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Data from: Vaginal host immune-microbiome interactions in a cohort of primarily African-American women who ultimately underwent spontaneous preterm birth or delivered at term
<p><strong>Background</strong>: Recent studies suggest that alterations in the vaginal microbiome allow for the assessment of the risk for spontaneous preterm birth (PTB), the leading cause of neonatal morbidity and mortality worldwide. However, the associations between the local immune response and the vaginal microbiome are still poorly understood. Herein, we characterize the vaginal host immune-microbiome interactions in women who ultimately underwent PTB and in those who delivered at term.</p> <p><strong>Methods</strong>: Vaginal fluid samples from 52 pregnant women (of whom 18 underwent PTB and 34 delivered at term) were collected from 10-32 weeks in a case-control study. Concentrations of 33 immune mediators were determined using sensitive and specific immunoassays. The previously published 16S rRNA gene sequence and bacterial phylotype data of these subjects were utilized in this study. Linear mixed effects models were utilized to test associations between vaginal immune mediator concentrations and bacterial phylotype relative abundances.</p> <p><strong>Results</strong>: 1) Specific immune mediators (β-defensins 2 and 3, IL-1β, CXCL10, CCL2, CCL3, SLPI, and VEGF) correlated with 18 different vaginal bacterial phylotypes in the overall study population; 2) vaginal concentrations of CXCL10, CCL2, CCL3, SLP1 and VEGF negatively correlated with non-Lactobacillus members of the vaginal microbiome; 3) vaginal concentrations of CXCL10 were negatively correlated with 15 bacterial phylotypes, most of which are typical members of Community State Type IV of the vaginal microbiome, such as Gardnerella vaginalis, Megasphaera sp. type 1, and Atopobium vaginae; 4) Gemella spp. were negatively correlated with vaginal concentrations of VEGF, CCL2, CCL3, SLPI, and CXCL10; 5) when comparing PTB cases to term controls, five soluble immune mediators (CCL26, CCL22 and CCL2, CXCL10 and IL-16), and especially CCL26, were negatively correlated with five typical members of Community State Type IV: Sneathia sanguinegens, Parvimonas micra, Veillonellaceae, BVAB2, and Gemella spp; and 6) Sneathia sanguinegens had stronger negative associations with all five soluble immune mediators (CCL26, CCL22 and CCL2, CXCL10 and IL-16) in PTB cases than in term controls.</p> <p><strong>Conclusions</strong>: The assessment of vaginal host immune-microbiome interactions revealed that specific soluble immune mediators, mainly CXCL10, negatively correlated with typical members of Community State Type IV of the vaginal microbiome. In addition, this assessment particularly showed that Sneathia sanguinegens had stronger negative associations with different immune mediators, including CXCL10 and CCL26, in women who ultimately had a PTB compared to those who delivered at term. These findings provide insight into the vaginal host immune-microbiome interactions in normal and complicated pregnancies.</p>
Data from: Comparative phylogeography of three host sea anemones in the Indo-Pacific
<p><span><span><span><span><span><span><span><span><span><span><span><b>Aim</b></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span>The mutualistic relationship between anemones and anemonefishes is one of the most iconic examples of symbiosis. However, while anemonefishes have been extensively studied in terms of genetic connectivity, such information is lacking entirely for host sea anemones. Here, we provide the first information on the broad-scale population structure and phylogeographic patterns of three species of host sea anemone, <i>Heteractis magnifica, Stichodactyla mertensii, </i>and <i>Entacmaea quadricolor</i>. We evaluate if there is concordance in genetic structure across several distinct biogeographic areas within the Indo-Pacific region and to what extent the observed patterns may concur with those found for anemonefishes. </span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><b>Location</b></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span>Indo-Pacific, including the Red Sea.</span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><b>Taxon</b></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><i>Heteractis magnifica</i>, <i>Stichodactyla mertensii, </i>and <i>Entacmaea quadricolor</i></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><b>Methods</b></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span>Microsatellite markers and a combination of statistical methods includingBayesian clustering, Isolation by Distance (IBD), Analysis of Molecular Variance (AMOVA), and Principal Components Analysis (PCA) were used to determine population structure. The congruence among distance matrices method (CADM) was used to assess similarity in spatial genetic patterns among species.</span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><b>Results</b></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span>Significant population structure was identified in the three host anemone species. Each species is likely composed of at least two genetic clusters corresponding to two biogeographic regions, the Red Sea and the rest of the Indo-Pacific. Two of the three anemone species seem to be experiencing admixture where the two main clusters overlap (the Maldives). IBD analyses in the Red Sea revealed differences in gene flow among species, suggesting more limited dispersal potential for <i>E. quadricolor</i>than for<i>S. mertensii</i>and <i>H. magnifica</i>. Clonality is documented in <i>S. mertensii </i>for the first time.</span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span><b>Main conclusions</b></span></span></span></span></span></span></span></span></span></span></span></p> <p><span><span><span><span><span><span><span><span><span><span><span>This research documents the genetic population structure for three ecologically important host sea anemones across the Indo-Pacific and provides valuable insights regarding their biogeography and evolution. Specifically, we found high levels of genetic divergence between populations across different biogeographic regions, suggesting different evolutionary lineages within species. At the same time, common geographic overlap of population structures suggests similar evolutionary histories among all three species. Interestingly, the observed patterns are congruent to some extent with structure reported for several anemonefish species, reflecting their close ecological association.</span></span></span></span></span></span></span></span></span></span></span></p>
Data for: Immobilization of molecular catalysts on electrode surfaces using host–guest interactions
<p>Anchoring molecular catalysts on electrode surfaces combines the high selectivity and activity of molecular systems with the practicality of heterogeneous systems. Molecular catalysts, however, are far less stable than traditional heterogeneous electrocatalysts, and therefore a method to easily replace anchored molecular catalysts that have degraded could make such electrosynthetic systems more attractive. Here, we apply a non-covalent 'click' chemistry approach to reversibly bind molecular electrocatalysts to electrode surfaces through host–guest complexation with surface-anchored cyclodextrins. The host–guest interaction is remarkably strong and enables the flow of electrons between the electrode and the guest catalyst. Electrosynthesis in both organic and aqueous media was demonstrated on metal oxide electrodes, with stability on the order of hours. The catalytic surfaces can be recycled by controlled release of the guest from the host cavities and readsorption of fresh guest. </p>
Data from: Abundance data applied to a novel model invertebrate host sheds new light on parasite community assembly in nature
<ol> <li>Understanding how environmental drivers influence the assembly of parasite communities, in addition to how parasites may interact at an infracommunity level, are fundamental requirements for the study of parasite ecology. Knowledge of how parasite communities are assembled will help to predict the risk of parasitism for hosts, and model how parasite communities may change under variable conditions. However, studies frequently rely on presence-absence data and examine multiple host species or sites, metrics which may be too coarse to characterise nuanced within-host patterns.</li> <li>We utilised a novel host system, the freshwater mussel <i>Anodonta anatina</i>, to investigate the drivers of community structure and explore parasite interactions. In addition, we aimed to highlight consistencies and inconsistencies between presence-absence and abundance data.</li> <li>Our analysis incorporated 14 parasite taxa and 720 replicate infracommunities. Using redundancy analysis, a joint species distribution model and a Markov random fields approach, we modelled the impact of both host-level and environment-level characteristics on parasite structure, as well as parasite-parasite correlations after accounting for all other factors. This approach was repeated for both the presence and abundance of all parasites.</li> <li>We demonstrated that the regional species pool, individual host characteristics (mussel length and gravidity) and predicted parasite-parasite interactions are all important but to varying degrees across parasite species, suggesting that applying generalities to parasite community construction is too simplistic. Further, we showed that presence-absence data fails to capture important density-dependent effects of parasite load for parasites with high abundance, and in general performs poorly for high-intensity parasites.</li> <li>Host and parasite traits, as well as broader environmental factors, all contribute to parasite community structure, emphasising that an integrated approach is required to study community assembly. However, care must be taken with the data used to infer patterns, as presence-absence data may lead to incorrect ecological inference.</li> </ol>
Data from: Whole-genome duplication and host genotype affect rhizosphere microbial communities
<p>The composition of microbial communities found in association with plants is influenced by host phenotype and genotype. Yet, the ways in which specific genetic architectures of host plants shape microbiomes is unknown. Genome duplication events are common in the evolutionary history of plants, influence many important plant traits, and, thus, they may affect associated microbial communities. Using experimentally induced whole genome duplication (WGD), we tested the effect of WGD on rhizosphere bacterial communities in<i> Arabidopsis thaliana</i>. We performed 16S rRNA amplicon sequencing to characterize differences between microbiomes associated with specific host genetic backgrounds (Columbia <i>vs</i>. Landsberg) and ploidy levels (diploid <i>vs</i>. tetraploid). We modeled relative abundances of bacterial taxa using the Dirichlet and multinomial distributions via a hierarchical Bayesian approach. We found that host genetic background and ploidy level affected rhizosphere community composition. We then tested to what extent microbiomes derived from a specific genetic background or ploidy level affected plant performance by inoculating sterile seedlings with microbial communities harvested from a prior generation. We found a negative effect of the tetraploid Columbia microbiome on growth of all four plant genetic backgrounds. These findings suggest an interplay between host genetic architecture and bacterial community assembly with potential ramifications for host fitness. Moreover, we uncovered an intriguing role of ploidy-level for shaping plant microbiomes. Given the prevalence of ploidy-level variation in both wild and managed plant populations, the effects on microbiomes of this aspect of host genetic architecture could be a widespread driver of differences in plant microbiomes.</p>
Data from: Host-targeted RAD-Seq reveals genetic changes in the coral Oculina patagonica associated with range expansion along the Spanish Mediterranean coast
Many organisms are expanding their ranges in response to changing environmental conditions. Understanding the patterns of genetic diversity and adaptation along an expansion front is crucial to assessing a species' long-term success. While next-generation sequencing techniques can reveal these changes in fine detail, ascribing them to a particular species can be difficult for organisms that live in close association with symbionts. Using a novel modified restriction-site associated DNA sequencing (RAD-Seq) protocol to target coral DNA, we collected 595 coral-specific single nucleotide polymorphisms (SNPs) from 189 colonies of the invasive coral Oculina patagonica from the Spanish Mediterranean coast, including established core populations and two expansion fronts. Surprisingly, populations from the recent northern expansion are genetically distinct from the westward expansion and core populations, and also harbor greater genetic diversity. We found that temperature may have driven adaptation along the northern expansion, as genome scans for selection found three candidate loci associated with temperature in the north but none in the west. We found no genomic signature of selection associated with artificial substrate, which has been proposed for explaining the rapid spread of O. patagonica. This suggests that this coral is simply an opportunistic colonizer of free space made available by coastal habitat modifications. Our results suggest that unique genetic variation, possibly due to limited dispersal across the Ibiza Channel, an influx of individuals from different depths, and/or adaptation to cooler temperatures along the northern expansion front may have facilitated the northward range expansion of O. patagonica in the western Mediterranean.
Data from: Cryptic diversity hides host and habitat specialization In a gorgonian-algal symbiosis
Shallow water anthozoans, the major builders of modern coral reefs, enhance their metabolic and calcification rates with algal symbionts. Controversy exists over whether these anthozoan-algae associations are flexible over the lifetimes of individual hosts, promoting acclimative plasticity, or are closely linked, such that hosts and symbionts coevolve across generations. Given the diversity of algal symbionts and the morphological plasticity of many host species, cryptic variation within either partner could potentially confound studies of anthozoan-algal associations. Here, we used ribosomal, organelle, and nuclear sequences, along with microsatellite variation, to study the relationship between lineages of a common Caribbean gorgonian and its algal symbionts. The gorgonian Eunicea flexuosa is a broadcast spawner, composed of two recently diverged, genetically distinct lineages largely segregated by depth. We sampled colonies of the two lineages across depth gradients at three Caribbean locations. We find that each host lineage is associated with a unique Symbiodinium B1/184 phylotype. This relationship between host and symbiont is maintained when host colonies are reciprocally transplanted, although cases of within phylotype switching were also observed. Even when the phylotypes of both partners are present at intermediate depths, the specificity between host and symbiont lineages remained absolute. Unrecognized cryptic diversity may mask host-symbiont specificity and change the inference of evolutionary processes in mutualistic associations. Symbiotic specificity thus likely contributes to the ecological divergence of the two partners, generating species diversity within coral reefs.
Data from: Parasite-induced plasticity in host social behaviour depends on sex and susceptibility
Understanding the effects of parasites on host behaviour, of host behaviour on parasite infection, and the reciprocal interactions between these processes is vital to improving our understanding of animal behaviour and disease dynamics. However, behaviour and parasite infection are both highly variable within and between individual hosts, and how this variation affects behaviour-parasite feedbacks is poorly understood. For example, it is unclear how an individual's behaviour before infection might change once it becomes infected, or as the infection progresses, and how these changes depend on the host's parasite susceptibility. Here, using the guppy, Poecilia reticulata, and a directly-transmitted ectoparasite, Gyrodactylus turnbulli, I show that parasite-induced behavioural plasticity depends on host sex and susceptibility. Among females, time spent shoaling ('sociality'), a behaviour that increases parasite transmission, did not depend on infection status (infected/not) or susceptibility. By contrast, male sociality in the absence of infection was negatively correlated with susceptibility, suggesting the most susceptible males use behaviour to avoid infection. However, in late infection when parasite transmission is most likely, male sociality and susceptibility became positively correlated, suggesting susceptible males modify their behaviour upon infection potentially to increase transmission and mating opportunities. I discuss the implications of these patterns for disease dynamics.
Data from: Host species composition influences infection severity among amphibians in the absence of spillover transmission
Wildlife epidemiological outcomes can depend strongly on the composition of an ecological community, particularly when multiple host species are affected by the same pathogen. However, the relationship between host species richness and disease risk can vary with community context and with the degree of spillover transmission that occurs among co-occurring host species. We examined the degree to which host species composition influences infection by Batrachochytrium dendrobatidis (Bd), a widespread fungal pathogen associated with amphibian population declines around the world, and whether transmission occurs from one highly susceptible host species to other co-occurring host species. By manipulating larval assemblages of three sympatric amphibian species in the laboratory, we characterized the relationship between host species richness and infection severity, whether infection mediates growth and survivorship differently across various combinations of host species, and whether Bd is transmitted from experimentally inoculated tadpoles to uninfected tadpoles. We found evidence of a dilution effect where Bd infection severity was dramatically reduced in the most susceptible of the three host species (Anaxyrus boreas). Infection also mediated survival and growth of all three host species such that the presence of multiple host species had both positive (e.g., infection reduction) and negative (e.g., mortality) effects on focal species. However, we found no evidence that Bd infection is transmitted by this species. While these results demonstrate that host species richness as well as species identity underpin infection dynamics in this system, dilution is not the product of reduced transmission via fewer infectious individuals of a susceptible host species. We discuss various mechanisms, including encounter reduction and antagonistic interactions such as competition and opportunistic cannibalism that may act in concert to mediate patterns of infection severity, growth, and mortality observed in multihost communities.
Data from: Phylogenetic signal in module composition and species connectivity in compartmentalized host-parasite networks
Across different taxa, networks of mutualistic or antagonistic interactions show consistent architecture. Most networks are modular, with modules being distinct species subsets connected mainly with each other and having few connections to other modules. We investigate the phylogenetic relatedness of species within modules and whether a phylogenetic signal is detectable in the within- and among module connectivity of species using 27 mammal-flea networks from the Palaearctic. In the 24 networks that were modular, closely-related hosts co-occurred in the same module more often than expected by chance; in contrast, this was rarely the case for parasites. The within- and among-module connectivity of the same host or parasite species varied geographically. However, among-module but not within-module connectivity of host and parasites was somewhat phylogenetically constrained. These findings suggest that the establishment of host-parasite networks results from the interplay between phylogenetic influences acting mostly on hosts and local factors acting on parasites, to create an asymmetrically constrained pattern of geographic variation in modular structure. Modularity in host-parasite networks seems to result from the shared evolutionary history of hosts and by trait convergence among unrelated parasites. This suggests profound differences between hosts and parasites in the establishment and functioning of bipartite antagonistic networks.
Data from: Fur seal microbiota are shaped by the social and physical environment, show mother-offspring similarities and are associated with host genetic quality
Despite an increasing appreciation of the importance of host-microbe interactions in ecological and evolutionary processes, the factors shaping microbial communities in wild populations remain poorly understood. We therefore exploited a natural experiment provided by two adjacent Antarctic fur seal (<i>Arctocephalus gazella</i>) colonies of high and low social density and combined 16S rRNA metabarcoding with microsatellite profiling of mother-offspring pairs to investigate environmental and genetic influences on skin microbial communities. Seal-associated bacterial communities differed profoundly between the two colonies, despite the host populations themselves being genetically undifferentiated. Consistent with the hypothesis that social stress depresses bacterial diversity, we found that microbial alpha diversity was significantly lower in the high-density colony. Seals from one of the colonies that contained a stream also carried a subset of freshwater-associated bacteria, indicative of an influence of the physical environment. Furthermore, mothers and their offspring shared similar microbial communities, in support of the notion that microbes may facilitate mother-offspring recognition. Finally, a significant negative association was found between bacterial diversity and heterozygosity, a measure of host genetic quality. Our study thus uncovers a complex interplay between environmental and host genetic effects, while also providing empirical support for the leash model of host control, which posits that bacterial communities are driven not only by bottom-up species interactions, but also by top-down host regulation. Taken together, our findings have broad implications for understanding host-microbe interactions as well as prokaryotic diversity in general.
Data from: Description of a new species of Hedruris Nitzsch, 1821 (Nematoda, Hedruridae) from freshwater turtles in Argentina, with information on its life cycle and a review of the genus's host and geographic distribution
Hedruris dratini n. sp. (Nematoda, Hedruridae) is described from freshwater turtles in Argentina and information about its life cycle provided. The new species differs from the remaining species of the genus by possessing an excretory pore, and the nerve ring and deirids being positioned at equal distance from the anterior end. Additionally, H. dratini n. sp. has mammilated eggs and males possess nine pairs of caudal papillae. The first life cycle within the genus including an amphipod as intermediate host and a reptile as a definitive host is presented. Furthermore, the host and geographic distribution of species of the genus Hedruris Nitzsch, 1821 are analyzed. Although the genus has a cosmopolitan distribution and parasitizes a great diversity of hosts, the majority of its species follow a Gondwanian distribution and its preferred hosts are amphibians.
Data from: Pathogens manipulate the preference of vectors, slowing disease spread in a multi-host system
The spread of vector‐borne pathogens depends on a complex set of interactions among pathogen, vector, and host. In single‐host systems, pathogens can induce changes in vector preferences for infected vs. healthy hosts. Yet it is unclear if pathogens also induce changes in vector preference among host species, and how changes in vector behaviour alter the ecological dynamics of disease spread. Here, we couple multi‐host preference experiments with a novel model of vector preference general to both single and multi‐host communities. We show that viruliferous aphids exhibit strong preferences for healthy and long‐lived hosts. Coupling experimental results with modelling to account for preference leads to a strong decrease in overall pathogen spread through multi‐host communities due to non‐random sorting of viruliferous vectors between preferred and non‐preferred host species. Our results demonstrate the importance of the interplay between vector behaviour and host diversity as a key mechanism in the spread of vectored‐diseases.
Data from: Stress hormones predict a host superspreader phenotype in the West Nile virus system
Glucocorticoid stress hormones, such as corticosterone (CORT), have profound effects on the behaviour and physiology of organisms, and thus have the potential to alter host competence and the contributions of individuals to population- and community-level pathogen dynamics. For example, CORT could alter the rate of contacts among hosts, pathogens and vectors through its widespread effects on host metabolism and activity levels. CORT could also affect the intensity and duration of pathogen shedding and risk of host mortality during infection. We experimentally manipulated songbird CORT, asking how CORT affected behavioural and physiological responses to a standardized West Nile virus (WNV) challenge. Although all birds became infected after exposure to the virus, only birds with elevated CORT had viral loads at or above the infectious threshold. Moreover, though the rate of mortality was faster in birds with elevated CORT compared with controls, most hosts with elevated CORT survived past the day of peak infectiousness. CORT concentrations just prior to inoculation with WNV and anti-inflammatory cytokine concentrations following viral exposure were predictive of individual duration of infectiousness and the ability to maintain physical performance during infection (i.e. tolerance), revealing putative biomarkers of competence. Collectively, our results suggest that glucocorticoid stress hormones could directly and indirectly mediate the spread of pathogens.
Data from: Toxins or medicines? Phytoplankton diets mediate host and parasite fitness in a freshwater system
Diets must satisfy the everyday metabolic requirements of organisms and can also serve as medicines to combat disease. Currently, the medicinal role of diets is much better understood in terrestrial than in aquatic ecosystems. This is surprising because phytoplankton species synthesize secondary metabolites with known antimicrobial properties. Here, we investigated the medicinal properties of phytoplankton (including toxin-producing cyanobacteria) against parasites of the dominant freshwater herbivore, Daphnia. We fed Daphnia dentifera on green algae and toxic cyanobacteria diets known to vary in their nutritional quality and toxin production, and an additional diet of Microcystis with added pure microcystin-LR. We then exposed Daphnia to fungal and bacterial parasites. Anabaena, Microcystis and Chlorella diets prevented infection of Daphnia by the fungal parasite Metschnikowia, while Nodularia toxins increased offspring production by infected hosts. In contrast to their medicinal effects against Metschnikowia, toxic phytoplankton generally decreased the fitness of Daphnia infected with the bacterial parasite, Pasteuria. We also measured the amount of toxin produced by phytoplankton over time. Concentrations of anatoxin-a produced by Anabaena increased in the presence of Metschnikowia, suggesting parasite-induced toxin production. Our research illustrates that phytoplankton can serve as toxins or medicines for their consumers, depending upon the identity of their parasites.
Data from: Establishment and maintenance of aphid endosymbionts after horizontal transfer is dependent on host genotype
Animal-associated microbial communities have important effects on host phenotypes. Individuals within and among species differ in the strains and species of microbes that they harbour, but how natural selection shapes the distribution and abundance of symbionts in natural populations is not well understood. Symbionts can be beneficial in certain environments but also impose costs on their hosts. Consequently, individuals that can or cannot associate with symbionts will be favoured under different ecological circumstances. As a result, we predict that individuals within a species vary in terms of how well they accept and maintain symbionts. In pea aphids, the frequency of endosymbionts varies among host-plant-associated populations ('biotypes'). We show that aphid genotypes from different biotypes vary in how well they accept and maintain symbionts after horizontal transfer. We find that aphids from biotypes that frequently harbour symbionts are better able to associate with novel symbionts than those from biotypes that less frequently harbour symbionts. Intraspecific variation in the ability of hosts to interact with symbionts is an understudied factor explaining patterns of host–symbiont association.
Data from: Host specificity shapes population structure of pinworm parasites in Caribbean reptiles
Host specificity is one of the potential factors affecting parasite diversification because gene flow may be facilitated or constrained by the number of host species that a parasite can exploit. We test this hypothesis using a costructure approach, comparing two sympatric pinworm parasites that differ in host specificity – Parapharyngodon cubensis and Spauligodon anolis – on the Puerto Rican Bank and St. Croix in the Caribbean. Spauligodon anolis specializes on Anolis lizards, whereas P. cubensis parasitizes Anolis lizards as well as many other species of lizards and snakes. We collected lizards from across the Puerto Rican Bank and St. Croix, sampled them for S. anolis and P. cubensis and generated nuclear and mitochondrial sequence data from the parasites. We used these data to show that P. cubensis is comprised of multiple cryptic species that exhibit limited population structure relative to S. anolis, which is consistent with our prediction based on their host specificity. We also provide evidence that the distribution of P. cubensis species is maintained by competitive exclusion, and in contrast to previous theoretical work, the parasites with the greatest number of host species also reach the highest prevalence rates. Overall, our results are consistent with the hypothesis that host specificity shapes parasite diversification, and suggest that even moderate differences in host specificity may contribute to substantial differences in diversification.
Data from: Simplifying understory complexity in oil palm plantations is associated with a reduction in the density of a cleptoparasitic spider, Argyrodes miniaceus (Araneae: Theridiidae), in host (Araneae: Nephilinae) webs
Expansion of oil palm agriculture is currently one of the main drivers of habitat modification in Southeast Asia. Habitat modification can have significant effects on biodiversity, ecosystem function, and interactions between species by altering species abundances or the available resources in an ecosystem. Increasing complexity within modified habitats has the potential to maintain biodiversity and preserve species interactions. We investigated trophic interactions between Argyrodes miniaceus, a cleptoparasitic spider, and its Nephila spp. spider hosts in mature oil palm plantations in Sumatra, Indonesia. A. miniaceus co-occupy the webs of Nephila spp. females and survive by stealing prey items caught in the web. We examined the effects of experimentally manipulated understory vegetation complexity on the density and abundance of A. miniaceus in Nephila spp. webs. Experimental understory treatments included enhanced complexity, standard complexity, and reduced complexity understory vegetation, which had been established as part of the ongoing Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Project. A. miniaceus density ranged from 14.4 to 31.4 spiders per square meter of web, with significantly lower densities found in reduced vegetation complexity treatments compared with both enhanced and standard treatment plots. A. miniaceus abundance per plot was also significantly lower in reduced complexity than in standard and enhanced complexity plots. Synthesis and applications: Maintenance of understory vegetation complexity contributes to the preservation of spider host–cleptoparasite relationships in oil palm plantations. Understory structural complexity in these simplified agroecosystems therefore helps to support abundant spider populations, a functionally important taxon in agricultural landscapes. In addition, management for more structurally complex agricultural habitats can support more complex trophic interactions in tropical agroecosystems.
Data from: Divergence before the host shift? Prezygotic reproductive isolation among three varieties of a specialist fly on a single host plant
1. Although divergence via host-plant shifting is a common theme in the speciation of some phytophagous insects, it is not clear whether host shifts are typically initiators of speciation or if they instead contribute to divergence events already in progress. While host shifts appear to be generally associated with speciation events for flies in the genus Strauzia, three sympatric varieties of the sunflower fly [Strauzia longipennis (Wiedemann)] co-occur on the same host plant in the Midwestern United States and may have evolved reproductive barriers without a host shift. 2. The strength of two prezygotic reproductive barriers was compared among the three S. longipennis varieties: one barrier that is often associated with divergent ecological selection (allochronic isolation), and another that is more likely to be independent of ecological selection (pre-copulatory sexual isolation). The presence and relative strength of each barrier between fly varieties were evaluated using microsatellites, no choice mating experiments, studies of allochronic isolation, and field collection data. 3. Evidence for both allochronic isolation and pre-copulatory sexual isolation was detected between the three varieties of S. longipennis. The measure of isolation calculated for each barrier between the three varieties was lower than measures calculated between different species of Strauzia found on different hosts, suggesting that subsequent host shifts may increase the degree of reproductive isolation. For Strauzia and other specialist insects, some reproductive isolation may evolve prior to, and indeed may facilitate, host shifts.
Data from: Genetic variation in resistance and fecundity tolerance in a natural host-pathogen interaction
Individuals vary in their ability to defend against pathogens. Determining how natural selection maintains this variation is often difficult, in part because there are multiple ways that organisms defend themselves against pathogens. One important distinction is between mechanisms of resistance that fight off infection, and mechanisms of tolerance that limit the impact of infection on host fitness without influencing pathogen growth. Theory predicts variation among genotypes in resistance, but not necessarily in tolerance. Here, we study variation among pea aphid (Acyrthosiphon pisum) genotypes in defense against the fungal pathogen Pandora neoaphidis. It has been well established that pea aphids can harbor symbiotic bacteria that protect them from fungal pathogens. However, it is unclear whether aphid genotypes vary in defense against Pandora in the absence of protective symbionts. We therefore measured resistance and tolerance to fungal infection in aphid lines collected without symbionts, and found variation among lines in survival and in the percent of individuals that formed a sporulating cadaver. We also found evidence of variation in tolerance to the effects of pathogen infection on host fecundity, but no variation in tolerance of pathogen-induced mortality. We discuss these findings in light of theoretical predictions about host-pathogen coevolution.
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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.