23 Works

Resistance correlations influence infection by foreign pathogens

Michael E. Hood, Noah Lerner, Victoria Luizzi, Janis Antonovics & Emily Bruns
Reciprocal selection promotes the specificity of host-pathogen associations and resistance polymorphisms in response to disease. However, plants and animals also vary in response to pathogen species not previously encountered in nature, with potential effects on new disease emergence. Using anther-smut disease, we show that resistance (measured as infection rates) to foreign pathogens can be correlated with standing variation in resistance to an endemic pathogen. In Silene vulgaris, genetic variation in resistance to its endemic anther-smut...

Can disease resistance evolve independently at different ages? Genetic variation in age-dependent resistance to disease in three wild plant species

Emily Bruns, Michael Hood, Janis Antonovics, Indigo Ballister, Sarah Troy & Jae Hoon Cho
1. Juveniles are typically less resistant (more susceptible) to infectious disease than adults, and this difference in susceptibility can help fuel the spread of pathogens in age-structured populations. However evolutionary explanations for this variation in resistance across age remain to be tested. 2. One hypothesis is that natural selection has optimized resistance to peak at ages where disease exposure is greatest. A central assumption of this hypothesis is that hosts have the capacity to evolve...

Data from: Mutational analysis of Rab3 function for controlling active zone protein composition at the Drosophila neuromuscular junction

Shirui Chen, Hannah K. Gendelman, John P. Roche, Peter Alsharif & Ethan R. Graf
At synapses, the release of neurotransmitter is regulated by molecular machinery that aggregates at specialized presynaptic release sites termed active zones. The complement of active zone proteins at each site is a determinant of release efficacy and can be remodeled to alter synapse function. The small GTPase Rab3 was previously identified as playing a novel role that controls the distribution of active zone proteins to individual release sites at the Drosophila neuromuscular junction. Rab3 has...

Infection data and spore counts for cross inoculation experiments

Emily Bruns, Janis Antonovics & Michael Hood
Determining the processes that drive the evolution of pathogen host range can inform our understanding of disease dynamics and the potential for host-shifts. In natural populations, patterns of host range could be driven by genetically based differences in pathogen infectivity or ecological differences in host availability. In northwestern Italy, four reproductively isolated lineages of the fungal plant-pathogen Microbotryum have been shown to co-occur on several species in the genus Dianthus. We carried out cross-inoculation experiments...

Data from: Is there a disease-free halo at species range limits? The co-distribution of anther-smut disease and its host species

Emily L. Bruns, Janis Antonovics & Michael Hood
1. While disease is widely recognized as affecting host population size, it has rarely been considered to play a role in determining host range limits. Many diseases may not be able to persist near the range limit if host population density falls below the critical threshold level for pathogen invasion. However, in vector- and sexually-transmitted diseases, pathogen transmission may be largely independent of host density and theory demonstrates that diseases with frequency-dependent transmission may persist...

Data from: Avoidance, tolerance, and resistance to ectoparasites in nestling and adult tree swallows

Joely G. DeSimone, Ethan D. Clotfelter, Elizabeth C. Black & Sarah A. Knutie
We examined avoidance, tolerance, and resistance strategies of nestling and adult tree swallows Tachycineta bicolor in response to ectoparasitic blowflies Protocalliphora sialia. Tree swallows avoided settling in north-facing nest boxes early in the breeding season. These boxes were more likely to be parasitized later in the season, suggesting that box selection may facilitate blowfly avoidance. After experimentally manipulating blowfly intensity, we found that nestlings were generally tolerant of parasitism. Parasites significantly reduced nestling blood hemoglobin...

La crisis electoral de Venezuela (Les Études du CERI, n° 233-234)

Javier Corrales
Cuando se suele hablar de la gran crisis actual de Venezuela, lo típico es enfocarse en el tema económico. La narrativa es la siguiente: el colapso de los precios del petróleo (2014) y años acumulados de mal manejo del boom económico (2004-2013) han ocasionado una de las peores crisis económicas del mundo.

Data from: Exploring density and frequency dependent interactions experimentally: an R program for generating hexagonal fan designs.

Carly Rozins, Janis Antonovics, Michael Hood & Jae Hoon Cho
Species interactions and diversity are strongly impacted by local processes, with both the density of a focal species and its frequency in the community having an impact on its growth, survival, and fecundity. Yet, studies that attempt to control for variation in both frequency and density have traditionally required a large number of replicates. Hexagonal fan designs can include a range of both densities and frequencies in a single plot, providing large economies in space...

Data from: Morphology, performance and fluid dynamics of the crayfish escape response

Jocelyn Hunyadi, Todd Currier, Yahya Modarres-Sadeghi, Brooke Flammang & Ethan Clotfelter
Sexual selection can result in an exaggerated morphology that constrains locomotor performance. We studied the relationship between morphology and the tail-flip escape response in male and female rusty crayfish (Faxonius rusticus), a species in which males have enlarged claws (chelae). We found that females had wider abdomens and longer uropods (terminal appendage of the tail fan) than males, while males possessed deeper abdomens and larger chelae, relative to total length. Chelae size was negatively associated...

Behavioural and morphological traits influence sex-specific floral resource use by hummingbirds

Maria Alejandra Maglianesi, Pietro Maruyama, Ethan Temeles, Matthias Schleuning, Thais Zanata, Marlies Sazima, Aquiles Gutiérrez-Zamora, Oscar Marín-Gómez, Liliana Rosero-Lasprilla, Monica Ramirez Burbano, Alejandra Ruffini, Ricardo Salamanca-Reyes, Ivan Sazima, Laura E. Nuñez-Rosas, María Del Coro Arizmendi, Carsten Rahbek & Bo Dalsgaard
Research on resource partitioning in plant-pollinator mutualistic systems is mainly concentrated at the levels of species and communities, whereas differences between males and females are typically ignored. Nevertheless, pollinators often show large sexual differences in behaviour and morphology, which may lead to sex-specific patterns of resource use with the potential to differentially affect plant reproduction and diversification. We investigated variation in behavioural and morphological traits between sexes of hummingbird species as potential mechanisms underlying sex-specific...

Data from: Rate of resistance evolution and polymorphism in long- and short-lived hosts

Emily L. Bruns, Michael E. Hood, Janis Antonovics & Emily Bruns
Recent theoretical work has shown that long-lived hosts are expected to evolve higher equilibrium levels of disease resistance than shorter-lived hosts, but questions of how longevity affects the rate of resistance evolution and the maintenance of polymorphism remain unanswered. Conventional wisdom suggests that adaptive evolution should occur more slowly in long-lived organisms than in short-lived organisms. However, the opposite may be true for the evolution of disease-resistance traits where exposure to disease, and therefore the...

Data from: Sibling competition arena: selfing and a competition arena can combine to constitute a barrier to gene flow in sympatry

Amanda Kyle Gibson, Michael E. Hood & Tatiana Giraud
Closely-related species coexisting in sympatry provide critical insight into the mechanisms underlying speciation and the maintenance of genetic divergence. Selfing may promote reproductive isolation by facilitating local adaptation, causing reduced hybrid fitness in parental environments. Here, we propose a novel mechanism by which selfing can further impair interspecific gene flow: selfing may act to ensure that non-hybrid progeny systematically co-occur whenever hybrid genotypes are produced. Under a competition arena, the fitness differentials between non-hybrid and...

La crise électorale au Venezuela (Les Études du CERI, n° 233-234)

Javier Corrales
Lorsque l’on aborde la grave crise actuelle du Venezuela, il est de coutume de se focaliser sur sa dimension économique. Certes, la chute des cours du pétrole en 2014 et l’accumulation d’années de mauvaise gestion du boom économique des années 2004-2013 ont provoqué l’une des pires crises économiques du monde, et le pays souffre des effets d’un effondrement économique brutal. Mais à ne commenter que l’aspect économique, on perd de vue la véritable bombe qui...

Supporting Data for: Differential gene expression associated with a floral scent polymorphism in the evening primrose Oenothera harringtonii (Onagraceae)

Norman Wickett, Lindsey Bechen, Geoffrey Broadhead, Rachel Levin, Rick Overson, Tania Jogesh, Jeremie Fant, Robert Raguso & Krissa Skogen
Background: Plant volatiles play an important role in both plant-pollinator and plant-herbivore interactions. Intraspecific polymorphisms in volatile production are ubiquitous, but studies that explore underlying differential gene expression are rare. Oenothera harringtonii populations are polymorphic in floral emission of the monoterpene (R)-(-)-linalool; some plants emit (R)-(-)-linalool (linalool+ plants) while others do not (linalool- plants). However, the genes associated with differential production of this floral volatile in Oenothera are unknown. We used RNA-Seq to broadly characterize...

Data from: Sympatry and interference of divergent Microbotryum pathogen species.

Michael E Hood, Janis Antonovics, Monroe Wolf, Zachariah L Stern, Tatiana Giraud & Jessie L Abbate
The impact of infectious diseases in natural ecosystems is strongly influenced by the degree of pathogen specialization and by the local assemblies of potential host species. This study investigated anther-smut disease, caused by fungi in the genus Microbotryum, among natural populations of plants in the Caryophyllaceae. A broad geographic survey focused on sites of the disease on multiple host species in sympatry. Analysis of molecular identities for the pathogens revealed that sympatric disease was most...

Data from: Co-occurrence and hybridization of anther-smut pathogens specialized on Dianthus hosts

Elsa Petit, Casey Silver, Amandine Cornille, Pierre Gladieux, Lisa Rosenthal, Emily Bruns, Sarah Yee, Janis Antonovics, Tatiana Giraud & Michael Hood
Host specialization has important consequences for the diversification and ecological interactions of obligate pathogens. The anther-smut disease of natural plant populations, caused by Microbotryum fungi, has been characterized by specialized host-pathogen interactions, which contribute in part to the isolation among these numerous fungal species. This study investigated the molecular variation of Microbotryum pathogens within the geographic and host-specific distributions on wild Dianthus species in southern European Alps. In contrast to prior studies on this pathogen...

Data from: The population biology of fungal invasions

Pierre Gladieux, Alice Feurtey, Michael E. Hood, Alodie Snirc, Joanne Clavel, Cyril Dutech, Melanie Roy & Tatiana Giraud
Fungal invasions are increasingly recognized as a significant component of global changes, threatening ecosystem health and damaging food production. Invasive fungi also provide excellent models to evaluate the generality of results based on other eukaryotes. We first consider here the reasons why fungal invasions have long been overlooked: they tend to be inconspicuous, and inappropriate methods have been used for species recognition. We then review the information available on the patterns and mechanisms of fungal...

Data from: Transmission and temporal dynamics of anther-smut disease (Microbotryum) on alpine carnation (Dianthus pavonius)

Emily L. Bruns, Janis Antonovics, Valentina Carasso & Michael Hood
1. Theory has shown that sterilizing diseases with frequency-dependent transmission (characteristics shared by many sexually transmitted diseases) can drive host populations to extinction. 2. Anther-smut disease (caused by Microbotryum sp.) has become a model plant pathogen system for studying the dynamics of vector and sexually transmitted diseases: infected individuals are sterilized, producing spores instead of pollen, and the disease is spread between reproductive individuals by insect pollinators. We investigated anther-smut disease in a heavily infected...

Data from: Pollinator-mediated selection in a specialized hummingbird-Heliconia system in the eastern Caribbean

Ethan J. Temeles, Yoon J. Rah, Jonathan Andicoechea, Katerina L. Byanova, Geoffrey S. J. Giller, Shaylon B. Stolk & W. J. Kress
Phenotypic matches between plants and their pollinators often are interpreted as examples of reciprocal selection and adaptation. For the two co-occurring plant species, Heliconia bihai and H. caribaea in the Eastern Caribbean, we evaluated for five populations over two years the strength and direction of natural selection on corolla length and number of bracts per inflorescence. These plant traits correspond closely to the bill lengths and body masses of their primary pollinators, female or male...

Data from: Effect of the anther-smut fungus Microbotryum on the juvenile growth of its host Silene latifolia

Janis Antonovics, Jessica L. Abbate, Emily L. Bruns, Peter D. Fields, Nicole J. Forrester, Kimberley Gilbert, Michael E. Hood, Timothy Park & Douglas R. Taylor
Premise of the Study: Plant pathogens that form persistent systemic infections within plants have the potential to affect multiple plant life history traits, yet we tend to focus only on visible symptoms. Anther-smut disease of Silene latifolia caused by the fungus Microbotryum lychnidis-dioicae induces the anthers of its host to produce fungal spores in place of pollen, and the pathogen is primarily transmitted among flowering plants by pollinators. Nevertheless, most of its life cycle is...

Data from: Neural correlates of individual differences in circadian behavior

Jennifer A. Evans, Tanya L. Leise, Oscar Castanon-Cervantes & Alec J. Davidson
Daily rhythms in mammals are controlled by the circadian system, which is a collection of biological clocks regulated by a central pacemaker within the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Changes in SCN function have pronounced consequences for behaviour and physiology; however, few studies have examined whether individual differences in circadian behaviour reflect changes in SCN function. Here, PERIOD2::LUCIFERASE mice were exposed to a behavioural assay to characterize individual differences in baseline entrainment, rate...

Data from: Specificity and seasonal prevalence of anther-smut disease Microbotryum on sympatric Himalayan Silene species

Hui Tang, Michael E. Hood, Zongxin Ren, Haidong Li, Yan-Hui Zhao, Lorne M. Wolfe, De-Zhu Li & Hong Wang
Host sympatry provides opportunities for cross‐species disease transmission and compounded disease effects on host population and community structure. Using the Silene‐Microbotryum interaction (the castrating “anther‐smut” disease), eleven Himalayan Silene species were assessed in regions of high host diversity to ascertain levels of pathogen specificity. We also investigated disease prevalence, seasonal dynamics of infection and flowering patterns in five co‐blooming Silene species. We identified several new Microbotryum lineages with varying degrees of specialization that is likely...

Does blood loss explain higher resting metabolic rates in nestling birds with hematophagous ectoparasites?

Natalie Sun, Sarah Goodwin, Michael Griego, Alexander Gerson & Ethan Clotfelter
Nestlings of many bird species are hosts to hematophagous ectoparasites. Parasitism of nestlings is usually sub-lethal, but its effects can extend into the fledgling and adult stages. Nestling hosts lose enough blood to become anemic, but the effects of reduced oxygen-carrying capacity on metabolic rate are poorly understood. This study examined the consequences of parasitism by larval blow flies Protocalliphora sialia for nestling tree swallows Tachycineta bicolor. We found that nestlings with more parasites had...

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Resource Types

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  • Amherst College
  • University of Virginia
  • University of Massachusetts Amherst
  • University of Maryland, Baltimore
  • University of Paris-Sud
  • Biology and Genetics of Plant-Pathogen Interactions
  • University of Montana
  • National Museum of Natural History
  • University of North Carolina
  • University of Quindío