scholarly journals Host-parasite coevolution can promote the evolution of seed banking as a bet-hedging strategy

Evolution ◽  
2018 ◽  
Vol 72 (7) ◽  
pp. 1362-1372 ◽  
Author(s):  
Mélissa Verin ◽  
Aurélien Tellier
Keyword(s):  
Bet Hedging ◽  
Hedging Strategy ◽  
Host Parasite

scholarly journals Host-parasite coevolution can promote the evolution of seed banking as a bet-hedging strategy

2018 ◽  
Author(s):  
Mélissa Verin ◽  
Aurélien Tellier
Keyword(s):  
Genetic Linkage ◽  
Bet Hedging ◽  
Gene Model ◽  
Hedging Strategy ◽  
Resistant Genotype ◽  
Additional Hypothesis ◽  
Delayed Emergence ◽  
Environmental Unpredictability ◽  
Banking Strategy ◽  
Host Parasite

AbstractSeed (egg) banking is a common bet-hedging strategy maximizing the fitness of organisms facing environmental unpredictability by the delayed emergence of offspring. Yet, this condition often requires fast and drastic stochastic shifts between good and bad years. We hypothesize that the host seed banking strategy can evolve in response to coevolution with parasites because the coevolutionary cycles promote a gradually changing environment over longer times than seed persistence. We study the evolution of host germination fraction as a quantitative trait using both pairwise competition and multiple mutant competition methods, while the germination locus can be genetically linked or unlinked with the host locus under coevolution. In a gene-for-gene model of coevolution, hosts evolve a seed bank strategy under unstable coevolutionary cycles promoted by moderate to high costs of resistance or strong disease severity. Moreover, when assuming genetic linkage between coevolving and germination loci, the resistant genotype always evolves seed banking in contrast to susceptible hosts. Under a matching-allele interaction, both hosts’ genotypes exhibit the same seed banking strategy irrespective of the genetic linkage between loci. We suggest host-parasite coevolution as an additional hypothesis for the evolution of seed banking as a temporal bet-hedging strategy.

scholarly journals Individual reversible plasticity as a genotype‐level bet‐hedging strategy

2021 ◽  
Author(s):  
Thomas R. Haaland ◽  
Jonathan Wright ◽  
Irja I. Ratikainen
Keyword(s):  
Bet Hedging ◽  
Hedging Strategy

Cleistogamy as a bet‐hedging strategy in Oxalis acetosella , a perennial herb

1998 ◽  
Vol 86 (3) ◽  
pp. 491-500 ◽  
Author(s):  
Henrik Berg ◽  
Peter Redbo‐torstensson
Keyword(s):  
Perennial Herb ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Oxalis Acetosella

scholarly journals Different resource allocation in a Bacillus subtilis population displaying bimodal motility

2021 ◽  
Author(s):  
Simon Syvertsson ◽  
Biwen Wang ◽  
Jojet Staal ◽  
Yongqiang Gao ◽  
Remco Kort ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Exponential Growth ◽  
Environmental Changes ◽  
Feedback Regulation ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Negative Feedback Regulation ◽  
Continuous Increase ◽  
Motile Cells

To cope with sudden changes in their environment, bacteria can use a bet-hedging strategy by dividing the population into cells with different properties. This so-called bimodal or bistable cellular differentiation is generally controlled by positive feedback regulation of transcriptional activators. Due to the continuous increase in cell volume, it is difficult for these activators to reach an activation threshold concentration when cells are growing exponentially. This is one reason why bimodal differentiation is primarily observed from the onset of the stationary phase when exponential growth ceases. An exception is the bimodal induction of motility in Bacillus subtilis, which occurs early during exponential growth. Several mechanisms have been put forward to explain this, including double negative-feedback regulation and the stability of the mRNA molecules involved. In this study, we used fluorescence-assisted cell sorting to compare the transcriptome of motile and non-motile cells and noted that expression of ribosomal genes is lower in motile cells. This was confirmed using an unstable GFP reporter fused to the strong ribosomal rpsD promoter. We propose that the reduction in ribosomal gene expression in motile cells is the result of a diversion of cellular resources to the synthesis of the chemotaxis and motility systems. In agreement, single-cell microscopic analysis showed that motile cells are slightly shorter than non-motile cells, an indication of slower growth. We speculate that this growth rate reduction can contribute to the bimodal induction of motility during exponential growth. IMPORTANCE To cope with sudden environmental changes, bacteria can use a bet-hedging strategy and generate different types of cells within a population, so called bimodal differentiation. For example, a Bacillus subtilis culture can contain both motile and non-motile cells. In this study we compared the gene expression between motile and non-motile cells. It appeared that motile cells express less ribosomes. To confirm this, we constructed a ribosomal promoter fusion that enabled us to measure expression of this promoter in individual cells. This reporter fusion confirmed our initial finding. The re-allocation of cellular resources from ribosome synthesis towards synthesis of the motility apparatus results in a reduction in growth. Interestingly, this growth reduction has been shown to stimulate bimodal differentiation.

A bet-hedging strategy rather than just a classic fast life-history strategy exhibited by invasive fall armyworm

2021 ◽  
Author(s):  
Pengxiang Wu ◽  
Qilin Ren ◽  
Wei Wang ◽  
Zhuo Ma ◽  
Runzhi Zhang
Keyword(s):  
Life History ◽  
Life History Strategy ◽  
Fall Armyworm ◽  
Bet Hedging ◽  
Hedging Strategy

scholarly journals Costs and benefits of maternally inherited algal symbionts in coral larvae

2017 ◽  
Vol 284 (1857) ◽  
pp. 20170852 ◽  
Author(s):  
Valérie F. Chamberland ◽  
Kelly R. W. Latijnhouwers ◽  
Jef Huisman ◽  
Aaron C. Hartmann ◽  
Mark J. A. Vermeij
Keyword(s):  
Marine Invertebrates ◽  
Costs And Benefits ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Coral Larvae ◽  
Stony Coral ◽  
Algal Symbionts ◽  
Settlement Success ◽  
Spatio Temporal ◽  
Endosymbiotic Algae

Many marine invertebrates provide their offspring with symbionts. Yet the consequences of maternally inherited symbionts on larval fitness remain largely unexplored. In the stony coral Favia fragum (Esper 1797), mothers produce larvae with highly variable amounts of endosymbiotic algae, and we examined the implications of this variation in symbiont density on the performance of F. fragum larvae under different environmental scenarios. High symbiont densities prolonged the period that larvae actively swam and searched for suitable settlement habitats. Thermal stress reduced survival and settlement success in F. fragum larvae, whereby larvae with high symbiont densities suffered more from non-lethal stress and were five times more likely to die compared with larvae with low symbiont densities. These results show that maternally inherited algal symbionts can be either beneficial or harmful to coral larvae depending on the environmental conditions at hand, and suggest that F. fragum mothers use a bet-hedging strategy to minimize risks associated with spatio-temporal variability in their offspring's environment.

scholarly journals Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker

2015 ◽  
Vol 282 (1816) ◽  
pp. 20151742 ◽  
Author(s):  
Walter D. Koenig ◽  
Eric L. Walters
Keyword(s):  
Reproductive Success ◽  
Cooperative Breeding ◽  
Group Living ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Ecological Conditions ◽  
Variable Environments ◽  
Melanerpes Formicivorus ◽  
Mean Fitness

Cooperative breeding is generally considered an adaptation to ecological constraints on dispersal and independent breeding, usually due to limited breeding opportunities. Although benefits of cooperative breeding are typically thought of in terms of increased mean reproductive success, it has recently been proposed that this phenomenon may be a bet-hedging strategy that reduces variance in reproductive success (fecundity variance) in populations living in highly variable environments. We tested this hypothesis using long-term data on the polygynandrous acorn woodpecker ( Melanerpes formicivorus ). In general, fecundity variance decreased with increasing sociality, at least when controlling for annual variation in ecological conditions. Nonetheless, decreased fecundity variance was insufficient to compensate for reduced per capita reproductive success of larger, more social groups, which typically suffered lower estimated mean fitness. We did, however, find evidence that sociality in the form of larger group size resulted in increased fitness in years following a small acorn crop due to reduced fecundity variance. Bet-hedging, although not the factor driving sociality in general, may play a role in driving acorn woodpecker group living when acorns are scarce and ecological conditions are poor.

scholarly journals Diapause is not selected as a bet-hedging strategy in insects: a meta-analysis of reaction norm shapes

2019 ◽  
Author(s):  
Jens Joschinski ◽  
Dries Bonte
Keyword(s):  
Climate Change ◽  
Phenotypic Plasticity ◽  
Meta Analysis ◽  
Reaction Norm ◽  
Geographic Range ◽  
Bet Hedging ◽  
Hedging Strategy ◽  
Apparent Lack ◽  
Environmental Predictability ◽  
Hedging Strategies

AbstractMany organisms escape from lethal climatological conditions by entering a resistant resting stage called diapause, which needs to be optimally timed with seasonal change. As climate change exerts selection pressure on phenology, the evolution of mean diapause timing, but also of phenotypic plasticity and bet-hedging strategies is expected. Especially the latter as a strategy to cope with unpredictability is little considered in the context of climate change.Contemporary patterns of phenological strategies across a geographic range may provide information about their evolvability. We thus extracted 458 diapause reaction norms from 60 studies. First, we correlated mean diapause timing with mean winter onset. Then we partitioned the reaction norm variance into a temporal component (phenotypic plasticity) and among-offspring variance (diversified bet-hedging) and correlated this variance composition with predictability of winter onset. Mean diapause timing correlated reasonably well with mean winter onset, except for populations at high latitudes, which apparently failed to track early onsets. Variance among offspring was, however, limited and correlated only weakly with environmental predictability, indicating little scope for bet-hedging. The apparent lack of phenological bet-hedging strategies may pose a risk in a less predictable climate, but we also highlight the need for more data on alternative strategies.

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