scholarly journals Disentangling unspecific and specific transgenerational immune priming components in host-parasite interactions

2018 ◽  
Author(s):  
Frida Ben-Ami ◽  
Christian Orlic ◽  
Roland R. Regoes
Keyword(s):  
Bacterial Pathogen ◽  
Immune Memory ◽  
High Dose ◽  
Immune Priming ◽  
Host Parasite Interactions ◽  
Pasteuria Ramosa ◽  
Wide Range ◽  
Different Strains ◽  
Host Parasite ◽  
First Time

AbstractExposure to a pathogen primes many organisms to respond faster or more efficiently to subsequent exposures. Such priming can be unspecific or specific, and has been found to extend across generations. Disentangling and quantifying specific and unspecific effects is essential for understanding the genetic epidemiology of a system. By combining a large infection experiment and mathematical modeling, we disentangle different transgenerational effects in the crustacean model Daphnia magna exposed to different strains of the bacterial parasite Pasteuria ramosa. In the experiments, we exposed hosts to a high-dose of one of three parasite strains, and subsequently challenged their offspring with multiple doses of the same or a different strain, i. e. homologously or heterogously. We find that exposure to Pasteuria decreases the susceptibility of a host’s offspring by approximately 50%. This transgenerational protection is not larger for homologous than for heterologous parasite challenges. Our work represents an important contribution not only to the analysis of immune priming in ecological systems, but also to the experimental assessment of vaccines. We present for the first time an inference framework to investigate specific and unspecific effects of immune priming on the susceptibility distribution of hosts — effects that are central to understanding immunity and the effect of vaccines.Author summaryImmune memory is a feature of immune systems that forms the basis of vaccination. In opposition to textbook accounts, the ability to specifically remember previous exposures has been found to extend to invertebrates and shown to be able to be passed on from mother to off-spring, i. e. to be transgenerational. In this paper, we investigate the extent of this specificity in unprecedented detail in water fleas. We exposed water flea mothers to different strains of a bacterial pathogen and challenged their offspring with a wide range of doses of a strain that were either identical to (homologous) or different from (heterologous) the strain, to which the mother had been exposed. We find that, while exposure of the mother reduces the susceptibility of the offspring, this effect is not specific. This work outlines the limits of specific transgenerational immune memory in this invertebrate system.

scholarly journals Disentangling non-specific and specific transgenerational immune priming components in host–parasite interactions

2020 ◽  
Vol 287 (1920) ◽  
pp. 20192386
Author(s):  
Frida Ben-Ami ◽  
Christian Orlic ◽  
Roland R. Regoes
Keyword(s):  
Genetic Epidemiology ◽  
Ecological Systems ◽  
High Dose ◽  
Immune Priming ◽  
Specific Effects ◽  
Host Parasite Interactions ◽  
Pasteuria Ramosa ◽  
Different Strains ◽  
Host Parasite ◽  
First Time

Exposure to a pathogen primes many organisms to respond faster or more efficiently to subsequent exposures. Such priming can be non-specific or specific, and has been found to extend across generations. Disentangling and quantifying specific and non-specific effects is essential for understanding the genetic epidemiology of a system. By combining a large infection experiment and mathematical modelling, we disentangle different transgenerational effects in the crustacean model Daphnia magna exposed to different strains of the bacterial parasite Pasteuria ramosa . In the experiment, we exposed hosts to a high dose of one of three parasite strains, and subsequently challenged their offspring with multiple doses of the same (homologous) or a different (heterologous) strain. We find that exposure of Daphnia to Pasteuria decreases the susceptibility of their offspring by approximately 50%. This transgenerational protection is not larger for homologous than for heterologous parasite challenges. Methodologically, our work represents an important contribution not only to the analysis of immune priming in ecological systems but also to the experimental assessment of vaccines. We present, for the first time, an inference framework to investigate specific and non-specific effects of immune priming on the susceptibility distribution of hosts—effects that are central to understanding immunity and the effect of vaccines.

scholarly journals Experimental evolution of insect immune memory versus pathogen resistance

2017 ◽  
Vol 284 (1869) ◽  
pp. 20171583 ◽  
Author(s):  
Imroze Khan ◽  
Arun Prakash ◽  
Deepa Agashe
Keyword(s):  
Secondary Infection ◽  
Pathogen Resistance ◽  
Immune Memory ◽  
High Dose ◽  
Basal Resistance ◽  
Immune Priming ◽  
Resistance To Infection ◽  
Empirical Tests ◽  
Rapid Modulation ◽  
Specific Priming

Under strong pathogen pressure, insects often evolve resistance to infection. Many insects are also protected via immune memory (immune priming), whereby sublethal exposure to a pathogen enhances survival after secondary infection. Theory predicts that immune memory should evolve when the pathogen is highly virulent, or when pathogen exposure is relatively rare. However, there are no empirical tests of these hypotheses, and the adaptive benefits of immune memory relative to direct resistance against a pathogen are poorly understood. To determine the selective pressures and ecological conditions that shape immune evolution, we imposed strong pathogen selection on flour beetle ( Tribolium castaneum ) populations, infecting them with Bacillus thuringiensis (Bt) for 11 generations. Populations injected first with heat-killed and then live Bt evolved high basal resistance against multiple Bt strains. By contrast, populations injected only with a high dose of live Bt evolved a less effective but strain-specific priming response. Control populations injected with heat-killed Bt did not evolve priming; and in the ancestor, priming was effective only against a low Bt dose. Intriguingly, one replicate population first evolved priming and subsequently evolved basal resistance, suggesting the potential for dynamic evolution of different immune strategies. Our work is the first report showing that pathogens can select for rapid modulation of insect priming ability, allowing hosts to evolve divergent immune strategies (generalized resistance versus specific immune memory) with potentially distinct mechanisms.

High levels of genetic diversity inNosema ceranaewithinApis melliferacolonies

Parasitology ◽  
2013 ◽  
Vol 141 (4) ◽  
pp. 475-481 ◽  
Author(s):  
TAMARA GÓMEZ-MORACHO ◽  
XULIO MASIDE ◽  
RAQUEL MARTÍN-HERNÁNDEZ ◽  
MARIANO HIGES ◽  
CAROLINA BARTOLOMÉ
Keyword(s):  
Genetic Recombination ◽  
Population Expansion ◽  
Single Copy ◽  
Recent Population Expansion ◽  
Colony Losses ◽  
Bee Colony ◽  
Host Parasite Interactions ◽  
Recent Origin ◽  
Different Strains ◽  
Host Parasite

SUMMARYNosema ceranaeis a widespread honeybee parasite, considered to be one of the pathogens involved in the colony losses phenomenon. To date, little is known about its intraspecific genetic variability. The few studies onN. ceranaevariation have focused on the subunits of ribosomal DNA, which are not ideal for this purpose and have limited resolution. Here we characterized three single copy loci (Actin, Hsp70andRPB1) in threeN. ceranaeisolates from Hungary and Hawaii. Our results provide evidence of unexpectedly high levels of intraspecific polymorphism, the coexistence of a wide variety of haplotypes within each bee colony, and the occurrence of genetic recombination inRPB1. Most haplotypes are not shared across isolates and derive from a few frequent haplotypes by a reduced number of singletons (mutations that appear usually just once in the sample), which suggest that they have a fairly recent origin. Overall, our data indicate that this pathogen has experienced a recent population expansion. The presence of multiple haplotypes within individual isolates could be explained by the existence of different strains ofN. ceranaeinfecting honeybee colonies in the field which complicates, and must not be overlooked, further analysis of host–parasite interactions.

Modeling of Damage Evolution During Ion Implantation Into Silicon: A Monte Carlo Approach

1996 ◽  
Vol 439 ◽  
Author(s):  
S. Tian ◽  
M. Morris ◽  
S. J. Morris ◽  
B. Obradovic ◽  
A. F. Tasch
Keyword(s):  
Ion Implantation ◽  
Damage Evolution ◽  
Damage Model ◽  
Amorphous Layer ◽  
High Dose ◽  
Defect Production ◽  
Implantation Damage ◽  
Wide Range ◽  
Physically Based ◽  
First Time

AbstractWe present for the first time a physically based ion implantation damage model which successfully predicts both the as-implanted impurity range profiles and the damage profiles for a wide range of implant conditions for arsenic, boron, phosphorus, and BF2 implants into single-crystal (100) silicon. In addition, the amorphous layer thicknesses predicted by this damage model for high dose implants are also generally in excellent agreement with experiments. This damage model explicitly simulates the defect production and its subsequent evolution into the experimentally observable profiles for the first time. The microscopic mechanisms for damage evolution are further discussed.

scholarly journals Louse (Insecta: Phthiraptera) infestations of the Amur Falcon (Falco amurensis) and the Red-footed Falcon

2015 ◽  
Vol 23 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Imre Sándor Piross ◽  
Péter Fehérvári ◽  
Zoltán Vas ◽  
Szabolcs Solt ◽  
Éva Horváth ◽  
...  
Keyword(s):  
South Africa ◽  
Life History ◽  
Host Species ◽  
Life History Traits ◽  
Population Parameters ◽  
Model Species ◽  
Host Parasite Interactions ◽  
Louse Species ◽  
Host Parasite ◽  
First Time

Abstract Little is known about the louse species harboured by Red-footed and Amur Falcons despite the fact that various life-history traits of these hosts make them good model species to study host-parasite interactions. We collected lice samples from fully grown Amur (n=20) and Red-footed Falcons (n=59), and from nestlings of Red-footed Falcons (n=179) in four countries: Hungary, India, Italy and South Africa. We identified 3 louse species on both host species, namely Degeeriella rufa, Colpocephalum subzerafae and Laembothrion tinnunculi. The latter species has never been found on these hosts. Comparing population parameters of lice between hosts we found significantly higher prevalence levels of D. rufa and C. subzerafae on Amur Falcons. Adult Red-footed Falcons had higher D. rufa prevalence compared to C. subzerafae. For the first time we also show inter-annual shift in prevalence and intensity levels of these species on Red-footed Falcons; in 2012 on adult hosts C. subzerafae had higher intensity levels than D. rufa, however in 2014 D. rufa had significantly higher intensity compared to C. subzerafae. In case of nestlings both louse species had significantly higher preva lence levels than in 2014. The exact causes of such inter-annual shifts are yet to be understood.

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 Pectobacterium brasiliense (soft rot and blackleg of ornamentals and potato).

2021 ◽  
Author(s):  
Janak Raj Joshi ◽  
Yuan Zeng ◽  
Amy Charkowski
Keyword(s):  
South Africa ◽  
Bacterial Pathogen ◽  
Soft Rot ◽  
Varietal Resistance ◽  
Seed Certification ◽  
Wide Range ◽  
Cultivated Potatoes ◽  
North And South America ◽  
First Time ◽  
North And South

Abstract Pectobacterium brasiliense is a bacterial pathogen primarily infecting potato and other vegetables and ornamentals. The earliest reports of the bacterium causing disease were from Brazil in 2004 (El-Tassa and Duarte, 2004; Duarte et al., 2004). This pathogen was reported for the first time in Europe (Belgium) in 2012 (van der Wolf et al., 2017). Since then, the pathogen has been reported in many regions of Europe, Asia, Africa, Australia, North and South America. The bacterium has adapted itself to a wide range of temperatures and host species, thus it is considered a culprit for significant losses in China, South Africa, Brazil, Netherlands, Switzerland and UK (Meng et al., 2017; van der Wolf et al., 2017). Symptoms caused by P. brasiliense are indistinguishable from other soft rot Pectobacterium and Dickeya, therefore it is impossible to identify this species on the basis of field and laboratory symptoms. Unfortunately, there is no evidence of curative measures and varietal resistance (in cultivated potatoes) against this group of bacteria, so farmers rely on seed certification, exclusion and sanitation to mitigate its worst effects.

Transcriptomics of host-specific interactions in natural populations of the parasitic plant purple witchweed (Striga hermonthica)

Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 397-411 ◽  
Author(s):  
Lua Lopez ◽  
Emily S. Bellis ◽  
Eric Wafula ◽  
Sarah J. Hearne ◽  
Loren Honaas ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Natural Populations ◽  
Allelic Frequency ◽  
Genomic Diversity ◽  
Sub Saharan Africa ◽  
Striga Hermonthica ◽  
Specific Interactions ◽  
Host Parasite Interactions ◽  
Wide Range ◽  
Host Parasite

AbstractHost-specific interactions can maintain genetic and phenotypic diversity in parasites that attack multiple host species. Host diversity, in turn, may promote parasite diversity by selection for genetic divergence or plastic responses to host type. The parasitic weed purple witchweed [Striga hermonthica (Delile) Benth.] causes devastating crop losses in sub-Saharan Africa and is capable of infesting a wide range of grass hosts. Despite some evidence for host adaptation and host-by-Striga genotype interactions, little is known about intraspecific Striga genomic diversity. Here we present a study of transcriptomic diversity in populations of S. hermonthica growing on different hosts (maize [Zea mays L.] vs. grain sorghum [Sorghum bicolor (L.) Moench]). We examined gene expression variation and differences in allelic frequency in expressed genes of aboveground tissues from populations in western Nigeria parasitizing each host. Despite low levels of host-based genome-wide differentiation, we identified a set of parasite transcripts specifically associated with each host. Parasite genes in several different functional categories implicated as important in host–parasite interactions differed in expression level and allele on different hosts, including genes involved in nutrient transport, defense and pathogenesis, and plant hormone response. Overall, we provide a set of candidate transcripts that demonstrate host-specific interactions in vegetative tissues of the emerged parasite S. hermonthica. Our study shows how signals of host-specific processes can be detected aboveground, expanding the focus of host–parasite interactions beyond the haustorial connection.

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