scholarly journals Dopamine mediates life-history responses to food abundance in Daphnia

2020 ◽  
Vol 287 (1930) ◽  
pp. 20201069 ◽  
Author(s):  
Semona Issa ◽  
Marlène Gamelon ◽  
Tomasz Maciej Ciesielski ◽  
Kristine Vike-Jonas ◽  
Alexandros G. Asimakopoulos ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Somatic Growth ◽  
Food Abundance ◽  
Reaction Norms ◽  
Life History Trait ◽  
Dopamine System ◽  
Food Ration ◽  
Endogenous Dopamine ◽  
Wide Range

Expression of adaptive reaction norms of life-history traits to spatio-temporal variation in food availability is crucial for individual fitness. Yet little is known about the neural signalling mechanisms underlying these reaction norms. Previous studies suggest a role for the dopamine system in regulating behavioural and morphological responses to food across a wide range of taxa. We tested whether this neural signalling system also regulates life-history reaction norms by exposing the zooplankton Daphnia magna to both dopamine and the dopamine reuptake inhibitor bupropion, an antidepressant that enters aquatic environments via various pathways. We recorded a range of life-history traits across two food levels. Both treatments induced changes to the life-history reaction norm slopes. These were due to the effects of the treatments being more pronounced at restricted food ration, where controls had lower somatic growth rates, higher age and larger size at maturation. This translated into a higher population growth rate ( r ) of dopamine and bupropion treatments when food was restricted. Our findings show that the dopamine system is an important regulatory mechanism underlying life-history trait responses to food abundance and that bupropion can strongly influence the life history of aquatic species such as D. magna . We discuss why D. magna do not evolve towards higher endogenous dopamine levels despite the apparent fitness benefits.

scholarly journals Mapping the adaptive landscape of a major agricultural pathogen reveals evolutionary constraints across heterogeneous environments

2021 ◽  
Author(s):  
Anik Dutta ◽  
Fanny E. Hartmann ◽  
Carolina Sardinha Francisco ◽  
Bruce A. McDonald ◽  
Daniel Croll
Keyword(s):  
Life History ◽  
Large Scale ◽  
Life History Traits ◽  
Genetic Correlations ◽  
Stress Factors ◽  
Life History Trait ◽  
Adaptive Landscape ◽  
Heterogeneous Environments ◽  
Growth Responses ◽  
Trade Offs

AbstractThe adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen’s ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.

scholarly journals Natural variation in fecundity is correlated with species-wide levels of divergence in Caenorhabditis elegans

2021 ◽  
Author(s):  
Gaotian Zhang ◽  
Jake D Mostad ◽  
Erik C Andersen
Keyword(s):  
Life History ◽  
Caenorhabditis Elegans ◽  
Life History Traits ◽  
Life History Trait ◽  
Selective Sweeps ◽  
C Elegans ◽  
Genome Wide ◽  
Genetic Complexity ◽  
Genomic Regions ◽  
Global Population

Abstract Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g. a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. Additionally, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.

scholarly journals Loci, genes, and gene networks associated with life history variation in a model ecological organism,Daphnia pulex(complex)

2018 ◽  
Author(s):  
Jacob W. Malcom ◽  
Thomas E. Juenger ◽  
Mathew A. Leibold
Keyword(s):  
Gene Expression ◽  
Genetic Variation ◽  
Life History ◽  
Molecular Basis ◽  
Life History Traits ◽  
Evolutionary Dynamics ◽  
Daphnia Pulex ◽  
Life History Trait ◽  
Life History Variation ◽  
Trait Variation

ABSTRACTBackgroundIdentifying the molecular basis of heritable variation provides insight into the underlying mechanisms generating phenotypic variation and the evolutionary history of organismal traits. Life history trait variation is of central importance to ecological and evolutionary dynamics, and contemporary genomic tools permit studies of the basis of this variation in non-genetic model organisms. We used high density genotyping, RNA-Seq gene expression assays, and detailed phenotyping of fourteen ecologically important life history traits in a wild-caught panel of 32Daphnia pulexclones to explore the molecular basis of trait variation in a model ecological species.ResultsWe found extensive phenotypic and a range of heritable genetic variation (~0 < H2< 0.44) in the panel, and accordingly identify 75-261 genes—organized in 3-6 coexpression modules—associated with genetic variation in each trait. The trait-related coexpression modules possess well-supported promoter motifs, and in conjunction with marker variation at trans- loci, suggest a relatively small number of important expression regulators. We further identify a candidate genetic network with SNPs in eight known transcriptional regulators, and dozens of differentially expressed genes, associated with life history variation. The gene-trait associations include numerous un-annotated genes, but also support several a priori hypotheses, including an ecdysone-induced protein and several Gene Ontology pathways.ConclusionThe genetic and gene expression architecture ofDaphnialife history traits is complex, and our results provide numerous candidate loci, genes, and coexpression modules to be tested as the molecular mechanisms that underlieDaphniaeco-evolutionary dynamics.

scholarly journals A novel experimental approach for studying life-history traits of phytophagous arthropods utilizing an artificial culture medium

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kamila Karpicka-Ignatowska ◽  
Alicja Laska ◽  
Lechosław Kuczyński ◽  
Brian G. Rector ◽  
Mariusz Lewandowski ◽  
...  
Keyword(s):  
Life History ◽  
Host Plant ◽  
Life History Traits ◽  
Culture Medium ◽  
Interspecific Interactions ◽  
Suitable Condition ◽  
Mite Species ◽  
Artificial Culture ◽  
Wide Range ◽  
Artificial Culture Medium

AbstractExperimental approaches to studying life-history traits in minute herbivorous arthropods are hampered by the need to work with detached host plant material and the difficulty of maintaining that material in a suitable condition to support the animal throughout the duration of the test. In order to address this shortcoming, we developed a customizable agar-based medium modified from an established plant cell-culture medium to nourish detached leaves laid atop it while also preventing arthropods from escaping the experimental arena. The artificial culture medium was tested with two herbivorous mite species: the wheat curl mite (Aceria tosichella; Eriophyidae) and two-spotted spider mite (Tetranychus urticae; Tetranychidae). The proposed approach was a major improvement over a standard protocol for prolonged studies of individual eriophyid mites and also provided some benefits for experiments with spider mites. Moreover, the described method can be easily modified according to the requirements of host plant species and applied to a wide range of microherbivore species. Such applications include investigations of life-history traits and other ecological and evolutionary questions, e.g. mating or competitive behaviours or interspecific interactions, assessing invasiveness potential and predicting possible outbreaks. The approach presented here should have a significant impact on the advancement of evolutionary and ecological research on microscopic herbivores.

scholarly journals Ecological Characteristics of Ventenata dubia in the Intermountain Pacific Northwest

2015 ◽  
Vol 8 (1) ◽  
pp. 57-71 ◽  
Author(s):  
John M. Wallace ◽  
Pamela L. S. Pavek ◽  
Timothy S. Prather
Keyword(s):  
Life History ◽  
Soil Moisture ◽  
Pacific Northwest ◽  
Seed Bank ◽  
Life History Traits ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Habitat Types ◽  
Wide Range

AbstractVentenata dubia is an exotic winter annual grass that has invaded Conservation Reserve Program (CRP) lands, improved pastures, intensively managed hay fields, and rangelands within the Intermountain Pacific Northwest (PNW). Currently, producers are attempting to develop V. dubia management strategies with little knowledge of its life history traits. We conducted several studies to characterize V. dubia life history patterns. Preliminary germination trials were completed to describe primary and secondary dormancy characteristics. Field studies were conducted to evaluate (1) seed bank persistence patterns, (2) seedling emergence patterns under V. dubia litter, and (3) seedling emergence and phenological development patterns within timothy hay, CRP, and rangeland habitats. Preliminary germination trials suggest that the after-ripening period required for loss of dormancy does not exceed 30 d and that dormancy breakdown peaks at approximately 90 d, after which germination occurs over a wide range of temperatures (9 to 29 C). A small fraction (< 1%) of the seed bank remained germinable up to 3 yr after burial at 2 cm depth in a grassland habitat. Seedling emergence and survival was significantly greater under high V. dubia litter layers (100% cover) compared with bare surface during the drier study year because of higher soil moisture levels maintained under litter. Across habitat types, mean seedling emergence (50% of total) occurred between 33 and 94 growing degree days (GDD) after soil moisture rose above the permanent wilting point in the fall. Seedling emergence periodicity varied among habitat types in relation to spring seedling emergence, ranging from 0 to 13% of total emergence per year. Phenological development differed across sites and years by up to several hundred GDDs but was closely aligned to Julian days. This collection of studies improves our understanding of V. dubia life history traits and will aid integrated weed management strategies in the Intermountain PNW.

Mutational divergence of life-history traits in an obligate parthenogen

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 33-35 ◽  
Author(s):  
C. Anna Toline ◽  
Michael Lynch
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Sole Source ◽  
Morphological Characters ◽  
The Other ◽  
Life History Trait ◽  
Adaptive Changes ◽  
Significant Divergence ◽  
Polygenic Variation

Three lines of obligately parthenogenetic Daphnia were allowed to diverge for a 4-year period (approximately 150 generations) with mutation as the sole source of variability. Life-history traits and morphological characters were then surveyed for between-line differences. Significant divergence was found with respect to both number and size of offspring, with no difference in total offspring biomass. No significant differences were found in any of the other characters. These results confirm the hypothesis that purely asexual lines can accumulate enough polygenic variation via mutation to support potentially adaptive changes on a microevolutionary time scale.Key words: Daphnia, life-history trait, mutational divergence, microevolution.

scholarly journals Comparative analysis of life history traits and trends of abundance in coral reefs of the orange-spotted grouper (Epinephelus coioides) from two regions of the Arabian Gulf

2019 ◽  
Vol 76 (4) ◽  
pp. 987-998 ◽  
Author(s):  
Yu-Jia Lin ◽  
Edwin M Grandcourt ◽  
Lotfi Rabaoui ◽  
Rommel H Maneja ◽  
Mohammad A Qurban ◽  
...  
Keyword(s):  
Life History ◽  
Comparative Analysis ◽  
Coral Reefs ◽  
Life History Traits ◽  
Arabian Gulf ◽  
Somatic Growth ◽  
Biological Knowledge ◽  
Epinephelus Coioides ◽  
Reproductive Tactics ◽  
Bidirectional Sex Change

Abstract The orange-spotted grouper Epinephelus coioides is one of the most important commercially exploited fish species in the Arabian Gulf. Studies to establish the basic biological knowledge necessary for sustainable exploitation are few and of limited spatial extent. We carry out a comparative analysis of life history traits of this sequential hermaphrodite and of trends of abundance in coral reefs, northern vs. southern Gulf. We found remarkable differences in sex proportion by length and age, rates of somatic growth, size at maturity and production of gonadic biomass, and no differences in the age composition, mode of growth, timing and duration of spawning, natural mortality rate, and trends of abundance. In the northern Gulf, the reproductive tactics could be diandric protogyny or protandric because males disappear at higher size and later age. In the southern Gulf, the strategy is protogyny, with full predominance of females in early life and full predominance of males in late life. In the northern Gulf, the orange-spotted grouper could exhibit bidirectional sex change. We suggest that fisheries policies should be versatile, consisting of regional-wide as well as local management measures, to account for local differences and regional-wide commonalities in life history traits and trends of abundance.

scholarly journals Impact of global warming scenarios on life-history traits of Tetranychus evansi (Acari: Tetranychidae)

BMC Ecology ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Noureldin Abuelfadl Ghazy ◽  
Tetsuo Gotoh ◽  
Takeshi Suzuki
Keyword(s):  
Global Warming ◽  
Life History ◽  
Life History Traits ◽  
Distribution Range ◽  
Intrinsic Rate Of Increase ◽  
Biological Traits ◽  
Tetranychus Evansi ◽  
Future Global Warming ◽  
Wide Range ◽  
Summer Temperatures

Abstract Background The tomato red spider mite, Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae), is an agricultural pest of solanaceous crops. Although T. evansi is of South American subtropical origin, it has recently expanded its distribution range to many tropical and temperate areas around the world. Its potential distribution range in response to scenarios of global warming was recently modeled, confirming its current and possible future distributions. Here, we experimentally investigated the biological traits of T. evansi in the context of the current and future global warming (2100) scenarios. Using an environmental simulation system, we tested the life-history traits of T. evansi under current summer temperatures (as of June, July, and August 2016) and under expected temperature increases based on two IPCC scenarios: RCP2.6 (+ 1 °C) and RCP8.5 (+ 3.7 °C). The mites were introduced into each scenario on 1 June and their sequential progeny were used for testing in each following month. Results The mite could develop and reproduce under all scenarios. There was a decrease in the duration of lifespan and female fecundity at RCP8.5 during June and August, but this may be compensated for by the high intrinsic rate of increase, which implies faster population growth and shorter generation time. Conclusion Our study and other reports reveal the high adaptability of T. evansi to a wide range of summer temperatures; this may explain its current distribution. We anticipate that global warming will favor the spread of T. evansi and may further expand its distribution to a large area of the globe. These findings should be of ecological and practical relevance for designing prevention and control strategies.

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