Host‐parasite dynamics shaped by temperature and genotype: quantifying the role of underlying vital rates

SUMMARYThe frontal and sub-parietal glands of the pentastomidReighardia sternaeelaborate lamellate secretion which is poured on to the cuticle. The entire surface of the cuticle, including the mouth, hook pits and reproductive apertures, is coated with secretion. Electron microscope studies indicate that the glands are continuously active, which implies a turnover of surface membranes. The postulated function of these membranes is to protect certain vital areas of the host–parasite interface, notably the pores of ion-transporting cells, from the host immune response. The available evidence suggests that pentastomids do evoke a strong immune response but since most are long-lived they must circumvent it. We believe the surface membrane system to be instrumental in this. Studies on another pentastomid,Porocephalus crotaliin rats have shown that an immune response stimulated by a primary infection will kill subsequent infections and that the surface membranes are strongly immunogenic. Obvious parallels between this situation and that of schistosome infections in mammals are discussed. An alternative explanation of concomitant immunity is proposed.

Download Full-text

B Chromosomes in Populations of Mammals Revisited

Genes ◽

10.3390/genes9100487 ◽

2018 ◽

Vol 9 (10) ◽

pp. 487 ◽

Cited By ~ 11

Author(s):

Mladen Vujošević ◽

Marija Rajičić ◽

Jelena Blagojević

Keyword(s):

Mammalian Species ◽

B Chromosome ◽

Molecular Techniques ◽

B Chromosomes ◽

General View ◽

Protein Coding ◽

Host Parasite Interactions ◽

Quantitative Characteristics ◽

Host Parasite

The study of B chromosomes (Bs) started more than a century ago, while their presence in mammals dates since 1965. As the past two decades have seen huge progress in application of molecular techniques, we decided to throw a glance on new data on Bs in mammals and to review them. We listed 85 mammals with Bs that make 1.94% of karyotypically studied species. Contrary to general view, a typical B chromosome in mammals appears both as sub- or metacentric that is the same size as small chromosomes of standard complement. Both karyotypically stable and unstable species possess Bs. The presence of Bs in certain species influences the cell division, the degree of recombination, the development, a number of quantitative characteristics, the host-parasite interactions and their behaviour. There is at least some data on molecular structure of Bs recorded in nearly a quarter of species. Nevertheless, a more detailed molecular composition of Bs presently known for six mammalian species, confirms the presence of protein coding genes, and the transcriptional activity for some of them. Therefore, the idea that Bs are inert is outdated, but the role of Bs is yet to be determined. The maintenance of Bs is obviously not the same for all species, so the current models must be adapted while bearing in mind that Bs are not inactive as it was once thought.

Download Full-text

The role of parasite dispersal in shaping a host–parasite system at multiple evolutionary scales

Molecular Ecology ◽

10.1111/mec.14937 ◽

2018 ◽

Vol 27 (24) ◽

pp. 5104-5119 ◽

Cited By ~ 12

Author(s):

Andrew D. Sweet ◽

Kevin P. Johnson

Keyword(s):

Host Parasite

Download Full-text

Causation without correlation: parasite-mediated frequency-dependent selection and infection prevalence

10.1101/2021.11.13.468422 ◽

2021 ◽

Author(s):

Curtis M Lively ◽

Julie Xu ◽

Frida Ben-Ami

Keyword(s):

Genetic Diversity ◽

Natural Populations ◽

Infection Prevalence ◽

Strong Positive Correlation ◽

Frequency Dependent ◽

Frequency Dependent Selection ◽

Host Diversity ◽

Host Genetic ◽

Host Parasite

Parasite-mediated selection is thought to maintain host genetic diversity for resistance. We might thus expect to find a strong positive correlation between host genetic diversity and infection prevalence across natural populations. Here we used computer simulations to examine host-parasite coevolution in 20 simi-isolated clonal populations across a broad range of values for both parasite virulence and parasite fecundity. We found that the correlation between host genetic diversity and infection prevalence can be significantly positive for intermediate values of parasite virulence and fecundity. But the correlation can also be weak and statistically non-significant, even when parasite-mediated frequency-dependent selection is the sole force maintaining host diversity. Hence correlational analyses of field populations, while useful, might underestimate the role of parasites in maintaining host diversity.

Download Full-text

How host phenology impacts multi-season epidemic cycles

10.1101/2021.06.07.447391 ◽

2021 ◽

Author(s):

Hannelore MacDonald ◽

Dustin Brisson

Keyword(s):

Mathematical Model ◽

Population Dynamics ◽

Population Cycles ◽

Seasonal Activity ◽

Host Interactions ◽

Host Phenology ◽

Demographic Impact ◽

Host Parasite ◽

Parasite Populations ◽

Parasite Dynamics

Parasite-host interactions can result in periodic population dynamics when parasites over-exploit host populations. The timing of host seasonal activity, or host phenology, determines the frequency and demographic impact of parasite-host interactions which may govern if the parasite can sufficiently over-exploit their hosts to drive population cycles. We describe a mathematical model of a monocyclic, obligate-killer parasite system with seasonal host activity to investigate the consequences of host phenology on host-parasite dynamics. The results suggest that parasites can reach the densities necessary to destabilize host dynamics and drive cycling in only some phenological scenarios, such as environments with short seasons and synchronous host emergence. Further, only parasite lineages that are sufficiently adapted to phenological scenarios with short seasons and synchronous host emergence can achieve the densities necessary to over-exploit hosts and produce population cycles. Host-parasite cycles can also generate an eco-evolutionary feedback that slows parasite adaptation to the phenological environment as rare advantageous phenotypes are driven to extinction when introduced in phases of the cycle where host populations are small and parasite populations are large. The results demonstrate that seasonal environments can drive population cycling in a restricted set of phenological patterns and provides further evidence that the rate of adaptive evolution depends on underlying ecological dynamics.

Download Full-text

Host-parasite dynamics of Sorghum bicolor and Striga hermonthica – The influence of soil organic matter amendments of different C:N ratio

Crop Protection ◽

10.1016/j.cropro.2011.08.009 ◽

2011 ◽

Vol 30 (12) ◽

pp. 1613-1622 ◽

Cited By ~ 5

Author(s):

G.C. Ayongwa ◽

T.J. Stomph ◽

T.W. Kuyper

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Sorghum Bicolor ◽

C:N Ratio ◽

Striga Hermonthica ◽

Host Parasite ◽

Parasite Dynamics

Download Full-text

Role of the Genetics and Physiology of Bordetella pertussis in the Production of Vaccine and the Study of Host–Parasite Relationships in Pertussis

Advances in Applied Microbiology Volume 20 - Advances in Applied Microbiology ◽

10.1016/s0065-2164(08)70107-2 ◽

1976 ◽

pp. 27-42 ◽

Cited By ~ 10

Author(s):

Charlotte Parker

Keyword(s):

Bordetella Pertussis ◽

Host Parasite

Download Full-text

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

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.0285 ◽

2018 ◽

Vol 285 (1879) ◽

pp. 20180285 ◽

Cited By ~ 11

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.

Download Full-text