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

2018 ◽  
Vol 27 (24) ◽  
pp. 5104-5119 ◽  
Author(s):  
Andrew D. Sweet ◽  
Kevin P. Johnson
Keyword(s):  
Host Parasite

The possible role of the frontal and sub-parietal gland systems of the pentastomidReighardia sternae(Diesing, 1864) in the evasion of the host immune response

Parasitology ◽  
1979 ◽  
Vol 78 (1) ◽  
pp. 53-66 ◽  
Author(s):  
J. Riley ◽  
J. L. James ◽  
A. A. Banaja
Keyword(s):  
Immune Response ◽  
Alternative Explanation ◽  
Surface Membrane ◽  
Membrane System ◽  
Host Immune Response ◽  
Entire Surface ◽  
Strong Immune Response ◽  
Concomitant Immunity ◽  
Host Parasite

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.

scholarly journals B Chromosomes in Populations of Mammals Revisited

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 487 ◽  
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.

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

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.

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.

NEAR-WILT OF PEAS IN ONTARIO

1959 ◽  
Vol 39 (4) ◽  
pp. 483-490
Author(s):  
Blair H. MacNeill ◽  
Helen Howard
Keyword(s):  
Fusarium Oxysporum ◽  
Wilt Disease ◽  
Disease Response ◽  
New Era ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Race 2 ◽  
Host Parasite

It has been found that the near-wilt disease of peas, caused by Fusarium oxysporum f. pisi race 2 (Linford) Snyder & Hansen, is now present in the canning districts of Ontario. Conclusions as to the identity of the fungus associated with the wilting condition in field plants have been based upon a study of the differential disease-response of the pea varieties Little Marvel, W.R. Perfection and New Era, the histology of infection in the susceptible pea host, and the characteristics of the fungus when in culture. The capacity of the fungus to establish a symptomless host-parasite relationship with certain legumes not normally regarded as susceptible to the near-wilt pathogen has been demonstrated. The possible role of such "non-susceptible hosts" in perpetuating the fungus between pea crops has been discussed.

Role of sea lice secretome in host-parasite interaction: Immune modulation of SHK-1 cells exposed to Caligus rogercresseyi secretome

2019 ◽  
Vol 91 ◽  
pp. 459
Author(s):  
Y. Leal ◽  
V. Valenzuela-Muñoz ◽  
B. Benavente ◽  
C. Carrera-Naipil ◽  
A. Casuso ◽  
...  
Keyword(s):  
Immune Modulation ◽  
Sea Lice ◽  
Host Parasite

Role of lipids in host-parasite relations of a mycoparasite

1980 ◽  
Vol 17 (3) ◽  
pp. 319-328 ◽  
Author(s):  
M.S. Manocha
Keyword(s):  
Host Parasite

The role of the phagocyte in host-parasite interactions

1973 ◽  
Vol 117 (5) ◽  
pp. 671-678 ◽  
Author(s):  
A.A. Jacobs ◽  
R.J. Selvaraj ◽  
R.R. Strauss ◽  
B.B. Paul ◽  
G.W. Mitchell ◽  
...  
Keyword(s):  
Host Parasite Interactions ◽  
Host Parasite
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