scholarly journals Maternal effects in disease resistance: poor maternal environment increases offspring resistance to an insect virus

2012 ◽  
Vol 279 (1744) ◽  
pp. 4009-4014 ◽  
Author(s):  
Mike Boots ◽  
Katherine E. Roberts
Keyword(s):  
Disease Resistance ◽  
Maternal Effects ◽  
Resource Availability ◽  
Evolutionary Dynamics ◽  
Disease Risk ◽  
Insect Virus ◽  
Maternal Environment ◽  
Resource Levels ◽  
Host Parasite ◽  
Parasite Exposure

Maternal effects can be adaptive and because of their intrinsic time delays may have important effects on population dynamics. In vertebrates, and increasingly invertebrates, it is well established that offspring defence is in part determined by maternal parasite exposure. It has also been suggested that there may be indirect maternal effects on immunity mediated by other components of the maternal environment, including density and resource availability. Here, we examine the effect maternal resource availability has on the immunity of offspring in an insect—virus system. We use five different maternal resource levels and examine immunity in the offspring both directly, by challenge with a virus, and by measuring a major component of the immune system, across three offspring environments. Both the direct infection assay and the measure of immunocompetence show clearly that offspring from mothers in poor environments are more resistant to parasites. This may result from life-history optimization of mothers in poor environments, or because the poor environment acts as a cue for higher disease risk in the next generation. This emphasizes the importance of maternal effects on disease resistance, mediated through indirect environmental factors that will have important implications to both the ecological and evolutionary dynamics of host–parasite interactions.

scholarly journals Host age modulates within-host parasite competition

2015 ◽  
Vol 11 (5) ◽  
pp. 20150131 ◽  
Author(s):  
Rony Izhar ◽  
Jarkko Routtu ◽  
Frida Ben-Ami
Keyword(s):  
Evolutionary Dynamics ◽  
Parasite Prevalence ◽  
Host Age ◽  
Individual Level ◽  
Pasteuria Ramosa ◽  
Age Dependent ◽  
The Individual ◽  
Host Parasite ◽  
Parasite Exposure ◽  
Age At Exposure

In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa , we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters.

scholarly journals Diversity and host assemblage of avian haemosporidians in different terrestrial ecoregions of Peru

2021 ◽  
Author(s):  
Luz Garcia-Longoria ◽  
Jaime Muriel ◽  
Sergio Magallanes ◽  
Zaira Hellen Villa-Galarce ◽  
Leonila Ricopa ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Evolutionary Dynamics ◽  
Bird Species ◽  
Host Community ◽  
Bird Diversity ◽  
New Host ◽  
Parasite Richness ◽  
Haemosporidian Parasites ◽  
Avian Haemosporidians ◽  
Host Parasite

Abstract Characterizing the diversity and structure of host-parasite communities is crucial to understanding their eco-evolutionary dynamics. Malaria and related haemosporidian parasites are responsible for fitness loss and mortality in bird species worldwide. However, despite exhibiting the greatest ornithological biodiversity, avian haemosporidians from Neotropical regions are quite unexplored. Here, we analyse the genetic diversity of bird haemosporidian parasites (Plasmodium and Haemoproteus) in 1,336 individuals belonging to 206 bird species to explore for differences in diversity of parasite lineages and bird species across five well-differentiated Peruvian ecoregions. We detected 70 different haemosporidian lineages infecting 74 bird species. We showed that 25 out of the 70 haplotypes had not been previously recorded. Moreover, we also identified 81 new host – parasite interactions representing new host records for these haemosporidian parasites. Our outcomes revealed that the effective diversity (as well as the richness, abundance, and Shannon-Weaver index) for both birds and parasite lineages was higher in Amazon basin ecoregions. Furthermore, we also showed that ecoregions with greater diversity of bird species also had high parasite richness, hence suggesting that host community is crucial in explaining parasite richness. Generalist parasites were found in ecoregions with lower bird diversity, implying that the abundance and richness of hosts may shape the exploitation strategy followed by haemosporidian parasites. These outcomes reveal that Neotropical region is a major reservoir of unidentified haemosporidian lineages. Further studies analysing host distribution and specificity of these parasites in the tropics will provide important knowledge about phylogenetic relationships, phylogeography, and patterns of evolution and distribution of haemosporidian parasites.

Resource availability, maternal effects, and longevity

1983 ◽  
Vol 18 (2) ◽  
pp. 147-165 ◽  
Author(s):  
Michael Lynch ◽  
Richard Ennis
Keyword(s):  
Maternal Effects ◽  
Resource Availability

scholarly journals Communication Among Harvesters Leads to Sustainable Fishing Behaviour in a Continuous Time Common Pool Resource Experiment

2021 ◽  
Vol 8 ◽  
Author(s):  
Kwabena A. Owusu ◽  
Micaela M. Kulesz ◽  
Agostino Merico
Keyword(s):  
Resource Availability ◽  
Continuous Time ◽  
Empirical Studies ◽  
Sustainable Use ◽  
Large Body ◽  
Common Pool ◽  
Use Of Resources ◽  
Extraction Behaviour ◽  
The Commons ◽  
Resource Levels

The sustainable use of common pool resources (CPRs) such as fisheries constitutes a major challenge for society. A large body of empirical studies conducted in discrete time indicates that resource users are able to prevent the ‘tragedy of the commons' under institutional arrangements that can promote cooperation. However, the variability exhibited by the human behaviour and the dynamic nature of renewable resources require continuous time experiments to fully explain the mechanisms underpinning the sustainable use of resources. We conducted CPR experiments in continuous time to investigate how the extraction behaviour of resource users changes in real-time in response to changes in resource availability under communication and no communication. We find that when communication is allowed, users adjust their extraction efforts based on knowledge of previous resource availability. In contrast, when communication is not allowed, users do not incorporate resource availability into their utility function. These results suggest that communication does not merely provide a forum for coordination but mediates a causal relationship between resource levels and extraction behaviour. Our findings may help the development of effective resource management policies.

scholarly journals Maternal yolk androgens stimulate territorial behaviour in black-headed gull chicks

2009 ◽  
Vol 5 (5) ◽  
pp. 586-588 ◽  
Author(s):  
Wendt Müller ◽  
Cor Dijkstra ◽  
Ton G. G. Groothuis
Keyword(s):  
Social Interactions ◽  
Territorial Behaviour ◽  
Social Competition ◽  
Maternal Environment ◽  
Yolk Androgens ◽  
The Social ◽  
Food Conditions ◽  
High Concentrations ◽  
Colonial Breeding ◽  
Parasite Exposure

Avian eggs contain substantial amounts of maternal androgens. The concentrations of these yolk androgens are affected by the maternal environment, such as the level of social competition, parasite exposure or food conditions. Since yolk androgens have been shown to affect a wide array of offspring traits, they may adjust the chicks to the expected post-hatching environment, but experimental evidence is still scarce. We investigate in colonial breeding black-headed gulls whether high concentrations of yolk androgens, such as those found in environments with high numbers of social interactions, facilitate aggressiveness and territorial behaviour of the chicks. Black-headed gulls are highly suitable for this, as the semi-precocial chicks defend the natal territory and food against intruders. We manipulated yolk androgen concentrations and investigated their role in both within-nest and between-nest aggression. We found that chicks hatching from androgen-treated eggs defended the natal territory more often than their nest mates from control eggs, without increasing sibling aggression. This suggests that variation in yolk androgen concentrations in relation to the social environment of the mother may indeed allow adjustment of the offspring's behaviour to the expected frequency of territorial interactions with conspecifics post-hatching.

scholarly journals Melanin-based coloration and host–parasite interactions under global change

2018 ◽  
Vol 285 (1879) ◽  
pp. 20180285 ◽  
Author(s):  
J. Côte ◽  
A. Boniface ◽  
S. Blanchet ◽  
A. P. Hendry ◽  
J. Gasparini ◽  
...  
Keyword(s):  
Global Change ◽  
Potential Role ◽  
Disease Risk ◽  
Multiple Stressors ◽  
Colour Polymorphism ◽  
Host Parasite Interactions ◽  
To Come ◽  
Colour Morphs ◽  
Host Parasite

The role of parasites in shaping melanin-based colour polymorphism, and the consequences of colour polymorphism for disease resistance, remain debated. Here we review recent evidence of the links between melanin-based coloration and the behavioural and immunological defences of vertebrates against their parasites. First we propose that (1) differences between colour morphs can result in variable exposure to parasites, either directly (certain colours might be more or less attractive to parasites) or indirectly (variations in behaviour and encounter probability). Once infected, we propose that (2) immune variation between differently coloured individuals might result in different abilities to cope with parasite infection. We then discuss (3) how these different abilities could translate into variable sexual and natural selection in environments varying in parasite pressure. Finally, we address (4) the potential role of parasites in the maintenance of melanin-based colour polymorphism, especially in the context of global change and multiple stressors in human-altered environments. Because global change will probably affect both coloration and the spread of parasitic diseases in the decades to come, future studies should take into account melanin-based coloration to better predict the evolutionary responses of animals to changing disease risk in human-altered environments.

Evolution of behavioral resistance in host-pathogen systems

2020 ◽  
Author(s):  
Caroline R. Amoroso ◽  
Janis Antonovics
Keyword(s):  
Social Interactions ◽  
Evolutionary Dynamics ◽  
Disease Risk ◽  
Disease Outbreaks ◽  
Mixed Strategies ◽  
Costs And Benefits ◽  
Parasite Resistance ◽  
Costs Of Disease ◽  
Physiological Resistance ◽  
Behavioral Resistance

AbstractBehavioral resistance to parasites is widespread in animals, yet little is known about the evolutionary dynamics that have shaped these strategies. We show that theory developed for the evolution of physiological parasite resistance can only be applied to behavioral resistance under limited circumstances. We find that accounting explicitly for the behavioral processes, including the detectability of infected individuals, leads to novel dynamics that are strongly dependent on the nature of the costs and benefits of social interactions. As with physiological resistance, the evolutionary dynamics can also lead to mixed strategies that balance the costs of disease risk and the benefits of social interaction, with implications for understanding avoidance strategies in human disease outbreaks.

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