a total species response comprising the same genotypes, which was not significantly different in the coccolithophores. Assessing species reaction norms to different environmental conditions on short time scale in a genotype-mix could thus reduce sampling effort while increasing predictive power.

Nontuberculous Mycobacteria in Cystic Fibrosis

2018 ◽  
Vol 39 (03) ◽  
pp. 383-391 ◽  
Author(s):  
Patrick Flume ◽  
Brian Furukawa
Keyword(s):  
Cystic Fibrosis ◽  
Nontuberculous Mycobacteria ◽  
Population Level ◽  
Common Species ◽  
Mycobacterium Abscessus ◽  
Multisystem Disease ◽  
Treatment Regimens ◽  
Lung Microbiome ◽  
Raising Awareness ◽  
Potential Interactions

AbstractNontuberculous mycobacteria (NTM) can cause chronic pulmonary infection in susceptible hosts. Individuals with cystic fibrosis (CF), a multisystem disease predominated by progressive structural lung disease, are particularly vulnerable. Only recently have NTM been recognized for their potential to cause lung deterioration in CF patients. The reported prevalence varies widely from 4 to 40%, significantly more common than in the general population, but this varies because of multiple factors including inconsistent screening practices. Mycobacterium abscessus complex and Mycobacterium avium complex are the two most common species recovered. Defining NTM pulmonary disease in a CF patient can present challenges as it can be difficult to distinguish from the other potentially pathogenic organisms in the lung microbiome. In general, treatment regimens do not differ from the non-CF population but the clinician should be aware of potential interactions with other CF therapies. Recent population-level genomics has raised serious concern for indirect person-to-person transmission of several dominating NTM clones worldwide, raising awareness for increase prevention strategies when CF patients potentially congregate, such as clinic visits. Lung transplantation is controversial in those with NTM present in sputum culture but the available evidence suggests that this is not an absolute contraindication.

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