scholarly journals Comparative analysis of the ftness of Drosophila virilis lines contrasting in response to stress

2019 ◽  
Vol 22 (8) ◽  
pp. 1090-1096
Author(s):  
E. K. Karpova ◽  
I. Yu. Rauschenbach ◽  
N. E. Gruntenko
Keyword(s):  
Heat Stress ◽  
Natural Populations ◽  
Population Level ◽  
Stress Reaction ◽  
Egg Laying ◽  
Drosophila Virilis ◽  
Gonadotropic Hormone ◽  
Adverse Conditions ◽  
Low Intensity ◽  
Response To Stress

One of the crucial elements contributing to the adaptation of organisms to unfavorable environmental conditions is the reaction of stress. The study of its genetic control and role in adaptation to unfavorable conditions are of special interest. The juvenile hormone (JH) acts as a gonadotropic hormone in adult insects controlling the development of the ovaries, inducing vitellogenesis and oviposition. It was shown that a decrease in JH degradation in individuals reacting to adverse conditions by stress reaction (R­individuals) causes delay in egg laying and seems to allow the population to “wait out” the unfavorable conditions, thereby contributing to the adaptation at the population level. However, monitoring natural populations of D. melanogaster for the capability of stress reaction demonstrated that they have a high percentage of individuals incapable of it (NR­individuals). The study of reproductive characteristics of R­ and NR­individuals showed that under normal conditions R­individuals have the advantage of procreating offspring. Under unfavorable conditions, if the stressor is intense enough, NR­individuals die, but if its intensity is low, then they, unlike R­individuals, continue to produce offspring. Based on these data, it was hypothesized that the balance of R­ and NR­alleles in the population ensures its adaptation under frequent stresses of low intensity. To verify the hypothesis by an experiment, the ftness characteristics (lifespan, fecundity) of the R and NR lines of D. virilis were studied under normal conditions and under regular heat stress of various frequency.

scholarly journals Comparative analysis of the ftness of Drosophila virilis lines contrasting in response to stress

2019 ◽  
Vol 22 (8) ◽  
pp. 1090-1096
Author(s):  
E. K. Karpova ◽  
I. Yu. Rauschenbach ◽  
N. E. Gruntenko
Keyword(s):  
Heat Stress ◽  
Natural Populations ◽  
Population Level ◽  
Stress Reaction ◽  
Egg Laying ◽  
Drosophila Virilis ◽  
Gonadotropic Hormone ◽  
Adverse Conditions ◽  
Low Intensity ◽  
Response To Stress

One of the crucial elements contributing to the adaptation of organisms to unfavorable environmental conditions is the reaction of stress. The study of its genetic control and role in adaptation to unfavorable conditions are of special interest. The juvenile hormone (JH) acts as a gonadotropic hormone in adult insects controlling the development of the ovaries, inducing vitellogenesis and oviposition. It was shown that a decrease in JH degradation in individuals reacting to adverse conditions by stress reaction (R­individuals) causes delay in egg laying and seems to allow the population to “wait out” the unfavorable conditions, thereby contributing to the adaptation at the population level. However, monitoring natural populations of D. melanogaster for the capability of stress reaction demonstrated that they have a high percentage of individuals incapable of it (NR­individuals). The study of reproductive characteristics of R­ and NR­individuals showed that under normal conditions R­individuals have the advantage of procreating offspring. Under unfavorable conditions, if the stressor is intense enough, NR­individuals die, but if its intensity is low, then they, unlike R­individuals, continue to produce offspring. Based on these data, it was hypothesized that the balance of R­ and NR­alleles in the population ensures its adaptation under frequent stresses of low intensity. To verify the hypothesis by an experiment, the ftness characteristics (lifespan, fecundity) of the R and NR lines of D. virilis were studied under normal conditions and under regular heat stress of various frequency.

scholarly journals Comparative analysis of the fitness of Drosophila virilis lines contrasting in response to stress

2015 ◽  
Vol 19 (6) ◽  
pp. 1-7
Author(s):  
E. K. Karpova ◽  
I. Yu. Rauschenbach ◽  
N. E. Gruntenko
Keyword(s):  
Heat Stress ◽  
Natural Populations ◽  
Population Level ◽  
Stress Reaction ◽  
Egg Laying ◽  
Drosophila Virilis ◽  
Gonadotropic Hormone ◽  
Adverse Conditions ◽  
Low Intensity ◽  
Response To Stress

One of the crucial elements contributing to the adaptation of organisms to unfavorable environmental conditions is the reaction of stress. The study of its genetic control and role in adaptation to unfavorable conditions are of special interest. The juvenile hormone (JH) acts as a gonadotropic hormone in adult insects controlling the development of the ovaries, inducing vitellogenesis and oviposition. It was shown that a decrease in JH degradation in individuals reacting to adverse conditions by stress reaction (R-individuals) causes delay in egg laying and seems to allow the population to “wait out” the unfavorable conditions, thereby contributing to the adaptation at the population level. However, monitoring natural populations of D. melanogaster for the capability of stress reaction demonstrated that they have a high percentage of individuals incapable of it (NR-individuals). The study of reproductive characteristics of R- and NR-individuals showed that under normal conditions R-individuals have the advantage of procreating offspring. Under unfavorable conditions, if the stressor is intense enough, NR-individuals die, but if its intensity is low, then they, unlike R-individuals, continue to produce offspring. Based on these data, it was hypothesized that the balance of R- and NR-alleles in the population ensures its adaptation under frequent stresses of low intensity. To verify the hypothesis by an experiment, the fitness characteristics (lifespan, fecundity) of the R and NR lines of D. virilis were studied under normal conditions and under regular heat stress of various frequency.

scholarly journals Natural variation in yolk fatty acids, but not androgens, predicts offspring fitness in a wild bird

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lucia Mentesana ◽  
Martin N. Andersson ◽  
Stefania Casagrande ◽  
Wolfgang Goymann ◽  
Caroline Isaksson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Maternal Effects ◽  
Natural Variation ◽  
De Novo ◽  
Natural Populations ◽  
Egg Laying ◽  
Interactive Effects ◽  
Free Living ◽  
Offspring Fitness

Abstract Background In egg-laying animals, mothers can influence the developmental environment and thus the phenotype of their offspring by secreting various substances into the egg yolk. In birds, recent studies have demonstrated that different yolk substances can interactively affect offspring phenotype, but the implications of such effects for offspring fitness and phenotype in natural populations have remained unclear. We measured natural variation in the content of 31 yolk components known to shape offspring phenotypes including steroid hormones, antioxidants and fatty acids in eggs of free-living great tits (Parus major) during two breeding seasons. We tested for relationships between yolk component groupings and offspring fitness and phenotypes. Results Variation in hatchling and fledgling numbers was primarily explained by yolk fatty acids (including saturated, mono- and polyunsaturated fatty acids) - but not by androgen hormones and carotenoids, components previously considered to be major determinants of offspring phenotype. Fatty acids were also better predictors of variation in nestling oxidative status and size than androgens and carotenoids. Conclusions Our results suggest that fatty acids are important yolk substances that contribute to shaping offspring fitness and phenotype in free-living populations. Since polyunsaturated fatty acids cannot be produced de novo by the mother, but have to be obtained from the diet, these findings highlight potential mechanisms (e.g., weather, habitat quality, foraging ability) through which environmental variation may shape maternal effects and consequences for offspring. Our study represents an important first step towards unraveling interactive effects of multiple yolk substances on offspring fitness and phenotypes in free-living populations. It provides the basis for future experiments that will establish the pathways by which yolk components, singly and/or interactively, mediate maternal effects in natural populations.

scholarly journals From individual to population level: Temperature and snow cover modulate fledging success through breeding phenology in greylag geese (Anser anser)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Didone Frigerio ◽  
Petra Sumasgutner ◽  
Kurt Kotrschal ◽  
Sonia Kleindorfer ◽  
Josef Hemetsberger
Keyword(s):  
Ambient Temperature ◽  
Reproductive Output ◽  
Population Level ◽  
Egg Laying ◽  
Future Research ◽  
Breeding Phenology ◽  
Anser Anser ◽  
Fledging Success ◽  
Average Annual Temperature ◽  
Greylag Geese

AbstractLocal weather conditions may be used as environmental cues by animals to optimize their breeding behaviour, and could be affected by climate change. We measured associations between climate, breeding phenology, and reproductive output in greylag geese (Anser anser) across 29 years (1990–2018). The birds are individually marked, which allows accurate long-term monitoring of life-history parameters for all pairs within the flock. We had three aims: (1) identify climate patterns at a local scale in Upper Austria, (2) measure the association between climate and greylag goose breeding phenology, and (3) measure the relationship between climate and both clutch size and fledging success. Ambient temperature increased 2 °C across the 29-years study period, and higher winter temperature was associated with earlier onset of egg-laying. Using the hatch-fledge ratio, average annual temperature was the strongest predictor for the proportion of fledged goslings per season. There is evidence for an optimum time window for egg-laying (the earliest and latest eggs laid had the lowest fledging success). These findings broaden our understanding of environmental effects and population-level shifts which could be associated with increased ambient temperature and can thus inform future research about the ecological consequences of climate changes and reproductive output in avian systems.

Thermal and Starvation Stress Response of Escherichia coli O157:H7 Isolates Selected from Agricultural Environments

2016 ◽  
Vol 79 (10) ◽  
pp. 1673-1679 ◽  
Author(s):  
ACHYUT ADHIKARI ◽  
ANDY BARY ◽  
CRAIG COGGER ◽  
CALEB JAMES ◽  
GÜLHAN ÜNLÜ ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Stress ◽  
Stress Response ◽  
Weibull Model ◽  
Stress Conditions ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
Starvation Stress ◽  
E Coli ◽  
Response To Stress

ABSTRACT Pathogens exposed to agricultural production environments are subject to multiple stresses that may alter their survival under subsequent stress conditions. The objective of this study was to examine heat and starvation stress response of Escherichia coli O157:H7 strains isolated from agricultural matrices. Seven E. coli O157:H7 isolates from different agricultural matrices—soil, compost, irrigation water, and sheep manure—were selected, and two ATCC strains were used as controls. The E. coli O157:H7 isolates were exposed to heat stress (56°C in 0.1% peptone water for up to 1 h) and starvation (in phosphate-buffered saline at 37°C for 15 days), and their survival was examined. GInaFiT freeware tool was used to perform regression analyses of the surviving populations. The Weibull model was identified as the most appropriate model for response of the isolates to heat stress, whereas the biphasic survival curves during starvation were fitted using the double Weibull model, indicating the adaptation to starvation or a resistant subpopulation. The inactivation time during heating to achieve the first decimal reduction time (δ) calculated with the Weibull parameters was the highest (45 min) for a compost isolate (Comp60A) and the lowest (28 min) for ATCC strain 43895. Two of the nine isolates (ATCC 43895 and a manure isolate) had β < 1, indicating that surviving populations adapted to heat stress, and six strains demonstrated downward concavity (β > 1), indicating decreasing heat resistance over time. The ATCC strains displayed the longest δ2 (>1,250 h) in response to starvation stress, compared with from 328 to 812 h for the environmental strains. The considerable variation in inactivation kinetics of E. coli O157:H7 highlights the importance of evaluating response to stress conditions among individual strains of a specific pathogen. Environmental isolates did not exhibit more robust response to stress conditions in this study compared with ATCC strains.

scholarly journals Epigenetic mediation of the onset of reproduction in a songbird

2020 ◽  
Author(s):  
Melanie Lindner ◽  
Veronika N. Laine ◽  
Irene Verhagen ◽  
Heidi M. Viitaniemi ◽  
Marcel E. Visser ◽  
...  
Keyword(s):  
Climate Change ◽  
Dna Methylation ◽  
Phenotypic Plasticity ◽  
Regulatory Region ◽  
Natural Populations ◽  
Parus Major ◽  
Great Tit ◽  
Egg Laying ◽  
Avian Reproduction ◽  
Directional Variation

ABSTRACTClimate change significantly impacts natural populations, particularly phenology traits, like the seasonal onset of reproduction in birds. This impact is mainly via plastic responses in phenology traits to changes in the environment, but the molecular mechanism mediating this plasticity remains elusive. Epigenetic modifications can mediate plasticity and consequently constitute promising candidates for mediating phenology traits. Here, we used genome-wide DNA methylation profiles of individual great tit (Parus major) females that we blood sampled repeatedly throughout the breeding season. We demonstrate rapid and directional variation in DNA methylation within the regulatory region of genes known to play key roles in avian reproduction that are in line with observed changes in gene expression in chickens. Our findings provide an important step towards unraveling the molecular mechanism mediating a key life history trait, an essential knowledge-gap for understanding how natural populations may cope with future climate change.IMPACT SUMMARYNatural populations are increasingly challenged by changing environmental conditions like global increases in temperature. A key way for species to adapt to global warming is via phenotypic plasticity, i.e. the ability to adjust the expression of traits to the environment. We, however, know little about how the environment can interact with an organism’s genetic make-up to shape its trait value. Epigenetic marks are known to vary with the environment and can modulate the expression of traits without any change in the genetic make-up and therefore have the potential to mediate phenotypic plasticity.To study the role of epigenetics for phenotypic plasticity, we here focus on the great tit (Parus major), a species that is strongly affected by global warming and plastic for temperature in an essential phenology trait, the seasonal onset of egg laying. As a first step, we investigated whether great tit females show within-individual and short-term variation in DNA methylation that corresponds to changes in the reproductive state of females. We therefore housed breeding pairs in climate-controlled aviaries to blood sample each female repeatedly throughout the breeding season and used these repeated samples for methylation profiling.We found rapid and directional variation in DNA methylation at the time females prepared to initiate egg laying that is located within the regulatory region of genes that have previously described functions for avian reproduction. Although future work is needed to establish a causal link between the observed temporal variation in DNA methylation and the onset of reproduction in female great tits, our work highlights the potential role for epigenetic modifications in mediating an essential phenology trait that is sensitive to temperatures.

scholarly journals Perspectives from animal demography on incorporating evolutionary mechanism into plant population dynamics

2018 ◽  
Author(s):  
Maria Paniw
Keyword(s):  
Environmental Change ◽  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Population Level ◽  
Plant Population ◽  
Future Research ◽  
Phenotypic Traits ◽  
Plant Population Dynamics ◽  
Future Research Agenda ◽  
Powerful Approach

AbstractWith a growing number of long-term, individual-based data on natural populations available, it has become increasingly evident that environmental change affects populations through complex, simultaneously occurring demographic and evolutionary processes. Analyses of population-level responses to environmental change must therefore integrate demography and evolution into one coherent framework. Integral projection models (IPMs), which can relate genetic and phenotypic traits to demographic and population-level processes, offer a powerful approach for such integration. However, a rather artificial divide exists in how plant and animal population ecologists use IPMs. Here, I argue for the integration of the two sub-disciplines, particularly focusing on how plant ecologists can diversify their toolset to investigate selection pressures and eco-evolutionary dynamics in plant population models. I provide an overview of approaches that have applied IPMs for eco-evolutionary studies and discuss a potential future research agenda for plant population ecologists. Given an impending extinction crisis, a holistic look at the interacting processes mediating population persistence under environmental change is urgently needed.

The relation between food, age and flight in the Rutherglen bug, Nysiusm vinitor (Hemiptera : Lygaeidae)

1973 ◽  
Vol 21 (3) ◽  
pp. 427 ◽  
Author(s):  
M Kehat ◽  
M Wyndham
Keyword(s):  
Emerging Adults ◽  
Adult Stage ◽  
Egg Laying ◽  
Flight Activity ◽  
Causal Factors ◽  
Adverse Conditions ◽  
Flight Response ◽  
Species Displacement ◽  
Food Consumed

The relationships between food, egg-laying, age, and flight were studied with the aim of providing a better understanding of the causal factors of displacement flights in N. vinitor. The distinction in N. vinitor between "fliers" and "non-fliers" is, most probably, a reflection of the environment. Thus, an increased proportion of individuals taking off and of distinctively prolonged flights were a response to inadequate food either during the nymphal or adult stage. Shortage of water during the adult stage resulted also in increased flight activity. The quality of the food consumed by the nymphs rather than its quantity affected the behavioural flight response of emerging adults. Immature females, whether virgin or not, had different flight responses from egg-laying females and are probably the true migrants of the species. Displacement flights in N. vinitor are always triggered by adverse conditions in the nymphal or adult stage, but the type of flight changes as females become older; flights are migratory in the immature females and dispersive in the mature ones.

scholarly journals Ecological Immunology of mosquito-malaria interactions: Of non-natural versus natural model systems and their inferences

Parasitology ◽  
2009 ◽  
Vol 136 (14) ◽  
pp. 1935-1942 ◽  
Author(s):  
F. TRIPET
Keyword(s):  
Immune Responses ◽  
Population Biology ◽  
Experimental Studies ◽  
Natural Populations ◽  
Population Level ◽  
Model Systems ◽  
Ecological Immunology ◽  
Experimental Systems ◽  
Evolutionary Context ◽  
And Function

SUMMARYThere has been a recent shift in the literature on mosquito/Plasmodium interactions with an increasingly large number of theoretical and experimental studies focusing on their population biology and evolutionary processes. Ecological immunology of mosquito-malaria interactions – the study of the mechanisms and function of mosquito immune responses to Plasmodium in their ecological and evolutionary context – is particularly important for our understanding of malaria transmission and how to control it. Indeed, describing the processes that create and maintain variation in mosquito immune responses and parasite virulence in natural populations may be as important to this endeavor as describing the immune responses themselves. For historical reasons, Ecological Immunology still largely relies on studies based on non-natural model systems. There are many reasons why current research should favour studies conducted closer to the field and more realistic experimental systems whenever possible. As a result, a number of researchers have raised concerns over the use of artificial host-parasite associations to generate inferences about population-level processes. Here I discuss and review several lines of evidence that, I believe, best illustrate and summarize the limitations of inferences generated using non-natural model systems.

N6-methyladenosine modification modulate in the heat stress of sheep (Ovis aries)

2019 ◽  
Author(s):  
Zengkui Lu ◽  
Huihua Wang ◽  
Youji Ma ◽  
Mingxing Chu ◽  
Kai Quan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Signaling Pathways ◽  
Stress Responses ◽  
Large Scale ◽  
Ovis Aries ◽  
Stop Codons ◽  
Coding Regions ◽  
Mrna Methylation ◽  
Response To Stress ◽  
And Control

Abstract Background: Intensive and large-scale development of the sheep industry and increases in global temperature are increasingly exposing sheep to heat stress. N6-methyladenosine (m6A) mRNA methylation varies in response to stress, and can link external stress with complex transcriptional and post-transcriptional processes. However, no m6A mRNA methylation map has been obtained for sheep, nor is it known what effect this has on regulating heat stress in sheep. Results: A total of 8,306 and 12,958 m6A peaks were detected in heat stress and control groups, respectively, with 2,697 and 5,494 genes associated with each. Peaks were mainly enriched in coding regions and near stop codons with classical RRACH motifs. Methylation levels of heat stress and control sheep were higher near stop codons, although methylation was significantly lower in heat stress sheep. GO revealed that differential m6A-containing genes were mainly enriched in the nucleus and were involved in several stress responses and substance metabolism processes. KEGG pathway analysis found that differential m6A-containing genes were significantly enriched in Rap1, FoxO, MAPK, and other signaling pathways of the stress response, and TGF-beta, AMPK, Wnt, and other signaling pathways involved in fat metabolism. These m6A-modified genes were moderately expressed in both heat stress and control sheep, and the enrichment of m6A modification was significantly negatively correlated with gene expression. Conclusions: Our results showed that m6A mRNA methylation modifications regulate heat stress in sheep, and it also provided a new way for the study of animal response to heat stress.

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