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462 results for “Mutualisms”
Data from: Economy of scale: third partner strengthens a keystone ant-plant mutualism
While foundation species can stabilize ecosystems at landscape scales, their ability to persist is often underlain by keystone interactions occurring at smaller scales. Acacia drepanolobium is a foundation tree, comprising >95% of woody cover in East African black-cotton savanna ecosystems. Its dominance is underlain by a keystone mutualistic interaction with several symbiotic ant species in which it provides housing (swollen thorns) and carbohydrate-rich nectar from extra-floral nectaries (EFN). In return, it gains protection from catastrophic damage from mega-herbivores. Crematogaster mimosae is the ecologically dominant symbiotic ant in this system, also providing the highest protection services. In addition to tending EFN, C. mimosae tend scale insects for carbohydrate-rich honeydew. We investigated the role of scale insects in this specialized ant-plant interaction. Specifically, does this putatively redundant third partner strengthen the ant-plant mutualism by making the ant a better protector of the tree? Or does it weaken the mutualism by being costly to the tree while providing no additional benefit to the ant-plant mutualism? We coupled observational surveys with two scale-manipulation experiments and found evidence that this third partner strengthens the ant-plant mutualism. Trees with scale insects experimentally removed experienced a 2.5X increase in elephant damage compared to trees with scale insects present over 10 months. Reduced protection was driven by scale removal causing a decrease in ant colony size and per capita baseline activity and defensive behavior. We also found that ants increased scale-tending and the density of scale insects on trees when EFN were experimentally reduced. Thus, in this system, scale insects and EFN are likely complementary, rather than redundant, resources with scale insects benefitting ants when EFN production is low (such as during annual dry periods in this semi-arid ecosystem). This study reveals that a third-partner strengthens an ant-plant mutualism that serves to stabilize a whole ecosystem.
Data from: Does biological intimacy shape ecological network structure? A test using a brood pollination mutualism on continental and oceanic islands
Biological intimacy—the degree of physical proximity or integration of partner taxa during their life cycles—is thought to promote the evolution of reciprocal specialization and modularity in the networks formed by co‐occurring mutualistic species, but this hypothesis has rarely been tested. Here, we test this "biological intimacy hypothesis" by comparing the network architecture of brood pollination mutualisms, in which specialized insects are simultaneously parasites (as larvae) and pollinators (as adults) of their host plants to that of other mutualisms which vary in their biological intimacy (including ant‐myrmecophyte, ant‐extrafloral nectary, plant‐pollinator and plant‐seed disperser assemblages). We use a novel dataset sampled from leafflower trees (Phyllanthaceae: Phyllanthus s. l. [Glochidion]) and their pollinating leafflower moths (Lepidoptera: Epicephala) on three oceanic islands (French Polynesia) and compare it to equivalent published data from congeners on continental islands (Japan). We infer taxonomic diversity of leafflower moths using multilocus molecular phylogenetic analysis and examine several network structural properties: modularity (compartmentalization), reciprocality (symmetry) of specialization and algebraic connectivity. We find that most leafflower‐moth networks are reciprocally specialized and modular, as hypothesized. However, we also find that two oceanic island networks differ in their modularity and reciprocal specialization from the others, as a result of a supergeneralist moth taxon which interacts with nine of 10 available hosts. Our results generally support the biological intimacy hypothesis, finding that leafflower‐moth networks (usually) share a reciprocally specialized and modular structure with other intimate mutualisms such as ant‐myrmecophyte symbioses, but unlike nonintimate mutualisms such as seed dispersal and nonintimate pollination. Additionally, we show that generalists—common in nonintimate mutualisms—can also evolve in intimate mutualisms, and that their effect is similar in both types of assemblages: once generalists emerge they reshape the network organization by connecting otherwise isolated modules.
Data from: Colony personality and plant health in the Azteca-Cecropia mutualism
For interspecific mutualisms, the behavior of one partner can influence the fitness of the other, especially in the case of symbiotic mutualisms where partners live in close physical association for much of their lives. Behavioral effects on fitness may be particularly important if either species in these long-term relationships displays personality. We conducted a field study on collective personality in Azteca constructor colonies that live in Cecropia trees, one of the most successful and prominent mutualisms of the neotropics. These pioneer plants provide hollow internodes for nesting and nutrient-rich food bodies; in return, the ants provide protection from herbivores and encroaching vines. We tested the consistency and correlation of five colony-level behavioral traits, censused colonies, and measured the amount of leaf damage for each plant. Four of five traits were both consistent within colonies and correlated among colonies. This reveals a behavioral syndrome along a docile-aggressive axis, with higher-scoring colonies showing greater activity, aggression, and responsiveness. Scores varied substantially between colonies and were independent of colony size and age. Host plants of more active, aggressive colonies had less leaf damage, suggesting a link between a colony's personality and effective defense of its host, though the directionality of this link remains uncertain. Our field study shows that colony personality is an ecologically relevant phenomenon and sheds light on the importance of behavioral differences within mutualism dynamics.
Data from: Do impacts of an invasive nitrogen-fixing shrub on Douglas-fir and its ectomycorrhizal mutualism change over time following invasion?
1. Impacts of invasive species may change in magnitude and even direction with invasion age. Impacts could increase as the population increases, individuals grow in size, and ecological changes accumulate. 2. We used a chronosequence approach to characterize the development of soil impacts over time following the invasion of Cytisus scoparius, a widespread nitrogen-fixing shrub thought to limit reforestation success. In a greenhouse experiment, we evaluated how abundance of ectomycorrhizal fungi, Douglas-fir performance, and leaf nitrogen changed across a 3-31 year chronosequence of invasion. Each of the chronosequence sites were clearcuts where reforestation efforts were unsuccessful and where C. scoparius invaded. To estimate the contributions of the invasion separately from contributions of the accompanying disturbance, i.e. deforestation, we included soils from both invaded and uninvaded patches in each site of the chronosequence. In a complementary soil conditioning experiment, we examined the separate effects of host absence and invader presence on the mycorrhizal mutualism, leaf nitrogen, and seedling growth. 3. Ectomycorrhizal colonization was lower in invaded soil, but this effect did not intensify with time. Despite the suppression of the mutualism, Douglas-fir grew larger in invaded soils. This positive response is likely due to nitrogen fertilization, a conclusion supported by higher concentrations of leaf nitrogen of Douglas-fir grown in invaded soils. While leaf N concentration increased with invasion duration, Douglas-fir survival and growth did not. Synthesis. Our findings suggest that soil impacts of an invader can develop rapidly and can be surprisingly stable over time. In such systems, recently invaded areas may be as difficult to restore as long invaded areas, especially where ectomycorrhizal fungi are important drivers of reforestation success. More chronosequence studies or long time series are needed to evaluate whether this is a general pattern.
Data from: Polyploid plants obtain greater fitness benefits from a nutrient acquisition mutualism
<p>Polyploidy is a key driver of ecological and evolutionary processes in plants, yet little is known about its effects on biotic interactions. This gap in knowledge is especially profound for nutrient acquisition mutualisms, despite the fact that they regulate global nutrient cycles and structure ecosystems. Generalism in mutualistic interactions depends on the range of potential partners (niche breadth), the benefits obtained, and ability to maintain benefits across a variety of partners (fitness plasticity). Here, we determine how each of these is influenced by polyploidy in the legume-rhizobium mutualism. We inoculated a broad geographic sample of natural diploid and autotetraploid alfalfa (<i>Medicago sativa</i>)<i> </i>lineages with a diverse panel of <i>Sinorhizobium </i>bacterial symbionts. To analyze the extent and mechanism of generalism, we measured host growth benefits and functional traits. Autotetraploid plants obtained greater fitness enhancement from mutualistic interactions and were better able to maintain this across diverse rhizobial partners (i.e., low plasticity in fitness) relative to diploids. These benefits were not attributed to increases in niche breadth, but instead reflect increased rewards from investment in the mutualism. Polyploid plants displayed greater generalization in bacterial mutualisms relative to diploids illustrating another axis of advantage for polyploids over diploids.</p>
The potential for genotype-by-environment interactions to maintain genetic variation in a model legume–rhizobia mutualism
<p>The maintenance of genetic variation in mutualism-related traits is key for understanding mutualism evolution, yet the mechanisms maintaining variation remain unclear. We asked whether genotype-by-environment (G×E) interaction is a potential mechanism maintaining variation in the model legume–rhizobia system, <em>Medicago truncatula–Ensifer meliloti</em>. We planted 50 legume genotypes in a greenhouse under ambient light and shade to reflect reduced carbon availability for plants. We found an expected reduction under shaded conditions for plant performance traits, such as leaf number, aboveground and belowground biomass, and a mutualism-related trait, nodule number. We also found G×E for nodule number, with ∼83% of this interaction due to shifts in genotype fitness rank order across light environments, coupled with strong positive directional selection on nodule number regardless of light environment. Our results suggest that G×E can maintain genetic variation in a mutualism-related trait that is under consistent positive directional selection across light environments.</p>
Warmer nights offer no respite for a defensive mutualism
1. Ecologically-relevant symbioses are widespread in terrestrial arthropods but based on recent findings these specialized interactions are likely to be especially vulnerable to climate warming. Importantly, empirical data and climate models indicate that warming is occurring asynchronously, with nighttime temperatures increasing faster than daytime temperatures. Daytime (DTW) and nighttime warming (NTW) may impact ectothermic animals and their interactions differently as DTW results in greater daily temperature variation and moves organisms nearer to their thermal limits, while NTW avoids thermal limits and may relieve constraints of cooler nighttime temperatures; a nuance that has largely been ignored in the literature. 2. In laboratory experiments, we investigated how the timing of warming influences a widespread defensive mutualism involving the pea aphid, <i>Acyrthosiphon pisum</i>, and its heritable symbiont, <i>Hamiltonella defensa</i>, which protects against an important natural enemy, the parasitic wasp <i>Aphidius ervi</i>. 3. Three aphid sublines were experimentally created from single aphid genotype susceptible to A. ervi: one line infected with a highly protective H. defensa strain (APSE-3), one infected with a moderately protective strain (APSE-8), and one without any facultative symbiont. We examined aphid fitness in the presence and absence of parasitoids and when exposed to an average 2.5°C increase occurring across three warming scenarios (nighttime vs. daytime vs. uniform) relative to no-warming controls. 4. An increase of 2.5°C, as predicted to occur by the IPCC before 2100, was sufficient to disable the aphid defensive mutualism regardless of the timing of warming; a surprising result given that the daily maxima for control and nighttime warming scenarios were identical. We also found that warming negatively impacted i) symbiont-mediated interactions between host and parasitoid more than symbiont-free ones, ii) species interactions (host-parasitoid) more than each participant independently, and iii) aphids more than parasitoids even though higher trophic levels are generally predicted to be more affected by warming. 5. Here we show that 2.5°C warming, regardless of timing, negatively impacted a common microbe-mediated defensive mutualism. While this was a lab-based study, results suggest that temperature increases predicted in the near-term may disrupt the many ecological symbioses present in terrestrial ecosystems. 30-Mar-2020
Novel plant-microbe interactions: rapid evolution of a legume-rhizobium mutualism in restored prairies
1. When plants colonize new habitats, the novel interactions they form with new mutualists or enemies can immediately affect plant performance. These novel interactions also may provoke rapid evolutionary responses and can be ideal scenarios for investigating how species interactions influence plant evolution. 2. To explore how mutualists influence the evolution of colonizing plant populations, we capitalized on an experiment in which two former agricultural fields were seeded with identical prairie seed mixes in 2010. Six years later, we compared how populations of the legume Chamaecrista fasciculata from these sites and their original (shared) source population responded to nitrogen-fixing rhizobia from the restoration sites in a greenhouse reciprocal cross-inoculation experiment. 3. We found that the two populations differed both from their original source population and from each other in the benefits they derive from rhizobia, that one population has evolved reduced allocation to rhizobia (i.e., forms fewer rhizobium-housing nodules). 4. Synthesis. Our results suggest that these plant populations have evolved different ways of interacting with rhizobia, potentially in response to differences in rhizobium quality between sites. Our study illustrates how microbial mutualists may shape plant evolution in new environments and highlights how variation in microbial mutualists potentially may select for different evolutionary strategies in plant hosts.
Data from: Multi-modal defenses in aphids offer redundant protection and increased costs likely impeding a protective mutualism
1.The pea aphid, Acyrthosiphon pisum, maintains extreme variation in resistance to its most common parasitoid wasp enemy, Aphidius ervi, which is sourced from two known mechanisms: protective bacterial symbionts, most commonly Hamiltonella defensa, or endogenously encoded defenses. We have recently found that individual aphids may employ each defense individually, occasionally both defenses together, or neither. 2.In field populations, Hamiltonella-infected aphids are found at low to moderate frequencies and while less is known about the frequency of resistant genotypes, they show up less often than susceptible genotypes in field collections. To better understand these patterns, we sought to compare the strengths and costs of both types of defense, individually and together, in order to elucidate the selective pressures that maintain multi-modal defense mechanisms or that may favor one over the other. 3.We experimentally infected five aphid genotypes (two lowly and three highly resistant), each with two symbiont strains, Hamiltonella-APSE8 (moderate protection) and Hamiltonella-APSE3 (high protection). This resulted in three sublines per genotype: uninfected, +APSE8, and +APSE3. Each of the fifteen total sublines was first subjected to a parasitism assay to determine its resistance phenotype and in a second experiment a subset were chosen to compare fitness (fecundity and survivorship) in presence and absence of parasitism. 4.In susceptible aphid genotypes, parasitized sublines infected with Hamiltonella generally showed increased protection with direct fitness benefits, but clear infection costs to fitness in the absence of parasitism. In resistant genotypes, Hamiltonella infection rarely conferred additional protection, often further reduced fecundity and survivorship when enemy challenged, and resulted in constitutive fitness costs in the absence of parasitism. We also identified strong aphid-genotype X symbiont-strain interactions, such that the best defensive strategy against parasitoids varied for each aphid genotype; one performed best with no protective symbionts, the others with particular strains of Hamiltonella. 5.This surprising variability in outcomes helps explain why Hamiltonella infection frequencies are often intermediate and do not strongly track parasitism frequencies in field populations. We also find that variation in endogenous traits, such as resistance, among host genotypes may offer redundancy and generally limit the invasion potential of mutualistic microbes in insects.
Mutual neutralisation of NO+ with O-
<p>The data files found here contain the data as obtained and displayed in "Mutual neutralisation of NO+ with O-" published in Physical Review Letters.</p>
Data From: Lighting pathways to success in STEM: A virtual Lab Meeting Program (LaMP) mutually benefits mentees and host labs
<p>Developing robust professional networks can help shape the trajectories of early career scientists. Yet, historical inequities in STEM fields make access to these networks highly variable across academic programs, and senior academics often have little time for mentoring. Here, we illustrate the success of a Virtual Lab Meeting Program (LaMP). In this program, we matched students ("Mentees") with a more experienced researcher ("Mentors") from a research group. The Mentees then attended the Mentors' lab meetings during the academic year with two lab meetings specifically dedicated to the Mentee's professional development. Survey results indicate that Mentees expanded their knowledge of the hidden curriculum as well as their professional network, while only requiring a few extra hours of their Mentor's time over eight months. In addition, host labs benefitted from Mentees sharing new perspectives and knowledge in lab meetings. The diversity of the Mentees was significantly higher than the Mentors, suggesting that the program increased the participation of traditionally underrepresented groups. Finally, we found that providing a stipend was very important to many mentees. We conclude that Virtual Lab Meeting Programs can be an inclusive and cost-effective way to foster trainee development and increase diversity within STEM fields with little additional time commitment.</p>
Mutual neutralisation of O2+ with O-
<p>The data files found here contain the data as obtained and displayed in the manuscript "Disentangling vibrationally-dependent molecular dynamics in mutual neutralisation reactions".</p>
Data from: The mutualism-antagonism continuum in Neotropical palm-frugivore interactions: from interaction outcomes to ecosystem dynamics
<p>Frugivory, i.e. feeding on fruits, pulp or seeds by animals, is usually considered a mutualism when interactions involve seed dispersal, and an antagonism when it results in the predation and destruction of seeds. Nevertheless, most frugivory interactions involve both benefits and disadvantages for plants, and the net interaction outcomes thus tend to vary along a continuum from mutualism to antagonism. Quantifying outcome variation is challenging and the ecological contribution of frugivorous animals to plant demography thus remains little explored. This is particularly true for interactions in which animals do not ingest entire fruits, i.e. in seed-eating and pulp-eating. Here, we provide a comprehensive review of Neotropical palm–frugivore interactions, with a focus on how frugivore consumption behaviour (i.e. digestive processing, caching behaviour and fruit-handling ability) and feeding types (fruit-eating, pulp-eating and seed-eating) influence interaction outcomes at different demographic stages of palms. We compiled a total of 1043 species-level palm–frugivore interaction records that explicitly captured information on which parts of palm fruits are eaten by animals. These records showed consumption of fruits of 106 Neotropical palm species by 273 vertebrate species, especially birds (50%) and mammals (45%), but also fish (3%) and reptiles (2%). Fruit-eating involved all four taxonomic vertebrate classes whereas seed-eating and pulp-eating were only observed among birds and mammals. Most fruit-eating interactions (77%) resulted in positive interaction outcomes for plants (e.g. gut-passed seeds are viable or seeds are successfully dispersed), regardless of the digestive processing type of vertebrate consumers (seed defecation versus regurgitation). The majority of pulp-eating interactions (91%) also resulted in positive interaction outcomes, for instance via pulp removal that promoted seed germination or via dispersal of intact palm seeds by external transport, especially if animals have a good fruit-handling ability (e.g. primates, and some parrots). By contrast, seed-eating interactions mostly resulted in dual outcomes (60%), where interactions had both negative effects on seed survival and positive outcomes through seed caching and external (non-digestive) seed dispersal. A detailed synthesis of available field studies with qualitative and quantitative information provided evidence that 12 families and 27 species of mammals and birds are predominantly on the mutualistic side of the continuum whereas five mammalian families, six mammal and one reptile species are on the antagonistic side. The synthesis also revealed that most species can act as partial mutualists, even if they are typically considered antagonists. Our review demonstrates how different consumption behaviours and feeding types of vertebrate fruit consumers can influence seed dispersal and regeneration of palms, and thus ultimately affect the structure and functioning of tropical ecosystems. Variation in feeding types of animal consumers will influence ecosystem dynamics via effects on plant population dynamics and differences in long-distance seed dispersal, and may subsequently affect ecosystem functions such as carbon storage. The quantification of intra- and inter-specific variation in outcomes of plant–frugivore interactions – and their positive and negative effects on the seed-to-seedling transition of animal-dispersed plants – should be a key research focus to understand better the mutualism–antagonism continuum and its importance for ecosystem dynamics.</p>
Morphological trait matching in plant–Hymenoptera and plant–Diptera mutualisms across an elevational gradient
<p>Morphological trait-matching and species abundance are thought to be the main factors affecting the frequency and strength of mutualistic interactions. However, the relative importance of trait-matching and species abundance in shaping species interactions across environmental gradients remains poorly understood, especially for plant–insect mutualisms involving generalist species.</p> <p>Here, we characterised variation in species and trait composition and the relative importance of trait-matching and species abundance in shaping plant–Hymenoptera and plant–Diptera mutualisms in four meadows across an elevational gradient (2,725–3,910 m) in Yulong Snow Mountain, Southwest China. We also evaluated the effects of morphological traits of flower visitors and plant composition on their foraging specialisation (d' and normalised degree).</p> <p>There was a high degree of dissimilarity in the composition of Hymenoptera and Diptera visitors and their visited plants between communities. This variation was mainly driven by the spatial replacement of species. Both for plant–Hymenoptera and plant–Diptera networks, trait-matching between nectar tube depth and proboscis length was a stronger predictor of the interactions between temporally co-occurring plants and flower visitors than species abundance. Fourth-corner analyses revealed statistically significant trait-matching between nectar tube depth and proboscis length in plant–Hymenoptera networks at all sites, suggesting that Hymenoptera consistently foraged on plant species with nectar tube depths matching their proboscis lengths. By contrast, significant trait-matching in plant–Diptera networks was only observed at the two lower elevation sites. The species-level specialisation d' of flower visitors increased significantly as the proboscis length and the difference in nectar tube depth between the plant community and the plants visited by flower visitors increased.</p> <p>Our results highlight that the importance of trait-matching in shaping pairwise interactions and niche partitioning depends on the specific features (e.g. species composition and trait availability) of the plant-pollinator system. For specialised plant-Hymenoptera systems, trait-matching is an important determinant of species interactions, whereas for generalist plant-Diptera systems, trait-matching is relatively unimportant.</p>
Context dependent host-symbiont interactions: shifts along the parasitism-mutualism continuum
<p>Symbiotic interactions can shift along a mutualism to parasitism continuum. While there are many studies examining dynamics typically considered to be mutualistic that sometimes shift towards parasitism, little is known about conditions underlying shifts from parasitism towards mutualism. In lake populations, we observed that infection by a microsporidian gut symbiont sometimes conferred a reproductive advantage and other times a disadvantage to its <i>Daphnia </i>host. We hypothesized that the microsporidian might benefit its host by reducing infection by more virulent parasites, which attack via the gut. In a lab study using field-collected animals, we found that spores of a virulent fungal parasite were much less capable of penetrating the guts of <i>Daphnia </i>harboring the microsporidian gut symbiont. We predicted that this altered gut penetrability could cause differential impacts on host fitness depending on ecological context. Using data from field surveys, we found that microsporidian-infected <i>Daphnia </i>hosts experienced a reproductive advantage when virulent parasites were common and a reproductive disadvantage when resources were scarce and virulent parasites were rare. Our findings highlight the importance of considering multiparasite community context and resource availability in host-parasite studies and open the door for future research into conditions driving shifts along parasitism to mutualism gradients.</p>
Lost mutualisms: seed dispersal by Sumatran rhinos, the world's most threatened megafauna
<p>Diverse assemblages of seed-dispersing megafauna once existed in Asian rainforests, but are now almost solely represented by elephants. Asia's rhinos persist in remnant, ecologically-extinct populations and the most threatened of these is the Sumatran rhino, Dicerorhinus sumatrensis. To understand the seed dispersal role of Sumatran rhinos, we consolidated information on fruit consumption, seed dispersal and fruit traits from a two-month field study (Sumatra), local ecological knowledge (Peninsular Malaysia), and published and unpublished accounts. We evaluated differences between the taxa and traits of fruits dispersed by rhinos and elephants, and identified other dispersers of megafaunal-syndrome fruits that were rhino-dispersed. At least 79 plant species were dispersed by rhinos: overstorey plants (trees and climbers; 78% of species) had large, usually "mammal-coloured", fruits and seeds, and were mainly drupes and berries; 61% of these were megafaunal-syndrome fruits (>4 cm wide). Understorey plants (herbs, shrubs, small trees) had small, often capsular, fruits and seeds that are potentially dispersed following the "foliage-is-the-fruit" hypothesis. Rhinos were the only known disperser for 35% of the megafaunal-fruit genera. The highest dispersal overlap shown was with elephants: fruits dispersed by rhinos tended to be capsular and were smaller than fruits dispersed by both elephants and rhinos. Given these findings and the different foraging and ranging behaviour of Sumatran rhinos and elephants, we suggest these megafauna had important differences in their seed dispersal roles. Asian rainforests have, therefore, lost an important seed dispersal mutualist. Conservation efforts should aim to protect and restore the ecological function of these unique creatures.</p>
Post-association barrier to host switching maintained despite strong selection in a novel mutualism
<p class="MsoNormal"><span>Following a host shift, repeated co-passaging of a mutualistic pair is expected to increase fitness over time in one or both species.<span> </span>Without adaptation, a novel association may be evolutionarily short-lived as it is likely to be outcompeted by native pairings.<span> </span>Here we test whether experimental evolution can rescue a low-fitness novel pairing between two sympatric species of <em>Steinernema</em> nematodes and their symbiotic <em>Xenorhabdus</em> bacteria.<span> </span>Despite low mean fitness in the novel association, considerable variation in nematode reproduction was observed across replicate populations.<span> </span>We selected the most productive infections, co-passaging this novel mutualism nine times to determine whether selection could improve fitness of either or both partners.<span> </span>We found that neither partner showed increased fitness over time.<span> </span>Our results suggest that the variation in association success was not heritable and that mutational input was insufficient to allow evolution to facilitate this host shift.<span> </span>Thus, post-association costs of host switching may represent a formidable barrier to novel partnerships among sympatric mutualists. </span></p>
How efficient is symbiont-mediated protection to heat under daily fluctuating thermal environments? A study on an aphid-bacterium mutualism
<p>These are the two datasets for the article "<strong>How efficient is symbiont-mediated protection to heat under daily fluctuating thermal environments? A study on an aphid-bacterium mutualism</strong>".</p> <p>We examined the effects of four thermal regimes defined by their combination of mean temperature (18 or 25°C) and diurnal thermal range (day-night fluctuations: 5 or 10°C) on the interaction between the aphid <em>Acyrthosiphon pisum</em>, its obligate symbiont <em>Buchnera aphidicola </em>and the facultative heat-protective symbiont <em>Serratia symbiotica</em>. We used two clonal lines of <em>A. pisum </em>uninfected (5A) or infected with <em>S. symbiotica </em>(5AR). Thermal treatments were applied form aphid birth to death. We recorded both aphid traits (immature survival rate, longevity, immature development time, total fecundity, body size) and symbiont titres at the onset of reproduction (for both <em>B. aphidicola </em>and <em>S. symbiotica</em>), expressed relatively to aphid gene copy number through quantitative PCRs (qPCRs).</p> <p><strong>Aphid traits</strong></p> <p>. Individual = identification of the individual</p> <p>. Line = aphid clonal line, either deprived of (5A) or infected with <em>S. symbiotica </em>(5AR)</p> <p>. MT = Mean Temperature, either 18°C or 25°C</p> <p>. DTR = Diurnal Temperature Range (day-night fluctuations), either 5°C or 10°C</p> <p>. surv.adult = whether (Y) or not (N) the individual survived until reaching reproduction (immature survival rate)</p> <p>. adulthood = time elapsed between birth and first reproduction (in days)</p> <p>. lifespan = time elapsed between birth and death (in days)</p> <p>. offspring = total number of larvae produced by each aphid throughout lifetime</p> <p>. tibia = hind tibia length as a proxy of body size (in mm)</p> <p>. wing = whether (Y) or not (N) the individual developed wings following imaginal moult</p> <p> </p> <p><strong>Symbiont titres</strong></p> <p>. Individual = identification of the individual</p> <p>. Line = aphid clonal line, either deprived of (A) or infected with <em>S. symbiotica </em>(AR)</p> <p>. MT = Mean Temperature, either 18°C or 25°C</p> <p>. DTR = Diurnal Temperature Range (day-night fluctuations), either 5°C or 10°C</p> <p>. QPCR = identification of the microplate used during qPCR analyses (to handle pseudoreplication)</p> <p>. EfAlph = number of copies of aphid housekeeping gene elongation factor 1-alpha (<em>EF1-α</em>)</p> <p>. SdEfAlph = standard deviation of the aphid gene copy number, calculated over three technical replicates</p> <p>. DnaKBa = number of copies of <em>B. aphidicola </em>gene <em>dnaK</em></p> <p>. SdDnaKBa = standard deviation of <em>B. aphidicola </em>gene copy number, calculated over three technical replicates</p> <p>. DnakSs = number of copies of <em>S. symbiotica </em>gene <em>dnaK</em></p> <p>. SdDnaKSs = standard deviation of <em>S. symbiotica </em>gene copy number, calculated over three technical replicates</p> <p>. RappBa = ratio between DnaKBa and EfAlph to calculate relative titre of <em>B. aphidicola</em></p> <p>. RappSs = ratio between DnaKSs and EfAlph to calculate relative titre of <em>S. symbiotica</em></p>
Predation risk can modify the foraging behaviour of frugivorous carnivores: implications of rewilding apex predators for plant-animal mutualisms
<p>Apex predators play key roles in food webs and their recovery can trigger trophic cascades in some ecosystems. Intra-guild competition can reduce the abundances of smaller predators and perceived predation risk can alter their foraging behaviour thereby limiting seed dispersal by frugivorous carnivores. However, little is known about how plant-frugivore mutualism could be disturbed in the presence of larger predators.</p> <p>We evaluated the top-down effect of the regional superpredator, the Iberian lynx (Lynx pardinus), on the number of visits and fruits consumed by medium-sized frugivorous carnivores, as well as the foraging behaviour of identified individuals, by examining the consumption likelihood and the foraging time.</p> <p>We carried out a field experiment in which we placed Iberian pear (Pyrus bourgaeana) fruits beneath fruiting trees and monitored pear removal by frugivorous carnivores, both inside and outside of lynx ranges. Using camera traps, we recorded the presence of the red fox (Vulpes vulpes), the Eurasian badger (Meles meles) and the stone marten (Martes foina), as well as the number of fruits they consumed and their time spent foraging.</p> <p>Red fox was the most frequent fruit consumer carnivore. We found there were fewer visits and less fruit consumed by foxes inside of lynx ranges, but lynx presence did not seem to affect badgers. We did not observe any stone marten visits inside of lynx territories. The foraging behaviour of red foxes was also altered when inside of lynx ranges whereby foxes were less efficient, consuming less fruit per unit of time and having shorter visits. Local availability of fruit resources, forest coverage and individual personality also were important variables to understand visitation and foraging in a landscape of fear. 5. Our results show a potential trophic cascade from apex predators to primary producers. The presence of lynx can reduce frugivorous carnivore numbers and induce shifts in their feeding behaviour that may modify the seed dispersal patterns with likely consequences for the demography of many fleshy-fruited plant species. We conclude that knowledge of the ecological interactions making up trophic webs is anasset to design effective conservation strategies, particularly in rewilding programs.</p>
Mutualism has its limits: consequences of asymmetric interactions between a well-defended plant and its herbivorous pollinator
<p>Concern for pollinator health has focused on social bees and their agricultural services, but not all pollinators are bees, and their ecosystem services also promote biodiversity and conservation. Pollinating herbivores generate ecological conflicts when they utilize the same plant as a nectar source and larval host. We tracked individual-level metrics of pollinator health – growth, survivorship, fecundity – across the life cycle of a pollinating herbivore, the hawkmoth Hyles lineata, through its interactions with Oenothera harringtonii, a rare plant polymorphic for the floral volatile (R)-(-)-linalool. Linalool had no impact on moth attraction to O. harringtonii flowers but suppressed oviposition on experimentally supplemented plants. Leaves of O. harringtonii showed robust resistance against herbivory by H. lineata from leaf-disc to wholeplant scales, through poor larval growth and survivorship. Higher larval performance on other Oenothera species indicates that constitutive herbivore resistance by O. harringtonii is not generic. Leaf volatiles differed among populations of O. harringtonii but were not induced by larval herbivory. Elagitannins and other phenolics varied among leaf, bud and seed tissues but showed no evidence of herbivore induction. Our findings highlight asymmetric plant-pollinator interactions and the importance of third parties, such as alternative host plants, in maintaining pollinator health.</p>
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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.