Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
1,737
datasets available to search
ShareScore release 0.9.0
Dataset results
1,737 results for “host data”
Data from: No evidence for host specialization or host-race formation in the European bitterling (Rhodeus amarus), a fish that parasitizes freshwater mussels
Coevolutionary relationships between parasites and hosts can elevate the rate of evolutionary changes due to reciprocal adaptations between coevolving partners. Such relationships can result in the evolution of host specificity. Recent methodological advances have permitted the recognition of cryptic lineages, with important consequences for our understanding of biological diversity. We used the European bitterling (Rhodeus amarus), a freshwater fish that parasitizes unionid mussels, to investigate host specialization across regions of recent and ancient sympatry between coevolving partners. We combined genetic data (12 microsatellite and 2 mitochondrial markers) from five populations with experimental data for possible mechanisms of host species recognition (imprinting and conditioning). We found no strong evidence for the existence of cryptic lineages in R. amarus, though a small proportion of variation among individuals in an area of recent bitterling-mussel association was statistically significant in explaining host specificity. No other measures supported the existence of host-specific lineages. Behavioural data revealed a weak effect of conditioning that biased behavioural preferences toward specific host species. Host imprinting had no effect on oviposition behaviour. Overall, we established that populations of R. amarus show limited potential for specialization, manifested as weak effects of host conditioning and genetic within-population structure. Rhodeus amarus is the only species of mussel-parasitizing fish in Europe, which contrasts with the species-rich communities of bitterling in eastern Asia where several host-specific bitterling occur. We discuss costs and constraints on the evolution of host-specific lineages in our study system and more generally.
Data from: Host stress hormones alter vector feeding preferences, success, and productivity
Stress hormones might represent a key link between individual-level infection outcome, population-level parasite transmission, and zoonotic disease risk. Although the effects of stress on immunity are well known, stress hormones could also affect host–vector interactions via modification of host behaviours or vector-feeding patterns and subsequent reproductive success. Here, we experimentally manipulated songbird stress hormones and examined subsequent feeding preferences, feeding success, and productivity of mosquito vectors in addition to defensive behaviours of hosts. Despite being more defensive, birds with elevated stress hormone concentrations were approximately twice as likely to be fed on by mosquitoes compared to control birds. Moreover, stress hormones altered the relationship between the timing of laying and clutch size in blood-fed mosquitoes. Our results suggest that host stress could affect the transmission dynamics of vector-borne parasites via multiple pathways.
Data from: Parasite and host elemental content and parasite effects on host nutrient excretion and metabolic rate
Ecological stoichiometry uses the mass balance of elements to predict energy and elemental fluxes across different levels of ecological organization. A specific prediction of ecological stoichiometry is the growth rate hypothesis (GRH), which states that organisms with faster growth or reproductive rates will require higher phosphorus content for nucleic acid and protein synthesis. Although parasites are found ubiquitously throughout ecosystems, little is understood about how they affect nutrient imbalances in ecosystems. We (1) tested the GRH by determining the carbon (C), nitrogen (N), and phosphorus (P) content of parasitic trematodes and their intermediate host, the freshwater snail Elimia livescens, and (2) used this framework to determine the trematode effects on host nutrient excretion and metabolism. Snail and parasite tissues were analyzed for elemental content using a CHN analyzer and soluble reactive phosphorus (SRP) methods. Ammonium and SRP assays were used to estimate N and P excretion rates. A respirometer was used to calculate individual snail metabolism. Trematode tissues contained lower C:P and N:P (more P per unit C and N) than the snail tissues. Snail gonadal tissues more closely resembled the elemental content of parasite tissues, although P content was 13% higher in the gonad than the trematode tissues. Despite differences in elemental content, N and P excretion rates of snails were not affected by the presence of parasites. Parasitized snails maintained faster metabolic rates than nonparasitized snails. However, the species of parasite did not affect metabolic rate. Together, this elemental imbalance between parasite and host, and the altered metabolic rate of infected snails may lead to broader parasite effects in stream ecosystems.
Data from: Consequences of divergent temperature optima in a host-parasite system
It was suggested that parasite infections become more severe with rising temperature, as expected during global warming. In ectothermic systems, the growth of a parasite and therefore its reproductive capacity is expected to increase with temperature. However, the outcome of the interaction depends on the temperature optima of both host and parasite. Here we used experimental infections of three-spined stickleback fish (Gasterosteus aculeatus) with its specific tapeworm parasite Schistocephalus solidus to investigate in detail the temperature optima for both host and parasite. We analyzed the fitness consequences thereof, focusing on growth and immunity of the host, and growth and offspring production of the parasite as fitness correlates. We checked for potential differences among populations, using the offspring of hosts and parasites derived from four study sites in Iceland, Germany and Spain that differ in average annual temperature ranging between 4.8 °C and 18.4 °C. We found differences in temperature optima of host and parasites that were quite consistent across the populations: while sticklebacks grew faster and had higher immune activity at low temperatures, the parasites did not even grow fast enough to reach sexual maturity in these conditions. By contrast, with increasing temperatures, parasite growth, egg production and offspring hatching increased strongly while host immunity and growth were impaired. Our results show that divergent temperature optima of hosts and parasites can have drastic fitness consequences and support the expectation that some parasites will benefit from global warming.
Data from: Allopatric origin of cryptic butterfly species that were discovered feeding on distinct host plants in sympatry
Surveys of tropical insects are increasingly uncovering cryptic species - morphologically similar yet reproductively isolated taxa once thought to comprise a single interbreeding entity. The vast majority of such species are described from a single location. This leaves us with little information on geographic range and intraspecific variation and limits our ability to infer the forces responsible for generating such diversity. For example, in herbivorous and parasitic insects, multiple specialists are often discovered within what were thought to be single more generalized species. Host shifts are likely to have contributed to speciation in these cases. But when and where did those shifts occur, and were they facilitated by geographic isolation? We attempted to answer these questions for two cryptic species within the butterfly Cymothoe egesta that were recently discovered on different host plants in central Cameroon. We first used mtDNA markers to separate individuals collected on the two hosts within Cameroon and then extended our analysis to incorporate individuals collected across the entire pan-Afrotropical range of the original taxon. To our surprise, we found that the species are almost entirely allopatric, dividing the original range and overlapping only in the narrow zone of West-Central Africa where they were first discovered in sympatry. This finding, combined with analyses of genetic variation within each butterfly species, strongly suggests that speciation occurred in allopatry, probably during the Pleistocene. We discuss the implications of our results for understanding speciation among other cryptic species recently discovered in the tropics and argue that more work is needed on geographic patterns and host usage in such taxa.
Data from: Functional genotypes are associated with commensal Escherichia coli strain abundance within host individuals and populations
The selective pressures that determine genotype abundance and distribution frequently vary between ecological levels. Thus, it is often unclear whether the same functional genotypes will become abundant at different levels and how selection acting at these different scales are linked. In this study, we examined whether particular functional genotypes, defined by the presence or absence of 34 genes, of commensal E. coli strains were associated with within-host abundance and/or host population abundance in a wild population of 54 adult mountain brushtail possums (Trichosurus cunninghami). Our results revealed that there was a positive correlation between a strain's relative abundance within individuals and the strain's abundance in the host population. We also found that strain abundance at both ecological levels was predicted by the same group of functional genes (agn43, focH, micH47, iroN, ygiL, ompT, kspmT2 and K1) that had associated patterns of occurrence. We propose that direct selection on the same functional genes at both levels may in part be responsible for the observed correlation between the ecological levels. However, a potential link between abundance within the host and excretion rate may also contribute.
Data from: Plant host and soil origin influence fungal and bacterial assemblages in the roots of woody plants
Microbial communities in plant roots provide critical links between above and belowground processes in terrestrial ecosystems. Variation in root communities has been attributed to plant host effects and microbial host preferences, as well as to factors pertaining to soil conditions, microbial biogeography and the presence of viable microbial propagules. To address hypotheses regarding the influence of plant host and soil biogeography on root fungal and bacterial communities we designed a trap-plant bioassay experiment. Replicate Populus, Quercus, and Pinus plants were grown in three soils originating from alternate field sites. Fungal and bacterial community profiles in the root of each replicate were assessed through multiplex 454 amplicon sequencing of 4 loci (i.e. 16S, SSU, ITS, LSU rDNA). Soil origin had a larger effect on fungal community composition than did host species, but the opposite was true for bacterial communities. Populus hosted the highest diversity of rhizospheric fungi and bacteria. Root communities on Quercus and Pinus were more similar to each other than to Populus. Overall, fungal root symbionts appear to be more constrained by dispersal and biogeography than by host availability.
Data from: Host-adapted aphid populations differ in their migratory patterns and capacity to colonize crops
Although phytophagous insects can vary genetically in host use and exhibit long-range movements, the combined implications of these phenomena for pest management have received limited attention. To address this, we surveyed the genetic diversity of pea aphid Acyrthosiphon pisum using twelve microsatellite loci and assessed host association patterns and annual movement from a putative source region (Columbia River Basin) to the Palouse region of northern Idaho and western Washington, where the aphid is a pest of pea Pisum sativum. A total of 320 identified unique genotypes clustered into four genetic groups, with two host plant associations: alfalfa Medicago sativa (three genetic groups), and pea Pisum sativum and vetch Vicia villosa (one genetic group). All four genetic groups occurred in the Columbia River Basin and in migrant aphids collected in pan traps during spring colonization in the Palouse during 2 years of this study. Patterns of group arrival on the Palouse were spatially structured early in the season, consistent with differing migration patterns. Despite genetic diversity of migrants, a single genetic group became predominant in pea crops each year. Clonal laboratory colonies of pea aphids established from field-collected specimens and representing two predominant genetic groups exhibited reciprocal performance trade-offs, with alfalfa being a poor host for a pea-associated aphid genotype and vice versa. Synthesis and applications. Annual spring migrants of pea aphids in the pea production region of the Palouse are genetically diverse, with different host plant affinities consistent with origination from source populations in the Columbia River Basin. As the season progresses, a single genetic group adapted to pea becomes predominant in the crop. Management of pea aphid in the Palouse will be improved by monitoring the temporal and spatial variation of specific genetic groups of the aphid arriving as immigrants during each crop season, providing this information to producers and adjusting estimates of risk of crop damage accordingly. The principle could apply to other pest species with host-adapted populations that colonize crops on an annual basis.
Data from: Host plant associations and geography interact to shape diversification in a specialist insect herbivore
Disentangling the processes underlying geographic and environmental patterns of biodiversity challenges biologists as such patterns emerge from eco-evolutionary processes confounded by spatial autocorrelation among sample units. The herbivorous insect, Belonocnema treatae (Hymenoptera: Cynipidae), exhibits regional specialization on three plant species whose geographic distributions range from sympatry through allopatry across the southern USA. Using range-wide sampling spanning the geographic ranges of the three host plants and genotyping-by-sequencing of 1,217 individuals, we tested whether this insect herbivore exhibited host-plant-associated genomic differentiation while controlling for spatial autocorrelation among the 58 sample sites. Population genomic structure based on 40,699 SNPs was evaluated using the hierarchical Bayesian model ENTROPY to assign individuals to genetic clusters and estimate admixture proportions. To control for spatial autocorrelation, distance-based Moran's eigenvector mapping was used to construct regression variables summarizing spatial structure inherent among sample sites. Distance based redundancy analysis (dbRDA) incorporating the spatial variables was then applied to partition host-plant-associated differentiation (HAD) from spatial autocorrelation. By combining ENTROPY and dbRDA to analyze SNP data we unveiled a complex mosaic of highly structured differentiation within and among gall former populations finding evidence that geography, HAD and spatial autocorrelation all play significant roles in explaining patterns of genomic differentiation in B. treatae. While dbRDA confirmed host association as a significant predictor of patterns of genomic variation, spatial autocorrelation among sites explained the largest proportion of variation. Our results demonstrate the value of combining dbRDA with hierarchical structural analyses to partition spatial/environmental patterns of genomic variation.
Data from: The effect of Wolbachia on the lifetime reproductive success of its insect host in the field
Wolbachia is a widespread endosymbiont that induces dramatic manipulations of its host's reproduction. Although there has been substantial progress in the developing theory for Wolbachia–host interactions and in measuring the effects of Wolbachia on host fitness in the laboratory, there is a widely recognized need to quantify the effects of Wolbachia on the host fitness in the field. The wasp Anagrus sophiae, an egg parasitoid of planthoppers, carries a Wolbachia strain that induces parthenogenesis, but its effects on the fitness of its Anagrus host are unknown. We developed a method to estimate the realized lifetime reproductive success of female wasps by collecting them soon after they die naturally in the field, counting the number of eggs remaining in their ovaries and quantifying Wolbachia density in their body. We sampled from a highly infected A. sophiae population and found no evidence for Wolbachia virulence and possible evidence for positive effects of Wolbachia on realized reproductive success.
Data from: Males, but not females, perform strategic mate searching movements between host plants in a leaf beetle with scramble competition polygyny
1. Mate searching is assumed to be performed mostly by males, but when females benefit from multiple mating or are under risk of failing to mate, they may also perform mate searching. This is especially important in scramble competition polygynies, in which mate searching is the main mechanism of mate competition. Typically, more mobile individuals are expected to achieve higher mating success because mobility increases their probability of finding mates. 2. If we assume individual movements are mainly explained by mate searching in scramble competition polygynies, we can investigate searching strategies by asking when individuals should leave their location and where they should go. We hypothesize that individuals will leave their locations when mating opportunities are scarce and will seek spatially close sites with better mating opportunities. 3. We tested these hypotheses for males and females of Leptinotarsa undecimlineata, a leaf beetle with scramble competition polygyny in which both sexes are promiscuous. Individuals mate and feed exclusively on Solanum plants, thus individual movements can be described as switches between plants. 4. Females were less likely than males to leave isolated plants, and both males and females moved preferentially to neighbouring plants. Males were more likely to leave when the local number of females was low, and the number of males was high. They moved to plants with more females, a behaviour consistent with a mate searching strategy. Females were more likely to move to plants with fewer males and many females, a behaviour consistent with male harassment avoidance. 5. Strategic movement is widely considered in foraging context, but seldom in a mate searching context. Considering that selection to minimize searching costs, maximize mating success, and minimize harassment may be ubiquitous in nature, we argue that strategic movements by mate searching individuals are likely to occur in many species.
Data from: Demographic and spatiotemporal patterns of avian influenza infection at the continental scale, and in relation to annual life cycle of a migratory host
Since the spread of highly pathogenic avian influenza (HPAI) H5N1 in the eastern hemisphere, numerous surveillance programs and studies have been undertaken to detect the occurrence, distribution, or spread of avian influenza viruses (AIV) in wild bird populations worldwide. To identify demographic determinants and spatiotemporal patterns of AIV infection in long distance migratory waterfowl in North America, we fitted generalized linear models with binominal distribution to analyze results from 13,574 blue-winged teal (Anas discors, BWTE) sampled in 2007 to 2010 year round during AIV surveillance programs in Canada and the United States. Our analyses revealed that during late summer staging (July-August) and fall migration (September-October), hatch year (HY) birds were more likely to be infected than after hatch year (AHY) birds, however there was no difference between age categories for the remainder of the year (winter, spring migration, and breeding period), likely due to maturing immune systems and newly acquired immunity of HY birds. Probability of infection increased non-linearly with latitude, and was highest in late summer prior to fall migration when densities of birds and the proportion of susceptible HY birds in the population are highest. Birds in the Central and Mississippi flyways were more likely to be infected compared to those in the Atlantic flyway. Seasonal cycles and spatial variation of AIV infection were largely driven by the dynamics of AIV infection in HY birds, which had more prominent cycles and spatial variation in infection compared to AHY birds. Our results demonstrate demographic as well as seasonal, latitudinal and flyway trends across Canada and the US, while illustrating the importance of migratory host life cycle and age in driving cyclical patterns of prevalence.
Data from: The contribution of host cell-directed vs. parasite-directed immunity to the disease and dynamics of malaria infections
<p>Hosts defend themselves against pathogens by mounting an immune response. Fully understanding the immune response as a driver of host disease and pathogen evolution requires a quantitative account of its impact on parasite population dynamics. Here, we use a data-driven modeling approach to quantify the birth and death processes underlying the dynamics of infections of the rodent malaria parasite, <span>Plasmodium chabaudi</span>, and the red blood cells (RBCs) it targets. We decompose the immune response into 3 components, each with a distinct effect on parasite and RBC vital rates, and quantify the relative contribution of each component to host disease and parasite density. Our analysis suggest that these components are deployed in a coordinated fashion to realize distinct resource-directed defense strategies that complement the killing of parasitized cells. Early in the infection, the host deploys a strategy reminiscent of siege and scorched-earth tactics, in which it both destroys RBCs and restricts their supply. Late in the infection, a "juvenilization" strategy, in which turnover of RBCs is accelerated, allows the host to recover from anemia while holding parasite proliferation at bay. By quantifying the impact of immunity on both parasite fitness and host disease. we reveal that phenomena often interpreted as immunopathology may in fact be beneficial to the host. Finally, we show that, across mice, the components of the host response are consistently related to each other, even when infections take qualitatively different trajectories. This suggests the existence of simple rules that govern the immune system's deployment.</p>
Data from: Biogeography and host-related factors trumps parasite life-history: limited congruence among the genetic structures of specific ectoparasitic lice and their rodent hosts
Parasites and hosts interact across both micro- and macroevolutionary scales where congruence among their phylogeographic and phylogenetic structures may be observed. Within southern Africa, the four-striped mouse genus, Rhabdomys, is parasitized by the ectoparasitic sucking louse, Polyplax arvicanthis. Molecular data recently suggested the presence of two cryptic species within P. arvicanthis that are sympatrically distributed across the distributions of four putative Rhabdomys species. We tested the hypotheses of phylogeographic congruence and cophylogeny among the two parasite lineages and the four host taxa, utilizing mitochondrial and nuclear sequence data. Despite the documented host-specificity of P. arvicanthis, limited phylogeographic correspondence and nonsignificant cophylogeny was observed. Instead, the parasite–host evolutionary history is characterized by limited codivergence and several duplication, sorting and host-switching events. Despite the elevated mutational rates found for P. arvicanthis, the spatial genetic structure was not more pronounced in the parasite lineages compared with the hosts. These findings may be partly attributed to larger effective population sizes of the parasite lineages, the vagility and social behaviour of Rhabdomys, and the lack of host-specificity observed in areas of host sympatry. Further, the patterns of genetic divergence within parasite and host lineages may also be largely attributed to historical biogeographic changes (expansion-contraction cycles). It is thus evident that the association between P. arvicanthis and Rhabdomys has been shaped by the synergistic effects of parasite traits, host-related factors and biogeography over evolutionary time.
Data from: Epiphytes improve host plant water use by microenvironment modification
1. Epiphytes have the potential to modify the canopy environments in which they grow. Accurately evaluating the impact of epiphytes can be challenging, since plants without epiphytes may also otherwise differ from host plants, and experimental removal is impractical and difficult to replicate in many forests. 2. We studied the impacts of epiphytes (primarily fruticose lichens and Tillandsia spp.) on host plants (Eulychnia saint-pieana and Caesalpinia spinosa) in two fog ecosystems in Chile (Pan de Azucar) and Peru (Atiquipa). These desert ecosystems sustain very high epiphyte loads and depend heavily on fog-water inputs. Using a combination of artificial substrates and epiphyte removals we show significant impacts of epiphytes on their host plants. 3. The presence of epiphytes reduced throughfall volumes, reducing fog and rainfall inputs to the soil beneath host plant canopies. 4. Soil moisture loss rate was increased below cacti after removal of epiphytes from sun-facing but not shade-facing branches. This suggests epiphyte effects on hosts are microclimatic. 5. Epiphytes also buffered temperature fluctuations and reduced daytime vapour pressure deficit (VPD). 6. Epiphytes can have strong effects on host plant ecophysiology and forest ecosystem processes, making them an important component for models and studies of canopy environments.
Data from: Environmentally dependent host-pathogen and vector-pathogen interactions in the barley yellow dwarf virus pathosystem
1. Understanding environmentally dependent variation in interspecific interactions is needed for evaluating how agroecosystems respond to abiotic stressors, including climate change. Both biotic and abiotic conditions shape crop responses to stress events, but interactions between environmental conditions and insect borne plant pathogens remain poorly understood. 2. We tested the hypothesis that drought stress, as applied by experimental water deprivation, drives conditional outcomes in host–pathogen and host–vector interactions using a cereal–aphid–virus association and greenhouse experiments. 3. Under conditions of ample water supply, infection of wheat plants with Barley yellow dwarf virus (BYDV) resulted in reduced above-ground growth, seed set, seed yields and seed germination compared with plants exposed only to non-infected (non-viruliferous) aphids or control plants not subjected to aphid infestation. However, when water was chronically limiting, infection with Barley yellow dwarf virus did not significantly affect plant performance. 4. When wheat was subjected to acute drought stress, plants infected with Barley yellow dwarf virus surpassed both control plants and plants exposed to non-infected aphids in all measured performance traits. 5. Feeding experiments with aphid vectors (Rhopalosiphum padi) and subsequent life table analysis revealed that aphid fecundity improved by 47% when feeding on Barley yellow dwarf virus-infected plants when water inputs were chronically low. However, when plants received ample water, aphid fecundity was enhanced by only 23% from feeding on BYDV-infected plants. 6. Synthesis and applications. Collectively, our experiments suggest that wheat– Barley yellow dwarf virus interactions shift along gradients of water stress severity and duration. When Barley yellow dwarf virus infection preceded water deprivation, plant performance was not reduced from virus infection, and infected plants recovered from severe stress events more readily than non-infected plants. However, vector–pathogen mutualism resulting in enhanced reproduction of aphids on virus-infected plants is likely to amplify direct plant injury from herbivory in the field. Our findings indicate that during periods of drought, management of Barley yellow dwarf virus infection may not be needed and infection could benefit wheat under conditions of acute water stress.
Data from: Buchnera has changed flatmate but the repeated replacement of co-obligate symbionts is not associated with the ecological expansions of their aphid hosts
Symbiotic associations with bacteria have facilitated important evolutionary transitions in insects and resulted in long-term obligate interactions. Recent evidence suggests that these associations are not always evolutionarily stable and that symbiont replacement and/or supplementation of an obligate symbiosis by an additional bacterium has occurred during the history of many insect groups. Yet, the factors favoring one symbiont over another in this evolutionary dynamic are not well understood; progress has been hindered by our incomplete understanding of the distribution of symbionts across phylogenetic and ecological contexts. While many aphids are engaged into an obligate symbiosis with a single Gammaproteobacterium, Buchnera aphidicola, in species of the Lachninae subfamily, this relationship has evolved into a "ménage à trois", in which Buchnera is complemented by a co-symbiont, usually Serratia symbiotica. Using deep sequencing of 16S rRNA bacterial genes from 128 species of Cinara (the most diverse Lachninae genus), we reveal a highly dynamic dual symbiotic system in this aphid lineage. Most species host both Serratia and Buchnera but, in several clades, endosymbionts related to Sodalis, Erwinia or an unnamed member of the Enterobacteriaceae have replaced Serratia. Endosymbiont genome sequences from four aphid species confirm that these co-resident symbionts fulfill essential metabolic functions not ensured by Buchnera. We further demonstrate through comparative phylogenetic analyses that co-symbiont replacement is not associated with the adaptation of aphids to new ecological conditions. We propose that symbiont succession was driven by factors intrinsic to the phenomenon of endosymbiosis, such as rapid genome deterioration or competitive interactions between bacteria with similar metabolic capabilities.
Data from: Are aphid parasitoids locally adapted to the prevalence of defensive symbionts in their hosts?
Background: Insect parasitoids are under strong selection to overcome their hosts' defences. In aphids, resistance to parasitoids is largely determined by the presence or absence of protective endosymbionts such as Hamiltonella defensa. Hence, parasitoids may become locally adapted to the prevalence of this endosymbiont in their host populations. To address this, we collected isofemale lines of the aphid parasitoid Lysiphlebus fabarum from 17 sites in Switzerland and France, at which we also estimated the frequency of infection with H. defensa as well as other bacterial endosymbionts in five important aphid host species. The parasitoids' ability to overcome H. defensa-mediated resistance was then quantified by estimating their parasitism success on a single aphid clone (Aphis fabae fabae) that was either uninfected or experimentally infected with one of three different isolates of H. defensa. Results: The five aphid species (Aphis fabae fabae, A. f. cirsiiacanthoides, A. hederae, A. ruborum, A. urticata) differed strongly in the relative frequencies of infection with different bacterial endosymbionts, but there was also geographic variation in symbiont prevalence. Specifically, the frequency of infection with H. defensa ranged from 22 to 47 % when averaged across species. Parasitoids from sites with a high prevalence of H. defensa tended to be more infective on aphids possessing H. defensa, but this relationship was not significant, thus providing no conclusive evidence that L. fabarum is locally adapted to the occurrence of H. defensa. On the other hand, we observed a strong interaction between parasitoid line and H. defensa isolate on parasitism success, indicative of a high specificity of symbiont-conferred resistance. Conclusions: This study is the first, to our knowledge, to test for local adaptation of parasitoids to the frequency of defensive symbionts in their hosts. While it yielded useful information on the occurrence of facultative endosymbionts in several important host species of L. fabarum, it provided no clear evidence that parasitoids from sites with a high prevalence of H. defensa are better able to overcome H. defensa-conferred resistance. The strong genetic specificity in their interaction suggests that it may be more important for parasitoids to adapt to the particular strains of H. defensa in their host populations than to the general prevalence of this symbiont, and it highlights the important role symbionts can play in mediating host-parasitoid coevolution.
Data from: Effect of haemosporidian infections on host survival and recapture rate in the blue tit
Parasites are ubiquitous in the wild and by imposing fitness costs on their hosts they constitute an important selection factor. One of the most common parasites of wild birds are Plasmodium and Haemoproteus, protozoans inhabiting the blood, which cause avian malaria and malaria-like disease, respectively. Although they are expected to cause negative effects in infected individuals, in many cases studies in natural populations failed to detect such effect. Using data from seven breeding seasons (2008 - 2014), we applied a multistate capture – mark – recapture approach to study the effect of infection with malaria and malaria-like parasites, individual age and sex on the probability of survival and recapture rate in a small passerine, the blue tit (Cyanistes caeruleus), inhabiting the island of Gotland, Sweden. We found no effect of infection on survival prospects. However, the recapture rate of infected individuals was higher than that of uninfected ones. Thus, while our data do not support the presence of infection costs in terms of host survival, it suggests that parasites from the genera Plasmodium and Haemoproteus may affect some aspects of host behaviour, which translates into biased estimation of infection frequency at the population level.
Data from: Spatial population genetic structure of a bacterial parasite in close coevolution with its host
Knowledge of a species' population genetic structure can provide insight into fundamental ecological and evolutionary processes including gene flow, genetic drift, and adaptive evolution. Such inference is of particular importance for parasites, as an understanding of their population structure can illuminate epidemiological and coevolutionary dynamics. Here we describe the population genetic structure of the bacterium Pasteuria ramosa, a parasite that infects planktonic crustaceans of the genus Daphnia. This system has become a model for investigations of host-parasite interactions and represents an example of coevolution via negative frequency-dependent selection (a.k.a. 'Red Queen' dynamics). To sample P. ramosa, we experimentally infected a panel of Daphnia hosts with natural spore banks from the sediments of 25 ponds throughout much of the species range in Europe and Western Asia. Using 12 polymorphic VNTR loci, we identified substantial genetic diversity both within and among localities that was structured geographically among ponds. Genetic diversity was also structured among host genotypes within ponds, though this pattern varied by locality, with P. ramosa at some localities partitioned into distinct host-specific lineages, and other localities where recombination had shuffled genetic variation among different infection phenotypes. Across the sample range, there was a pattern of isolation-by-distance, and principal components analysis coupled with Procrustes rotation identified congruence between patterns of genetic variation and geography. Our findings support the hypothesis that Pasteuria is an endemic parasite coevolving closely with its host. These results provide important context for previous studies of this model system and inform hypotheses for future research.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.