scholarly journals What Can Phages Tell Us about Host-Pathogen Coevolution?

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
John J. Dennehy
Keyword(s):  
Experimental Studies ◽  
Arms Race ◽  
Gene Model ◽  
Genetic Population ◽  
Life History Data ◽  
Heterogeneous Landscape ◽  
Host Parasite Interactions ◽  
In The Wild ◽  
Host Parasite ◽  
Abiotic Interactions

The outcomes of host-parasite interactions depend on the coevolutionary forces acting upon them, but because every host-parasite relation is enmeshed in a web of biotic and abiotic interactions across a heterogeneous landscape, host-parasite coevolution has proven difficult to study. Simple laboratory phage-bacteria microcosms can ameliorate this difficulty by allowing controlled, well-replicated experiments with a limited number of interactors. Genetic, population, and life history data obtained from these studies permit a closer examination of the fundamental correlates of host-parasite coevolution. In this paper, I describe the results of phage-bacteria coevolutionary studies and their implications for the study of host-parasite coevolution. Recent experimental studies have confirmed phage-host coevolutionary dynamics in the laboratory and have shown that coevolution can increase parasite virulence, specialization, adaptation, and diversity. Genetically, coevolution frequently proceeds in a manner best described by the Gene for Gene model, typified by arms race dynamics, but certain contexts can result in Red Queen dynamics according to the Matching Alleles model. Although some features appear to apply only to phage-bacteria systems, other results are broadly generalizable and apply to all instances of antagonistic coevolution. With laboratory host-parasite coevolutionary studies, we can better understand the perplexing array of interactions that characterize organismal diversity in the wild.

scholarly journals Genome analysis of Excretory/Secretory proteins in Taenia solium reveals their Abundance of Antigenic Regions (AAR)

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Sandra Gomez ◽  
Laura Adalid-Peralta ◽  
Hector Palafox-Fonseca ◽  
Vito Adrian Cantu-Robles ◽  
Xavier Soberón ◽  
...  
Keyword(s):  
Taenia Solium ◽  
Experimental Studies ◽  
Cost Effective ◽  
Sequence Length ◽  
Secretory Proteins ◽  
Parasitic Diseases ◽  
Host Parasite Interactions ◽  
Antigenic Proteins ◽  
Host Parasite ◽  
Antigenic Regions

Abstract Excretory/Secretory (ES) proteins play an important role in the host-parasite interactions. Experimental identification of ES proteins is time-consuming and expensive. Alternative bioinformatics approaches are cost-effective and can be used to prioritize the experimental analysis of therapeutic targets for parasitic diseases. Here we predicted and functionally annotated the ES proteins in T. solium genome using an integration of bioinformatics tools. Additionally, we developed a novel measurement to evaluate the potential antigenicity of T. solium secretome using sequence length and number of antigenic regions of ES proteins. This measurement was formalized as the Abundance of Antigenic Regions (AAR) value. AAR value for secretome showed a similar value to that obtained for a set of experimentally determined antigenic proteins and was different to the calculated value for the non-ES proteins of T. solium genome. Furthermore, we calculated the AAR values for known helminth secretomes and they were similar to that obtained for T. solium. The results reveal the utility of AAR value as a novel genomic measurement to evaluate the potential antigenicity of secretomes. This comprehensive analysis of T. solium secretome provides functional information for future experimental studies, including the identification of novel ES proteins of therapeutic, diagnosis and immunological interest.

scholarly journals Identification of an ancient endogenous retrovirus, predating the divergence of the placental mammals

2013 ◽  
Vol 368 (1626) ◽  
pp. 20120503 ◽  
Author(s):  
Adam Lee ◽  
Alison Nolan ◽  
Jason Watson ◽  
Michael Tristem
Keyword(s):  
Rapid Evolution ◽  
Endogenous Retrovirus ◽  
Arms Race ◽  
Endogenous Retroviruses ◽  
Selfish Genetic Elements ◽  
Host Parasite Interactions ◽  
Combined Use ◽  
Minimum Age ◽  
Host Parasite ◽  
First Time

The evolutionary arms race between mammals and retroviruses has long been recognized as one of the oldest host–parasite interactions. Rapid evolution rates in exogenous retroviruses have often made accurate viral age estimations highly problematic. Endogenous retroviruses (ERVs), however, integrate into the germline of their hosts, and are subjected to their evolutionary rates. This study describes, for the first time, a retroviral orthologue predating the divergence of placental mammals, giving it a minimum age of 104–110 Myr. Simultaneously, other orthologous selfish genetic elements (SGEs), inserted into the ERV sequence, provide evidence for the oldest individual mammalian-wide interspersed repeat and medium-reiteration frequency interspersed repeat mammalian repeats, with the same minimum age. The combined use of shared SGEs and reconstruction of viral orthologies defines new limits and increases maximum ‘lookback’ times, with subsequent implications for the field of paleovirology.

scholarly journals Three tick species parasitizing a rock python in Sri Lanka

2012 ◽  
Vol 4 (1) ◽  
pp. 54-56
Author(s):  
T.S.P. Fernando ◽  
H.K.A.V.A. Kulasena Fernando
Keyword(s):  
Immune Response ◽  
Population Dynamics ◽  
Sri Lanka ◽  
Food Webs ◽  
Tick Species ◽  
Ecosystem Health ◽  
Driving Forces ◽  
Host Parasite Interactions ◽  
In The Wild ◽  
Host Parasite

Parasitism is a relationship where one of the parties (the parasite) either harms its host or lives at the expense of it. Host parasite interactions are important driving forces in population dynamics and even extinction. These interactions are also indicators of ecosystem health and they are important in stabilizing food webs. A parasite may cause mechanical injury, stimulate a damaging inflammatory or immune response, or simply rob the host of nutrition. However in the wild most parasites must live in harmony with their hosts. If the parasites kill the host, they themselves would ultimately die without shelter and nutrition. Reptiles become hosts to a number of parasitic organisms ranging from protozoans to arthropods. Among these, ticks (hard and soft) are the most common arthropod group that parasitizes reptiles.

scholarly journals Evolution of transgenerational immunity in invertebrates

2016 ◽  
Vol 283 (1839) ◽  
pp. 20161136 ◽  
Author(s):  
R. Pigeault ◽  
R. Garnier ◽  
A. Rivero ◽  
S. Gandon
Keyword(s):  
Experimental Studies ◽  
Ecological Factors ◽  
Immune Protection ◽  
Vertebrate Species ◽  
Invertebrate Species ◽  
Host Parasite Interactions ◽  
Expected Longevity ◽  
Host Parasite ◽  
The Impact ◽  
Evolution Of Immunity

Over a decade ago, the discovery of transgenerational immunity in invertebrates shifted existing paradigms on the lack of sophistication of their immune system. Nonetheless, the prevalence of this trait and the ecological factors driving its evolution in invertebrates remain poorly understood. Here, we develop a theoretical host–parasite model and predict that long lifespan and low dispersal should promote the evolution of transgenerational immunity. We also predict that in species that produce both philopatric and dispersing individuals, it may pay to have a plastic allocation strategy with a higher transgenerational immunity investment in philopatric offspring because they are more likely to encounter locally adapted pathogens. We review all experimental studies published to date, comprising 21 invertebrate species in nine different orders, and we show that, as expected, longevity and dispersal correlate with the transfer of immunity to offspring. The validity of our prediction regarding the plasticity of investment in transgenerational immunity remains to be tested in invertebrates, but also in vertebrate species. We discuss the implications of our work for the study of the evolution of immunity, and we suggest further avenues of research to expand our knowledge of the impact of transgenerational immune protection in host–parasite interactions.

scholarly journals Nutrient stoichiometry shapes microbial coevolution

2017 ◽  
Author(s):  
Megan L. Larsen ◽  
Steven W. Wilhelm ◽  
Jay T. Lennon
Keyword(s):  
Arms Race ◽  
Lytic Phage ◽  
Nutrient Stoichiometry ◽  
P Limitation ◽  
Host Parasite Interactions ◽  
Negative Frequency Dependent Selection ◽  
Selection For ◽  
The Stability ◽  
Host Parasite

ABSTRACTCoevolution is a force contributing to the generation and maintenance of biodiversity. It is influenced by environmental conditions including the scarcity of essential resources, which can drive the evolution of defense and virulence traits. We conducted a long-term chemostat experiment where the marine cyanobacterium Synechococcus was challenged with a lytic phage under nitrogen (N) or phosphorus (P) limitation. This manipulation of nutrient stoichiometry altered the stability of host-parasite interactions and the underlying mode of coevolution. By assessing infectivity with >18,000 pairwise challenges, we documented directional selection for increased phage resistance, consistent with arms-race dynamics while phage infectivity fluctuated through time, as expected when coevolution is driven by negative frequency-dependent selection. The resulting infection networks were 50 % less modular under N-versus P-limitation reflecting host-range contraction and asymmetric coevolutionary trajectories. Nutrient stoichiometry affects eco-evolutionary feedbacks in ways that may alter the dynamics and functioning of environmental and host-associated microbial communities.

Living with Two Genomes: Grafting and Its Implications for Plant Genome-to-Genome Interactions, Phenotypic Variation, and Evolution

2019 ◽  
Vol 53 (1) ◽  
pp. 195-215 ◽  
Author(s):  
Brandon S. Gaut ◽  
Allison J. Miller ◽  
Danelle K. Seymour
Keyword(s):  
Host Resistance ◽  
Arms Race ◽  
Plant Genome ◽  
Long Term Effects ◽  
Evolutionary Innovation ◽  
Host Parasite Interactions ◽  
Artificial Grafts ◽  
Genome Interactions ◽  
Host Parasite

Plant genomes interact when genetically distinct individuals join, or are joined, together. Individuals can fuse in three contexts: artificial grafts, natural grafts, and host–parasite interactions. Artificial grafts have been studied for decades and are important platforms for studying the movement of RNA, DNA, and protein. Yet several mysteries about artificial grafts remain, including the factors that contribute to graft incompatibility, the prevalence of genetic and epigenetic modifications caused by exchanges between graft partners, and the long-term effects of these modifications on phenotype. Host–parasite interactions also lead to the exchange of materials, and RNA exchange actively contributes to an ongoing arms race between parasite virulence and host resistance. Little is known about natural grafts except that they can be frequent and may provide opportunities for evolutionary innovation through genome exchange. In this review, we survey our current understanding about these three mechanisms of contact, the genomic interactions that result, and the potential evolutionary implications.

Histopathological changes in the liver and stomach ofDidelphis virginiana(Didelphimorphia: Didelphidae) during natural infection withGnathostoma turgidum(Nematoda: Gnathostomidae)

2017 ◽  
Vol 92 (6) ◽  
pp. 765-768 ◽  
Author(s):  
E.H. Torres-Montoya ◽  
J.M. Zazueta-Moreno ◽  
L.U. Osuna-Martínez ◽  
H. Castillo-Ureta ◽  
G. Silva-Hidalgo ◽  
...  
Keyword(s):  
Endemic Area ◽  
Morphological Changes ◽  
Natural Infection ◽  
Didelphis Virginiana ◽  
Histopathological Study ◽  
Host Parasite Interactions ◽  
In The Wild ◽  
Worm Expulsion ◽  
Human Infections ◽  
Host Parasite

AbstractGnathostoma turgidumis a nematode parasite that exploits the stomach of Virginian opossums,Didelphis virginiana,in Latin America. The opossum is the definitive host ofG. turgidumin the wild. Intrahepatic growth and maturation of the parasite, subsequent migration to the stomach and spontaneous expulsion are common. However, the histopathological lesions caused byG. turgidumare poorly described. A better understanding of the life cycle of this parasite and the pathological changes in natural host–parasite interactions could help to clarify the progression of human infections caused byGnathostoma binucleatum. The aim of this work was to study morphological changes in the liver and stomach ofD. virginianaduring natural infection and adult worm expulsion. Three opossums naturally infected withG. turgidumwere captured from an endemic area of gnathostomosis. Three uninfected opossums captured from a non-endemic area were used as controls. The opossums were sacrificed at different stages of infection (March, May and December), and a histopathological study of their livers and stomachs was conducted. Injuries in livers were observed by histopathology – areas of necrosis and collagen septa were identified. Parasites caused nodules with necrosis on the periphery of lesions, and collagen fibres were also observed in stomachs. Collagen septa may be caused by antigenic remains of the parasite. Further immunological studies are necessary to verify that stimulation is caused by these factors.

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