共查询到20条相似文献，搜索用时 15 毫秒
1.
Catherine G. Haase Nathan W. Fuller Yvonne A. Dzal C. Reed Hranac David T. S. Hayman Cori L. Lausen Kirk A. Silas Sarah H. Olson Raina K. Plowright 《Ecology and evolution》2021,11(1):506-515
In multihost disease systems, differences in mortality between species may reflect variation in host physiology, morphology, and behavior. In systems where the pathogen can persist in the environment, microclimate conditions, and the adaptation of the host to these conditions, may also impact mortality. White‐nose syndrome (WNS) is an emerging disease of hibernating bats caused by an environmentally persistent fungus, Pseudogymnoascus destructans. We assessed the effects of body mass, torpid metabolic rate, evaporative water loss, and hibernaculum temperature and water vapor deficit on predicted overwinter survival of bats infected by P. destructans. We used a hibernation energetics model in an individual‐based model framework to predict the probability of survival of nine bat species at eight sampling sites across North America. The model predicts time until fat exhaustion as a function of species‐specific host characteristics, hibernaculum microclimate, and fungal growth. We fit a linear model to determine relationships with each variable and predicted survival and semipartial correlation coefficients to determine the major drivers in variation in bat survival. We found host body mass and hibernaculum water vapor deficit explained over half of the variation in survival with WNS across species. As previous work on the interplay between host and pathogen physiology and the environment has focused on species with narrow microclimate preferences, our view on this relationship is limited. Our results highlight some key predictors of interspecific survival among western bat species and provide a framework to assess impacts of WNS as the fungus continues to spread into western North America. 相似文献
2.
Xueling Yi Deahn M. Donner Paula E. Marquardt Jonathan M. Palmer Michelle A. Jusino Jacqueline Frair Daniel L. Lindner Emily K. Latch 《Ecology and evolution》2020,10(18):10031-10043
White‐nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans (Pd), has driven alarming declines in North American hibernating bats, such as little brown bat (Myotis lucifugus). During hibernation, infected little brown bats are able to initiate anti‐Pd immune responses, indicating pathogen‐mediated selection on the major histocompatibility complex (MHC) genes. However, such immune responses may not be protective as they interrupt torpor, elevate energy costs, and potentially lead to higher mortality rates. To assess whether WNS drives selection on MHC genes, we compared the MHC DRB gene in little brown bats pre‐ (Wisconsin) and post‐ (Michigan, New York, Vermont, and Pennsylvania) WNS (detection spanning 2014–2015). We genotyped 131 individuals and found 45 nucleotide alleles (27 amino acid alleles) indicating a maximum of 3 loci (1–5 alleles per individual). We observed high allelic admixture and a lack of genetic differentiation both among sampling sites and between pre‐ and post‐WNS populations, indicating no signal of selection on MHC genes. However, post‐WNS populations exhibited decreased allelic richness, reflecting effects from bottleneck and drift following rapid population declines. We propose that mechanisms other than adaptive immunity are more likely driving current persistence of little brown bats in affected regions. 相似文献
3.
Julie Faure‐Lacroix Andr Desrochers Louis Imbeau Anouk Simard 《Ecology and evolution》2020,10(12):5226-5239
In North America, the greatest and most sudden threat to hibernating bats is white‐nose syndrome (WNS), which has caused massive declines in populations since 2006. Other determinants of bat dynamics, such as the climate, and the effect of reduction in the number of individuals sharing foraging space and summer roosting habitat may have an effect on population dynamics. We analyzed transect acoustic bat surveys conducted with ultrasonic detectors in 16 regions in Quebec, Canada, between 2000 and 2015. We used piecewise regression to describe changes in activity over time for each species and a meta‐analytic approach to measure its association with the North Atlantic Oscillation (NAO). As expected, mouse‐eared bat (Myotis spp.) activity sharply declined after the onset of WNS, down by 79% after 3 years. In contrast, big brown/silver‐haired bat activity increased over the same period, possibly due to a release of competition. Hoary bats and red bats remained present, although their activity did not increase. Myotis activity was positively correlated with a one‐year lag to the NAO index, associated with cold conditions in winter, but warm autumns. Big brown/silver‐haired and hoary bats were also more active during NAO‐positive years but without a lag. We conclude that combinations of threats may create rapid shifts in community compositions and that a more balanced research agenda that integrates a wider range of threats would help better understand and manage those changes. 相似文献
4.
《Evolutionary Applications》2017,10(10):1076-1090
White‐nose syndrome (WNS) has devastated populations of hibernating bats in eastern North America, leading to emergency conservation listings for several species including the previously ubiquitous little brown myotis (Myotis lucifugus). However, some bat populations near the epicenter of the WNS panzootic appear to be stabilizing after initial precipitous declines, which could reflect a selective immunogenetic sweep. To investigate the hypothesis that WNS exerts significant selection on the immunome of affected bat populations, we developed a novel, high‐throughput sequence capture assay targeting 138 adaptive, intrinsic, and innate immunity genes of putative adaptive significance, as well as their respective regulatory regions (~370 kbp of genomic sequence/individual). We used the assay to explore baseline immunogenetic variation in M. lucifugus and to investigate whether particular immune genes/variants are associated with WNS susceptibility. We also used our assay to detect 1,038 putatively neutral single nucleotide polymorphisms and characterize contemporary population structure, providing context for the identification of local immunogenetic adaptation. Sequence capture provided a cost‐effective, “all‐in‐one” assay to test for neutral genetic and immunogenetic structure and revealed fine‐scale, baseline immunogenetic differentiation between sampling sites <600 km apart. We identified functional immunogenetic variants in M. lucifugus associated with WNS susceptibility. This study lays the foundations for future investigations of rangewide immunogenetic adaptation to WNS in M. lucifugus and provides a blueprint for studies of evolutionary rescue in other host–pathogen systems. 相似文献
5.
Alexander M. Hecht‐Hger Beate C. Braun Eberhard Krause Angelika Meschede Rüdiger Krahe Christian C. Voigt Alex D. Greenwood Gbor . Czirjk 《Molecular ecology》2020,29(9):1745-1755
Emerging fungal diseases have become challenges for wildlife health and conservation. North American hibernating bat species are threatened by the psychrophilic fungus Pseudogymnoascus destructans (Pd) causing the disease called white‐nose syndrome (WNS) with unprecedented mortality rates. The fungus is widespread in North America and Europe, however, disease is not manifested in European bats. Differences in epidemiology and pathology indicate an evolution of resistance or tolerance mechanisms towards Pd in European bats. We compared the proteomic profile of blood plasma in healthy and Pd‐colonized European Myotis myotis and North American Myotis lucifugus in order to identify pathophysiological changes associated with Pd colonization, which might also explain the differences in bat survival. Expression analyses of plasma proteins revealed differences in healthy and Pd‐colonized M. lucifugus, but not in M. myotis. We identified differentially expressed proteins for acute phase response, constitutive and adaptive immunity, oxidative stress defence, metabolism and structural proteins of exosomes and desmosomes, suggesting a systemic response against Pd in North American M. lucifugus but not European M. myotis. The differences in plasma proteomic profiles between European and North American bat species colonized by Pd suggest European bats have evolved tolerance mechanisms towards Pd infection. 相似文献
6.
Winifred F. Frick Sébastien J. Puechmaille Joseph R. Hoyt Barry A. Nickel Kate E. Langwig Jeffrey T. Foster Kate E. Barlow Tomáš Bartonička Dan Feller Anne‐Jifke Haarsma Carl Herzog Ivan Horáček Jeroen van der Kooij Bart Mulkens Boyan Petrov Rick Reynolds Luísa Rodrigues Craig W. Stihler Gregory G. Turner A. Marm Kilpatrick 《Global Ecology and Biogeography》2015,24(7):741-749
7.
The white‐nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans, is threatening the cave‐dwelling bat fauna of North America by killing individuals by the thousands in hibernacula each winter since its appearance in New York State less than ten years ago. Epidemiological models predict that WNS will reach the western coast of the USA by 2035, potentially eliminating most populations of susceptible bat species in its path (Frick et al. 2015; O'Regan et al. 2015). These models were built and validated using distributional data from the early years of the epidemic, which spread throughout eastern North America following a route driven by cave density and winter severity (Maher et al. 2012). In this issue of Molecular Ecology, Wilder et al. (2015) refine these findings by showing that connectivity among host populations, as assessed by population genetic markers, is crucial in determining the spread of the pathogen. Because host connectivity is much reduced in the hitherto disease free western half of North America, Wilder et al. make the reassuring prediction that the disease will spread more slowly west of the Great Plains. 相似文献
8.
Tiziana Annesi Laura Luongo Salvatore Vitale Massimo Galli Alessandra Belisario 《Journal of Phytopathology》2016,164(6):412-416
In March 2014, an outbreak of shoot cankers was observed on grafted Castanea sativa plants in a glasshouse in central Italy. Morphological characteristics led to the identification of isolates of Phomopsis recovered from cankered stems and shoots. Based on the morphological characteristics of colony appearance, shape of conidia and conidiomata as well as sequences of internal transcribed spacer regions (ITS), actin (ACT) and translation elongation factor (TEF‐1α), the fungus was identified as Phomopsis theicola/Diaporthe foeniculina. Pathogenicity test showed that P. theicola isolates were pathogenic to C. sativa when artificially inoculated, reproducing the symptoms originally observed. Koch's postulates were fulfilled by re‐isolating the pathogen. This is the first report of P. theicola/D. foeniculina causing stem and shoot cankers and dieback on C. sativa in Italy or elsewhere. 相似文献
9.
10.
While anthropogenic land‐use changes threaten wildlife globally, some species take advantage of such changes and disperse into urban areas. The wildlife in urban areas often promotes conflicts with humans, notably when the animals are associated with the spread of zoonotic diseases. In Israel, current urban invasion of rock hyraxes (Procavia capensis) draws public attention, since the species is a reservoir host of cutaneous leishmaniasis, a serious skin disease. The rock hyrax, however, has seldom been studied in densely populated areas, and the drivers for its urban expansion, as well as its abilities to live and spread in core urban areas, are relatively unknown. Here, we explore the rock hyrax expansion to urban areas process by examining the availability, characteristics and use of shelter along an urban gradient. Our findings suggest that a series of factors determines shelter availability and quality for the rock hyrax, which facilitates its dispersion across the urban gradient. We found that rock hyraxes from the Judean Desert expand to the peri‐urban region of Jerusalem by colonizing new rocky shelters formed as by‐products of urban development. With their populations reaching extreme densities in this area and saturating the available shelters, there is some spill over to the adjacent core urban areas where they colonize littered sites, which are made available due to the local socio‐economic conditions and cultural norms of waste disposal and illegal placement of temporary structures. Our work emphasizes the significance of the urban gradient approach for studying the mechanisms promoting wildlife expansion to cities. Our findings suggest that changes in shelter availability and quality due to urban development, and cultural norms promote shifts of the hyrax population by pushing from the already established areas and pulling into new environment across the urban gradient. 相似文献
11.
Landscape complexity influences patterns of animal dispersal, which in turn may affect both gene flow and the spread of pathogens. White‐nose syndrome (WNS) is an introduced fungal disease that has spread rapidly throughout eastern North America, causing massive mortality in bat populations. We tested for a relationship between the population genetic structure of the most common host, the little brown myotis (Myotis lucifugus), and the geographic spread of WNS to date by evaluating logistic regression models of WNS risk among hibernating colonies in eastern North America. We hypothesized that risk of WNS to susceptible host colonies should increase with both geographic proximity and genetic similarity, reflecting historical connectivity, to infected colonies. Consistent with this hypothesis, inclusion of genetic distance between infected and susceptible colonies significantly improved models of disease spread, capturing heterogeneity in the spatial expansion of WNS despite low levels of genetic differentiation among eastern populations. Expanding our genetic analysis to the continental range of little brown myotis reveals strongly contrasting patterns of population structure between eastern and western North America. Genetic structure increases markedly moving westward into the northern Great Plains, beyond the current distribution of WNS. In western North America, genetic differentiation of geographically proximate populations often exceeds levels observed across the entire eastern region, suggesting infrequent and/or locally restricted dispersal, and thus relatively limited opportunities for pathogen introduction in western North America. Taken together, our analyses suggest a possibly slower future rate of spread of the WNS pathogen, at least as mediated by little brown myotis. 相似文献
12.
Laura M. Bergner Richard J. Orton Julio A. Benavides Daniel J. Becker Carlos Tello Roman Biek Daniel G. Streicker 《Molecular ecology》2020,29(1):26-39
Viruses infect all forms of life and play critical roles as agents of disease, drivers of biochemical cycles and sources of genetic diversity for their hosts. Our understanding of viral diversity derives primarily from comparisons among host species, precluding insight into how intraspecific variation in host ecology affects viral communities or how predictable viral communities are across populations. Here we test spatial, demographic and environmental hypotheses explaining viral richness and community composition across populations of common vampire bats, which occur in diverse habitats of North, Central and South America. We demonstrate marked variation in viral communities that was not consistently predicted by a null model of declining community similarity with increasing spatial or genetic distances separating populations. We also find no evidence that larger bat colonies host greater viral diversity. Instead, viral diversity follows an elevational gradient, is enriched by juvenile‐biased age structure, and declines with local anthropogenic food resources as measured by livestock density. Our results establish the value of linking the modern influx of metagenomic sequence data with comparative ecology, reveal that snapshot views of viral diversity are unlikely to be representative at the species level, and affirm existing ecological theories that link host ecology not only to single pathogen dynamics but also to viral communities. 相似文献
13.
Rosalba Flores‐Flores Miguel G. Velázquez‐del Valle Renato León‐Rodriguez Hilda E. Flores‐Moctezuma Ana N. Hernández‐Lauzardo 《Journal of Phytopathology》2013,161(7-8):544-552
México is the most important producer of prickly pear (Opuntia ficus‐indica) in the world. There are several fungal diseases that can have a negative impact on their yields. In this study, there was a widespread fungal richness on cladodes spot of prickly pears from México. A total of 41 fungi isolates were obtained from cladodes spot; 11 of them were morphologically different. According to the pathogenicity test, seven isolates caused lesions on cladodes. The morphological and molecular identification evidenced the isolation of Colletotrichum gloeosporioides, Alternaria alternata, Fusarium lunatum, Curvularia lunata. All these species caused similar symptoms of circular cladodes spot. However, it is noticeable that some lesions showed perforation and detachment of affected tissues by Fusarium lunatum. To our knowledge, this is the first report of the Fusarium lunatum as phytopathogenic fungus of cladodes of prickly pear. The chitosan inhibited the mycelium growth in the seven isolates of phytopathogenic fungi. Chitosan applications diminished the disease incidence caused by C. gloeosporioies and F. lunatum in 40 and 100%, respectively. Likewise, the lesion severity index in cladodes decreased. There are no previous reports about the application of chitosan on cladodes of prickly pears for the control of phytopathogenic fungi. Therefore, this research could contribute to improve the strategies for the management of diseases in prickly pear. 相似文献
14.
Fungal endophytes have been documented in almost all terrestrial plant groups. Although the endophyte infection syndrome in agronomic cultivars is well studied, relatively little work addresses questions of spatial ecology and fire effects on epichloae endophyte infection in native grasses, and none, to our knowledge, in sub‐Saharan Africa. We sampled seven populations of the native Festuca costata Nees along the spline of the Drakensberg range in South Africa at several spatial scales, including both recently burned and unburned stands. We tested epichloae presence and prevalence with immunoblot assays, PCR and genetic sequencing. We found epichloae endophytes were present and prevalent (38–98% infection rates depending on location). Variation in infection rates occurred primarily among locations, but also among bunches. There was little evidence that endophyte infection rates varied with fire. Novel evidence of epichloae infection of a native Festuca in South Africa opens the door to several new research questions, from the phylogenetic relationship between epichloae of sub‐Saharan Africa and other continents to the ecological advantages or disadvantages that endophytes confer upon their hosts, especially in a fire‐prone ecosystem vulnerable to global environmental change. 相似文献
15.
Marie L. Davey Einar Heegaard Rune Halvorsen Håvard Kauserud Mikael Ohlson 《Molecular ecology》2013,22(2):368-383
Although bryophytes are a dominant vegetation component of boreal and alpine ecosystems, little is known about their associated fungal communities. HPLC assays of ergosterol (fungal biomass) and amplicon pyrosequencing of the ITS2 region of rDNA were used to investigate how the fungal communities associated with four bryophyte species changed across an elevational gradient transitioning from conifer forest to the low‐alpine. Fungal biomass and OTU richness associated with the four moss hosts did not vary significantly across the gradient (P > 0.05), and both were more strongly affected by host and tissue type. Despite largely constant levels of fungal biomass, distinct shifts in community composition of fungi associated with Hylocomium, Pleurozium and Polytrichum occurred between the elevation zones of the gradient. This likely is a result of influence on fungal communities by major environmental factors such as temperature, directly or indirectly mediated by, or interacting with, the response of other components of the vegetation (i.e. the dominant trees). Fungal communities associated with Dicranum were an exception, exhibiting spatial autocorrelation between plots, and no significant structuring by elevation. Nevertheless, the detection of distinct fungal assemblages associated with a single host growing in different elevation zones along an elevational gradient is of particular relevance in the light of the ongoing changes in vegetation patterns in boreal and alpine systems due to global climate warming. 相似文献
16.
Emma J. Steel Joseph B. Fontaine Katinka X. Ruthrof Treena I. Burgess Giles E. St. J. Hardy 《Austral ecology》2019,44(8):1438-1450
Worldwide, extreme climatic events such as drought and heatwaves are associated with forest mortality. However, the precise drivers of tree mortality at individual and stand levels vary considerably, with substantial gaps in knowledge across studies in biomes and continents. In 2010–2011, a drought‐associated heatwave occurred in south‐western Australia and drove sudden and rapid forest canopy collapse. Working in the Northern Jarrah (Eucalyptus marginata) Forest, we quantified the response of key overstory (E. marginata, Corymbia calophylla) and midstory (Banksia grandis, Allocasuarina fraseriana) tree species to the extreme climate event. Using transects spanning a gradient of drought impacts (minimal (50–100 m), transitional (100–150 m) and severe (30–60 m)), tree species mortality in relation to stand characteristics (stand basal area and stem density) and edaphic factors (soil depth) was determined. We show differential mortality between the two overstory species and the two midstory species corresponding to the drought‐associated heatwave. The dominant overstory species, E. marginata, had significantly higher mortality (~19%) than C. calophylla (~7%) in the severe zone. The midstory species, B. grandis, demonstrated substantially higher mortality (~59%) than A. fraseriana (~4%) in the transitional zone. Banksia grandis exhibited a substantial shift in structure in response to the drought‐associated heatwave in relation to tree size, basal area and soil depth. This study illustrates the role of climate extremes in driving ecosystem change and highlights the critical need to identify and quantify the resulting impact to help predict future forest die‐off events and to underpin forest management and conservation. 相似文献
17.
Dandan Guo Jiali Jing Wenjie Hu Shrishail S. Navi Lan Jing 《Journal of Phytopathology》2016,164(2):141-146
Two basidiomycete‐specific primers ITS1‐F and ITS4‐B were used in identification of the genus Puccinia. The primers showed good specificity for the genus with an 816‐bp product that was amplified exclusively. Twenty sequences of internal transcribed spacer (ITS) regions of Puccinia helianthi isolates from China remain unchanged. The whole ITS length (including ITS1 sequence 194 bp, 5.8S rRNA gene 156 bp, ITS2 sequence 206 bp) was 556 bp. By comparing the aligned ITS sequences of several Puccinia isolates from China, Spain and the United States, ITS homogeneity among these sunflower rust isolates was >99%. Genetic homology and phylogeny of P. helianthi with other Puccinia spp. was investigated. Nineteen sequences of rDNA ITS1 and ITS2 were determined and used as phylogenetic markers. Phylogenetic analysis of ITS regions showed that Puccinia spp. of sunflower was clustered in one clade with P. komarovii and P. violae, divergent from Puccinia spp. of Chrysanthemum, P. tenaceti of tansy (Tanacetum vulgare) and Puccina spp. of big sagebrush (Artemisia tridentate) indicating sunflower rust had distant phylogenetic relationships with other Compositae rusts. With the specified primers SR‐1 and SR‐2, either from purified urediniospores or symptomless (but infected) sunflower leaves could be examined specifically. Therefore, results of this study help in detection and polygenetic study of rust fungi occurring on sunflower. 相似文献
18.
Rebecca T. Trubitt Torre J. Hovick Erin H. Gillam Devan A. McGranahan 《Ecology and evolution》2019,9(1):598-608
Land‐use change has resulted in rangeland loss and degradation globally. These changes include conversion of native grasslands for row‐crop agriculture as well as degradation of remaining rangeland due to fragmentation and changing disturbance regimes. Understanding how these and other factors influence wildlife use of rangelands is important for conservation and management of wildlife populations. We investigated bat habitat associations in a working rangeland in southeastern North Dakota. We used Petterson d500x acoustic detectors to systematically sample bat activity across the study area on a 1‐km point grid. We identified calls using Sonobat autoclassification software. We detected five species using this working rangeland, which included Lasionycteris noctivagans (2,722 detections), Lasiurus cinereus (2,055 detections), Eptesicus fuscus (749 detections), Lasiurus borealis (62 detections), and Myotis lucifugus (1 detection). We developed generalized linear mixed‐effects models for the four most frequently detected species based on their ecology. The activity of three bat species increased with higher tree cover. While the scale of selection varied between the four species, all three investigated scales were explanatory for at least one bat species. The broad importance of trees to bats in rangelands may put their conservation needs at odds with those of obligate grassland species. Focusing rangeland bat conservation on areas that were treed prior to European settlement, such as riparian forests, can provide important areas for bat conservation while minimizing negative impacts on grassland species. 相似文献
19.
Molly C. Bletz Andrew H. Loudon Matthew H. Becker Sara C. Bell Douglas C. Woodhams Kevin P. C. Minbiole Reid N. Harris 《Ecology letters》2013,16(6):807-820
Probiotic therapy through bioaugmentation is a feasible disease mitigation strategy based on growing evidence that microbes contribute to host defences of plants and animals. Amphibians are currently threatened by the rapid global spread of the pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis. Bioaugmentation of locally occurring protective bacteria on amphibians has mitigated this disease effectively in laboratory trials and one recent field trial. Areas still naïve to Bd provide an opportunity for conservationists to proactively implement probiotic strategies to prevent further amphibian declines. In areas where Bd is endemic, bioaugmentation can facilitate repatriation of susceptible amphibians currently maintained in assurance colonies. Here, we synthesise the current research in amphibian microbial ecology and bioaugmentation to identify characteristics of effective probiotics in relation to their interactions with Bd, their host, other resident microbes and the environment. To target at‐risk species and amphibian communities, we develop sampling strategies and filtering protocols that result in probiotics that inhibit Bd under ecologically relevant conditions and persist on susceptible amphibians. This filtering tool can be used proactively to guide amphibian disease mitigation and can be extended to other taxa threatened by emerging infectious diseases. 相似文献
20.
Molecular ecology of Listeria spp., Salmonella,Escherichia coli O157:H7 and non‐O157 Shiga toxin‐producing E. coli in pristine natural environments in Northern Colorado 
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下载免费PDF全文 C.A. Ahlstrom C.S. Manuel H.C. Den Bakker M. Wiedmann K.K. Nightingale 《Journal of applied microbiology》2018,124(2):511-521