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Sample records for host species implications

  1. New African species of Echinobothrium (Cestoda: Diphyllidea) and implications for the identities of their skate hosts.

    Science.gov (United States)

    Caira, J N; Rodriguez, N; Pickering, M

    2013-10-01

    Two new species of diphyllidean cestodes of the genus Echinobothrium, each hosted by a different skate species in the Raja miraletus complex, are described. Echinobothrium mercedesae n. sp. is described from R. cf. miraletus 2 off Senegal. Echinobothrium yiae n. sp. is described from R. cf. miraletus 1 off South Africa. Both species are small worms that differ from their 29 described congeners in the combination of number of cephalic peduncle spines per column, hook formula, number and arrangement of testes, and arrangement of vitelline follicles. They are easily distinguished from one another in that whereas the vitelline follicles of E. yiae n. sp. are circumcortical, they are lateral in E. mercedesae n. sp., and also in number of cephalic peduncle spines per column (14-17 vs. 10-12). Echinobothrium yiae n. sp. is also unusual in that the cephalic peduncle spines stop short of the anterior margin of the peduncle. In addition, although the paucity of available material precluded their formal description, evidence of 2 additional new species parasitizing R. miraletus also from Senegal is presented. In combination these worms provide support for the interpretation that what is currently recognized as Raja miraletus actually consists of a complex of geographically restricted species, rather than a polymorphic species of multiple parapatric or allopatrically distributed populations. This interpretation is not only supported by previously published molecular data, but also by newly collected morphological data involving differences in the color patterns of disc ocelli among host specimens of the 3 forms available as a result of digital efforts to ensure the accuracy of host identifications, which are also presented here.

  2. Thelazia callipaeda (Spirurida, Thelaziidae) in wild animals: report of new host species and ecological implications.

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    Otranto, Domenico; Dantas-Torres, Filipe; Mallia, Egidio; DiGeronimo, Peter M; Brianti, Emanuele; Testini, Gabriella; Traversa, Donato; Lia, Riccardo P

    2009-12-23

    Thelazia callipaeda infects the eyes of carnivores and humans in Far Eastern Asiatic and European countries. Studies have demonstrated the occurrence of T. callipaeda in foxes from areas where canine thelaziosis is endemic. However, there is little information on the role of wild carnivores as hosts of this nematode. From May 2003 to May 2009, a total of 130 carcasses of red foxes (Vulpes vulpes; n=75), wolves (Canis lupus; n=2), beech martens (Martes foina; n=22), brown hares (Lepus europaeus; n=13), Eurasian badgers (Meles meles; n=10), and wild cats (Felis silvestris; n=8) were examined in an area of southern Italy where canine thelaziosis is highly prevalent. At necropsy, animals were examined and nematodes were collected from the conjunctival sacs of both eyes. All nematodes were morphologically identified and at least five specimens from each of the five host species were molecularly processed by PCR amplification and sequencing of a partial mitochondrial cytochrome c oxidase subunit 1 gene (cox1). Five out of the six wild animal species examined were found to be infected with eyeworms. The overall infection rate, excluding the Eurasian badgers that were all negative, was 39.1%. All the 189 adult nematodes collected (intensity of infection=4+/-2.2) were morphologically identified as T. callipaeda. The molecular analysis confirmed that the only haplotype of T. callipaeda circulating in Europe (i.e., haplotype 1) is present in that area. The competence of red foxes, wolves, beech martens, brown hares, and wild cats as definitive hosts for T. callipaeda is discussed in relationship to their ecology and their likely exposure to the vector Phortica variegata in the study area. The role the wild fauna plays in maintaining and spreading eyeworm infection in humans and domestic animals is also discussed.

  3. Dynamic effects of parasitism by an endoparasitoid wasp on the development of two host species: implications for host quality and parasitoid fitness

    NARCIS (Netherlands)

    Harvey, J.A.

    2000-01-01

    1. The study reported here examined growth and developmental interactions between the gregarious larval koinobiont endoparasitoid Cotesia glomerata (Hymenoptera: Braconidae) and two of its hosts that vary considerably in growth potential: Pieris rapae and the larger P. brassicae (Lepidoptera:

  4. Patterns in root traits of woody species hosting arbuscular and ectomycorrhizas: implications for the evolution of belowground strategies

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    Despite large variation in root traits among species, we have limited understanding of how traits are related to diverse soil resource acquisition strategies. We examined root trait variation among 33 species co-existing in Northeastern US forests that form the two most common mutualisms with mycorr...

  5. Morphological and molecular characterization of a new species of leech (Glossiphoniidae, Hirudinida): Implications for the health of its imperiled amphibian host (Cryptobranchus alleganiensis).

    Science.gov (United States)

    Hopkins, William A; Moser, William E; Garst, David W; Richardson, Dennis J; Hammond, Charlotte I; Lazo-Wasem, Eric A

    2014-01-01

    The hellbender (Cryptobranchus alleganiensis) is among the most intriguing and imperiled amphibians in North America. Since the 1970s and 80s, western populations of the Ozark and eastern subspecies in Missouri have declined by nearly 80%. As a result of population declines, the Ozark hellbender was recently federally protected as an endangered species, and the eastern subspecies was granted protection under CITES. Although habitat degradation is probably the biggest threat to hellbender populations, recent evidence suggests that pathogens including chytrid fungus and "flesh-eating" bacteria may also contribute to declines in Ozark hellbenders. Leeches, which are very common on Ozark hellbenders, have recently been implicated as possible vectors of disease among Ozark hellbenders but have not been described in eastern hellbenders or outside of Missouri and Arkansas. We discovered a population of leeches on eastern hellbenders in southwest Virginia and confirmed that the species of leech is within the genus Placobdella, but is morphologically and genetically distinct from all previously described leech species. We named the new species Placobdella appalachiensis sp. n. Moser and Hopkins, based on the mountainous region in which it was discovered. Our surveys over a three consecutive year period suggested that this leech species may be patchily distributed and/or have a narrow geographic range. We consistently detected leeches at one site (mean prevalence in 80 hellbenders = 27.5%; median intensity = 3.0 leeches per parasitized hellbender [range 1 - >250 leeches]) during three years of surveys, but we never found leeches in any of our other seven study sites in two streams (mean prevalence in 139 hellbenders = 0%). We found a significant positive relationship between hellbender body size and the intensity of parasitism, and we suggest the possibility that the behavioral ecology of adults leading up to reproduction may increase their encounter rates with parasites. We

  6. Patterns of host adaptation in fly infecting Entomophthora species

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Jensen, Annette Bruun; Eilenberg, Jørgen

    .g. Entomophthora, Strongwellsea and Entomophaga). Species diversification of the obligate IPF within Entomophthoromycota thus seems to be primarily driven by co-evolutionary host adaptation to specific insect families, genera or species-complexes, but the underlying genetic factors of host adaptation...... in this fungal order are largely unknown and leave many unanswered questions. For example are the number of virulence factors increasing, or decreasing when fungal pathogens adapt to a narrow range of potential hosts? And, are host specialization based on many genetic changes with small effect or few with large...... differences and similarities in order to detect patterns of host-specific molecular adaptation....

  7. Fish, fans and hydroids: host species of pygmy seahorses

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    Bastian Reijnen

    2011-06-01

    Full Text Available An overview of the octocoral and hydrozoa host species of pygmy seahorses is provided, based on recently collected data for H. bargibanti, H. denise and H. pontohi and literature records. Seven new interspecific host-species associations are recognized, and an overview of the so far documented number of host species is given. Detailed re-examination of octocoral type material and a review of the taxonomic history are included, as a baseline for further studies. The host-specificity and colour morphs of pygmy seahorses are discussed, as well as the validity of (previous identifications and conservations issues.

  8. Fish, fans and hydroids: host species of pygmy seahorses

    NARCIS (Netherlands)

    Reijnen, B.T.; Meij, van der S.E.T.; Ofwegen, van L.P.

    2011-01-01

    An overview of the octocoral and hydrozoan host species of pygmy seahorses is provided based on literature records and recently collected field data for Hippocampus bargibanti, H. denise and H. pontohi. Seven new associations are recognized and an overview of the so far documented host species is

  9. Directional Selection from Host Plants Is a Major Force Driving Host Specificity in Magnaporthe Species.

    Science.gov (United States)

    Zhong, Zhenhui; Norvienyeku, Justice; Chen, Meilian; Bao, Jiandong; Lin, Lianyu; Chen, Liqiong; Lin, Yahong; Wu, Xiaoxian; Cai, Zena; Zhang, Qi; Lin, Xiaoye; Hong, Yonghe; Huang, Jun; Xu, Linghong; Zhang, Honghong; Chen, Long; Tang, Wei; Zheng, Huakun; Chen, Xiaofeng; Wang, Yanli; Lian, Bi; Zhang, Liangsheng; Tang, Haibao; Lu, Guodong; Ebbole, Daniel J; Wang, Baohua; Wang, Zonghua

    2016-05-06

    One major threat to global food security that requires immediate attention, is the increasing incidence of host shift and host expansion in growing number of pathogenic fungi and emergence of new pathogens. The threat is more alarming because, yield quality and quantity improvement efforts are encouraging the cultivation of uniform plants with low genetic diversity that are increasingly susceptible to emerging pathogens. However, the influence of host genome differentiation on pathogen genome differentiation and its contribution to emergence and adaptability is still obscure. Here, we compared genome sequence of 6 isolates of Magnaporthe species obtained from three different host plants. We demonstrated the evolutionary relationship between Magnaporthe species and the influence of host differentiation on pathogens. Phylogenetic analysis showed that evolution of pathogen directly corresponds with host divergence, suggesting that host-pathogen interaction has led to co-evolution. Furthermore, we identified an asymmetric selection pressure on Magnaporthe species. Oryza sativa-infecting isolates showed higher directional selection from host and subsequently tends to lower the genetic diversity in its genome. We concluded that, frequent gene loss or gain, new transposon acquisition and sequence divergence are host adaptability mechanisms for Magnaporthe species, and this coevolution processes is greatly driven by directional selection from host plants.

  10. Dinucleotide Composition in Animal RNA Viruses Is Shaped More by Virus Family than by Host Species.

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    Di Giallonardo, Francesca; Schlub, Timothy E; Shi, Mang; Holmes, Edward C

    2017-04-15

    Viruses use the cellular machinery of their hosts for replication. It has therefore been proposed that the nucleotide and dinucleotide compositions of viruses should match those of their host species. If this is upheld, it may then be possible to use dinucleotide composition to predict the true host species of viruses sampled in metagenomic surveys. However, it is also clear that different taxonomic groups of viruses tend to have distinctive patterns of dinucleotide composition that may be independent of host species. To determine the relative strength of the effect of host versus virus family in shaping dinucleotide composition, we performed a comparative analysis of 20 RNA virus families from 15 host groupings, spanning two animal phyla and more than 900 virus species. In particular, we determined the odds ratios for the 16 possible dinucleotides and performed a discriminant analysis to evaluate the capability of virus dinucleotide composition to predict the correct virus family or host taxon from which it was isolated. Notably, while 81% of the data analyzed here were predicted to the correct virus family, only 62% of these data were predicted to their correct subphylum/class host and a mere 32% to their correct mammalian order. Similarly, dinucleotide composition has a weak predictive power for different hosts within individual virus families. We therefore conclude that dinucleotide composition is generally uniform within a virus family but less well reflects that of its host species. This has obvious implications for attempts to accurately predict host species from virus genome sequences alone. IMPORTANCE Determining the processes that shape virus genomes is central to understanding virus evolution and emergence. One question of particular importance is why nucleotide and dinucleotide frequencies differ so markedly between viruses. In particular, it is currently unclear whether host species or virus family has the biggest impact on dinucleotide frequencies and

  11. Colletotrichum species with curved conidia from herbaceous hosts

    NARCIS (Netherlands)

    Damm, U.; Woudenberg, J.H.C.; Cannon, P.F.; Crous, P.W.

    2009-01-01

    Colletotrichum (Glomerellaceae, Sordariomycetes) species with dark setae and curved conidia are known as anthracnose pathogens of a number of economically important hosts and are often identified as C. dematium. Colletotrichum dematium has been synonymised with many species, including the type of

  12. Host manipulation by cancer cells: Expectations, facts, and therapeutic implications.

    Science.gov (United States)

    Tissot, Tazzio; Arnal, Audrey; Jacqueline, Camille; Poulin, Robert; Lefèvre, Thierry; Mery, Frédéric; Renaud, François; Roche, Benjamin; Massol, François; Salzet, Michel; Ewald, Paul; Tasiemski, Aurélie; Ujvari, Beata; Thomas, Frédéric

    2016-03-01

    Similar to parasites, cancer cells depend on their hosts for sustenance, proliferation and reproduction, exploiting the hosts for energy and resources, and thereby impairing their health and fitness. Because of this lifestyle similarity, it is predicted that cancer cells could, like numerous parasitic organisms, evolve the capacity to manipulate the phenotype of their hosts to increase their own fitness. We claim that the extent of this phenomenon and its therapeutic implications are, however, underappreciated. Here, we review and discuss what can be regarded as cases of host manipulation in the context of cancer development and progression. We elaborate on how acknowledging the applicability of these principles can offer novel therapeutic and preventive strategies. The manipulation of host phenotype by cancer cells is one more reason to adopt a Darwinian approach in cancer research. © 2016 WILEY Periodicals, Inc.

  13. Are cryptic host species also cryptic to parasites? Host specificity and geographical distribution of acanthocephalan parasites infecting freshwater Gammarus

    OpenAIRE

    Westram A. M.; Baumgartner C; Keller I; Jokela J.

    2011-01-01

    Many parasites infect multiple host species. In coevolving host parasite interactions theory predicts that parasites should be adapted to locally common hosts which could lead to regional shifts in host preferences. We studied the interaction between freshwater Gammarus (Crustacea Amphipoda) and their acanthocephalan parasites using a large scale field survey and experiments combined with molecular identification of cryptic host and parasite species. Gammarus pulex is a common host for multip...

  14. Bacterial communities of diverse Drosophila species: ecological context of a host-microbe model system.

    Science.gov (United States)

    Chandler, James Angus; Lang, Jenna Morgan; Bhatnagar, Srijak; Eisen, Jonathan A; Kopp, Artyom

    2011-09-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host-microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal-microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host-microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host-microbe interactions. Bacterial taxa used in experimental studies are rare or absent in wild

  15. Bacterial communities of diverse Drosophila species: ecological context of a host-microbe model system.

    Directory of Open Access Journals (Sweden)

    James Angus Chandler

    2011-09-01

    Full Text Available Drosophila melanogaster is emerging as an important model of non-pathogenic host-microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal-microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host-microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host-microbe interactions. Bacterial taxa used in experimental studies are rare

  16. Bat fly species richness in Neotropical bats: correlations with host ecology and host brain.

    Science.gov (United States)

    Bordes, Frédéric; Morand, Serge; Ricardo, Guerrero

    2008-11-01

    Patterns of ectoparasite species richness in mammals have been investigated in various terrestrial mammalian taxa such as primates, ungulates and carnivores. Several ecological or life traits of hosts are expected to explain much of the variability in species richness of parasites. In the present comparative analysis we investigate some determinants of parasite richness in bats, a large and understudied group of flying mammals, and their obligate blood-sucking ectoparasite, streblid bat flies (Diptera). We investigate the effects of host body size, geographical range, group size and roosting ecology on the species richness of bat flies in tropical areas of Venezuela and Peru, where both host and parasite diversities are high. We use the data from a major sampling effort on 138 bat species from nine families. We also investigate potential correlation between bat fly species richness and brain size (corrected for body size) in these tropical bats. We expect a relationship if there is a potential energetic trade-off between costly large brains and parasite-mediated impacts. We show that body size and roosting in cavities are positively correlated with bat fly species richness. No effects of bat range size and group size were observed. Our results also suggest an association between body mass-independent brain size and bat fly species richness.

  17. Association of host and microbial species diversity across spatial scales in desert rodent communities.

    Science.gov (United States)

    Gavish, Yoni; Kedem, Hadar; Messika, Irit; Cohen, Carmit; Toh, Evelyn; Munro, Daniel; Dong, Qunfeng; Fuqua, Clay; Clay, Keith; Hawlena, Hadas

    2014-01-01

    Relationships between host and microbial diversity have important ecological and applied implications. Theory predicts that these relationships will depend on the spatio-temporal scale of the analysis and the niche breadth of the organisms in question, but representative data on host-microbial community assemblage in nature is lacking. We employed a natural gradient of rodent species richness and quantified bacterial communities in rodent blood at several hierarchical spatial scales to test the hypothesis that associations between host and microbial species diversity will be positive in communities dominated by organisms with broad niches sampled at large scales. Following pyrosequencing of rodent blood samples, bacterial communities were found to be comprised primarily of broad niche lineages. These communities exhibited positive correlations between host diversity, microbial diversity and the likelihood for rare pathogens at the regional scale but not at finer scales. These findings demonstrate how microbial diversity is affected by host diversity at different spatial scales and suggest that the relationships between host diversity and overall disease risk are not always negative, as the dilution hypothesis predicts.

  18. Association of host and microbial species diversity across spatial scales in desert rodent communities.

    Directory of Open Access Journals (Sweden)

    Yoni Gavish

    Full Text Available Relationships between host and microbial diversity have important ecological and applied implications. Theory predicts that these relationships will depend on the spatio-temporal scale of the analysis and the niche breadth of the organisms in question, but representative data on host-microbial community assemblage in nature is lacking. We employed a natural gradient of rodent species richness and quantified bacterial communities in rodent blood at several hierarchical spatial scales to test the hypothesis that associations between host and microbial species diversity will be positive in communities dominated by organisms with broad niches sampled at large scales. Following pyrosequencing of rodent blood samples, bacterial communities were found to be comprised primarily of broad niche lineages. These communities exhibited positive correlations between host diversity, microbial diversity and the likelihood for rare pathogens at the regional scale but not at finer scales. These findings demonstrate how microbial diversity is affected by host diversity at different spatial scales and suggest that the relationships between host diversity and overall disease risk are not always negative, as the dilution hypothesis predicts.

  19. Prevalence and beta diversity in avian malaria communities: host species is a better predictor than geography.

    Science.gov (United States)

    Scordato, Elizabeth S C; Kardish, Melissa R

    2014-11-01

    Patterns of diversity and turnover in macroorganism communities can often be predicted from differences in habitat, phylogenetic relationships among species and the geographical scale of comparisons. In this study, we asked whether these factors also predict diversity and turnover in parasite communities. We studied communities of avian malaria in two sympatric, ecologically similar, congeneric host species at three different sites. We asked whether parasite prevalence and community structure varied with host population, host phylogeography or geographical distance. We used PCR to screen birds for infections and then used Bayesian methods to determine phylogenetic relationships among malaria strains. Metrics of both community and phylogenetic beta diversity were used to examine patterns of malaria strain turnover between host populations, and partial Mantel tests were used determine the correlation between malaria beta diversity and geographical distance. Finally, we developed microsatellite markers to describe the genetic structure of host populations and assess the relationship between host phylogeography and parasite beta diversity. We found that different genera of malaria parasites infect the two hosts at different rates. Within hosts, parasite communities in one population were phylogenetically clustered, but there was otherwise no correlation between metrics of parasite beta diversity and geographical or genetic distance between host populations. Patterns of parasite turnover among host populations are consistent with malaria transmission occurring in the winter rather than on the breeding grounds. Our results indicate greater turnover in parasite communities between different hosts than between different study sites. Differences in host species, as well as transmission location and vector ecology, seem to be more important in structuring malaria communities than the distance-decay relationships frequently found in macroorganisms. Determining the factors

  20. Determinants of host species range in plant viruses.

    Science.gov (United States)

    Moury, Benoît; Fabre, Frédéric; Hébrard, Eugénie; Froissart, Rémy

    2017-04-01

    Prediction of pathogen emergence is an important field of research, both in human health and in agronomy. Most studies of pathogen emergence have focused on the ecological or anthropic factors involved rather than on the role of intrinsic pathogen properties. The capacity of pathogens to infect a large set of host species, i.e. to possess a large host range breadth (HRB), is tightly linked to their emergence propensity. Using an extensive plant virus database, we found that four traits related to virus genome or transmission properties were strongly and robustly linked to virus HRB. Broader host ranges were observed for viruses with single-stranded genomes, those with three genome segments and nematode-transmitted viruses. Also, two contrasted groups of seed-transmitted viruses were evidenced. Those with a single-stranded genome had larger HRB than non-seed-transmitted viruses, whereas those with a double-stranded genome (almost exclusively RNA) had an extremely small HRB. From the plant side, the family taxonomic rank appeared as a critical threshold for virus host range, with a highly significant increase in barriers to infection between plant families. Accordingly, the plant-virus infectivity matrix shows a dual structure pattern: a modular pattern mainly due to viruses specialized to infect plants of a given family and a nested pattern due to generalist viruses. These results contribute to a better prediction of virus host jumps and emergence risks.

  1. Are cryptic host species also cryptic to parasites? Host specificity and geographical distribution of acanthocephalan parasites infecting freshwater Gammarus.

    Science.gov (United States)

    Westram, A M; Baumgartner, C; Keller, I; Jokela, J

    2011-07-01

    Many parasites infect multiple host species. In coevolving host-parasite interactions, theory predicts that parasites should be adapted to locally common hosts, which could lead to regional shifts in host preferences. We studied the interaction between freshwater Gammarus (Crustacea, Amphipoda) and their acanthocephalan parasites using a large-scale field survey and experiments, combined with molecular identification of cryptic host and parasite species. Gammarus pulex is a common host for multiple species of Acanthocephala in Europe but, in Switzerland, is less common than two cryptic members of the Gammarus fossarum species complex (type A and type B). We found that natural populations of these cryptic species were frequently infected by Pomphorhynchus tereticollis and Polymorphus minutus. Four additional parasite species occurred only locally. Parasites were more common in G. fossarum type B than in type A. Infection experiments using several host and parasite sources confirmed consistently lower infection rates in G. pulex than in G. fossarum type A, suggesting a general difference in susceptibility between the two species. In conclusion, we could show that cryptic host species differ in their interactions with parasites, but that these differences were much less dramatic than differences between G. fossarum (type A) and G. pulex. Our data suggest that the acanthocephalans in Switzerland have adapted to the two most common Gammarus species in this region where host species frequencies differ from near-by regions in Europe. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Panamanian frog species host unique skin bacterial communities

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    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  3. Trophic relationships between the parasitic plant species Phelipanche ramosa (L. and different hosts depending on host phenological stage and host growth rate

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    Delphine Moreau

    2016-07-01

    Full Text Available Phelipanche ramosa (L. Pomel (branched broomrape is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host's expense so that host-parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L. (oilseed rape and two weed species, Capsella bursa-pastoris (L. Medik. and Geranium dissectum (L.. Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34% to 84%. Brassica napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per

  4. Host switching in a generalist parasitoid: contrasting transient and transgenerational costs associated with novel and original host species

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    Jones, Thomas S; Bilton, Adam R; Mak, Lorraine; Sait, Steven M

    2015-01-01

    Parasitoids face challenges by switching between host species that influence survival and fitness, determine their role in structuring communities, influence species invasions, and affect their importance as biocontrol agents. In the generalist parasitoid, Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae), we investigated the costs in encapsulation, survival, and body size on juveniles when adult parasitoids switched from their original host, Plodia interpunctella (Hübner) (Lepidotera, Pyralidae) to a novel host, Ephestia kuehniella (Zeller) (Lepidoptera, Pyralidae), over multiple generations. Switching had an initial survival cost for juvenile parasitoids in the novel host, but increased survival occurred within two generations. Conversely, mortality in the original host increased. Body size, a proxy for fecundity, also increased with the number of generations in the novel host species, reflecting adaptation or maternal effects due to the larger size of the novel host, and therefore greater resources available to the developing parasitoid. Switching to a novel host appears to have initial costs for a parasitoid, even when the novel host may be better quality, but the costs rapidly diminish. We predict that the net cost of switching to a novel host for parasitoids will be complex and will depend on the initial reduction in fitness from parasitizing a novel host versus local adaptations against parasitoids in the original host. PMID:25691971

  5. Do parasitic trematode cercariae demonstrate a preference for susceptible host species?

    Directory of Open Access Journals (Sweden)

    Brittany F Sears

    Full Text Available Many parasites are motile and exhibit behavioural preferences for certain host species. Because hosts can vary in their susceptibility to infections, parasites might benefit from preferentially detecting and infecting the most susceptible host, but this mechanistic hypothesis for host-choice has rarely been tested. We evaluated whether cercariae (larval trematode parasites prefer the most susceptible host species by simultaneously presenting cercariae with four species of tadpole hosts. Cercariae consistently preferred hosts in the following order: Anaxyrus ( = Bufo terrestris (southern toad, Hyla squirella (squirrel tree frog, Lithobates ( = Rana sphenocephala (southern leopard frog, and Osteopilus septentrionalis (Cuban tree frog. These host species varied in susceptibility to cercariae in an order similar to their attractiveness with a correlation that approached significance. Host attractiveness to parasites also varied consistently and significantly among individuals within a host species. If heritable, this individual-level host variation would represent the raw material upon which selection could act, which could promote a Red Queen "arms race" between host cues and parasite detection of those cues. If, in general, motile parasites prefer to infect the most susceptible host species, this phenomenon could explain aggregated distributions of parasites among hosts and contribute to parasite transmission rates and the evolution of virulence. Parasite preferences for hosts belie the common assumption of disease models that parasites seek and infect hosts at random.

  6. The integrative taxonomic approach reveals host specific species in an encyrtid parasitoid species complex.

    Directory of Open Access Journals (Sweden)

    Douglas Chesters

    Full Text Available Integrated taxonomy uses evidence from a number of different character types to delimit species and other natural groupings. While this approach has been advocated recently, and should be of particular utility in the case of diminutive insect parasitoids, there are relatively few examples of its application in these taxa. Here, we use an integrated framework to delimit independent lineages in Encyrtus sasakii (Hymenoptera: Chalcidoidea: Encyrtidae, a parasitoid morphospecies previously considered a host generalist. Sequence variation at the DNA barcode (cytochrome c oxidase I, COI and nuclear 28S rDNA loci were compared to morphometric recordings and mating compatibility tests, among samples of this species complex collected from its four scale insect hosts, covering a broad geographic range of northern and central China. Our results reveal that Encyrtus sasakii comprises three lineages that, while sharing a similar morphology, are highly divergent at the molecular level. At the barcode locus, the median K2P molecular distance between individuals from three primary populations was found to be 11.3%, well outside the divergence usually observed between Chalcidoidea conspecifics (0.5%. Corroborative evidence that the genetic lineages represent independent species was found from mating tests, where compatibility was observed only within populations, and morphometric analysis, which found that despite apparent morphological homogeneity, populations clustered according to forewing shape. The independent lineages defined by the integrated analysis correspond to the three scale insect hosts, suggesting the presence of host specific cryptic species. The finding of hidden host specificity in this species complex demonstrates the critical role that DNA barcoding will increasingly play in revealing hidden biodiversity in taxa that present difficulties for traditional taxonomic approaches.

  7. Plasmodium prevalence across avian host species is positively associated with exposure to mosquito vectors.

    Science.gov (United States)

    Medeiros, Matthew C I; Ricklefs, Robert E; Brawn, Jeffrey D; Hamer, Gabriel L

    2015-11-01

    The prevalence of vector-borne parasites varies greatly across host species, and this heterogeneity has been used to relate infectious disease susceptibility to host species traits. However, a few empirical studies have directly associated vector-borne parasite prevalence with exposure to vectors across hosts. Here, we use DNA sequencing of blood meals to estimate utilization of different avian host species by Culex mosquitoes, and relate utilization by these malaria vectors to avian Plasmodium prevalence. We found that avian host species that are highly utilized as hosts by avian malaria vectors are significantly more likely to have Plasmodium infections. However, the effect was not consistent among individual Plasmodium taxa. Exposure to vector bites may therefore influence the relative number of all avian Plasmodium infections among host species, while other processes, such as parasite competition and host-parasite coevolution, delimit the host distributions of individual Plasmodium species. We demonstrate that links between avian malaria susceptibility and host traits can be conditioned by patterns of exposure to vectors. Linking vector utilization rates to host traits may be a key area of future research to understand mechanisms that produce variation in the prevalence of vector-borne pathogens among host species.

  8. Zoospore chemotaxis of closely related legume‐root infecting Phytophthora species towards host isoflavones

    National Research Council Canada - National Science Library

    Hosseini, S; Heyman, F; Olsson, U; Broberg, A; Funck Jensen, D; Karlsson, M

    2014-01-01

    .... Phytophthora niederhauserii is considered to have a broad host range. Zoospores of some P hytophthora species are chemotactically attracted to the isoflavones that are secreted by their host plants...

  9. Host species and developmental stage, but not host social structure, affects bacterial community structure in socially polymorphic bees.

    Science.gov (United States)

    McFrederick, Quinn S; Wcislo, William T; Hout, Michael C; Mueller, Ulrich G

    2014-05-01

    Social transmission and host developmental stage are thought to profoundly affect the structure of bacterial communities associated with honey bees and bumble bees, but these ideas have not been explored in other bee species. The halictid bees Megalopta centralis and M. genalis exhibit intrapopulation social polymorphism, which we exploit to test whether bacterial communities differ by host social structure, developmental stage, or host species. We collected social and solitary Megalopta nests and sampled bees and nest contents from all stages of host development. To survey these bacterial communities, we used 16S rRNA gene 454 pyrosequencing. We found no effect of social structure, but found differences by host species and developmental stage. Wolbachia prevalence differed between the two host species. Bacterial communities associated with different developmental stages appeared to be driven by environmentally acquired bacteria. A Lactobacillus kunkeei clade bacterium that is consistently associated with other bee species was dominant in pollen provisions and larval samples, but less abundant in mature larvae and pupae. Foraging adults appeared to often reacquire L. kunkeei clade bacteria, likely while foraging at flowers. Environmental transmission appears to be more important than social transmission for Megalopta bees at the cusp between social and solitary behavior. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  10. Microenvironment in the canopy rivals the host tree water status in controlling sap flow of a mistletoe species.

    Science.gov (United States)

    Yang, Da; Goldstein, Guillermo; Wang, Miao; Zhang, Wei-Wei; Wang, Ai-Ying; Liu, Yan-Yan; Hao, Guang-You

    2017-04-01

    Mistletoes absorb water from the vascular system of their hosts and thus the water use of mistletoes can be influenced by the water status of their hosts besides abiotic environmental conditions; however, there is a lack of studies on the dynamics of mistletoe water utilization in relation to both types of controlling factors. By building a canopy platform at 20 m above the ground, we monitored the dynamic changes of sap flow of Viscum coloratum (Kom.) Nakai (Loranthaceae) in combination with continuous measurements of microclimatic variables and volumetric water content (VWC) of its host tree branch xylem. We found that the host tree VWC exhibited substantial fluctuations during sunny days but lower VWC of the host did not negatively affect the sap flow of V. coloratum. Hourly and daily mean transpiration rates (Esap) of V. coloratum calculated from sap flow measurements showed strong positive correlations with photosynthetic photon flux density (PPFD) and vapor pressure deficit (VPD) measured in close vicinity to the point of mistletoe attachment. The mean Esap of V. coloratum was substantially higher than that of their host during clear days (4.55 ± 0.54 vs 2.01 ± 0.15 kg m-2 day-1). Moreover, the mistletoe-to-host transpiration ratio was not constant but became increasingly larger with the increase of PPFD or VPD on both hourly and daily bases, suggesting a weaker control of water loss in the mistletoe in comparison to its host species. The strong dependence of mistletoe Esap on micrometeorological variables and its decoupling from the host tree xylem water status suggests that the development of dense tree canopy functions as a potential mechanism for the host trees in reducing the competitive water use of mistletoes. These findings have important implications for the interactions between mistletoe species and their host trees in temperate forests. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email

  11. Covariance in species diversity and facilitation among non-interactive parasite taxa: all against the host.

    Science.gov (United States)

    Krasnov, B R; Mouillot, D; Khokhlova, I S; Shenbrot, G I; Poulin, R

    2005-10-01

    Different parasite taxa exploit different host resources and are often unlikely to interact directly. It is unclear, however, whether the diversity of any given parasite taxon is indirectly influenced by that of other parasite taxa on the same host. Some components of host immune defences may operate simultaneously against all kinds of parasites, whereas investment by the host in specific defences against one type of parasite may come at the expense of defence against other parasites. We investigated the relationships between the species diversity of 4 higher taxa of ectoparasites (fleas, sucking lice, mesostigmatid mites, and ixodid ticks), and between the species richness of ectoparasites and endoparasitic helminths, across different species of rodent hosts. Our analyses used 2 measures of species diversity, species richness and taxonomic distinctness, and controlled for the potentially confounding effects of sampling effort and phylogenetic relationships among host species. We found positive pairwise correlations between the species richness of fleas, mites and ticks; however, there was no association between species richness of any of these 3 groups and that of lice. We also found a strong positive relationship between the taxonomic distinctness of ecto- and endoparasite assemblages across host species. These results suggest the existence of a process of apparent facilitation among unrelated taxa in the organization of parasite communities. We propose explanations based on host immune responses, involving acquired cross-resistance to infection and interspecific variation in immunocompetence among hosts, to account for these patterns.

  12. Cophylogeny of the anther smut fungi and their caryophyllaceous hosts: Prevalence of host shifts and importance of delimiting parasite species for inferring cospeciation

    Directory of Open Access Journals (Sweden)

    Yockteng Roxana

    2008-03-01

    Full Text Available Abstract Background Using phylogenetic approaches, the expectation that parallel cladogenesis should occur between parasites and hosts has been validated in some studies, but most others provided evidence for frequent host shifts. Here we examine the evolutionary history of the association between Microbotryum fungi that cause anther smut disease and their Caryophyllaceous hosts. We investigated the congruence between host and parasite phylogenies, inferred cospeciation events and host shifts, and assessed whether geography or plant ecology could have facilitated the putative host shifts identified. For cophylogeny analyses on microorganisms, parasite strains isolated from different host species are generally considered to represent independent evolutionary lineages, often without checking whether some strains actually belong to the same generalist species. Such an approach may mistake intraspecific nodes for speciation events and thus bias the results of cophylogeny analyses if generalist species are found on closely related hosts. A second aim of this study was therefore to evaluate the impact of species delimitation on the inferences of cospeciation. Results We inferred a multiple gene phylogeny of anther smut strains from 21 host plants from several geographic origins, complementing a previous study on the delimitation of fungal species and their host specificities. We also inferred a multi-gene phylogeny of their host plants, and the two phylogenies were compared. A significant level of cospeciation was found when each host species was considered to harbour a specific parasite strain, i.e. when generalist parasite species were not recognized as such. This approach overestimated the frequency of cocladogenesis because individual parasite species capable of infecting multiple host species (i.e. generalists were found on closely related hosts. When generalist parasite species were appropriately delimited and only a single representative of

  13. Codivergence and multiple host species use by fig wasp populations of the Ficus pollination mutualism

    Directory of Open Access Journals (Sweden)

    McLeish Michael J

    2012-01-01

    Full Text Available Abstract Background The interaction between insects and plants takes myriad forms in the generation of spectacular diversity. In this association a species host range is fundamental and often measured using an estimate of phylogenetic concordance between species. Pollinating fig wasps display extreme host species specificity, but the intraspecific variation in empirical accounts of host affiliation has previously been underestimated. In this investigation, lineage delimitation and codiversification tests are used to generate and discuss hypotheses elucidating on pollinating fig wasp associations with Ficus. Results Statistical parsimony and AMOVA revealed deep divergences at the COI locus within several pollinating fig wasp species that persist on the same host Ficus species. Changes in branching patterns estimated using the generalized mixed Yule coalescent test indicated lineage duplication on the same Ficus species. Conversely, Elisabethiella and Alfonsiella fig wasp species are able to reproduce on multiple, but closely related host fig species. Tree reconciliation tests indicate significant codiversification as well as significant incongruence between fig wasp and Ficus phylogenies. Conclusions The findings demonstrate more relaxed pollinating fig wasp host specificity than previously appreciated. Evolutionarily conservative host associations have been tempered by horizontal transfer and lineage duplication among closely related Ficus species. Independent and asynchronistic diversification of pollinating fig wasps is best explained by a combination of both sympatric and allopatric models of speciation. Pollinator host preference constraints permit reproduction on closely related Ficus species, but uncertainty of the frequency and duration of these associations requires better resolution.

  14. Expression differences in Aphidius ervi (Hymenoptera: Braconidae) females reared on different aphid host species.

    Science.gov (United States)

    Ballesteros, Gabriel I; Gadau, Jürgen; Legeai, Fabrice; Gonzalez-Gonzalez, Angelica; Lavandero, Blas; Simon, Jean-Christophe; Figueroa, Christian C

    2017-01-01

    The molecular mechanisms that allow generalist parasitoids to exploit many, often very distinct hosts are practically unknown. The wasp Aphidius ervi, a generalist koinobiont parasitoid of aphids, was introduced from Europe into Chile in the late 1970s to control agriculturally important aphid species. A recent study showed significant differences in host preference and host acceptance (infectivity) depending on the host A. ervi were reared on. In contrast, no genetic differentiation between A. ervi populations parasitizing different aphid species and aphids of the same species reared on different host plants was found in Chile. Additionally, the same study did not find any fitness effects in A. ervi if offspring were reared on a different host as their mothers. Here, we determined the effect of aphid host species (Sitobion avenae versus Acyrthosiphon pisum reared on two different host plants alfalfa and pea) on the transcriptome of adult A. ervi females. We found a large number of differentially expressed genes (between host species: head: 2,765; body: 1,216; within the same aphid host species reared on different host plants: alfalfa versus pea: head 593; body 222). As expected, the transcriptomes from parasitoids reared on the same host species (pea aphid) but originating from different host plants (pea versus alfalfa) were more similar to each other than the transcriptomes of parasitoids reared on a different aphid host and host plant (head: 648 and 1,524 transcripts; body: 566 and 428 transcripts). We found several differentially expressed odorant binding proteins and olfactory receptor proteins in particular, when we compared parasitoids from different host species. Additionally, we found differentially expressed genes involved in neuronal growth and development as well as signaling pathways. These results point towards a significant rewiring of the transcriptome of A. ervi depending on aphid-plant complex where parasitoids develop, even if different biotypes

  15. Implicating roles of animal reservoir hosts in the resurgence of ...

    African Journals Online (AJOL)

    This paper reviews recent evidences based on molecular and other biotechnologies leading to the identification of mammalian hosts as reservoirs of T. b. gambiense and the roles of such hosts in transmission and resurgence of sleeping sickness in sub-Saharan Africa. African Journal of Biotechnology Vol. 4 (2), pp.

  16. Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize

    OpenAIRE

    Jordaan, Elizabeth M.; De Waele, D.

    1988-01-01

    The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae inf...

  17. Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) use of Opuntia host species in Argentina

    Science.gov (United States)

    A central aspect in biology and ecology is to determine the combination of factors that influence the distribution of species. In the case of herbivorous insects, the distribution of herbivorous species is necessarily associated with their host plants, a pattern often referred to as “host use”. Nove...

  18. Gene expression plasticity across hosts of an invasive scale insect species

    DEFF Research Database (Denmark)

    Christodoulides, Nicholas; Van Dam, Alex; Peterson, Daniel A.

    2017-01-01

    For plant-eating insects, we still have only a nascent understanding of the genetic basis of host-use promiscuity. Here, to improve that situation, we investigated host-induced gene expression plasticity in the invasive lobate lac scale insect, Paratachardina pseudolobata (Hemiptera: Keriidae). We...... of several recently published studies of other plant-eating insect species. Thus, across plant-eating insect species, there may be a common set of gene expression changes that enable host-use promiscuity....

  19. Still a host of hosts for Wolbachia: analysis of recent data suggests that 40% of terrestrial arthropod species are infected.

    Directory of Open Access Journals (Sweden)

    Roman Zug

    Full Text Available Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated the infection frequency of Wolbachia among arthropod hosts to be 66%. At the same time, the authors of this analysis highlighted some weaknesses of the underlying data and concluded that in order to improve the estimate, a larger number of individuals per species should be assayed and species be chosen more randomly. Here we apply the statistical approach to a more appropriate data set from a recent survey that tested both a broad range of species and a sufficient number of individuals per species. Indeed, we find a substantially different infection frequency: We now estimate the proportion of Wolbachia-infected species to be around 40% which is lower than the previous estimate but still points to a surprisingly high number of arthropods harboring the bacteria. Notwithstanding this difference, we confirm the previous result that, within a given species, typically most or only a few individuals are infected. Moreover, we extend our analysis to include several reproductive parasites other than Wolbachia that were also screened for in the aforementioned empirical survey. For these symbionts we find a large variation in estimated infection frequencies and corroborate the finding that Wolbachia are the most abundant endosymbionts among arthropod species.

  20. Infection of non-host model plant species with the narrow-host-range Cacao swollen shoot virus.

    Science.gov (United States)

    Friscina, Arianna; Chiappetta, Laura; Jacquemond, Mireille; Tepfer, Mark

    2017-02-01

    Cacao swollen shoot virus (CSSV) is a major pathogen of cacao (Theobroma cacao) in Africa, and long-standing efforts to limit its spread by the culling of infected trees have had very limited success. CSSV is a particularly difficult virus to study, as it has a very narrow host range, limited to several tropical tree species. Furthermore, the virus is not mechanically transmissible, and its insect vector can only be used with difficulty. Thus, the only efficient means to infect cacao plants that have been experimentally described so far are by particle bombardment or the agroinoculation of cacao plants with an infectious clone. We have genetically transformed three non-host species with an infectious form of the CSSV genome: two experimental hosts widely used in plant virology (Nicotiana tabacum and N. benthamiana) and the model species Arabidopsis thaliana. In transformed plants of all three species, the CSSV genome was able to replicate, and, in tobacco, CSSV particles could be observed by immunosorbent electron microscopy, demonstrating that the complete virus cycle could be completed in a non-host plant. These results will greatly facilitate the preliminary testing of CSSV control strategies using plants that are easy to raise and to transform genetically. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  1. Counteracting selective regimes and host preference evolution in ecotypes of two species of walking-sticks.

    Science.gov (United States)

    Sandoval, C P; Nosil, P

    2005-11-01

    The evolution of ecological specialization has been a central topic in ecology because specialized adaptations to divergent environments can result in reproductive isolation and facilitate speciation. However, the order in which different aspects of habitat adaptation and habitat preference evolve is unclear. Timema walking-stick insects feed and mate on the host plants on which they rest. Previous studies of T. cristinae ecotypes have documented divergent, host-specific selection from visual predators and the evolution of divergent host and mate preferences between populations using different host-plant species (Ceanothus or Adenostoma). Here we present new data that show that T. podura, a nonsister species of T. cristinae, has also formed ecotypes on these host genera and that in both species these ecotypes exhibit adaptive divergence in color-pattern and host preference. Color-pattern morphs exhibit survival trade-offs on different hosts due to differential predation. In contrast, fecundity trade-offs on different hosts do not occur in either species. Thus, host preference in both species has evolved before divergent physiological adaptation but in concert with morphological adaptations. Our results shed light onto which traits are involved in the initial stages of ecological specialization and ecologically based reproductive isolation.

  2. Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

    Directory of Open Access Journals (Sweden)

    QUEIROZ J. M.

    2002-01-01

    Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

  3. Seasonal changes in infection with trematode species utilizing jellyfish as hosts: evidence of transmission to definitive host fish via medusivory.

    Science.gov (United States)

    Kondo, Yusuke; Ohtsuka, Susumu; Hirabayashi, Takeshi; Okada, Shoma; Ogawa, Nanako O; Ohkouchi, Naohiko; Shimazu, Takeshi; Nishikawa, Jun

    2016-01-01

    In the Seto Inland Sea of western Japan, metacercariae of three species of trematodes, Lepotrema clavatum Ozaki, 1932, Cephalolepidapedon saba Yamaguti, 1970, and Opechona olssoni (Yamaguti, 1934), were found in the mesoglea of the jellyfish Aurelia aurita s.l., Chrysaora pacifica, and Cyanea nozakii. Moreover, these jellyfish frequently harbored juveniles of the fish species Psenopsis anomala, Thamnaconus modestus, and Trachurus japonicus. The former two fish species are well-known medusivores. We investigated seasonal changes in the prevalence and intensity of these metacercariae in their host jellyfish from March 2010 to September 2012 and presumed that infection by the trematodes of the definitive host fish occurs through these associations. The mean intensity of metacercariae in A. aurita s.l. clearly showed seasonality, being consistently high in June of each year. The intensity of metacercariae in C. nozakii was highest among all jellyfish hosts and appeared to be enhanced by medusivory of this second intermediate, and/or paratenic host. Trophic interactions between jellyfish and associated fish were verified using both gut content and stable isotope analyses. The detection of trematodes and nematocysts in the guts of P. anomala and T. modestus juveniles, in addition to stable isotope analysis, suggests that transmission of the parasites occurs via prey-predator relationships. In addition, the stable isotope analysis also suggested that P. anomala is more nutritionally dependent on jellyfish than Th. modestus and Tr. japonicus. © Y. Kondo et al., published by EDP Sciences, 2016.

  4. Cross-Species Virus-Host Protein-Protein Interactions Inhibiting Innate Immunity

    Science.gov (United States)

    2016-07-01

    virus families with know or suspected histories of changes in host-species tropism from animal to humans. In the Paramyxoviridae family, Hendra ...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-79 Cross-species virus -host...Cross-species virus -host protein-protein interactions inhibiting innate immunity What are the major goals of the project? List the major goals of

  5. Considering extinction of dependent species during translocation, ex situ conservation, and assisted migration of threatened hosts.

    Science.gov (United States)

    Moir, Melinda L; Vesk, Peter A; Brennan, Karl E C; Poulin, Robert; Hughes, Lesley; Keith, David A; McCarthy, Michael A; Coates, David J

    2012-04-01

    Translocation, introduction, reintroduction, and assisted migrations are species conservation strategies that are attracting increasing attention, especially in the face of climate change. However, preventing the extinction of the suite of dependent species whose host species are threatened is seldom considered, and the effects on dependent species of moving threatened hosts are unclear. There is no published guidance on how to decide whether to move species, given this uncertainty. We examined the dependent-host system of 4 disparate taxonomic groups: insects on the feather-leaf banksia (Banksia brownii), montane banksia (B. montana), and Stirling Range beard heath (Leucopogon gnaphalioides); parasites of wild cats; mites and ticks on Duvaucel's gecko (Hoplodactylus duvaucelii) and tuatara (Sphenodon punctatus); and internal coccidian parasites of Cirl Bunting (Emberiza cirlus) and Hihi (Notiomystis cincta). We used these case studies to demonstrate a simple process for use in species- and community-level assessments of efforts to conserve dependents with their hosts. The insects dependent on Stirling Range beard heath and parasites on tigers (Panthera tigris) appeared to represent assemblages that would not be conserved by ex situ host conservation. In contrast, for the cases of dependent species we examined involving a single dependent species (internal parasites of birds and the mite Geckobia naultina on Duvaucel's gecko), ex situ conservation of the host species would also conserve the dependent species. However, moving dependent species with their hosts may be insufficient to maintain viable populations of the dependent species, and additional conservation strategies such as supplementing populations may be needed. ©2012 Society for Conservation Biology.

  6. Host-related genetic differentiation in the anther smut fungus Microbotryum violaceum in sympatric, parapatric and allopatric populations of two host species Silene latifolia and S-dioica

    NARCIS (Netherlands)

    Van Putten, WF; Biere, A; Van Damme, JMM

    We investigated genetic diversity in West European populations of the fungal pathogen Microbotryum violaceum in sympatric, parapatric and allopatric populations of the host species Silene latifolia and S. dioica, using four polymorphic microsatellite loci. In allopatric host populations, the fungus

  7. Host-related genetic differentiation in the anther smut fungus Microbotryum violaceum in sympatric, parapatric and allopatric populations of two host species Silene latifolia and S. dioica

    NARCIS (Netherlands)

    Van Putten, W.F.; Biere, A.; Van Damme, J.M.M.

    2005-01-01

    We investigated genetic diversity in West European populations of the fungal pathogen Microbotryum violaceum in sympatric, parapatric and allopatric populations of the host species Silene latifolia and S. dioica, using four polymorphic microsatellite loci. In allopatric host populations, the fungus

  8. Tumor - host immune interactions in Ewing sarcoma : implications for therapy

    NARCIS (Netherlands)

    Berghuis, Dagmar

    2012-01-01

    In this thesis, we report on various aspects of tumor - host (immune) interactions in Ewing sarcoma patients with the aim to obtain leads for immunotherapeutic or targeted treatment strategies. We demonstrate a key role for interferon gamma (IFNg) in enhancing both Ewing sarcoma immunogenicity and

  9. CONDITIONS FOR COEXISTENCE OF FRESHWATER MUSSEL SPECIES VIA PARTITIONING OF FISH HOST RESOURCES

    Science.gov (United States)

    Riverine freshwater mussel species can be found in highly diverse communities where many similar species coexist. Mussel species potentially compete for food and space as adults, and for fish host resources during the larval (glochidial) stage. Resource partitioning at the larv...

  10. KEY TO THE POWDERY MILDEW SPECIES ON THE BASIS OF THE HOST PLANT FAMILIES AND GENERA

    Directory of Open Access Journals (Sweden)

    E. V. Rakhimova

    2015-05-01

    Full Text Available Key on the basis of the host plant taxonomy, symptoms of the infected plants and microscopic features of fungi was composed for identification of powdery mildews of the Kazakhstan. Features, which were used for identification of fungus, were the number of asci in cleistothecium, the number of ascospores in ascus and the type of appendages of cleistothecium. Key was composed for 81 species and 25 variations of Erysiphales fungi, infecting 739 species of host plants, which belong to 305 genera.

  11. Hybridization between two cestode species and its consequences for intermediate host range

    Directory of Open Access Journals (Sweden)

    Henrich Tina

    2013-02-01

    Full Text Available Abstract Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii, both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively. Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  12. Hybridization between two cestode species and its consequences for intermediate host range.

    Science.gov (United States)

    Henrich, Tina; Benesh, Daniel P; Kalbe, Martin

    2013-02-07

    Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F(1) hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii), both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively). We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  13. Padus serotina (Rosaceae, a new host plant for some species of parasitic microfungi

    Directory of Open Access Journals (Sweden)

    Nałgorzata Ruszkiewicz-Michalska

    2014-08-01

    Full Text Available Four species of parasitic microfungi were collected recenUy on Padus serotina (Ehrh. Borkh. (Rosaceae in Poland. Three species, Phyllactina guttata (Wallr. ex Fr. Lév. (Erysiphales, Monilia linhartiana Sacc. (Hyphomycetes, and Microsphaeropsis olivacea (Bonord. Höhn. (Coelomycetes, have not been reported before on thc plant, and Padus serotina is a new host for them. Monnilia linhartiana Sacc. is a new species for Poland. The fourth species, Podosphaera tridactyla (Wallr. de Baly var. tridactyla (Erysiphales, is known only from three localities in Europe, and has been collected on the host plant in Poland for the first time.

  14. Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae) Driven by Geographical Isolation and Host Plant Acquirement

    Science.gov (United States)

    Zhang, Ruiling; Huang, Xiaolei; Jiang, Liyun; Lei, Fumin; Qiao, Gexia

    2012-01-01

    The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP) and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families) and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI) and Cytochrome b (Cytb) genes, the nuclear elongation factor-1α (EF-1α) gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago)), Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya) was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall, it can be concluded that geographical isolation and the expansion of the host plant range may be the main factors driving species differentiation of Mollitrichosiphum. PMID:22949873

  15. Monogenean parasite species descriptions from Labeo spp. hosts in ...

    African Journals Online (AJOL)

    Specimens of Labeo capensis (n = 13) and Labeo umbratus (n = 26) from the Vaal Dam (South Africa) were collected and examined for gill and skin monogenean parasites. Three new Dactylogyrus and one new Dogielius species are described. Dactylogyrus iwani n.sp. (longer inner root on anchor and predominates on L.

  16. Characterization of Arabidopsis Transcriptional Responses to Different Aphid Species Reveals Genes that Contribute to Host Susceptibility and Non-host Resistance

    Science.gov (United States)

    Jaouannet, Maëlle; Morris, Jenny A.; Hedley, Peter E.; Bos, Jorunn I. B.

    2015-01-01

    Aphids are economically important pests that display exceptional variation in host range. The determinants of diverse aphid host ranges are not well understood, but it is likely that molecular interactions are involved. With significant progress being made towards understanding host responses upon aphid attack, the mechanisms underlying non-host resistance remain to be elucidated. Here, we investigated and compared Arabidopsis thaliana host and non-host responses to aphids at the transcriptional level using three different aphid species, Myzus persicae, Myzus cerasi and Rhopalosiphum pisum. Gene expression analyses revealed a high level of overlap in the overall gene expression changes during the host and non-host interactions with regards to the sets of genes differentially expressed and the direction of expression changes. Despite this overlap in transcriptional responses across interactions, there was a stronger repression of genes involved in metabolism and oxidative responses specifically during the host interaction with M. persicae. In addition, we identified a set of genes with opposite gene expression patterns during the host versus non-host interactions. Aphid performance assays on Arabidopsis mutants that were selected based on our transcriptome analyses identified novel genes contributing to host susceptibility, host defences during interactions with M. persicae as well to non-host resistance against R. padi. Understanding how plants respond to aphid species that differ in their ability to infest plant species, and identifying the genes and signaling pathways involved, is essential for the development of novel and durable aphid control in crop plants. PMID:25993686

  17. Characterization of Arabidopsis Transcriptional Responses to Different Aphid Species Reveals Genes that Contribute to Host Susceptibility and Non-host Resistance.

    Directory of Open Access Journals (Sweden)

    Maëlle Jaouannet

    2015-05-01

    Full Text Available Aphids are economically important pests that display exceptional variation in host range. The determinants of diverse aphid host ranges are not well understood, but it is likely that molecular interactions are involved. With significant progress being made towards understanding host responses upon aphid attack, the mechanisms underlying non-host resistance remain to be elucidated. Here, we investigated and compared Arabidopsis thaliana host and non-host responses to aphids at the transcriptional level using three different aphid species, Myzus persicae, Myzus cerasi and Rhopalosiphum pisum. Gene expression analyses revealed a high level of overlap in the overall gene expression changes during the host and non-host interactions with regards to the sets of genes differentially expressed and the direction of expression changes. Despite this overlap in transcriptional responses across interactions, there was a stronger repression of genes involved in metabolism and oxidative responses specifically during the host interaction with M. persicae. In addition, we identified a set of genes with opposite gene expression patterns during the host versus non-host interactions. Aphid performance assays on Arabidopsis mutants that were selected based on our transcriptome analyses identified novel genes contributing to host susceptibility, host defences during interactions with M. persicae as well to non-host resistance against R. padi. Understanding how plants respond to aphid species that differ in their ability to infest plant species, and identifying the genes and signaling pathways involved, is essential for the development of novel and durable aphid control in crop plants.

  18. Host-parasite interactions: Marine bivalve molluscs and protozoan parasites, Perkinsus species.

    Science.gov (United States)

    Soudant, Philippe; E Chu, Fu-Lin; Volety, Aswani

    2013-10-01

    This review assesses and examines the work conducted to date concerning host and parasite interactions between marine bivalve molluscs and protozoan parasites, belonging to Perkinsus species. The review focuses on two well-studied host-parasite interaction models: the two clam species, Ruditapes philippinarum and R. decussatus, and the parasite Perkinsus olseni, and the eastern oyster, Crassostrea virginica, and the parasite Perkinsus marinus. Cellular and humoral defense responses of the host in combating parasitic infection, the mechanisms (e.g., antioxidant enzymes, extracellular products) employed by the parasite in evading host defenses as well as the role of environmental factors in modulating the host-parasite interactions are described. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. No Effect of Host Species on Phenoloxidase Activity in a Mycophagous Beetle.

    Directory of Open Access Journals (Sweden)

    Vincent Formica

    Full Text Available Ecological immunology is an interdisciplinary field that helps elucidate interactions between the environment and immune response. The host species individuals experience have profound effects on immune response in many species of insects. However, this conclusion comes from studies of herbivorous insects even though species of mycophagous insects also inhabit many different host species. The goal of this study was to determine if fungal host species as well as individual, sex, body size, and host patch predict one aspect of immune function, phenoloxidase activity (PO. We sampled a metapopulation of Bolitotherus cornutus, a mycophagous beetle in southwestern Virginia. B. cornutus live on three species of fungus that differ in nutritional quality, social environment, and density. A filter paper phenoloxidase assay was used to quantify phenoloxidase activity. Overall, PO activity was significantly repeatable among individuals (0.57 in adult B. cornutus. While there was significant variance among individuals in PO activity, there were surprisingly no significant differences in PO activity among subpopulations, beetles living on different host species, or between the sexes; there was also no effect of body size. Our results suggest that other factors such as age, genotype, disease prevalence, or natal environment may be generating variance among individuals in PO activity.

  20. Do host species evolve a specific response to slave-making ants?

    Directory of Open Access Journals (Sweden)

    Delattre Olivier

    2012-12-01

    Full Text Available Abstract Background Social parasitism is an important selective pressure for social insect species. It is particularly the case for the hosts of dulotic (so called slave-making ants, which pillage the brood of host colonies to increase the worker force of their own colony. Such raids can have an important impact on the fitness of the host nest. An arms race which can lead to geographic variation in host defenses is thus expected between hosts and parasites. In this study we tested whether the presence of a social parasite (the dulotic ant Myrmoxenus ravouxi within an ant community correlated with a specific behavioral defense strategy of local host or non-host populations of Temnothorax ants. Social recognition often leads to more or less pronounced agonistic interactions between non-nestmates ants. Here, we monitored agonistic behaviors to assess whether ants discriminate social parasites from other ants. It is now well-known that ants essentially rely on cuticular hydrocarbons to discriminate nestmates from aliens. If host species have evolved a specific recognition mechanism for their parasite, we hypothesize that the differences in behavioral responses would not be fully explained simply by quantitative dissimilarity in cuticular hydrocarbon profiles, but should also involve a qualitative response due to the detection of particular compounds. We scaled the behavioral results according to the quantitative chemical distance between host and parasite colonies to test this hypothesis. Results Cuticular hydrocarbon profiles were distinct between species, but host species did not show a clearly higher aggression rate towards the parasite than toward non-parasite intruders, unless the degree of response was scaled by the chemical distance between intruders and recipient colonies. By doing so, we show that workers of the host and of a non-host species in the parasitized site displayed more agonistic behaviors (bites and ejections towards parasite

  1. Drivers of variation in species impacts for a multi-host fungal disease of bats.

    Science.gov (United States)

    Langwig, Kate E; Frick, Winifred F; Hoyt, Joseph R; Parise, Katy L; Drees, Kevin P; Kunz, Thomas H; Foster, Jeffrey T; Kilpatrick, A Marm

    2016-12-05

    Disease can play an important role in structuring species communities because the effects of disease vary among hosts; some species are driven towards extinction, while others suffer relatively little impact. Why disease impacts vary among host species remains poorly understood for most multi-host pathogens, and factors allowing less-susceptible species to persist could be useful in conserving highly affected species. White-nose syndrome (WNS), an emerging fungal disease of bats, has decimated some species while sympatric and closely related species have experienced little effect. We analysed data on infection prevalence, fungal loads and environmental factors to determine how variation in infection among sympatric host species influenced the severity of WNS population impacts. Intense transmission resulted in almost uniformly high prevalence in all species. By contrast, fungal loads varied over 3 orders of magnitude among species, and explained 98% of the variation among species in disease impacts. Fungal loads increased with hibernating roosting temperatures, with bats roosting at warmer temperatures having higher fungal loads and suffering greater WNS impacts. We also found evidence of a threshold fungal load, above which the probability of mortality may increase sharply, and this threshold was similar for multiple species. This study demonstrates how differences in behavioural traits among species-in this case microclimate preferences-that may have been previously adaptive can be deleterious after the introduction of a new pathogen. Management to reduce pathogen loads rather than exposure may be an effective way of reducing disease impact and preventing species extinctions.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  2. Phylogenetic and chemotypic diversity of Periglandula species in eight new morning glory hosts (Convolvulaceae).

    Science.gov (United States)

    Beaulieu, Wesley T; Panaccione, Daniel G; Ryan, Katy L; Kaonongbua, Wittaya; Clay, Keith

    2015-01-01

    Periglandula ipomoeae and P. turbinae (Ascomycota, Clavicipitaceae) are recently described fungi that form symbiotic associations with the morning glories (Convolvulaceae) Ipomoea asarifolia and Turbina corymbosa, respectively. These Periglandula species are vertically transmitted and produce bioactive ergot alkaloids in seeds of infected plants and ephemeral mycelia on the adaxial surface of young leaves. Whether other morning glories that contain ergot alkaloids also are infected by Periglandula fungi is a central question. Here we report on a survey of eight species of Convolvulaceae (Argyreia nervosa, I. amnicola, I. argillicola, I. gracilis, I. hildebrandtii, I. leptophylla, I. muelleri, I. pes-caprae) for ergot alkaloids in seeds and associated clavicipitaceous fungi potentially responsible for their production. All host species contained ergot alkaloids in four distinct chemotypes with concentrations of 15.8-3223.0 μg/g. Each chemotype was a combination of four or five ergot alkaloids out of seven alkaloids detected across all hosts. In addition, each host species exhibited characteristic epiphytic mycelia on adaxial surfaces of young leaves with considerable interspecific differences in mycelial density. We sequenced three loci from fungi infecting each host: the nuclear rDNA internal transcribed spacer region (ITS), introns of the translation factor 1-α gene (tefA) and the dimethylallyl-tryptophan synthase gene (dmaW), which codes for the enzyme that catalyzes the first step in ergot alkaloid biosynthesis. Phylogenetic analyses confirmed that these fungi are in the family Clavicipitaceae and form a monophyletic group with the two described Periglandula species. This study is the first to report Periglandula spp. from Asian, Australian, African and North American species of Convolvulaceae, including host species with a shrub growth form and host species occurring outside of the tropics. This study demonstrates that ergot alkaloids in morning glories

  3. Digenean parasites of Chinese marine fishes: a list of species, hosts and geographical distribution.

    Science.gov (United States)

    Liu, Sheng-fa; Peng, Wen-feng; Gao, Peng; Fu, Ming-jun; Wu, Han-zhou; Lu, Ming-ke; Gao, Ji-qing; Xiao, Jun

    2010-01-01

    In the literature, 630 species of Digenea (Trematoda) have been reported from Chinese marine fishes. These belong to 209 genera and 35 families. The names of these species, along with their hosts, geographical distribution and records, are listed in this paper.

  4. Genetic analysis of larval host-plant preference in two sibling species of Helicoverpa

    NARCIS (Netherlands)

    Tang, Q.B.; Jiang, J.W.; Yan, Y.H.; Loon, van J.J.A.; Wang, C.Z.

    2006-01-01

    The genetic basis of larval host-plant preference was investigated in reciprocal F1, F2, and backcrossed generations derived from hybrid crosses between the generalist species Helicoverpa armigera (Hu¿bner) and the closely related specialist species Helicoverpa assulta (Guene¿e) (Lepidoptera:

  5. How do PrPSc Prions Spread between Host Species, and within Hosts?

    Directory of Open Access Journals (Sweden)

    Neil A. Mabbott

    2017-11-01

    Full Text Available Prion diseases are sub-acute neurodegenerative diseases that affect humans and some domestic and free-ranging animals. Infectious prion agents are considered to comprise solely of abnormally folded isoforms of the cellular prion protein known as PrPSc. Pathology during prion disease is restricted to the central nervous system where it causes extensive neurodegeneration and ultimately leads to the death of the host. The first half of this review provides a thorough account of our understanding of the various ways in which PrPSc prions may spread between individuals within a population, both horizontally and vertically. Many natural prion diseases are acquired peripherally, such as by oral exposure, lesions to skin or mucous membranes, and possibly also via the nasal cavity. Following peripheral exposure, some prions accumulate to high levels within the secondary lymphoid organs as they make their journey from the site of infection to the brain, a process termed neuroinvasion. The replication of PrPSc prions within secondary lymphoid organs is important for their efficient spread to the brain. The second half of this review describes the key tissues, cells and molecules which are involved in the propagation of PrPSc prions from peripheral sites of exposure (such as the lumen of the intestine to the brain. This section also considers how additional factors such as inflammation and aging might influence prion disease susceptibility.

  6. How do PrPScPrions Spread between Host Species, and within Hosts?

    Science.gov (United States)

    Mabbott, Neil A

    2017-11-24

    Prion diseases are sub-acute neurodegenerative diseases that affect humans and some domestic and free-ranging animals. Infectious prion agents are considered to comprise solely of abnormally folded isoforms of the cellular prion protein known as PrP Sc . Pathology during prion disease is restricted to the central nervous system where it causes extensive neurodegeneration and ultimately leads to the death of the host. The first half of this review provides a thorough account of our understanding of the various ways in which PrP Sc prions may spread between individuals within a population, both horizontally and vertically. Many natural prion diseases are acquired peripherally, such as by oral exposure, lesions to skin or mucous membranes, and possibly also via the nasal cavity. Following peripheral exposure, some prions accumulate to high levels within the secondary lymphoid organs as they make their journey from the site of infection to the brain, a process termed neuroinvasion. The replication of PrP Sc prions within secondary lymphoid organs is important for their efficient spread to the brain. The second half of this review describes the key tissues, cells and molecules which are involved in the propagation of PrP Sc prions from peripheral sites of exposure (such as the lumen of the intestine) to the brain. This section also considers how additional factors such as inflammation and aging might influence prion disease susceptibility.

  7. Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae).

    Science.gov (United States)

    Zhou, Mei-Jiao; Xiao, Jin-Hua; Bian, Sheng-Nan; Li, Yan-Wei; Niu, Li-Ming; Hu, Hao-Yuan; Wu, Wen-Shan; Murphy, Robert W; Huang, Da-Wei

    2012-07-01

    Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching. © 2012 Blackwell Publishing Ltd.

  8. Host Life History Strategy, Species Diversity, and Habitat Influence Trypanosoma cruzi Vector Infection in Changing Landscapes

    Science.gov (United States)

    Gottdenker, Nicole L.; Chaves, Luis Fernando; Calzada, José E.; Saldaña, Azael; Carroll, C. Ronald

    2012-01-01

    Background Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. Methodology/Principal Findings R. pallescens vectors (N = 643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site. Conclusions/Significance In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially

  9. Host life history strategy, species diversity, and habitat influence Trypanosoma cruzi vector infection in Changing landscapes.

    Directory of Open Access Journals (Sweden)

    Nicole L Gottdenker

    Full Text Available Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama.R. pallescens vectors (N = 643 were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3% vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3% dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as r(max, the maximum intrinsic rate of population increase, and habitat type (forest fragments and peridomiciliary sites were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of r(max were positively associated with higher vector infection rate at a site.In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially by changing host community structure to favor hosts

  10. Climate driven range divergence among host species affects range-wide patterns of parasitism

    Directory of Open Access Journals (Sweden)

    Richard E. Feldman

    2017-01-01

    Full Text Available Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study, we tested whether the climate driven species range shift of Odocoileus virginianus (white-tailed deer accounts for predicted changes in parasitism of two other species from the family Cervidae, Alces alces (moose and Rangifer tarandus (caribou, in North America. We used MaxEnt models to predict the recent (2000 and future (2050 ranges (probabilities of occurrence of the cervids and a parasite Parelaphostrongylus tenuis (brainworm taking into account range shifts of the parasite’s intermediate gastropod hosts. Our models predicted that range overlap between A. alces/R. tarandus and P. tenuis will decrease between 2000 and 2050, an outcome that reflects decreased overlap between A. alces/R. tarandus and O. virginianus and not the parasites, themselves. Geographically, our models predicted increasing potential occurrence of P. tenuis where A. alces/R. tarandus are likely to decline, but minimal spatial overlap where A. alces/R. tarandus are likely to increase. Thus, parasitism may exacerbate climate-mediated southern contraction of A. alces and R. tarandus ranges but will have limited influence on northward range expansion. Our results suggest that the spatial dynamics of one host species may be the driving force behind future rates of parasitism for another host species.

  11. Definitive hosts of a fatal Versteria species (Cestoda: Taeniidae) in North America

    Science.gov (United States)

    We previously reported fatal metacestode infection in a captive orangutan (Pongo pygmaeus) with a novel taeniid tapeworm, Versteria sp. Data from ermine (Mustela erminea) and mink (Neovison vison) implicate mustelids as definitive North America hosts and expand known Versteria diversity. The orangu...

  12. Invasive North American bullfrogs transmit lethal fungus Batrachochytrium dendrobatidis infections to native amphibian host species

    OpenAIRE

    Miaud, C.; Dejean, T.; Savard, K.; Millery, A.; Valentini, A.; Gaudin, N. C. G.; Garner, T. W. J.

    2016-01-01

    Invasive species can be a threat to native species in several ways, including transmitting lethal infections caused by the parasites they carry. However, invasive species may also be plagued by novel and lethal infections they acquire when invading, making inferences regarding the ability of an invasive host to vector disease difficult from field observations of infection and disease. This is the case for the pathogenic fungus Batrachochytrium dendrobatidis (Bd) in Europe and one invasive hos...

  13. Frequent Cross-Species Transmission of Parvoviruses among Diverse Carnivore Hosts

    OpenAIRE

    Allison, Andrew B.; Kohler, Dennis J.; Fox, Karen A.; Brown, Justin D.; Gerhold, Richard W.; Shearn-Bochsler, Valerie I.; Dubovi, Edward J.; Parrish, Colin R.; Holmes, Edward C.

    2013-01-01

    Although parvoviruses are commonly described in domestic carnivores, little is known about their biodiversity in nondomestic species. A phylogenetic analysis of VP2 gene sequences from puma, coyote, gray wolf, bobcat, raccoon, and striped skunk revealed two major groups related to either feline panleukopenia virus (“FPV-like”) or canine parvovirus (“CPV-like”). Cross-species transmission was commonplace, with multiple introductions into each host species but, with the exception of raccoons, r...

  14. Yeast Communities of Diverse Drosophila Species: Comparison of Two Symbiont Groups in the Same Hosts

    Science.gov (United States)

    Eisen, Jonathan A.; Kopp, Artyom

    2012-01-01

    The combination of ecological diversity with genetic and experimental tractability makes Drosophila a powerful model for the study of animal-associated microbial communities. Despite the known importance of yeasts in Drosophila physiology, behavior, and fitness, most recent work has focused on Drosophila-bacterial interactions. In order to get a more complete understanding of the Drosophila microbiome, we characterized the yeast communities associated with different Drosophila species collected around the world. We focused on the phylum Ascomycota because it constitutes the vast majority of the Drosophila-associated yeasts. Our sampling strategy allowed us to compare the distribution and structure of the yeast and bacterial communities in the same host populations. We show that yeast communities are dominated by a small number of abundant taxa, that the same yeast lineages are associated with different host species and populations, and that host diet has a greater effect than host species on yeast community composition. These patterns closely parallel those observed in Drosophila bacterial communities. However, we do not detect a significant correlation between the yeast and bacterial communities of the same host populations. Comparative analysis of different symbiont groups provides a more comprehensive picture of host-microbe interactions. Future work on the role of symbiont communities in animal physiology, ecological adaptation, and evolution would benefit from a similarly holistic approach. PMID:22885750

  15. Gas exchange and water balance of a mistletoe species and its mangrove hosts.

    Science.gov (United States)

    Goldstein, G; Rada, F; Sternberg, L; Burguera, J L; Burguera, M; Orozco, A; Montilla, M; Zabala, O; Azocar, A; Canales, M J; Celis, A

    1989-02-01

    The gas exchange and water relations of the hemiparasite Pthirusa maritima and two its mangrove host species, Conocarpus erectus and Coccoloba uvifera, were studied in an intertidal zone of the Venezuelan coast. Carbon uptake and transpiration, leaf osmotic and total water potential, as well as nutrient content in the xylem sap and leaves of mistletoes and hosts were followed through the dry and wet season. In addition, carbon isotope ratios of leaf tissue were measured to further evaluate water use efficiency. Under similar light and humidity conditions, mistletoes had higher transpiration rates, lower leaf water potentials, and lower water use efficiencies than their hosts. Potassium content was much higher in mistletoes than in host leaves, but mineral nutrient content in the xylem sap of mistletoes was relatively low. The resistance of the liquid pathway from the soil to the leaf surface of mistletoes was larger than the total liquid flow resistance of host plants. Differences in the daily cycles of osmotic potential of the xylem sap also indicate the existence of a high resistance pathway along the vascular connection between the parasite pathway along the vascular connection between the parasite and its host. P. maritima mistletoes adjust to the different physiological characteristics of the host species which it parasitizes, thus ensuring an adequate water and carbon balance.

  16. Alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species.

    Science.gov (United States)

    Igic, Branislav; Braganza, Kim; Hyland, Margaret M; Silyn-Roberts, Heather; Cassey, Phillip; Grim, Tomas; Rutila, Jarkko; Moskát, Csaba; Hauber, Mark E

    2011-11-07

    Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, and their respective hosts. Using tools developed for materials science, we discovered a novel correlate of increased strength of parasite eggs: the common cuckoo's egg exhibits a greater microhardness, especially in the inner region of the shell matrix, relative to its host and sympatric non-host species. We then tested predictions of four potential mechanisms of shell strength: (i) increased relative thickness overall, (ii) greater proportion of the structurally harder shell layers, (iii) higher concentration of inorganic components in the shell matrix, and (iv) elevated deposition of a high density compound, MgCO(3), in the shell matrix. We confirmed support only for hypothesis (i). Eggshell characteristics did not differ between parasite eggs sampled from different host nests in distant geographical sites, suggesting an evolutionarily shared microstructural mechanism of stronger parasite eggshells across diverse host-races of brood parasitic cuckoos.

  17. Attraction of two lacewing species to volatiles produced by host plants and aphid prey

    Science.gov (United States)

    Zhu, J.; Obrycki, J. J.; Ochieng, Samuel A.; Baker, Thomas C.; Pickett, J. A.; Smiley, D.

    2005-06-01

    It is well documented that host-related odors enable many species of parasitoids and predatory insects to locate their prey and prey habitats. This study reports the first characterization of prey and prey host odor reception in two species of lacewings, Chrysoperla carnea (Say) and Chrysopa oculata L. 2-Phenylethanol, one of the volatiles emitted from their prey’s host plants (alfalfa and corn) evoked a significant EAG response from antennae of C. carnea. Traps baited with this compound attracted high numbers of adult C. carnea, which were predominantly females. One of the sex pheromone components (1R,4aS,7S,7aR)-nepetalactol of an aphid species, Acyrthosiphon pisum (Harris) attracted only C. oculata adults. Single sensillum recordings showed that the olfactory neurons of C. carnea responded to both 2-phenylethanol and aphid sex pheromone components, but those of C. oculata only responded to the latter.

  18. Stress responses in Streptococcus species and their effects on the host.

    Science.gov (United States)

    Nguyen, Cuong Thach; Park, Sang-Sang; Rhee, Dong-Kwon

    2015-11-01

    Streptococci cause a variety of diseases, such as dental caries, pharyngitis, meningitis, pneumonia, bacteremia, endocarditis, erysipelas, and necrotizing fasciitis. The natural niche of this genus of bacteria ranges from the mouth and nasopharynx to the skin, indicating that the bacteria will inevitably be subjected to environmental changes during invasion into the host, where it is exposed to the host immune system. Thus, the Streptococcus-host interaction determines whether bacteria are cleared by the host's defenses or whether they survive after invasion to cause serious diseases. If this interaction was to be deciphered, it could aid in the development of novel preventive and therapeutic agents. Streptococcus species possess many virulent factors, such as peroxidases and heat-shock proteins (HSPs), which play key roles in protecting the bacteria from hostile host environments. This review will discuss insights into the mechanism(s) by which streptococci adapt to host environments. Additionally, we will address how streptococcal infections trigger host stress responses; however, the mechanism by which bacterial components modulate host stress responses remains largely unknown.

  19. Variations in Host Preference among and within Populations of Heterodera trifolii and Related Species.

    Science.gov (United States)

    Wang, S; Riggs, R D

    1999-12-01

    Seven populations of Heterodera trifolii from Arkansas, Kentucky, Pennsylvania, and Australia plus 3 or 4 single-cyst isolates (SCI) from each population were tested for reproduction on seven species of plants to compare the host preferences among and within populations. Common lespedeza, Kummerowia striata cv. Kobe, was a good host for all populations and isolates. Therefore, a plant was considered to be a host if the number of females produced on it was 10% or more of the number on Kobe. All seven populations reproduced on Trifolium repens and T. pratense. None reproduced on Beta vulgaris or Glycine max. One single-cyst isolate from the Australian population produced a few females on T. pratense. The Australian population maintained on carnation, Dianthus caryophyllus, produced females on carnation but not on curly dock, Rumex crispus. However, its subpopulation maintained on T. repens produced females on R. crispus but not on carnation. Four of the other six populations produced females on R. crispus, and four produced females on carnation. Differences in host range were observed among seven of the mother populations and their SCI, and among isolates within each population. Five host range patterns were found in populations and SCI of H. trifolii. Significant quantitative differences occurred among populations in the numbers of females on most hosts, between isolates and their original populations, and among isolates from the same population. SCI selected from white clover produced fewer females on a series of test hosts and had host ranges the same as or narrower than those of the original populations. However, SCI selected from Kobe lespedeza had more females on some hosts and had host ranges the same as or wider than those of the original populations. The host ranges of all populations and SCI of H. trifolii were different from those of populations and SCI of race 3 of H. glycines and H. lespedezae.

  20. Food-web-based comparison of the drivers of helminth parasite species richness in coastal fish and bird definitive hosts

    NARCIS (Netherlands)

    Thieltges, D.W.; Poulin, R.

    2016-01-01

    Studies on the factors determining parasite richness in hosts are typically performedusing data compiled for various sets of species from disparate habitats. However, parasite transmissionis embedded within local trophic networks, and proper comparisons among host speciesof the drivers of parasite

  1. Diversity of Microbial Species Implicated in Keratitis: A Review

    Science.gov (United States)

    Karsten, Elisabeth; Watson, Stephanie Lousie; Foster, Leslie John Ray

    2012-01-01

    Background: Microbial keratitis is an infectious disease of the cornea characterised by inflammation and is considered an ophthalmic emergency requiring immediate attention. While a variety of pathogenic microbes associated with microbial keratitis have been identified, a comprehensive review identifying the diversity of species has not been completed. Methods: A search of peer-reviewed publications including case reports and research articles reporting microorganims implicated in keratitis was conducted. Search engines including PubMed, Scopus and Web of Science with years ranging from 1950-2012 were used. Results: 232 different species from 142 genera, representing 80 families were found to be implicated in microbial keratitis. Fungi exhibited the largest diversity with 144 species from 92 genera. In comparison, 77 species of bacteria from 42 genera, 12 species of protozoa from 4 genera and 4 types of virus were identified as the infectious agents. A comparison of their aetiologies shows reports of similarities between genera. Conclusions: The diversity of microbial species implicated in keratitis has not previously been reported and is considerably greater than suggested by incidence studies. Effective treatment is heavily reliant upon correct identification of the responsible microorganisms. Species identification, the risk factors associated with, and pathogenesis of microbial keratitis will allow the development of improved therapies. This review provides a resource for clinicians and researchers to assist in identification and readily source treatment information. PMID:23248737

  2. Host-plant species conservatism and ecology of a parasitoid fig wasp genus (Chalcidoidea; Sycoryctinae; Arachonia.

    Directory of Open Access Journals (Sweden)

    Michael J McLeish

    Full Text Available Parasitoid diversity in terrestrial ecosystems is enormous. However, ecological processes underpinning their evolutionary diversification in association with other trophic groups are still unclear. Specialisation and interdependencies among chalcid wasps that reproduce on Ficus presents an opportunity to investigate the ecology of a multi-trophic system that includes parasitoids. Here we estimate the host-plant species specificity of a parasitoid fig wasp genus that attacks the galls of non-pollinating pteromalid and pollinating agaonid fig wasps. We discuss the interactions between parasitoids and the Ficus species present in a forest patch of Uganda in context with populations in Southern Africa. Haplotype networks are inferred to examine intraspecific mitochondrial DNA divergences and phylogenetic approaches used to infer putative species relationships. Taxonomic appraisal and putative species delimitation by molecular and morphological techniques are compared. Results demonstrate that a parasitoid fig wasp population is able to reproduce on at least four Ficus species present in a patch. This suggests that parasitoid fig wasps have relatively broad host-Ficus species ranges compared to fig wasps that oviposit internally. Parasitoid fig wasps did not recruit on all available host plants present in the forest census area and suggests an important ecological consequence in mitigating fitness trade-offs between pollinator and Ficus reproduction. The extent to which parasitoid fig wasps exert influence on the pollination mutualism must consider the fitness consequences imposed by the ability to interact with phenotypes of multiple Ficus and fig wasps species, but not equally across space and time.

  3. Discrimination of the Social Parasite Ectatomma parasiticum by Its Host Sibling Species (E. tuberculatum

    Directory of Open Access Journals (Sweden)

    Renée Fénéron

    2013-01-01

    Full Text Available Among social parasites, workerless inquilines entirely depend on their host for survival and reproduction. They are usually close phylogenetic relatives of their host, which raises important questions about their evolutionary history and mechanisms of speciation at play. Here we present new findings on Ectatomma parasiticum, the only inquiline ant described in the Ectatomminae subfamily. Field data confirmed its rarity and local distribution in a facultative polygynous population of E. tuberculatum in Mexico. Genetic analyses demonstrated that the parasite is a sibling species of its host, from which it may have diverged recently. Polygyny is suggested to have favored the evolution of social parasite by sympatric speciation. Nevertheless, host workers from this population were able to discriminate parasites from their conspecifics. They treated the parasitic queens either as individuals of interest or as intruders, depending on their colonial origin, probably because of the peculiar chemical profile of the parasites and/or their reproductive status. We suggest that E. parasiticum could have conserved from its host sibling species the queen-specific substances that produce attracting and settling effect on workers, which, in return, would increase the probability to be detected. This hypothesis could explain the imperfect social integration of the parasite into host colonies.

  4. Host-parasite interaction between crustaceans of six fish species from the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Huann Carllo Gentil Vasconcelos

    2016-07-01

    Full Text Available Host-parasite interactions between crustaceans and six fish species (Psectrogaster falcata, Ageneiosus ucayalensis, Acestrorhynchus falcirostris, Hemiodus unimaculatus, Serrasalmus gibbus and Geophagus proximus from a reservoir in eastern Amazon, northern Brazil, were investigated. Eight hundred and seventy-eight parasites belonging to three crustacean species, Excorallana berbicensis, Argulus chicomendesi and Ergasilus turucuyus, which parasitized the hosts’ mouth, gills and tegument, were collected from 295 fish and examined. High infestation levels were caused by E. berbicensis on the body surface of the hosts. Excorallana berbicensis showed aggregate dispersion, except in S. gibbus, while E. turucuyus showed random dispersion in A. falcirostris. The host’s sex did not influence infestation by E. berbicensis, and high parasitism failed to affect the body conditions of the fish. In the case of some hosts, rainfall rates, temperature, dissolved oxygen levels and water pH affected the prevalence and abundance of E. berbicensis, the dominant parasite species. Results revealed that the environment and life-style of the hosts were determining factors in infestations by parasites. Current assay is the first report on E. berbicensis for the six hosts, as well as on A. chicomendesi for G. proximus and P. falcata.

  5. Niche segregation and genetic structure of Campylobacter jejuni populations from wild and agricultural host species.

    Science.gov (United States)

    Sheppard, Samuel K; Colles, Frances M; McCarthy, Noel D; Strachan, Norval J C; Ogden, Iain D; Forbes, Ken J; Dallas, John F; Maiden, Martin C J

    2011-08-01

    Bacterial populations can display high levels of genetic structuring but the forces that influence this are incompletely understood. Here, by combining modelling approaches with multilocus sequence data for the zoonotic pathogen Campylobacter, we investigated how ecological factors such as niche (host) separation relate to population structure. We analysed seven housekeeping genes from published C. jejuni and C. coli isolate collections from a range of food and wild animal sources as well as abiotic environments. By reconstructing genetic structure and the patterns of ancestry, we quantified C. jejuni host association, inferred ancestral populations, investigated genetic admixture in different hosts and determined the host origin of recombinant C. jejuni alleles found in hybrid C. coli lineages. Phylogenetically distinct C. jejuni lineages were associated with phylogenetically distinct wild birds. However, in the farm environment, phylogenetically distant host animals shared several C. jejuni lineages that could not be segregated according to host origin using these analyses. Furthermore, of the introgressed C. jejuni alleles found in C. coli lineages, 73% were attributed to genotypes associated with food animals. Our results are consistent with an evolutionary scenario where distinct Campylobacter lineages are associated with different host species but the ecological factors that maintain this are different in domestic animals such that phylogenetically distant animals can harbour closely related strains. © 2011 Blackwell Publishing Ltd.

  6. (macro- Evolutionary ecology of parasite diversity: From determinants of parasite species richness to host diversification

    Directory of Open Access Journals (Sweden)

    Serge Morand

    2015-04-01

    Full Text Available The present review summarized the factors or determinants that may explain parasite diversity among host species and the consequences of this parasite diversity on the evolution of host-life history traits. As host–parasite interactions are asymmetrical exploited–exploiter relationships, ecological and epidemiological theories produce hypotheses to find the potential determinants of parasite species richness, while life-history theory helps for testing potential consequences on parasite diversity on the evolution of hosts. This review referred only to studies that have specifically controlled or took into account phylogenetic information illustrated with parasites of mammals. Several points needing more investigation were identified with a special emphasis to develop the metabolic theory of epidemiology.

  7. Feeding behavior of two exotic aphid species on their original hosts in a new invaded area.

    Science.gov (United States)

    Lazzarotto, C M; Lazzari, S M N; Penteado, S R C

    2011-01-01

    Greenidea ficicola Takahashi and Greenidea psidii van der Goot (Aphididae: Greenideinae) are Asian aphid species newly introduced in Brazil associated with Moraceae and Myrtaceae. The feeding behavior of G. ficicola and G. psidii was investigated on their respective host plants, Ficus benjamina (Moraceae) and Psidium guajava (Myrtaceae), using the Electrical Penetration Graph (EPG). Fifteen females of each aphid species were monitored during 24h using a DC-EPG GIGA-4 monitor. The time spent in phloem phase (waveforms E1 and E2) was 13.6% of the total recording time for G. ficicola and 0.8% for G. psidii. The average time in the pathway phase (waveforms C and pd) represented 50% of the total time for both species. Aphids spent more time in non-penetration and stylet pathway activities than in the phloem phase or actual feeding. The principal component analysis (PCA) showed that the two species formed different groups in relation to EPG parameters, despite some overlapping. The probing patterns with multiple penetrations of short duration in the sieve elements for both species may indicate apparent unsuitability for sustained feeding on their respective host plants. These results suggest that these two exotic species are in the process of adaptation to their host plants in their new environment and/or the plants may present either chemical or physical barriers against these insects.

  8. Validation of a model for prediction of host damage by two nematode species.

    Science.gov (United States)

    Duncan, L W; Ferris, H

    1983-04-01

    PLANT ROOTS WERE MECHANICALLY INJURED OR SUBJECTED TO NEMATODE PARASITISM TO TEST THE MODEL OF HOST DAMAGE BY TWO NEMATODE SPECIES: y = m' + (l - m')c'z(P)z(P) for y 1.0, where m' = m + (m - m) (1 - y)/[(1 - y) + (l - y)] and c' = (z(-T) + z(-T))/2. Damage functions for greenhouse-grown radish plants (cv. Cherry Belle) mechanically injured with small or large steel needles were used to predict growth of plants injured by both needles. Growth predictions accounted for 94%, 87%, and 82% of mean treatment variation in plant height, stem weight, and root weight, respectively. Cowpea (cv. California Blackeye No. 5) damage functions, based on preplant population levels of Meloidogyne incognita and M. javanica, were used to predict seed yield of plants concomitantly infected with various levels of each species. Single species damage functions and population growth curves indicated significant host resistance to M. incognita and significantly lower virulence of that species compared to M. javanica. Model predictions accounted for 88% of mean seed yield variation in two-species treatments. In a separate experiment, mean top weights of 30-day-old cowpea plants, nniformly inoculated with 20,000 M. javanica eggs, increased with increasing levels of concomitantly inoculated M. incognita eggs. It is speculated that competitive interactions between M. incognita and M. javanica mitigated host damage by the more virulent species.

  9. Species of Mycosphaerellaceae and Teratosphaeriaceae on native Myrtaceae in Uruguay: evidence of fungal host jumps.

    Science.gov (United States)

    Pérez, C A; Wingfield, M J; Altier, N; Blanchette, R A

    2013-02-01

    Mycosphaerella species are well-known causal agents of leaf diseases on many economically and ecologically important plant species. In Uruguay, a relatively large number of Mycosphaerellaceae and Teratosphaeriaceae are found on Eucalyptus, but nothing is known of these fungi on native Myrtaceae. The aim of this study was to identify Mycosphaerellaceae and Teratosphaeriaceae species associated with leaf diseases on native Myrtaceae in Uruguay and to consider whether host jumps by the pathogen from introduced Eucalyptus to native Myrtaceae have occurred. Several native forests throughout the country were surveyed with special attention given to those located close to Eucalyptus plantations. Five species belonging to the Mycosphaerellaceae and Teratosphaeriaceae clades were found on native Myrtaceous trees and three of these had previously been reported on Eucalyptus in Uruguay. Those occurring both on Eucalyptus and native Myrtaceae included Pallidocercospora heimii, Pseudocercospora norchiensis, and Teratosphaeria aurantia. In addition, Mycosphaerella yunnanensis, a species known to occur on Eucalyptus but not previously recorded in Uruguay, was found on leaves of two native Myrtaceous hosts. Because most of these species occur on Eucalyptus in countries other than Uruguay, it appears that they were introduced in this country and have adapted to be able to infect native Myrtaceae. These apparent host jumps have the potential to result in serious disease problems and they should be carefully monitored. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  10. Geographic analysis of host use, development, and habitat use of an acanthocephalan species, Leptorhynchoides thecatus.

    Science.gov (United States)

    Steinauer, Michelle L; Parham, James E; Nickol, Brent B

    2006-06-01

    Leptorhynchoides thecatus (Linton, 1891), an acanthocephalan parasite of freshwater fishes, varies in host use, development, and habitat use throughout North America. Spatial structure of these characteristics was examined from data extracted from the literature. Geographic patterns were inferred from point comparisons using correllograms and then tested with Moran's I statistic for global and local significance, and visually from regional means within major river drainages. Species of Micropterus Lacepède, 1802 (black basses) were common hosts in most regions, except the Lower Mississippi and South Atlantic regions where species of Lepomis Rafinesque, 1819 (sunfishes) were common hosts. Development, described as the proportions of adults relative to cystacanths (extraintestinal juveniles), decreased with latitude. Habitat use of L. thecatus showed marked geographic patterns. Leptorhynchoides thecatus occurred in the intestine of sunfishes in the South Atlantic and Lower Mississippi regions, in the ceca in fish of all species included in the study in the Missouri and Texas-Gulf regions, and both in ceca and intestines in fish of all species in northern regions. Leptorhynchoides thecatus showed geographic patterning within the variable traits across the range of the species. These patterns may be the result of ecological factors or of genetic differences that might indicate L. thecatus comprises multiple cryptic species.

  11. Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host?Microbe Model System

    OpenAIRE

    James Angus Chandler; Jenna Morgan Lang; Srijak Bhatnagar; Eisen, Jonathan A; Artyom Kopp

    2011-01-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host-microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal-microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate mode...

  12. Do syntopic host species harbour similar symbiotic communities? The case of Chaetopterus spp. (Annelida: Chaetopteridae

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    Temir A. Britayev

    2017-02-01

    Full Text Available To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes, Chaetopterus sp. (n = 11 and Chaetopterus cf. appendiculatus (n = 83 living in soft sediments of Nhatrang Bay (South China Sea, Vietnam. The former harboured the porcellanid crabs Polyonyx cf. heok and Polyonyx sp., the pinnotherid crab Tetrias sp. and the tergipedid nudibranch Phestilla sp. The latter harboured the polynoid polychaete Ophthalmonoe pettiboneae, the carapid fish Onuxodon fowleri and the porcellanid crab Eulenaios cometes, all of which, except O. fowleri, seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher in Chaetopterus sp. than in C. cf. appendiculatus (1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively. We suggest that the lower density of Chaetopterus sp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% in C. cf. appenciculatus. Most Chaetopterus sp. harboured two symbiotic species, which was extremely rare in C. cf. appendiculatus, suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts of Chaetopterus sp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes of Chaetopterus sp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated with C. cf. appendiculatus established a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the

  13. Morphological and molecular analyses support the existence of host-specific Peronospora species infecting Chenopodium.

    Science.gov (United States)

    Choi, Young-Joon; Denchev, Cvetomir M; Shin, Hyeon-Dong

    2008-03-01

    About 20 species of Peronospora have been reported to cause downy mildew on Chenopodium, but, particularly in plant pathology literature, only one species, P. farinosa, is considered to be involved. We performed sequence analysis of the ITS rDNA to reveal the phylogenetic relationships of Peronospora specimens from five species of Chenopodium, viz. C. album, C. ambrosioides, C. bonus-henricus, C. hybridum, and C. polyspermum. The five clades corresponded to particular Chenopodium species, and showed a high level of sequence divergence. Differences in the morphology of the conidia and ultimate branchlets also supported the separation of the five groups at the host species level. These results suggest that the names P. variabilis, P. boni-henrici, P. chenopodii, and P. chenopodii-polyspermi should be used for the four downy mildew pathogens specific to C. album, C. bonus-henricus, C. hybridum, and C. polyspermum, respectively. The Peronospora on C. ambrosioides was found to be an independent species.

  14. Host Status of Seven Weed Species and Their Effects on Ditylenchus destructor Infestation of Peanut.

    Science.gov (United States)

    De Waele, D; Jordaan, E M; Basson, S

    1990-07-01

    The host suitability to Ditylenchus destructor of seven common weed species in peanut (Arachis hypogaea) fields in South Africa was determined. Based on the number of nematodes per root unit, white goosefoot (Chenopodium album), feathertop chloris (Chloris virgata), purple nutsedge (Cyperus rotundus), jimson weed (Datura stramonium), goose grass (Eleusine indica), khaki weed (Tagetes minuta), and cocklebur (Xanthium strumarium) were poor hosts. Ditylenchus destructor survived on all weed species; population densities increased in peanut hulls and caused severe damage to seeds of peanut grown after weeds. Roots of purple nutsedge left in the soil suppressed populations of D. destructor and root and pod development in peanut grown after the weed. However, nematode populations in peanut hulls and seeds were not suppressed. Some weed species, especially purple nutsedge which is common in peanut fields, can be used to indicate the presence of D. destructor in the absence of peanut.

  15. Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts

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    Sacchi L.

    2001-06-01

    Full Text Available The nurse cell-larva complex of nematodes of the genus Trichinella plays an Important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear, T. spiralis (horses and humans, T. pseudospiralis (a laboratory mouse and T. papuae (a laboratory mouse were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

  16. Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize.

    Science.gov (United States)

    Jordaan, E M; De Waele, D

    1988-10-01

    The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae infestation of subsequently grown maize. When goose grass, khaki weed, and mealie crotalaria were grown in association with maize in soil infested with P. zeae, goose grass and khaki weed severely suppressed maize root development; this resulted in a low number of nematodes per maize root system and a high number of nematodes per maize root unit. Mealie crotalaria did not restrict maize root growth and did not affect nematode densities per maize root system or maize root unit. Special attention should be given to the control of mealie crotalaria, which is a good host for P. zeae, and goose grass, which, in addition to its ability to compete with maize, is also a suitable host for P. zeae.

  17. A novel nematode effector suppresses plant immunity by activating host reactive oxygen species-scavenging system.

    Science.gov (United States)

    Lin, Borong; Zhuo, Kan; Chen, Shiyan; Hu, Lili; Sun, Longhua; Wang, Xiaohong; Zhang, Lian-Hui; Liao, Jinling

    2016-02-01

    Evidence is emerging that plant-parasitic nematodes can secrete effectors to interfere with the host immune response, but it remains unknown how these effectors can conquer host immune responses. Here, we depict a novel effector, MjTTL5, that could suppress plant immune response. Immunolocalization and transcriptional analyses showed that MjTTL5 is expressed specifically within the subventral gland of Meloidogyne javanica and up-regulated in the early parasitic stage of the nematode. Transgenic Arabidopsis lines expressing MjTTL5 were significantly more susceptible to M. javanica infection than wild-type plants, and vice versa, in planta silencing of MjTTL5 substantially increased plant resistance to M. javanica. Yeast two-hybrid, coimmunoprecipitation and bimolecular fluorescent complementation assays showed that MjTTL5 interacts specifically with Arabidopsis ferredoxin : thioredoxin reductase catalytic subunit (AtFTRc), a key component of host antioxidant system. The expression of AtFTRc is induced by the infection of M. javanica. Interaction between AtFTRc and MjTTL could drastically increase host reactive oxygen species-scavenging activity, and result in suppression of plant basal defenses and attenuation of host resistance to the nematode infection. Our results demonstrate that the host ferredoxin : thioredoxin system can be exploited cunningly by M. javanica, revealing a novel mechanism utilized by plant-parasitic nematodes to subjugate plant innate immunity and thereby promoting parasitism. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. Interaction of bovine peripheral blood polymorphonuclear cells and Leptospira species; innate responses in the natural bovine reservoir host.

    Science.gov (United States)

    Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and also be reservoir hosts of other Leptospira species such as L. kirschneri, and L. interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murin...

  19. Host selection in the forest interior: cowbirds target ground-nesting species

    Science.gov (United States)

    Hahn, D.C.; Hatfield, J.S.

    2000-01-01

    We investigated patterns of cowbird host selection in a large (1300 ha), unfragmented forest in eastern New York in 1992-3 to determine whether cowbird parasitism rates can be attributed to species-specific traits or to other features associated with nest sites. Nest height was significantly associated with parasitism (P = 0.003) in this community of 23 species (n = 430 nests, 23% parasitized). Further analysis revealed that the difference in mean nest heights between parasitized and unparasitized nests was due to species identity, and within each species there was no difference in mean nest heights between parasitized and unparasitized nests. These results imply that during 1992-3 cowbirds in this forest specialized on species that have low nests and did not necessarily select low nests regardless of species. This was further supported by a negative association across all 23 species between mean nest height and parasitism rate (P = 0.03). Thus, although most of the forest-nesting species in this community experienced cowbird parasitism, there was a tendency for higher parasitism rates on low-nesting species such as the Ovenbird, Black-and-white Warbler, Louisiana Waterthrush, Veery, and Hermit Thrush. The Wood Thrush, a mid-range nester which is heavily parasitized in southern Illinois, experienced only 10% parasitism in our site and ranked 9th in parasitism rate, although it was the most abundant species in this forest in terms of the number of nests found. A long-term study is necessary to determine whether this cowbird population consistently parasitizes the ground-nesting species of this forest community more often than those nesting at higher levels or whether they periodically shift among hosts at different heights and in different habitats across the local landscape.

  20. Differential Host Plant-Associated Genetic Variation Between Sympatric Mite Species of the Genus Oligonychus (Acari: Tetranychidae).

    Science.gov (United States)

    Guzman-Valencia, Stephanie; Santillán-Galicia, Ma Teresa; Guzmán-Franco, Ariel W; Vega-Muñoz, Ricardo

    2017-04-01

    Adaptation to different host plants can lead to host-associated differentiation (HAD). The mites Oligonychus perseae and Oligonychus punicae have a broad range of host plants, but, to date, records of them coexisting sympatrically had only been reported on avocado. However, our field observations showed both species coexisting on host plants other than avocado. The lack of previous records of these mites on the host plants studied here suggests only recent divergence to new host plant species. Previous studies showed that O. punicae had a limited migration capacity compared with O. perseae, suggesting that O. punicae is more likely to develop a close host plant relationship leading to HAD. Adults of both species were collected from trees hosting both mite species. Three genera of host plants considered were Persea, Salix, and Alnus; two species within one genus were Alnus jorullensis and Alnus acuminata; and three varieties within one species were Persea americana var. Fuerte, var. Hass, and var. Criollo, a noncommercial variety. Using sequence data from a segment of the mitochondrial cytochrome oxidase subunit I, the phylogenetic relationships and genetic population structure of both mite species in relation to the host plant were determined. Oligonychus perseae populations showed a significant population structure in relation to host plant at the species and genus level, but there was no effect of variety. In contrast, host plant explained none of the genetic variation among O. punicae populations. The potential role of coexistence mechanisms in the contrasting genetic population structure of both mite species is discussed. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Genetic differentiation associated with host plants and geography among six widespread species of South American Blepharoneura fruit flies (Tephritidae).

    Science.gov (United States)

    Ottens, K; Winkler, I S; Lewis, M L; Scheffer, S J; Gomes-Costa, G A; Condon, M A; Forbes, A A

    2017-04-01

    Tropical herbivorous insects are astonishingly diverse, and many are highly host-specific. Much evidence suggests that herbivorous insect diversity is a function of host plant diversity; yet, the diversity of some lineages exceeds the diversity of plants. Although most species of herbivorous fruit flies in the Neotropical genus Blepharoneura are strongly host-specific (they deposit their eggs in a single host plant species and flower sex), some species are collected from multiple hosts or flowers and these may represent examples of lineages that are diversifying via changes in host use. Here, we investigate patterns of diversification within six geographically widespread Blepharoneura species that have been collected and reared from at least two host plant species or host plant parts. We use microsatellites to (1) test for evidence of local genetic differentiation associated with different sympatric hosts (different plant species or flower sexes) and (2) examine geographic patterns of genetic differentiation across multiple South American collection sites. In four of the six fly species, we find evidence of local genetic differences between flies collected from different hosts. All six species show evidence of geographic structure, with consistent differences between flies collected in the Guiana Shield and flies collected in Amazonia. Continent-wide analyses reveal - in all but one instance - that genetically differentiated flies collected in sympatry from different host species or different sex flowers are not one another's closest relatives, indicating that genetic differences often arise in allopatry before, or at least coincident with, the evolution of novel host use. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  2. Calcium Regulation of Hemorrhagic Fever Virus Budding: Mechanistic Implications for Host-Oriented Therapeutic Intervention.

    Directory of Open Access Journals (Sweden)

    Ziying Han

    2015-10-01

    Full Text Available Hemorrhagic fever viruses, including the filoviruses (Ebola and Marburg and arenaviruses (Lassa and Junín viruses, are serious human pathogens for which there are currently no FDA approved therapeutics or vaccines. Importantly, transmission of these viruses, and specifically late steps of budding, critically depend upon host cell machinery. Consequently, strategies which target these mechanisms represent potential targets for broad spectrum host oriented therapeutics. An important cellular signal implicated previously in EBOV budding is calcium. Indeed, host cell calcium signals are increasingly being recognized to play a role in steps of entry, replication, and transmission for a range of viruses, but if and how filoviruses and arenaviruses mobilize calcium and the precise stage of virus transmission regulated by calcium have not been defined. Here we demonstrate that expression of matrix proteins from both filoviruses and arenaviruses triggers an increase in host cytoplasmic Ca2+ concentration by a mechanism that requires host Orai1 channels. Furthermore, we demonstrate that Orai1 regulates both VLP and infectious filovirus and arenavirus production and spread. Notably, suppression of the protein that triggers Orai activation (Stromal Interaction Molecule 1, STIM1 and genetic inactivation or pharmacological blockade of Orai1 channels inhibits VLP and infectious virus egress. These findings are highly significant as they expand our understanding of host mechanisms that may broadly control enveloped RNA virus budding, and they establish Orai and STIM1 as novel targets for broad-spectrum host-oriented therapeutics to combat these emerging BSL-4 pathogens and potentially other enveloped RNA viruses that bud via similar mechanisms.

  3. Structure of capsule around acanthocephalan Corynosoma strumosum from uncommon paratenic hosts-lizards of two species.

    Science.gov (United States)

    Skorobrechova, Ekaterina M; Nikishin, Vladimir P; Lisitsyna, Olga I

    2012-01-01

    Micromorphology and ultrastructure of capsule forming around acanthocephalan Corynosoma strumosum in uncommon paratenic hosts-lizards Lacerta agilis and Lacerta viridis-have been studied. Experimental infestation of the lizards by acanthocephalans obtained from naturally infested sea fishes showed that only small amount of parasites occurred in the intestine of the host was able to migrate into body cavity and to be encapsulated. Micromorphology of capsules of different ages from different species of lizards and micromorphology and ultrastructure of capsules at the age of 1.5 and 10 days appeared to be similar. In the capsule's structure cells of inflammatory rank were prevailing: mononuclear and multinuclear macrophages, eosinophils, and basophils. Fibroblasts were not numerous and were located only in the outer part of a capsule; exocellular collagen fibers were absent. Inflammatory character of capsule confirms the idea that lizards are unsuitable paratenic hosts for corynosomes.

  4. Remote sensing of the distribution and abundance of host species for spruce budworm in Northern Minnesota and Ontario

    Science.gov (United States)

    Peter T. Wolter; Philip A. Townsend; Brian R. Sturtevant; Clayton C. Kingdon

    2008-01-01

    Insects and disease affect large areas of forest in the U.S. and Canada. Understanding ecosystem impacts of such disturbances requires knowledge of host species distribution patterns on the landscape. In this study, we mapped the distribution and abundance of host species for the spruce budworm (Choristoneura fumiferana) to facilitate landscape scale...

  5. Marine protected areas facilitate parasite populations among four fished host species of central Chile.

    Science.gov (United States)

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan

    2013-11-01

    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  6. Effect of host species diversity on multiparasite systems in rodent communities.

    Science.gov (United States)

    Rendón-Franco, Emilio; Muñoz-García, Claudia I; Romero-Callejas, Evangelina; Moreno-Torres, Karla I; Suzán, Gerardo

    2014-01-01

    Reduced species diversity has been suggested to increase transmission rates and prevalence of infectious diseases. While this theory has been studied mostly in single pathogen systems, little is known regarding multiple pathogens systems in vertebrates at the community level. The aim of this study was to evaluate the effect of host richness and diversity on multiple parasite systems on a local scale. We captured small rodents and collected feces in three different vegetation types in a natural protected area in Janos, Chihuahua, Mexico. The flotation technique was used to identify parasite eggs or oocysts. Analysis of linear correlations was conducted between parasite prevalence and host and parasite diversity and richness. Negative correlation was detected between parasite prevalence and host diversity (p = 0.02 r(2) =-0.86), but no significant correlations was detected between parasite prevalence and host richness or parasite diversity or richness. Our study shows that at local scale, host diversity could affect multiple parasite systems in the same way that single pathogens do. Further studies should be performed on larger temporal and spatial scales to more thoroughly investigate the correlation observed in our analysis.

  7. Species boundaries and host range of tortoise mites (Uropodoidea phoretic on bark beetles (Scolytinae, using morphometric and molecular markers.

    Directory of Open Access Journals (Sweden)

    Wayne Knee

    Full Text Available Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae, but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1 morphologically defined species are supported by molecular data, and that (2 bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI and nuclear large subunit ribosomal DNA (28S. Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists.

  8. Species boundaries and host range of tortoise mites (Uropodoidea) phoretic on bark beetles (Scolytinae), using morphometric and molecular markers.

    Science.gov (United States)

    Knee, Wayne; Beaulieu, Frédéric; Skevington, Jeffrey H; Kelso, Scott; Cognato, Anthony I; Forbes, Mark R

    2012-01-01

    Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea) are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae), but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1) morphologically defined species are supported by molecular data, and that (2) bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI) and nuclear large subunit ribosomal DNA (28S). Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella) collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists.

  9. POD-DEIM APPROACH ON DIMENSION REDUCTION OF A MULTI-SPECIES HOST-PARASITOID SYSTEM

    Directory of Open Access Journals (Sweden)

    Gabriel Dimitriu

    2015-07-01

    Full Text Available In this study, we implement the DEIM algorithm (Discrete Empirical Interpolation Method combined with POD (Proper Orthogonal Decomposition to provide dimension reduction of a model describing the aggregative response of parasitoids to hosts in a coupled multi-species system. The model is defined by five reaction-diffusionchemotaxis equations. We show DEIM improves the efficiency of the POD approximation and achieves a complexity reduction of the nonlinear terms. Numerical results are presented.

  10. COI and ITS2 sequences delimit species, reveal cryptic taxa and host specificity of fig-associated Sycophila (Hymenoptera, Eurytomidae).

    Science.gov (United States)

    Li, Yanwei; Zhou, Xin; Feng, Gui; Hu, Haoyuan; Niu, Liming; Hebert, Paul D N; Huang, Dawei

    2010-01-01

    Although the genus Sycophila has broad host preferences, some species are specifically associated with figs as nonpollinator wasps. Because of their sexual dimorphism, morphological plasticity, cryptic mating behaviour and poorly known biology, species identifications are often uncertain. It is particularly difficult to match conspecific females and males. In this study, we employed two molecular markers, mitochondrial COI and nuclear ITS2, to identify Sycophila from six Chinese fig species. Morphological studies revealed 25 female and male morphs, while sequence results for both genes were consistent in supporting the presence of 15 species, of which 13 were host specialists and two used dual hosts. A single species of Sycophila was respectively found on four fig species, but six species were isolated from Ficus benjamina and a same number was reared from Ficus microcarpa. Sequence results revealed three male morphs in one species and detected two species that were overlooked by morphological analysis. © 2009 Blackwell Publishing Ltd.

  11. Phylogenetic analysis of Theileria and Babesia equi in relation to the establishment of parasite populations within novel host species and the development of diagnostic tests.

    Science.gov (United States)

    Katzer, F; McKellar, S; Kirvar, E; Shiels, B

    1998-09-01

    The divergence of parasites is important for maintenance within an established host and spread to novel host species. In this paper we have carried out phylogenetic analyses of Theileria parasites isolated from different host species. This was performed with small subunit ribosomal RNA sequences available in the data bases and a novel sequence amplified from Theileria lestoquardi DNA. Similar phylogenetic studies were carried out with sequences representing the major merozoite/piroplasm surface antigen (mMPSA) from the data base, and novel sequences representing 2 mMPSA alleles from T. lestoquardi, a full length sequence of a Theileria taurotragi mMPSA gene and partial sequences of two new allelic variants of the Babesia equi mMPSA gene homologue. The analysis indicated that the pathogenic sheep parasite T. lestoquardi has most probably evolved from a common ancestor of T. annulata. Interestingly, the level of mMPSA sequence diversity found for T. lestoquardi was surprisingly low, while diversity between the B. equi sequences was higher than that found within any of the classical Theileria species. The possible implications of these results for the establishment of Theileria parasites within novel species are discussed. Extensive cross-reactivity of a range of antisera was found when tested against recombinant mMPSA polypeptides from different Theileria (including B. equi) species. The cross-reactivity between mMPSA polypeptides and sequence diversity are relevant for the development of species specific diagnostic tests.

  12. Tests of ecological equivalence of two species of terrestrial gastropods as second intermediate hosts of Panopistus pricei (Trematoda: Brachylaimidae).

    Science.gov (United States)

    Barger, Michael A

    2011-02-01

    Metacercariae of Panopistus pricei (Brachylaimidae) are common parasites of 2 species of terrestrial gastropods (Neohelix albolabris; Webbhelix multilineata) in southeastern Nebraska. Field data were collected to determine if individuals of N. albolabris and W. multilineata function as ecologically equivalent second intermediate hosts of P. pricei along a transect on the western edge of the Missouri River. Metacercariae were recovered and measured from samples of 30 snails of each species collected at each of 6 sites; whole kidneys from snails of both species were examined to quantify microhabitat use. Microhabitat use of P. pricei did not differ between host species; in both N. albolabris and W. multilineata, metacercariae were concentrated in the primary ureter and occurred throughout the kidney proper. Prevalences and mean abundances did not differ between host species at any site, nor did the relationship between parasite abundance and host size. Prevalences and mean abundances across sites were positively correlated between host species. At 2 sites, demographics of metacercariae differed between host species, suggesting short-term differences in the history of encounters with cercariae in the environment and differences in transmission to shrew definitive hosts. Overall, N. albolabris and W. multilineata appear to be equivalent and required second intermediate hosts of P. pricei in the area studied.

  13. Endophytic Epichloë species and their grass hosts: from evolution to applications.

    Science.gov (United States)

    Saikkonen, Kari; Young, Carolyn A; Helander, Marjo; Schardl, Christopher L

    2016-04-01

    The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.

  14. Characterization of Cryptosporidium meleagridis of human origin passaged through different host species.

    Science.gov (United States)

    Akiyoshi, Donna E; Dilo, Julia; Pearson, Christine; Chapman, Susan; Tumwine, James; Tzipori, Saul

    2003-04-01

    Cryptosporidium meleagridis, a protozoon first observed in turkeys, has been linked by several investigators to cryptosporidiosis in humans. C. meleagridis is the only known Cryptosporidium species that infects both avian and mammalian species. We describe the successful propagation of C. meleagridis (isolate TU1867), originally purified from a patient with diarrhea, in laboratory animals including chickens, mice, piglets, and calves. TU1867 was readily transmitted from one animal host to another, maintaining genetic homogeneity and stability. The rate of infectivity and virulence of TU1867 for the mammalian species were similar to those of Cryptosporidium parvum. Laboratory propagation of genetically and phenotypically stable and well-characterized reference isolates, representing various Cryptosporidium species, particularly those infectious to humans, will improve considerably the spectrum and quality of laboratory and field investigations on this medically important protozoa.

  15. The Effect of Host-Plant Phylogenetic Isolation on Species Richness, Composition and Specialization of Insect Herbivores: A Comparison between Native and Exotic Hosts.

    Directory of Open Access Journals (Sweden)

    Julio Miguel Grandez-Rios

    Full Text Available Understanding the drivers of plant-insect interactions is still a key issue in terrestrial ecology. Here, we used 30 well-defined plant-herbivore assemblages to assess the effects of host plant phylogenetic isolation and origin (native vs. exotic on the species richness, composition and specialization of the insect herbivore fauna on co-occurring plant species. We also tested for differences in such effects between assemblages composed exclusively of exophagous and endophagous herbivores. We found a consistent negative effect of the phylogenetic isolation of host plants on the richness, similarity and specialization of their insect herbivore faunas. Notably, except for Jaccard dissimilarity, the effect of phylogenetic isolation on the insect herbivore faunas did not vary between native and exotic plants. Our findings show that the phylogenetic isolation of host plants is a key factor that influences the richness, composition and specialization of their local herbivore faunas, regardless of the host plant origin.

  16. Song learning in brood-parasitic indigobirds Vidua chalybeata: song mimicry of the host species.

    Science.gov (United States)

    Payne; Payne; Woods

    1998-06-01

    Brood-parasitic village indigobirds, Vidua chalybeata, were bred in captivity and foster-reared by their normal host, red-billed firefinch, Lagonosticta senegala, or by an experimental foster species, Bengalese finch, Lonchura striata. Male indigobirds reared by Bengalese finches developed the songs of Bengalese finches, and males reared by firefinches developed songs of firefinches. Males copied their foster father only when they had lived with him long after independence (45 days post-fledging), while males separated normally at independence (22-24 days post-fledging) copied songs of other individuals and not songs of their foster father. Males reared by Bengalese finches showed no preference to learn firefinch song over songs of the experimental foster species or other control finch species even when they had lived with firefinches as companions from the time of fledging to independence. Males copied several song themes, acquired the same number of mimicry songs, and acquired their songs at the same age, whether reared by Bengalese finches or by firefinches. When they lived with other indigobirds, the male indigobirds copied mimicry songs of male indigobirds that mimicked the same foster species. We predicted mimicry-song specificity and repertoire size in experimental indigobirds from a hypothesis of an early developmental period when young indigobirds focus their attention on their foster parents, and a later period when they direct their attention to other birds with similar songs. The predictions, based on field observations of wild birds, were that (1) males reared by a novel foster species other than the normal host would learn the song of that foster species, and (2) males that left their foster parents at the normal time of independence would copy the songs of other individuals, including other adult indigobirds that mimicked the same foster species. Begging calls of young indigobirds did not mimic the calls of young firefinches. Indigobirds reared alone

  17. Small Ruminant Lentiviruses (SRLVs Break the Species Barrier to Acquire New Host Range

    Directory of Open Access Journals (Sweden)

    Juliano Cezar Minardi da Cruz

    2013-07-01

    Full Text Available Zoonotic events of simian immunodeficiency virus (SIV from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS, one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2, the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV and Maedi-Visna virus (MVV, and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs, affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections

  18. Small ruminant lentiviruses (SRLVs) break the species barrier to acquire new host range.

    Science.gov (United States)

    Minardi da Cruz, Juliano Cezar; Singh, Dinesh Kumar; Lamara, Ali; Chebloune, Yahia

    2013-07-23

    Zoonotic events of simian immunodeficiency virus (SIV) from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS), one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2), the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections, in addition to

  19. Variations in infection levels and parasite-induced mortality among sympatric cryptic lineages of native amphipods and a congeneric invasive species: Are native hosts always losing?

    Directory of Open Access Journals (Sweden)

    Matthias Galipaud

    2017-12-01

    Full Text Available Shared parasites can strongly influence the outcome of competition between congeneric, sympatric hosts, and thus host population dynamics. Parasite-mediated competition is commonly hypothesized as an important factor in biological invasion success; invasive species often experience lower infection levels and/or parasite-induced mortality than native congeneric hosts. However, variation in infection levels among sympatric hosts can be due to contrasting abilities to avoid infection or different parasite-induced mortality rates following infection. Low parasite infection levels in a specific host can be due to either factor but have drastically different implications in interaction outcomes between sympatric hosts.We assessed acanthocephalan infection levels (prevalence and abundance among cryptic molecular taxonomic units (MOTU of the native G. pulex/G. fossarum species complex from multiple populations where they occur in sympatry. We concomitantly estimated the same parameters in the invasive Gammarus roeseli commonly found in sympatry with G. pulex/G. fossarum MOTUs. We then tested for potential differences in parasite-induced mortality among these alternative hosts. As expected, the invasive G. roeseli showed relatively low infection level and was not subject to parasite-induced mortality. We also found that both acanthocephalan infection levels and parasite-induced mortality varied greatly among cryptic MOTUs of the native amphipods. Contrary to expectations, some native MOTUs displayed levels of resistance to their local parasites similar to those observed in the invasive G. roeseli. Overall, cryptic diversity in native amphipods coupled with high levels of variability in infection levels and parasite-induced mortality documented here may strongly influence inter-MOTU interactions and native population dynamics as well as invasion success and population dynamics of the congeneric invasive G. roeseli. Keywords: Biological invasion

  20. Species identification, host range and diversity of Cecidophyopsis mites (Acari: Trombidiformes) infesting Ribes in Latvia.

    Science.gov (United States)

    Stalažs, Arturs; Moročko-Bičevska, Inga

    2016-06-01

    Cecidophyopsis mites are important pests in all cultivation regions of Ribes causing bud galls and sterility. Despite their economic importance, the knowledge on Cecidophyopsis species infesting Ribes in various areas of the world is still deficient. The present study was carried out to identify Cecidophyopsis species occurring in Latvia on cultivated and wild Ribes, to assess their host range and gain insight into the genetic diversity of these insufficiently studied pests by use of multiplex PCR, rDNA sequences and morphological characters. Cecidophyopsis alpina, C. aurea, C. spicata and C. selachodon were detected to occur in all surveyed habitats. For the first time, C. alpina was identified on blackcurrants and redcurrants, and C. aurea on redcurrants, blackcurrants and alpine currants. The presence of C. ribis was not confirmed with molecular tools during this study. Phylogenetic analyses confirmed the presence of four Cecidophyopsis species identified by multiplex PCR. A close phylogenetic relatedness was found for C. aurea and C. alpina, and for C. ribis and C. spicata highlighting the necessity for additional studies. Our findings suggest a need to consider also other Cecidophyopsis species besides C. ribis in breeding programs for host resistance to mites.

  1. Plants of the fynbos biome harbour host species-specific bacterial communities.

    Science.gov (United States)

    Miyambo, Tsakani; Makhalanyane, Thulani P; Cowan, Don A; Valverde, Angel

    2016-08-01

    The fynbos biome in South Africa is globally recognised as a plant biodiversity hotspot. However, very little is known about the bacterial communities associated with fynbos plants, despite interactions between primary producers and bacteria having an impact on the physiology of both partners and shaping ecosystem diversity. This study reports on the structure, phylogenetic composition and potential roles of the endophytic bacterial communities located in the stems of three fynbos plants (Erepsia anceps, Phaenocoma prolifera and Leucadendron laureolum). Using Illumina MiSeq 16S rRNA sequencing we found that different subpopulations of Deinococcus-Thermus, Alphaproteobacteria, Acidobacteria and Firmicutes dominated the endophytic bacterial communities. Alphaproteobacteria and Actinobacteria were prevalent in P. prolifera, whereas Deinococcus-Thermus dominated in L. laureolum, revealing species-specific host-bacteria associations. Although a high degree of variability in the endophytic bacterial communities within hosts was observed, we also detected a core microbiome across the stems of the three plant species, which accounted for 72% of the sequences. Altogether, it seems that both deterministic and stochastic processes shaped microbial communities. Endophytic bacterial communities harboured putative plant growth-promoting bacteria, thus having the potential to influence host health and growth. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Secreted effectors in Toxoplasma gondii and related species: determinants of host range and pathogenesis?

    Science.gov (United States)

    English, E D; Adomako-Ankomah, Y; Boyle, J P

    2015-01-01

    Recent years have witnessed the discovery of a number of secreted proteins in Toxoplasma gondii that play important roles in host–pathogen interactions and parasite virulence, particularly in the mouse model. However, the role that these proteins play in driving the unique features of T. gondii compared to some of its nearest apicomplexan relatives (Hammondia hammondi and Neospora caninum) is unknown. These unique features include distinct dissemination characteristics in vivo and a vast host range. In this review we comprehensively survey what is known about disease outcome, the host response and host range for T. gondii, H. hammondi, and N. caninum. We then review what is presently known about recently identified secreted virulence effectors in these three genetically related, but phenotypically distinct, species. Finally we exploit the existence of genome sequences for these three organisms and discuss what is known about the presence, and functionality, of key T. gondii effectors in these three species. PMID:25655311

  3. Host-pathogen interactions between Burkholderia species and lung epithelial cells

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    Jonathan eDavid

    2015-11-01

    Full Text Available Members of the Burkholderia species can cause a range of severe, often fatal, respiratory diseases. A variety of in vitro models of infection have been developed in an attempt to elucidate the mechanism by which Burkholderia spp. gain entry to and interact with the body. The majority of studies have tended to focus on the interaction of bacteria with phagocytic cells with a paucity of information available with regard to the lung epithelium. However, the lung epithelium is becoming more widely recognised as an important player in innate immunity and the early response to infections. Here we review the complex relationship between Burkholderia species and epithelial cells with an emphasis on the most pathogenic species, B. pseudomallei and B. mallei. The current gaps in knowledge in our understanding are highlighted along with the epithelial host-pathogen interactions that offer potential opportunities for therapeutic intervention.

  4. Mechanisms of Disease: Host-Pathogen Interactions between Burkholderia Species and Lung Epithelial Cells

    Science.gov (United States)

    David, Jonathan; Bell, Rachel E.; Clark, Graeme C.

    2015-01-01

    Members of the Burkholderia species can cause a range of severe, often fatal, respiratory diseases. A variety of in vitro models of infection have been developed in an attempt to elucidate the mechanism by which Burkholderia spp. gain entry to and interact with the body. The majority of studies have tended to focus on the interaction of bacteria with phagocytic cells with a paucity of information available with regard to the lung epithelium. However, the lung epithelium is becoming more widely recognized as an important player in innate immunity and the early response to infections. Here we review the complex relationship between Burkholderia species and epithelial cells with an emphasis on the most pathogenic species, Burkholderia pseudomallei and Burkholderia mallei. The current gaps in knowledge in our understanding are highlighted along with the epithelial host-pathogen interactions that offer potential opportunities for therapeutic intervention. PMID:26636042

  5. Resistance to rust fungi in Lolium perenne depends on within-species variation and performance of the host species in grasslands of different plant diversity.

    Science.gov (United States)

    Roscher, Christiane; Schumacher, Jens; Foitzik, Oliver; Schulze, Ernst-Detlef

    2007-08-01

    The hypothesis that plant species diversity and genetic variation of the host species decrease the severity of plant diseases is supported by studies of agricultural systems, but experimental evidence from more complex systems is scarce. In an experiment with grassland communities of varying species richness (1, 2, 4, 8, 16, and 60 species) and functional group richness (1, 2, 3, and 4 functional groups), we used different cultivars of Lolium perenne (perennial ryegrass) to study effects of biodiversity and cultivar identity on the occurrence and severity of foliar fungal diseases caused by Puccinia coronata (crown rust) and P. graminis (stem rust). Cultivar monocultures of perennial ryegrass revealed strong differences in pathogen susceptibility among these cultivars. Disease intensity caused by both rust fungi decreased significantly with growing species richness of species mixtures. The response to the diversity gradient was related to the decreased density and size of the host individuals with increasing species richness. The occurrence of other grass species known to be possible hosts of the pathogens in the experimental mixtures did not promote disease intensity in L. perenne, indicating that there was a high host specificity of pathogen strains. Differences in pathogen susceptibility among perennial ryegrass cultivars persisted independent of diversity treatment, host density and host individual size, but resulted in a cultivar-specific pattern of changes in pathogen infestation across the species-richness gradient. Our study provided evidence that within-species variation in pathogen susceptibility and competitive interactions of the host species with the environment, as caused by species diversity treatments, are key determinants of the occurrence and severity of fungal diseases.

  6. Deceptive behaviour of Colletotrichum truncatum: strategic survival as an asymptomatic endophyte on non-host species

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    Ranathunge Nalika Priyanwada

    2016-04-01

    Full Text Available Colletotrichum truncatum (syn. C. capsici, like many other members of the genus Colletotrichum, displays a highly developed infection mechanism against a number of agriculturally important crops. Among many survival strategies, C. truncatum is well known for its wide host range and high pathogenicity on several major crop species. Meticulous understanding of a pathogen’s infection mechanisms is the best way to achieve successful management of a disease. This study was carried out to evaluate the pathogenicity of C. truncatum on selected crop plants and weed species and to detect the possibility of non-host species to facilitate survival of the pathogen. Inoculation of an isolate of C. truncatum to four crops: curry chilli - Capsicum annuum (var. CA8, eggplant - Solanum melongena (var. Lena Iri, tomato - Solanum lycopersicum (var. Thilina and green chilli - C. annuum (var. KA2 and three weed species: little ironweed (Vernonia cinerea, billygoat-weed (Ageratum conyzoides and Bengal dayflower (Commelina benghalensis resulted in approximately 3.5 disease severity (DS (100% disease incidence-DI on S. lycopersicum and C. annuum (var. KA2, followed by 2.8 and 1.8 DS (100%, 75% DI on C. annuum (var. CA8 and S. melongena (var. Lena Iri, respectively. The three weed species were completely symptomless up to 8 weeks after the inoculation (WAI. However, microscopic studies and serial culturing of the inoculated tissues revealed the presence of the fungus in all the tested plants. Appressoria were present in all treated leaves and eventually broke their dormancy upon leaf senescence nearly 6 WAI. This study reveals the potential of C. truncatum infecting all tested crops and the capability of the three weed species in harboring the pathogen asymptomatically for several weeks. Thus, early management of inoculum in the field is suggested for C. truncatum diseases.

  7. Lack of population genetic structure and host specificity in the bat fly, Cyclopodia horsfieldi, across species of Pteropus bats in Southeast Asia.

    Science.gov (United States)

    Olival, Kevin J; Dick, Carl W; Simmons, Nancy B; Morales, Juan Carlos; Melnick, Don J; Dittmar, Katharina; Perkins, Susan L; Daszak, Peter; Desalle, Rob

    2013-08-08

    species in the region. We demonstrate the utility of parasite genetics as an additional layer of information to measure host movement and interspecific host contact. These approaches may have wide implications for understanding zoonotic, epizootic, and enzootic disease dynamics. Bat flies may play a role as vectors of disease in bats, and their competence as vectors of bacterial and/or viral pathogens is in need of further investigation.

  8. Population dynamics of Scirtothrips dorsalis (Thysanoptera: Thripidae) and other thrips species on two ornamental host plant species in Southern Florida.

    Science.gov (United States)

    Mannion, Catharine M; Derksen, Andrew I; Seal, Dakshina R; Osborne, Lance S; Martin, Cliff G

    2014-08-01

    Since its 2005 introduction into the United States, chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), has become a problematic pest of agronomic, vegetable, fruit, and ornamental plants. Knowledge of its population dynamics may help managers better monitor and control S. dorsalis. Population estimates were recorded for S. dorsalis and other thrips species on Knock-Out rose (Rosa 'Radrazz') and green buttonwood (Conocarpus erectus L.) from July 2007 to September 2008 in two field plots (one per plant species) in Homestead, FL. Yellow sticky card traps and samples of terminals, flowers, buds, and leaves were collected. S. dorsalis accounted for 95% of all thrips individuals collected from plants and 84% from traps with the remainder including at least 18 other thrips species. More thrips were caught on or flying near rose plants (47,438) than on or near buttonwoods (5,898), and on-plant densities of S. dorsalis appeared higher for rose than for buttonwood. Compared with rose leaves, rose buds, terminals, and flowers each had higher numbers of S. dorsalis, and buds and terminals had higher densities. On each host plant species, S. dorsalis density fluctuated over time with peaks in the late spring, summer, and fall, but populations were consistently low in the late winter and early spring. On roses, increased plant damage ratings correlated with reduced numbers of flowers and buds, reduced mean flower areas, and increased on-plant number and density of S. dorsalis. There were positive correlations over time between S. dorsalis density and plant damage rating for rose flowers (R = 0.78; P = 0.0003) and for buttonwood terminals (R = 0.90; P = 0.0001). Yellow sticky card traps were effective for monitoring S. dorsalis and may be especially useful and economically justified for the most susceptible hosts, but they also work well for less susceptible hosts. A good S. dorsalis scouting program should hence consider trap catches and symptoms such as leaf

  9. Establishment of the onset of host specificity in four phyllobothriid tapeworm species (Cestoda: Tetraphyllidea) using a molecular approach.

    Science.gov (United States)

    Randhawa, H S; Saunders, G W; Burt, M D B

    2007-08-01

    A parasitological survey in the Bay of Fundy, Canada, resulted in the recovery of mature specimens from 5 species of phyllobothriid tapeworms (Cestoda: Tetraphyllidea) from 4 rajid skates: Echeneibothrium canadensis and E. dubium abyssorum specimens from Amblyraja radiata; E. vernetae and Pseudanthobothrium n.sp. from Leucoraja erinacea and L. ocellata; and P. hanseni from A. radiata and Malacoraja senta. Partial sequence data of a variable region (D2) from the large subunit ribosomal DNA (LSU) were used here to determine the host distribution of immature specimens for 4 of these 5 species (E. d. abyssorum was not included in the analyses). Immature specimens from both Pseudanthobothrium spp. were identified in the same hosts as recorded previously for mature specimens, thus suggesting that there are mechanisms that prevent the attachment of the parasite in an 'unsuitable' host species. Immature E. canadensis specimens were recovered exclusively from A. radiata, whereas immature E. vernetae specimens were recovered from L. erinacea and A. radiata, despite the latter host species not harbouring mature E. vernetae specimens. Their presence in the latter host species may be explained by host restriction or resistance, which allows the attachment of the parasites in the 'wrong' host species, but not establishment or development.

  10. Comparative phylogeography between two generalist flea species reveal a complex interaction between parasite life history and host vicariance: parasite-host association matters.

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    van der Mescht, Luther; Matthee, Sonja; Matthee, Conrad A

    2015-06-10

    In parasitic taxa, life history traits such as microhabitat preference and host specificity can result in differential evolutionary responses to similar abiotic events. The present study investigates the influence of vicariance and host association on the genetic structure of two generalist flea species, Listropsylla agrippinae, and Chiastopsylla rossi. The taxa differ in the time spent on the host (predominantly fur vs. nest) and level of host specificity. A total of 1056 small mammals were brushed to collect 315 fleas originating from 20 geographically distinct localities in South Africa. Phylogeographic genetic structure of L. agrippinae and C. rossi were determined by making use of 315 mitochondrial COII and 174 nuclear EF1-α sequences. Both parasites show significant genetic differentiation among the majority of the sampling sites confirming limited dispersal ability for fleas. The generalist fur flea with a narrower host range, L. agrippinae, displayed geographic mtDNA spatial genetic structure at the regional scale and this pattern is congruent with host vicariance. The dating of the divergence between the L. agrippinae geographic clades co-insides with paleoclimatic changes in the region approximately 5.27 Ma and this provides some evidence for a co-evolutionary scenario. In contrast, the more host opportunistic nest flea, C. rossi, showed a higher level of mtDNA and nDNA spatial genetic structure at the inter-populational scale, most likely attributed to comparatively higher restrictions to dispersal. In the present study, the evolutionary history of the flea species could best be explained by the association between parasite and host (time spent on the host). The phylogeographic pattern of the fur flea with a narrower host range correspond to host spatial genetic structures, while the pattern in the host opportunistic nest flea correspond to higher genetic divergences between sampling localities that may also be associated with higher effective

  11. Predatory thrips species composition, their prey and host plant association in Northern Thailand

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    Samaporn Saengyot

    2016-09-01

    Full Text Available A survey of predatory thrips, their prey and associated host plants was carried out from February 2013 to February 2014 in Chiang Rai, Phayao, Chiang Mai, Lamphun and Lampang provinces in Northern Thailand. The survey revealed 10 species of predatory thrips in 5 genera in the Family Phlaeothripidae. They were: Aleurodothrips fasciapennis (Franklin, Androthrips flavipes Schmutz, Androthrips ramachandrai Karny, Karnyothrips flavipes (Jones, two indeterminate Karnyothrips sp.1 and sp.2, Leptothrips sp., Podothrips lucasseni (Krüger, and two indeterminate Podothrips sp. 1, and sp. 2. Eleven species of insect and mite pests serving as prey were found associated with 16 species of host plants in 13 families. They were: scale insects, Coccus viridis (Green and two Coccus spp.; spiraling whitefly, Aleurodicus dispersus Russell; unidentified gall-making Hemiptera; coffee berry borer, Hypothenemus hampei (Ferrari; unidentified crambid lepidopterous larvae; Kanzawa spider mite, Tetranychus kanzawai Kishida; santol gall mite, Eriophyes sandorici Nelepa; litchi rust mite, Aceria litchii (Keifer; and bamboo green mite, Aponychus corpuzae Rimando. The findings from this investigation could provide basic information necessary for further investigation in the use of some of these predatory thrips as biological control agents of insect and mite pests of economic importance in Thailand.

  12. Wildly Growing Asparagus (Asparagus officinalis L.) Hosts Pathogenic Fusarium Species and Accumulates Their Mycotoxins.

    Science.gov (United States)

    Stępień, Łukasz; Waśkiewicz, Agnieszka; Urbaniak, Monika

    2016-05-01

    Asparagus officinalis L. is an important crop in many European countries, likely infected by a number of Fusarium species. Most of them produce mycotoxins in plant tissues, thus affecting the physiology of the host plant. However, there is lack of information on Fusarium communities in wild asparagus, where they would definitely have considerable environmental significance. Therefore, the main scientific aim of this study was to identify the Fusarium species and quantify their typical mycotoxins present in wild asparagus plants collected at four time points of the season. Forty-four Fusarium strains of eight species--Fusarium acuminatum, Fusarium avenaceum, Fusarium culmorum, Fusarium equiseti, Fusarium oxysporum, Fusarium proliferatum, Fusarium sporotrichioides, and Fusarium tricinctum--were isolated from nine wild asparagus plants in 2013 season. It is the first report of F. sporotrichioides isolated from this particular host. Fumonisin B1 was the most abundant mycotoxin, and the highest concentrations of fumonisins B1-B3 and beauvericin were found in the spears collected in May. Moniliformin and enniatins were quantified at lower concentrations. Mycotoxins synthesized by individual strains obtained from infected asparagus tissues were assessed using in vitro cultures on sterile rice grain. Most of the F. sporotrichioides strains synthesized HT-2 toxin and F. equiseti strains were found to be effective zearalenone producers.

  13. Computational prediction of Escherichia coli proteins host subcellular targeting and their implications in colorectal cancer etiology.

    Science.gov (United States)

    Khan, Abdul Arif; Khan, Zakir; Malik, Abdul; Shrivastava, Abhinav; Jain, Sudhir K; Alshamsan, Aws

    2015-08-01

    Recent evidences indicate potential Escherichia coli involvement in colorectal cancer etiology. Colorectal cancer cells are exclusively colonized by enteroinvasive E. coli, which regulates several factors that can affect colorectal cancer progression in susceptible individuals. Earlier, we predicted nuclear targeting of E. coli proteins and their role in colorectal cancer etiology. In this study, we predict targeting of E. coli proteins in host cell mitochondria and cytoplasm and their role in colorectal cancer. Several important biological processes are regulated in the cell cytoplasm and mitochondria, where the targeting of E. coli proteins may have several possible implications. A total of 87/561 and 315/561 E. coli proteins were found to target host cell mitochondria and cytoplasm respectively. These include several proteins with the ability to influence normal growth behavior. The current article provides an outline for E. coli protein targeting in host cells and suggests that these proteins can contribute to the colorectal cancer etiology through a variety of strategies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Host feeding patterns of Culicoides species (Diptera: Ceratopogonidae) within the Picos de Europa National Park in northern Spain.

    Science.gov (United States)

    Calvo, J H; Berzal, B; Calvete, C; Miranda, M A; Estrada, R; Lucientes, J

    2012-12-01

    Blood meal identification can provide information about the natural host-feeding patterns or preferences of Culicoides species. Such information could indirectly provide data indicating which reservoirs are significant in associated vector-borne diseases. We positively identified the host species through DNA sequencing of the cytochrome b gene in 144 of the 170 (84.7%) blood meal specimens tested. In the remaining samples, identification of the blood-meal source was unsuccessful, possibly due to the post-ingestion time prior to sampling or the availability of the species-specific cytochrome b gene sequences in the database. The majority of identified blood meals were derived from mammalian blood (95.8%), and only six contained chicken blood. We identified five species as mammalian hosts for Culicoides spp.: sheep (87.7%), human (6.5%), cattle (3.7%) and Savi's Pine Vole (Micrototus savii) (2.1%). The results suggested that large mammals, specifically ruminants, were most frequently fed upon by biting midges (Culicoides spp.), but evidence of opportunistic feeding behaviour was also found. Host feeding behaviour of Culicoides species may also be influenced by the relative abundance of a particular host species in the area being studied. In this sense, Savi's Pine Vole, a wild species, was found to be a locally relevant host and a putative reservoir for viruses transmitted by species of biting midges belonging to the Culicoides genus. Finally, feeding on multiple potential host species was observed. One midge acquired blood meals from human and chicken hosts, while four other midges fed on two different sheep.

  15. Implication of haematophagous arthropod salivary proteins in host-vector interactions

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    Fontaine Albin

    2011-09-01

    Full Text Available Abstract The saliva of haematophagous arthropods contains an array of anti-haemostatic, anti-inflammatory and immunomodulatory molecules that contribute to the success of the blood meal. The saliva of haematophagous arthropods is also involved in the transmission and the establishment of pathogens in the host and in allergic responses. This survey provides a comprehensive overview of the pharmacological activity and immunogenic properties of the main salivary proteins characterised in various haematophagous arthropod species. The potential biological and epidemiological applications of these immunogenic salivary molecules will be discussed with an emphasis on their use as biomarkers of exposure to haematophagous arthropod bites or vaccine candidates that are liable to improve host protection against vector-borne diseases.

  16. Implication of haematophagous arthropod salivary proteins in host-vector interactions

    Science.gov (United States)

    2011-01-01

    The saliva of haematophagous arthropods contains an array of anti-haemostatic, anti-inflammatory and immunomodulatory molecules that contribute to the success of the blood meal. The saliva of haematophagous arthropods is also involved in the transmission and the establishment of pathogens in the host and in allergic responses. This survey provides a comprehensive overview of the pharmacological activity and immunogenic properties of the main salivary proteins characterised in various haematophagous arthropod species. The potential biological and epidemiological applications of these immunogenic salivary molecules will be discussed with an emphasis on their use as biomarkers of exposure to haematophagous arthropod bites or vaccine candidates that are liable to improve host protection against vector-borne diseases. PMID:21951834

  17. Is induction ability of seed germination of Phelipanche ramosa phylogenetically structured among hosts? A case study on Fabaceae species.

    Science.gov (United States)

    Perronne, Rémi; Gibot-Leclerc, Stéphanie; Dessaint, Fabrice; Reibel, Carole; Le Corre, Valérie

    2017-12-01

    Phelipanche ramosa is a major root-holoparasitic damaging weed characterized by a broad host range, including numerous Fabaceae species. In France, the agricultural threat posed by P. ramosa has increased over two decades due to the appearance of a genetically differentiated pathovar presenting a clear host specificity for oilseed rape. The new pathovar has led to a massive expansion of P. ramosa in oilseed rape fields. The germination rate of P. ramosa seeds is currently known to vary among P. ramosa pathovars and host species. However, only a few studies have investigated whether phylogenetic relatedness among potential host species is a predictor of the ability of these species to induce the seed germination of parasitic weeds by testing for phylogenetic signal. We focused on a set of 12 Fabaceae species and we assessed the rate of induction of seed germination by these species for two pathovars based on in vitro co-cultivation experiments. All Fabaceae species tested induced the germination of P. ramosa seeds. The germination rate of P. ramosa seeds varied between Fabaceae species and tribes studied, while pathovars appeared non-influential. Considering oilseed rape as a reference species, we also highlighted a significant phylogenetic signal. Phylogenetically related species therefore showed more similar rates of induction of seed germination than species drawn at random from a phylogenetic tree. In in vitro conditions, only Lotus corniculatus induced a significantly higher germination rate than oilseed rape, and could potentially be used as a catch crop after confirmation of these results under field conditions.

  18. Bumble bee nest abundance, foraging distance, and host-plant reproduction: implications for management and conservation.

    Science.gov (United States)

    Geib, Jennifer C; Strange, James P; Galenj, Candace

    2015-04-01

    Recent reports of global declines in pollinator species imply an urgent need to assess the abundance of native pollinators and density-dependent benefits for linked plants. In this study, we investigated (1) pollinator nest distributions and estimated colony abundances, (2) the relationship between abundances of foraging workers and the number of nests they represent, (3) pollinator foraging ranges, and (4) the relationship between pollinator abundance and plant reproduction. We examined these questions in an alpine ecosystem in the Colorado Rocky Mountains, focusing on four alpine bumble bee species (Bombus balteatus, B. flavifrons, B. bifarius, and B. sylvicola), and two host plants that differ in their degrees of pollinator specialization (Trifolium dasyphyllum and T. parryi). Using microsatellites, we found that estimated colony abundances among Bombus species ranged from ~18 to 78 colonies/0.01 km2. The long-tongued species B. balteatus was most common, especially high above treeline, but the subalpine species B. bifarius was unexpectedly abundant for this elevation range. Nests detected among sampled foragers of each species were correlated with the number of foragers caught. Foraging ranges were smaller than expected for all Bombus species, ranging from 25 to 110 m. Fruit set for the specialized plant, Trifolium parryi, was positively related to the abundance of its Bombus pollinator. In contrast, fruit set for the generalized plant, T. dasyphyllum, was related to abundance of all Bombus species. Because forager abundance was related to nest abundance of each Bombus species and was an equally effective predictor of plant fecundity, forager inventories are probably suitable for assessing the health of outcrossing plant populations. However, nest abundance, rather than forager abundance, better reflects demographic and genetic health in populations of eusocial pollinators such as bumble bees. Development of models incorporating the parameters we have measured

  19. Hippobosca longipennis - a potential intermediate host of a species of Acanthocheilonema in dogs in northern India

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    Irwin Peter J

    2011-07-01

    Full Text Available Abstract Background Hippobosca longipennis (the 'dog louse fly' is a blood sucking ectoparasite found on wild carnivores such as cheetahs and lions and domesticated and feral dogs in Africa, the Middle East and Asia, including China. Known as an intermediate host for Acanthocheilonema dracunculoides and a transport host for Cheyletiella yasguri, it has also been suggested that H. longipennis may be a vector for other pathogens, including Acanthocheilonema sp.? nov., which was recently reported to infect up to 48% of dogs in northern India where this species of fly is known to commonly infest dogs. To test this hypothesis, hippoboscid flies feeding on dogs in Ladakh in northern India were collected and subjected to microscopic dissection. Results A total of 12 infective larvae were found in 10 out of 65 flies dissected; 9 from the head, 2 from the thorax and 1 from the abdomen. The larvae averaged 2, 900 (± 60 μm in length and 34 (± 5 μm in width and possessed morphological features characteristic of the family Onchocercidae. Genetic analysis and comparison of the 18S, ITS-2, 12S and cox-1 genes confirmed the identity of the larvae as the Acanthocheilonema sp.? nov. reported in dogs in Ladakh. Conclusion This study provides evidence for a potential intermediate host-parasite relationship between H. longipennis and the canine Acanthocheilonema sp.? nov. in northern India.

  20. Virulence variation among strains of the emerging infectious fungus Batrachochytrium dendrobatidis (Bd) in multiple amphibian host species.

    Science.gov (United States)

    Dang, Trang D; Searle, Catherine L; Blaustein, Andrew R

    2017-05-11

    Emerging infectious diseases have been documented in numerous plant and animal populations. The infectious disease amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is associated with global amphibian population declines. While much Bd-amphibian research has centered on response variation in hosts, a paucity of information exists on how variation in the pathogen, such as strain differences, affects infection dynamics. To examine how different Bd strains may differentially impact multiple hosts, we conducted laboratory experiments to measure 2 infection outcomes, viz. host survival and pathogen load, in 3 amphibian host species (Pacific treefrog, western toad, and Cascades frog) after exposure to 3 different Bd strains (an additional fourth Bd strain was tested in toads only). Our results confirm that the infection response differs among host species. Western toads experienced significant mortality, but Pacific treefrogs and Cascades frogs did not. Interestingly, our experiment also captured strain-dependent virulence variation but only in 1 host species, the western toad. Increased mortality was observed in 2 of the 4 Bd strains tested in this host species. Toads were also the only host species found to have variable pathogen load dependent on strain type; individuals exposed to the Panama strain harbored significantly higher loads compared to all other strains. These findings underscore the dynamic nature of Bd infection, showing that virulence can vary contingent on host and strain type. We highlight the importance of both host- and pathogen-dependent factors in determining overall infection virulence and show the need for in vivo testing to fully assess pathogenicity.

  1. Effects of Intra- and Interpatch Host Density on Egg Parasitism by Three Species of Trichogramma

    Science.gov (United States)

    Grieshop, Matthew J.; Flinn, Paul W.; Nechols, James R.

    2010-01-01

    Host-foraging responses to different intra- and interpatch densities were used to assess three Trichogramma spp. (Hymenoptera: Trichogrammatidae) Trichogramma deion Pinto and Oatman, T. ostriniae Pang and Chen, and T. pretiosum Riley — as potential biological control agents for the Indian meal moth, Plodia interpunctella Hübner (Lepidoptera: Pyralidae). Single naïve females were allowed 6 h to forage in Plexiglas arenas with four different spatial arrangements of host eggs, nine single-egg patches), nine four-egg patches, 36 single-egg patches, and 36 four-egg patches. No significant differences were found among species in the number of patches parasitized. As expected, all three species parasitized the most eggs in the 36 four-egg patch treatment and the least in the nine single-egg patch treatment. T. deion parasitized significantly more eggs than T. pretiosum on the nine four-egg patches. T. ostriniae parasitized significantly more patches when intrapatch density was greater, regardless of interpatch density. In contrast, T. deion only parasitized more patches at the greater intrapatch density when the interpatch density was low. Patch density had no effect on T. pretiosum. The spatial pattern of parasitism was more aggregated for T. deion and T. ostriniae in the 36 four-egg patches treatment compared to the 36 single-egg patches treatment. Therefore, intrapatch density was more important than interpatch density for T. ostriniae, and potentially for T. deion, but not for T. pretiosum. T. deion may be the best candidate for augmentative biological control because it parasitized either slightly or significantly more eggs than the other two species in all four treatments. Furthermore, the pattern of parasitism by T. deion in the 36 four-egg patches treatment was the most aggregated among the three species, suggesting a more thorough searching pattern. In contrast, T. pretiosum had the least aggregated pattern of parasitism and therefore may have used a more

  2. Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae Driven by Geographical Isolation and Host Plant Acquirement

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    Gexia Qiao

    2012-08-01

    Full Text Available The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI and Cytochrome b (Cytb genes, the nuclear elongation factor-1α (EF-1α gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago, Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall, it can be concluded that geographical isolation and the expansion of the host plant range may be the main factors driving species differentiation of Mollitrichosiphum.

  3. Rodent-Borne Bartonella Infection Varies According to Host Species Within and Among Cities.

    Science.gov (United States)

    Peterson, Anna C; Ghersi, Bruno M; Alda, Fernando; Firth, Cadhla; Frye, Matthew J; Bai, Ying; Osikowicz, Lynn M; Riegel, Claudia; Lipkin, W Ian; Kosoy, Michael Y; Blum, Michael J

    2017-12-01

    It is becoming increasingly likely that rodents will drive future disease epidemics with the continued expansion of cities worldwide. Though transmission risk is a growing concern, relatively little is known about pathogens carried by urban rats. Here, we assess whether the diversity and prevalence of Bartonella bacteria differ according to the (co)occurrence of rat hosts across New Orleans, LA (NO), where both Norway (Rattus norvegicus) and roof rats (Rattus rattus) are found, relative to New York City (NYC) which only harbors Norway rats. We detected human pathogenic Bartonella species in both NYC and New Orleans rodents. We found that Norway rats in New Orleans harbored a more diverse assemblage of Bartonella than Norway rats in NYC and that Norway rats harbored a more diverse and distinct assemblage of Bartonella compared to roof rats in New Orleans. Additionally, Norway rats were more likely to be infected with Bartonella than roof rats in New Orleans. Flea infestation appears to be an important predictor of Bartonella infection in Norway rats across both cities. These findings illustrate that pathogen infections can be heterogeneous in urban rodents and indicate that further study of host species interactions could clarify variation in spillover risk across cities.

  4. New Raffaelea species (Ophiostomatales) from the USA and Taiwan associated with ambrosia beetles and plant hosts.

    Science.gov (United States)

    Simmons, D Rabern; de Beer, Z Wilhelm; Huang, Yin-Tse; Bateman, Craig; Campbell, Alina S; Dreaden, Tyler J; Li, You; Ploetz, Randy C; Black, Adam; Li, Hou-Feng; Chen, Chi-Yu; Wingfield, Michael J; Hulcr, Jiri

    2016-12-01

    Raffaelea (Ophiostomatales) is a genus of more than 20 ophiostomatoid fungi commonly occurring in symbioses with wood-boring ambrosia beetles. We examined ambrosia beetles and plant hosts in the USA and Taiwan for the presence of these mycosymbionts and found 22 isolates representing known and undescribed lineages in Raffaelea. From 28S rDNA and β-tubulin sequences, we generated a molecular phylogeny of Ophiostomatales and observed morphological features of seven cultures representing undescribed lineages in Raffaelea s. lat. From these analyses, we describe five new species in Raffaelea s. lat.: R. aguacate, R. campbellii, R. crossotarsa, R. cyclorhipidia, and R. xyleborina spp. nov. Our analyses also identified two plant-pathogenic species of Raffaelea associated with previously undocumented beetle hosts: (1) R. quercivora, the causative agent of Japanese oak wilt, from Cyclorhipidion ohnoi and Crossotarsus emancipatus in Taiwan, and (2) R. lauricola, the pathogen responsible for laurel wilt, from Ambrosiodmus lecontei in Florida. The results of this study show that Raffaelea and associated ophiostomatoid fungi have been poorly sampled and that future investigations on ambrosia beetle mycosymbionts should reveal a substantially increased diversity.

  5. Characterization of viral RNA splicing using whole-transcriptome datasets from host species.

    Science.gov (United States)

    Zhou, Chengran; Liu, Shanlin; Song, Wenhui; Luo, Shiqi; Meng, Guanliang; Yang, Chentao; Yang, Hua; Ma, Jinmin; Wang, Liang; Gao, Shan; Wang, Jian; Yang, Huanming; Zhao, Yun; Wang, Hui; Zhou, Xin

    2018-02-19

    RNA alternative splicing (AS) is an important post-transcriptional mechanism enabling single genes to produce multiple proteins. It has been well demonstrated that viruses deploy host AS machinery for viral protein productions. However, knowledge on viral AS is limited to a few disease-causing viruses in model species. Here we report a novel approach to characterizing viral AS using whole transcriptome dataset from host species. Two insect transcriptomes (Acheta domesticus and Planococcus citri) generated in the 1,000 Insect Transcriptome Evolution (1KITE) project were used as a proof of concept using the new pipeline. Two closely related densoviruses (Acheta domesticus densovirus, AdDNV, and Planococcus citri densovirus, PcDNV, Ambidensovirus, Densovirinae, Parvoviridae) were detected and analyzed for AS patterns. The results suggested that although the two viruses shared major AS features, dramatic AS divergences were observed. Detailed analysis of the splicing junctions showed clusters of AS events occurred in two regions of the virus genome, demonstrating that transcriptome analysis could gain valuable insights into viral splicing. When applied to large-scale transcriptomics projects with diverse taxonomic sampling, our new method is expected to rapidly expand our knowledge on RNA splicing mechanisms for a wide range of viruses.

  6. Swimmer's Itch in Belgium: First Recorded Outbreaks, Molecular Identification of the Parasite Species and Intermediate Hosts.

    Science.gov (United States)

    Caron, Yannick; Cabaraux, Ariane; Marechal, Françoise; Losson, Bertrand

    2017-03-01

    Cercarial dermatitis or swimmer's itch is a skin condition in humans due to the larval forms of bird schistosomes of some species of the genus Trichobilharzia. The life cycle of these schistosomes requires freshwater snails (intermediate host) and waterfowl (definitive host). Repeated exposures to cercariae can lead to skin sensitization with the induction of pruritic skin lesions. We describe, in this study, two outbreaks of human cercarial dermatitis at the Eau d'Heure Lakes, Belgium. In July and August 2012, a total of, respectively, 78 and 10 people reported a sudden skin rash accompanied by pruritus following recreational activities in the Plate Taille Lake. However, no ocellate furcocercariae were detected following light exposure of the snails collected between September 2012 and September 2013 (n = 402). No outbreaks were recorded in 2013 and 2014. In August 2015, about 30 new cases were recorded. Snails were collected (n = 270) in different locations around the lake. PCR was used to identify accurately the intermediate hosts and the parasite species involved. After light exposure, seven Radix spp. (2.6%) shed ocellate furcocercariae. Molecular identification based on the rDNA internal transcribed spacer 2 sequence ascribed the infected snails to R. balthica ( = R. peregra = R. ovata) (6/7) and R. auricularia (1/7). Based on the amplification of the D2 domain of the 28S rDNA, the cercariae were shown to belong to two different haplotypes of Trichobilharzia franki. This is the first record in Belgium of T. franki and associated skin condition.

  7. Are parasite richness and abundance linked to prey species richness and individual feeding preferences in fish hosts?

    Science.gov (United States)

    Cirtwill, Alyssa R; Stouffer, Daniel B; Poulin, Robert; Lagrue, Clément

    2016-01-01

    Variations in levels of parasitism among individuals in a population of hosts underpin the importance of parasites as an evolutionary or ecological force. Factors influencing parasite richness (number of parasite species) and load (abundance and biomass) at the individual host level ultimately form the basis of parasite infection patterns. In fish, diet range (number of prey taxa consumed) and prey selectivity (proportion of a particular prey taxon in the diet) have been shown to influence parasite infection levels. However, fish diet is most often characterized at the species or fish population level, thus ignoring variation among conspecific individuals and its potential effects on infection patterns among individuals. Here, we examined parasite infections and stomach contents of New Zealand freshwater fish at the individual level. We tested for potential links between the richness, abundance and biomass of helminth parasites and the diet range and prey selectivity of individual fish hosts. There was no obvious link between individual fish host diet and helminth infection levels. Our results were consistent across multiple fish host and parasite species and contrast with those of earlier studies in which fish diet and parasite infection were linked, hinting at a true disconnect between host diet and measures of parasite infections in our study systems. This absence of relationship between host diet and infection levels may be due to the relatively low richness of freshwater helminth parasites in New Zealand and high host-parasite specificity.

  8. Intraguild interactions implicating invasive species: Harmonia axyridis as a model species

    Directory of Open Access Journals (Sweden)

    Francis, F.

    2010-01-01

    Full Text Available Understanding the mechanisms that result in the success of exotic species will contribute to predicting future invasions and managing invaded systems. Exotic animal species, whether introduced accidentally or deliberately, may impact communities of native species through different intraguild interactions. As an effective generalist predator of aphids and other soft-body pests the harlequin ladybird Harmonia axyridis Pallas has been a successful biological control agent. This species was deliberately introduced into several countries for biological control of different arthropods pests, but it was also introduced accidentally into several other countries. It became an invasive species, affecting the dynamic and composition of several guilds through direct or indirect interactions. In this paper we will specifically review the existing data on mechanisms of intraguild interactions, within exotic guilds, that result in the success of H. axyridis as an invasive alien. We will use these studies to interpret the observed population declines in predator diversity in the field, and predict species at risk in regions not yet invaded. Finally, we will review the available data on the impact of intraguild interactions implicating H. axyridis on pest biocontrol.

  9. Molecular phylogeny and diagnosis of species of the family Protostrongylidae from caprine hosts in Uzbekistan.

    Science.gov (United States)

    Kuchboev, Abdurakhim E; Krücken, Jürgen; Ruziev, Bakhtiyor H; von Samson-Himmelstjerna, Georg

    2015-04-01

    Protostrongylids are important pulmonary parasites of ungulates, particularly caprines. Their complex life cycles involve terrestrian gastropods as intermediate hosts. Morphological discrimination of larvae in feces and snails is impossible to the species level, and molecular data are missing for many species. To improve diagnosis and epidemiology of protostrongylids, this study describes internal transcribed spacer 2 (ITS-2) sequences for five protostrongylid and one metastrongylid species from Uzbekistan. Morphological and molecular analyses identified Protostrongylus rufescens, Protostrongylus hobmaieri, Protostrongylus sp., Spiculocaulus leuckarti, and Cystocaulus ocreatus. Sequence differences between ITS-2 were sufficient to allow species identification, e.g., in the Protostrongylinae intraspecific and interspecific genetic distances ranged between 0-0.01 and 0.05 and 0.16, respectively. There was one exception in the Elaphostrongylidae with identical ITS-2 sequences in Elaphostrongylus cervi and Elaphostrongylus rangiferi questioning their status as valid species. Maximum likelihood analysis sequences largely supported the currently assumed phylogenetic relationships among Protostrongylidae as predicted using morphological characters. The monophyly of the subfamilies Varestrongylinae, Elaphostrongylinae, and Protostrongylinae was corroborated with support values in Shimodaira-Hasegawa or Bayesian modifications of the approximate likelihood ratio test (aLRT) ≥97%, but support for Muellerinae was weak (8 and 52%, respectively) since Muellerius capillaris differs significantly from the other Muellerinae. On the genus level, paraphyly of the genus Protostrongylus was confirmed since the members of the genera Spiculocaulus and Orthostrongylus were located within the Protostrongylus cluster (aLRT ≥99%). Maximum likelihood unequivocally assigned every unique sequence to the correct species confirming suitability of ITS-2 regions for diagnosis protostrongylids

  10. Determining Intermediate Hosts for Opecoelidae and Microphallidae Species (Platyhelminthes: Trematoda) in the Southeastern Pacific Coast, Using Molecular Markers.

    Science.gov (United States)

    Leiva, Natalia Verónica; López, Zambra; González, María Teresa; Muñoz, Gabriela

    2017-02-01

    Metacercarial stages of digeneans were collected from decapod crustaceans inhabiting intertidal rocky zones in central Chile. The digeneans were identified through a molecular analysis based on the V4 region of the 18S ribosomal RNA gene. We analyzed 356 crustaceans belonging to 10 species, 115 intertidal fish belonging to 6 species, and 4 specimens of 1 coastal bird species. In total, 74.1% of crustaceans were parasitized with metacercariae. We found 1 species of Opecoelidae. This species showed low genetic divergence (0% and 0.1%) with adult digeneans found in intertidal fish and with the species Helicometrina labrisomi infesting a subtidal fish from northern Chile (Labrisomus philippii). Additionally, we found 2 species of Microphallidae, 1 closely related to Maritrema (1.3% genetic distance) and the other related to Microphallus (5% genetic distance). Therefore, our findings showed that the decapod crustaceans are relevant hosts in food webs from the southeastern Pacific coast. Furthermore, we found 5 species of crustaceans as second intermediate hosts for H. labrisomi and 2 species as secondary intermediate hosts for 2 Microphallidae, which contribute to elucidate parts of their life cycles through molecular markers and extended the host distribution of H. labrisomi in the southeastern Pacific coast.

  11. Extensive transcription analysis of the Hyposoter didymator Ichnovirus genome in permissive and non-permissive lepidopteran host species.

    Science.gov (United States)

    Dorémus, Tristan; Cousserans, François; Gyapay, Gabor; Jouan, Véronique; Milano, Patricia; Wajnberg, Eric; Darboux, Isabelle; Cônsoli, Fernando Luis; Volkoff, Anne-Nathalie

    2014-01-01

    Ichnoviruses are large dsDNA viruses that belong to the Polydnaviridae family. They are specifically associated with endoparasitic wasps of the family Ichneumonidae and essential for host parasitization by these wasps. We sequenced the Hyposoter didymator Ichnovirus (HdIV) encapsidated genome for further analysis of the transcription pattern of the entire set of HdIV genes following the parasitization of four different lepidopteran host species. The HdIV genome was found to consist of at least 50 circular dsDNA molecules, carrying 135 genes, 98 of which formed 18 gene families. The HdIV genome had general features typical of Ichnovirus (IV) genomes and closely resembled that of the IV carried by Hyposoter fugitivus. Subsequent transcriptomic analysis with Illumina technology during the course of Spodoptera frugiperda parasitization led to the identification of a small subset of less than 30 genes with high RPKM values in permissive hosts, consisting with these genes encoding crucial virulence proteins. Comparisons of HdIV expression profiles between host species revealed differences in transcript levels for given HdIV genes between two permissive hosts, S. frugiperda and Pseudoplusia includens. However, we found no evident intrafamily gene-specific transcription pattern consistent with the presence of multigenic families within IV genomes reflecting an ability of the wasps concerned to exploit different host species. Interestingly, in two non-permissive hosts, Mamestra brassiccae and Anticarsia gemmatalis (most of the parasitoid eggs were eliminated by the host cellular immune response), HdIV genes were generally less strongly transcribed than in permissive hosts. This suggests that successful parasitism is dependent on the expression of given HdIV genes exceeding a particular threshold value. These results raise questions about the mecanisms involved in regulating IV gene expression according to the nature of the lepidopteran host species encountered.

  12. Extensive transcription analysis of the Hyposoter didymator Ichnovirus genome in permissive and non-permissive lepidopteran host species.

    Directory of Open Access Journals (Sweden)

    Tristan Dorémus

    Full Text Available Ichnoviruses are large dsDNA viruses that belong to the Polydnaviridae family. They are specifically associated with endoparasitic wasps of the family Ichneumonidae and essential for host parasitization by these wasps. We sequenced the Hyposoter didymator Ichnovirus (HdIV encapsidated genome for further analysis of the transcription pattern of the entire set of HdIV genes following the parasitization of four different lepidopteran host species. The HdIV genome was found to consist of at least 50 circular dsDNA molecules, carrying 135 genes, 98 of which formed 18 gene families. The HdIV genome had general features typical of Ichnovirus (IV genomes and closely resembled that of the IV carried by Hyposoter fugitivus. Subsequent transcriptomic analysis with Illumina technology during the course of Spodoptera frugiperda parasitization led to the identification of a small subset of less than 30 genes with high RPKM values in permissive hosts, consisting with these genes encoding crucial virulence proteins. Comparisons of HdIV expression profiles between host species revealed differences in transcript levels for given HdIV genes between two permissive hosts, S. frugiperda and Pseudoplusia includens. However, we found no evident intrafamily gene-specific transcription pattern consistent with the presence of multigenic families within IV genomes reflecting an ability of the wasps concerned to exploit different host species. Interestingly, in two non-permissive hosts, Mamestra brassiccae and Anticarsia gemmatalis (most of the parasitoid eggs were eliminated by the host cellular immune response, HdIV genes were generally less strongly transcribed than in permissive hosts. This suggests that successful parasitism is dependent on the expression of given HdIV genes exceeding a particular threshold value. These results raise questions about the mecanisms involved in regulating IV gene expression according to the nature of the lepidopteran host species

  13. Investigating differences across host species and scales to explain the distribution of the amphibian pathogen Batrachochytrium dendrobatidis.

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    Anna C Peterson

    Full Text Available Many pathogens infect more than one host species, and clarifying how these different hosts contribute to pathogen dynamics can facilitate the management of pathogens and can lend insight into the functioning of pathogens in ecosystems. In this study, we investigated a suite of native and non-native amphibian hosts of the pathogen Batrachochytrium dendrobatidis (Bd across multiple scales to identify potential mechanisms that may drive infection patterns in the Colorado study system. Specifically, we aimed to determine if: 1 amphibian populations vary in Bd infection across the landscape, 2 amphibian community composition predicts infection (e.g., does the presence or abundance of any particular species influence infection in others?, 3 amphibian species vary in their ability to produce infectious zoospores in a laboratory infection, 4 heterogeneity in host ability observed in the laboratory scales to predict patterns of Bd prevalence in the landscape. We found that non-native North American bullfrogs (Lithobates catesbeianus are widespread and have the highest prevalence of Bd infection relative to the other native species in the landscape. Additionally, infection in some native species appears to be related to the density of sympatric L. catesbeianus populations. At the smaller host scale, we found that L. catesbeianus produces more of the infective zoospore stage relative to some native species, but that this zoospore output does not scale to predict infection in sympatric wild populations of native species. Rather, landscape level infection relates most strongly to density of hosts at a wetland as well as abiotic factors. While non-native L. catesbeianus have high levels of Bd infection in the Colorado Front Range system, we also identified Bd infection in a number of native amphibian populations allopatric with L. catesbeianus, suggesting that multiple host species are important contributors to the dynamics of the Bd pathogen in this

  14. A Distinctive and Host-Restricted Gut Microbiota in Populations of a Cactophilic Drosophila Species.

    Science.gov (United States)

    Martinson, Vincent G; Carpinteyro-Ponce, Javier; Moran, Nancy A; Markow, Therese A

    2017-12-01

    Almost all animals possess gut microbial communities, but the nature of these communities varies immensely. For example, in social bees and mammals, the composition is relatively constant within species and is dominated by specialist bacteria that do not live elsewhere; in laboratory studies and field surveys of Drosophila melanogaster , however, gut communities consist of bacteria that are ingested with food and that vary widely among individuals and localities. We addressed whether an ecological specialist in its natural habitat has a microbiota dominated by gut specialists or by environmental bacteria. Drosophila nigrospiracula is a species that is endemic to the Sonoran Desert and is restricted to decaying tissues of two giant columnar cacti, Pachycereus pringlei (cardón cactus) and Carnegiea gigantea (saguaro cactus). We found that the D. nigrospiracula microbiota differs strikingly from that of the cactus tissue on which the flies feed. The most abundant bacteria in the flies are rare or completely absent in the cactus tissue and are consistently abundant in flies from different cacti and localities. Several of these fly-associated bacterial groups, such as the bacterial order Orbales and the genera Serpens and Dysgonomonas , have been identified in prior surveys of insects from the orders Hymenoptera, Coleoptera, Lepidoptera, and Diptera, including several Drosophila species. Although the functions of these bacterial groups are mostly unexplored, Orbales species studied in bees are known to break down plant polysaccharides and use the resulting sugars. Thus, these bacterial groups appear to be specialized to the insect gut environment, where they may colonize through direct host-to-host transmission in natural settings. IMPORTANCE Flies in the genus Drosophila have become laboratory models for microbiota research, yet the bacteria commonly used in these experiments are rarely found in wild-caught flies and instead represent bacteria also present in the food

  15. The Colletotrichum acutatum Species Complex as a Model System to Study Evolution and Host Specialization in Plant Pathogens

    Science.gov (United States)

    Baroncelli, Riccardo; Talhinhas, Pedro; Pensec, Flora; Sukno, Serenella A.; Le Floch, Gaetan; Thon, Michael R.

    2017-01-01

    Colletotrichum spp. infect a wide diversity of hosts, causing plant diseases on many economically important crops worldwide. The genus contains approximately 189 species organized into at least 11 major phylogenetic lineages, also known as species complexes. The Colletotrichum acutatum species complex is a diverse yet relatively closely related group of plant pathogenic fungi within this genus. Within the species complex we find a wide diversity of important traits such as host range and host preference, mode of reproduction and differences in the strategy used to infect their hosts. Research on fungal comparative genomics have attempted to find correlations in these traits and patterns of gene family evolution but such studies typically compare fungi from different genera or even different fungal Orders. The C. acutatum species complex contains most of this diversity within a group of relatively closely related species. This Perspective article presents a review of the current knowledge on C. acutatum phylogeny, biology, and pathology. It also demonstrates the suitability of C. acutatum for the study of gene family evolution on a fine scale to uncover evolutionary events in the genome that are associated with the evolution of phenotypic characters important for host interactions. PMID:29075253

  16. The Colletotrichum acutatum Species Complex as a Model System to Study Evolution and Host Specialization in Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Riccardo Baroncelli

    2017-10-01

    Full Text Available Colletotrichum spp. infect a wide diversity of hosts, causing plant diseases on many economically important crops worldwide. The genus contains approximately 189 species organized into at least 11 major phylogenetic lineages, also known as species complexes. The Colletotrichum acutatum species complex is a diverse yet relatively closely related group of plant pathogenic fungi within this genus. Within the species complex we find a wide diversity of important traits such as host range and host preference, mode of reproduction and differences in the strategy used to infect their hosts. Research on fungal comparative genomics have attempted to find correlations in these traits and patterns of gene family evolution but such studies typically compare fungi from different genera or even different fungal Orders. The C. acutatum species complex contains most of this diversity within a group of relatively closely related species. This Perspective article presents a review of the current knowledge on C. acutatum phylogeny, biology, and pathology. It also demonstrates the suitability of C. acutatum for the study of gene family evolution on a fine scale to uncover evolutionary events in the genome that are associated with the evolution of phenotypic characters important for host interactions.

  17. Effect of host diversity and species assemblage composition on bovine tuberculosis (bTB) risk in Ethiopian cattle

    NARCIS (Netherlands)

    Dejene, Sintayehu; Heitkonig, Ignas; Prins, Herbert; Tessema, Zewdu K.; Boer, de Fred

    2017-01-01

    Current theories on diversity–disease relationships describe host species diversity and species identity as important factors influencing disease risk, either diluting or amplifying disease prevalence in a community. Whereas the simple term ‘diversity’ embodies a set of animal community

  18. Effect of different hosts on feeding patterns and mortality of mosquitoes (Diptera: Culicidae and their implications on parasite transmission

    Directory of Open Access Journals (Sweden)

    Eliningaya J Kweka

    2010-01-01

    Full Text Available Aim: The host-response to hematophagus insects is still an important parameter in understanding disease transmission patterns. We investigated the feeding and mortality rates of three mosquito species, namely Culex quinquefasciatus, Aedes aegypti and Anopheles arabiensis against three different hosts. Materials and Methods: Unfed three to five-day-old female mosquitoes were released in a tunnel box that had a rabbit or guinea pig or mice as a host. The feeding succession patterns of mosquitoes in different hosts were An. arabiensis, Cx. quinquefasciatus and A. aegypti. Results: Mosquito mortality rate was 54.9% for mosquitoes introduced in mice as a host, 34.3% in the Guinea pig and 10.8% for those that introduced in the rabbit. Conclusion: The presence of defensive and tolerable hosts in environment emphasizes the relevance of studying epidemiological impact of these behaviors in relation to diseases transmission.

  19. Role of Multiple Hosts in the Cross-Species Transmission and Emergence of a Pandemic Parvovirus

    Science.gov (United States)

    Allison, Andrew B.; Harbison, Carole E.; Pagan, Israel; Stucker, Karla M.; Kaelber, Jason T.; Brown, Justin D.; Ruder, Mark G.; Keel, M. Kevin; Dubovi, Edward J.; Holmes, Edward C.

    2012-01-01

    Understanding the mechanisms of cross-species virus transmission is critical to anticipating emerging infectious diseases. Canine parvovirus type 2 (CPV-2) emerged as a variant of a feline parvovirus when it acquired mutations that allowed binding to the canine transferrin receptor type 1 (TfR). However, CPV-2 was soon replaced by a variant virus (CPV-2a) that differed in antigenicity and receptor binding. Here we show that the emergence of CPV involved an additional host range variant virus that has circulated undetected in raccoons for at least 24 years, with transfers to and from dogs. Raccoon virus capsids showed little binding to the canine TfR, showed little infection of canine cells, and had altered antigenic structures. Remarkably, in capsid protein (VP2) phylogenies, most raccoon viruses fell as evolutionary intermediates between the CPV-2 and CPV-2a strains, suggesting that passage through raccoons assisted in the evolution of CPV-2a. This highlights the potential role of alternative hosts in viral emergence. PMID:22072763

  20. Bio-organoclays based on phospholipids as immobilization hosts for biological species.

    Science.gov (United States)

    Wicklein, Bernd; Darder, Margarita; Aranda, Pilar; Ruiz-Hitzky, Eduardo

    2010-04-06

    A new type of hybrid biomaterials based on the clay minerals montmorillonite and sepiolite as well as phosphatidylcholine, acting as environment-friendly biomodifier, was prepared. The biohybrids were characterized by sampling of adsorption isotherms in different organic solvents. The results suggest bilayer formation both on the external sepiolite surface as well as in the intracrystalline space of the montmorillonite. The obtained supported lipid membranes were further investigated by X-ray diffraction, multinuclear solid state NMR, Fourier transformed IR spectroscopy and thermal analysis. From these results an adsorption model based on electrostatic interaction between the polar phospholipid headgroups and the silicate surface could be postulated. The versatility of bio-organoclays as immobilization host for biological species was demonstrated in a mycotoxin retention study.

  1. New species and host plants of Anastrepha (Diptera: Tephritidae) primarily from Peru and Bolivia.

    Science.gov (United States)

    Norrbom, Allen L; Rodriguez, Erick J; Steck, Gary J; Sutton, Bruce A; Nolazco, Norma

    2015-11-16

    Twenty-eight new species of Anastrepha are described and illustrated: A. acca (Bolivia, Peru), A. adami (Peru), A. amplidentata (Bolivia, Peru), A. annonae (Peru), A. breviapex (Peru), A. caballeroi (Peru), A. camba (Bolivia, Peru), A. cicra (Bolivia, Peru), A. disjuncta (Peru), A. durantae (Peru), A. echaratiensis (Peru), A. eminens (Peru), A. ericki (Peru), A. gonzalezi (Bolivia, Peru), A. guevarai (Peru), A. gusi (Peru), A. kimi (Colombia, Peru), A. korytkowskii (Bolivia, Peru), A. latilanceola (Bolivia, Peru), A. melanoptera (Peru), A. mollyae (Bolivia, Peru), A. perezi (Peru), A. psidivora (Peru), A. robynae (Peru), A. rondoniensis (Brazil, Peru), A. tunariensis (Bolivia, Peru), A. villosa (Bolivia), and A. zacharyi (Peru). The following host plant records are reported: A. amplidentata from Spondias mombin L. (Anacardiaceae); A. caballeroi from Quararibea malacocalyx A. Robyns & S. Nilsson (Malvaceae); A. annonae from Annona mucosa Jacq. and Annona sp. (Annonaceae); A. durantae from Duranta peruviana Moldenke (Verbenaceae); and A. psidivora from Psidium guajava L. (Myrtaceae).

  2. Host-specific parvovirus evolution in nature is recapitulated by in vitro adaptation to different carnivore species.

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    Andrew B Allison

    2014-11-01

    Full Text Available Canine parvovirus (CPV emerged as a new pandemic pathogen of dogs in the 1970s and is closely related to feline panleukopenia virus (FPV, a parvovirus of cats and related carnivores. Although both viruses have wide host ranges, analysis of viral sequences recovered from different wild carnivore species, as shown here, demonstrated that>95% were derived from CPV-like viruses, suggesting that CPV is dominant in sylvatic cycles. Many viral sequences showed host-specific mutations in their capsid proteins, which were often close to sites known to control binding to the transferrin receptor (TfR, the host receptor for these carnivore parvoviruses, and which exhibited frequent parallel evolution. To further examine the process of host adaptation, we passaged parvoviruses with alternative backgrounds in cells from different carnivore hosts. Specific mutations were selected in several viruses and these differed depending on both the background of the virus and the host cells in which they were passaged. Strikingly, these in vitro mutations recapitulated many specific changes seen in viruses from natural populations, strongly suggesting they are host adaptive, and which were shown to result in fitness advantages over their parental virus. Comparison of the sequences of the transferrin receptors of the different carnivore species demonstrated that many mutations occurred in and around the apical domain where the virus binds, indicating that viral variants were likely selected through their fit to receptor structures. Some of the viruses accumulated high levels of variation upon passage in alternative hosts, while others could infect multiple different hosts with no or only a few additional mutations. Overall, these studies demonstrate that the evolutionary history of a virus, including how long it has been circulating and in which hosts, as well as its phylogenetic background, has a profound effect on determining viral host range.

  3. A comparative analysis of genetic differentiation across six shared willow host species in leaf- and bud-galling sawflies.

    Directory of Open Access Journals (Sweden)

    Sanna A Leppänen

    Full Text Available Genetic divergence and speciation in plant-feeding insects could be driven by contrasting selection pressures imposed by different plant species and taxa. While numerous examples of host-associated differentiation (HAD have been found, the overall importance of HAD in insect diversification remains unclear, as few studies have investigated its frequency in relation to all speciation events. One promising way to infer the prevalence and repeatability of HAD is to estimate genetic differentiation in multiple insect taxa that use the same set of hosts. To this end, we measured and compared variation in mitochondrial COI and nuclear ITS2 sequences in population samples of leaf-galling Pontania and bud-galling Euura sawflies (Hymenoptera: Tenthredinidae collected from six Salix species in two replicate locations in northern Fennoscandia. We found evidence of frequent HAD in both species complexes, as individuals from the same willow species tended to cluster together on both mitochondrial and nuclear phylogenetic trees. Although few fixed differences among the putative species were found, hierarchical AMOVAs showed that most of the genetic variation in the samples was explained by host species rather than by sampling location. Nevertheless, the levels of HAD measured across specific pairs of host species were not correlated in the two focal galler groups. Hence, our results support the hypothesis of HAD as a central force in herbivore speciation, but also indicate that evolutionary trajectories are only weakly repeatable even in temporally overlapping radiations of related insect taxa.

  4. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest.

    Science.gov (United States)

    Victoriano-Romero, Elizabeth; Valencia-Díaz, Susana; Toledo-Hernández, Víctor Hugo; Flores-Palacios, Alejandro

    2017-01-01

    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4-5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds.

  5. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest

    Science.gov (United States)

    2017-01-01

    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4–5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds. PMID:28158320

  6. A transcriptomic analysis of Echinococcus granulosus larval stages: implications for parasite biology and host adaptation.

    Directory of Open Access Journals (Sweden)

    John Parkinson

    Full Text Available The cestode Echinococcus granulosus--the agent of cystic echinococcosis, a zoonosis affecting humans and domestic animals worldwide--is an excellent model for the study of host-parasite cross-talk that interfaces with two mammalian hosts. To develop the molecular analysis of these interactions, we carried out an EST survey of E. granulosus larval stages. We report the salient features of this study with a focus on genes reflecting physiological adaptations of different parasite stages.We generated ~10,000 ESTs from two sets of full-length enriched libraries (derived from oligo-capped and trans-spliced cDNAs prepared with three parasite materials: hydatid cyst wall, larval worms (protoscoleces, and pepsin/H(+-activated protoscoleces. The ESTs were clustered into 2700 distinct gene products. In the context of the biology of E. granulosus, our analyses reveal: (i a diverse group of abundant long non-protein coding transcripts showing homology to a middle repetitive element (EgBRep that could either be active molecular species or represent precursors of small RNAs (like piRNAs; (ii an up-regulation of fermentative pathways in the tissue of the cyst wall; (iii highly expressed thiol- and selenol-dependent antioxidant enzyme targets of thioredoxin glutathione reductase, the functional hub of redox metabolism in parasitic flatworms; (iv candidate apomucins for the external layer of the tissue-dwelling hydatid cyst, a mucin-rich structure that is critical for survival in the intermediate host; (v a set of tetraspanins, a protein family that appears to have expanded in the cestode lineage; and (vi a set of platyhelminth-specific gene products that may offer targets for novel pan-platyhelminth drug development.This survey has greatly increased the quality and the quantity of the molecular information on E. granulosus and constitutes a valuable resource for gene prediction on the parasite genome and for further genomic and proteomic analyses focused on

  7. Climate change risks and conservation implications for a threatened small-range mammal species

    National Research Council Canada - National Science Library

    Morueta-Holme, Naia; Fløjgaard, Camilla; Svenning, Jens-Christian

    2010-01-01

    .... We used species distribution modeling to assess the climate sensitivity, climate change risks and conservation implications for a threatened small-range mammal species, the Iberian desman (Galemys pyrenaicus...

  8. Identification of Anisakis species (Nematoda: Anisakidae) in marine fish hosts from Papua New Guinea.

    Science.gov (United States)

    Koinari, M; Karl, S; Elliot, A; Ryan, U; Lymbery, A J

    2013-03-31

    The third-stage larvae of several genera of anisakid nematodes are important etiological agents for zoonotic human anisakiasis. The present study investigated the prevalence of potentially zoonotic anisakid larvae in fish collected on the coastal shelves off Madang and Rabaul in Papua New Guinea (PNG) where fish represents a major component of the diet. Nematodes were found in seven fish species including Decapterus macarellus, Gerres oblongus, Pinjalo lewisi, Pinjalo pinjalo, Selar crumenophthalmus, Scomberomorus maculatus and Thunnus albacares. They were identified by both light and scanning electron microscopy as Anisakis Type I larvae. Sequencing and phylogenetic analysis of the ribosomal internal transcribed spacer (ITS) and the mitochondrial cytochrome C oxidase subunit II (cox2) gene identified all nematodes as Anisakis typica. This study represents the first in-depth characterisation of Anisakis larvae from seven new fish hosts in PNG. The overall prevalence of larvae was low (7.6%) and no recognised zoonotic Anisakis species were identified, suggesting a very low threat of anisakiasis in PNG. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Imprinting and the origin of parasite-host species associations in brood-parasitic indigobirds, Vidua chalybeata.

    Science.gov (United States)

    Payne; Payne; Woods; Sorenson

    2000-01-01

    Brood-parasitic village indigobirds, Vidua chalybeata, were bred in captivity and foster-reared by their normal host species, the red-billed firefinch, Lagonosticta senegala, or by an experimental foster species, the Bengalese finch, Lonchura striata. Captive-reared female indigobirds were tested as adults for mate choice and for host choice. In tests of mate choice, female indigobirds responded preferentially towards mimicry songs of male indigobirds that were similar to those of the females' own foster parents. Females reared by Bengalese finches responded to male songs that mimicked Bengalese finch song rather than to male songs that mimicked their normal host species, the firefinch. In tests of host choice, females reared by Bengalese finches laid in the nests of Bengalese finches, and females reared by firefinches laid in the nests of firefinches. Wild-caught females showed the same behaviours as captive-bred females reared by firefinches. A female indigobird's social companions (firefinch or Bengalese) following her independence of her foster parents had no effect on her sexual response to male mimicry song or her choice of a host species in brood parasitism. The results support the predictions of a model of imprinting-like behaviour development in which young indigobirds focus their attention on their foster parents, rather than a model of innate bias for songs and nests of their normal host species, or a null model of nonspecific brood parasitism and differential survival. The results provide experimental support for the recent origin of brood parasite-host associations and the significance of imprinting in speciation in these brood parasites. Copyright 2000 The Association for the Study of Animal Behaviour.

  10. Contrasting Plasticity in Ovariole Number Induced by A Dietary Effect of the Host Plants between Cactophilic Drosophila Species

    Directory of Open Access Journals (Sweden)

    Daniela Peluso

    2016-05-01

    Full Text Available Under the preference-performance hypothesis, natural selection will favor females that choose oviposition sites that optimize the fitness of their offspring. Such a preference-performance relationship may entail important consequences mainly on fitness-related traits. We used the well-characterized cactus-Drosophila system to investigate the reproductive capacity in the pair of sibling species D. buzzatii and D. koepferae reared in two alternative host plants. According to our hypothesis, ovariole number (as a proxy of reproductive capacity depends on host plant selection. Our results indicate that the capacity of D. buzzatii showed to be mild, only increasing the number of ovarioles by as much as 10% when reared in its preferred host. In contrast, D. koepferae exhibited a similar reproductive capacity across host cacti, even though it showed a preference for its primary host cactus. Our study also revealed that D. buzzatii has a larger genetic variation for phenotypic plasticity than its sibling, although ovariole number did not show clear-cut differences between species. We will discuss the weak preference-performance pattern observed in these cactophilic species in the light of nutritional and toxicological differences found between the natural host plants.

  11. New Meliolaceae from the Brazilian Atlantic forest 2: species on host families Annonaceae, Cecropiaceae, Meliaceae, Piperaceae, Rubiaceae, Rutaceae and Tiliaceae.

    Science.gov (United States)

    Pinho, Danilo Batista; Firmino, André Luiz; Ferreira-Junior, Walnir Gomes; Pereira, Olinto Liparini

    2013-01-01

    Continuing the study of black mildews in fragments of the Atlantic forest, three new species and five new records are described herein. Irenopsis luheae-grandiflorae, Meliola vicosensis and Meliola xylopia-sericiae are new species. Cecropia hololeuca, Piper gaudichaudianum and Trichilia lepidota are new hosts for Asteridiella leucosykeae, Asteridiella glabroides and Meliola trichiliae respectively. Asteridiella obesa and Meliola psychotriae var. chiococcae are reported for the first time from Brazil. The new species are described and illustrated based on light and scanning electron microscopy and tables with main characteristics of morphologically similar specimens with species collected in Viçosa are provided. Other species belonging to Meliolaceae collected on hosts belonging to the Annonaceae, Meliaceae and Tiliaceae in Brazil also were studied.

  12. Two new species of Psyttalia Walker (Hymenoptera, Braconidae, Opiinae reared from fruit-infesting tephritid (Diptera hosts in Kenya

    Directory of Open Access Journals (Sweden)

    Robert Wharton

    2009-09-01

    Full Text Available Two species of opiine Braconidae, reared from fruit-infesting Tephritidae in Kenya, are described. Psyttalia masneri sp. n. was reared from fruits of Dracaena fragrans (L. Ker Gawl. (Liliaceae infested with Taomyia marshalli Bezzi in western Kenya. Psyttalia masneri is the only opiine braconid known to attack members of the genus Taomyia. Unusual morphological features of P. masneri and its host are detailed. Psyttalia halidayi sp. n. was reared from fruits of Lettowianthus stellatus Diels (Annonaceae infested with Ceratitis rosa Karsch in coastal Kenya. Psyttalia halidayi is morphologically similar to several described species of Psyttalia that have previously been used in the biological control of tephritid pests. Unlike these other species, P. halidayi can attack and successfully develop on C. rosa, a serious pest of cultivated fruits. A list of valid species in Psyttalia is provided, along with comments on species groups and host records.

  13. What determines species richness of parasitic organisms? A meta-analysis across animal, plant and fungal hosts.

    Science.gov (United States)

    Kamiya, Tsukushi; O'Dwyer, Katie; Nakagawa, Shinichi; Poulin, Robert

    2014-02-01

    Although a small set of external factors account for much of the spatial variation in plant and animal diversity, the search continues for general drivers of variation in parasite species richness among host species. Qualitative reviews of existing evidence suggest idiosyncrasies and inconsistent predictive power for all proposed determinants of parasite richness. Here, we provide the first quantitative synthesis of the evidence using a meta-analysis of 62 original studies testing the relationship between parasite richness across animal, plant and fungal hosts, and each of its four most widely used presumed predictors: host body size, host geographical range size, host population density, and latitude. We uncover three universal predictors of parasite richness across host species, namely host body size, geographical range size and population density, applicable regardless of the taxa considered and independently of most aspects of study design. A proper match in the primary studies between the focal predictor and both the spatial scale of study and the level at which parasite species richness was quantified (i.e. within host populations or tallied across a host species' entire range) also affected the magnitude of effect sizes. By contrast, except for a couple of indicative trends in subsets of the full dataset, there was no strong evidence for an effect of latitude on parasite species richness; where found, this effect ran counter to the general latitude gradient in diversity, with parasite species richness tending to be higher further from the equator. Finally, the meta-analysis also revealed a negative relationship between the magnitude of effect sizes and the year of publication of original studies (i.e. a time-lag bias). This temporal bias may be due to the increasing use of phylogenetic correction in comparative analyses of parasite richness over time, as this correction yields more conservative effect sizes. Overall, these findings point to common underlying

  14. Molecular and morphological analysis reveals five new species of Zygophiala associated with flyspeck signs on plant hosts from China.

    Directory of Open Access Journals (Sweden)

    Liu Gao

    Full Text Available Species in the genus Zygophiala are associated with sooty blotch and flyspeck disease on a wide range of hosts. In this study, 63 Zygophiala isolates collected from flyspeck colonies on a range of plants from several regions of China were used for phylogeny, host range and geographic distribution analysis. Phylogenetic trees were constructed on four genes--internal transcribed spacer (ITS, partial translation elongation factor 1-alpha (TEF, β-tubulin (TUB2, and actin (ACT--both individually and in combination. Isolates were grouped into 11 clades among which five new species, Z. emperorae, Z. trispora, Z. musae, Z. inaequalis and Z. longispora, were described. Species of Zygophiala differed in observed host range and geographic distribution. Z. wisconsinensis and Z. emperorae were the most prevalent throughout the sampled regions of China, whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were collected only in southern China. The hosts of Z. wisconsinensis and Z. emperorae were mainly in the family Rosaceae whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were found mainly on banana (Musa spp.. Cross inoculation tests provided evidence of host specificity among SBFS species.

  15. Aggressiveness and host range of Phoma medicaginis isolated from Medicago species growing in Tunisia

    Directory of Open Access Journals (Sweden)

    Naceur DJEBALI

    2013-05-01

    Full Text Available Aggressiveness of 14 Phoma medicaginis isolates obtained from Medicago truncatula (barrel medic and M. ciliaris (ciliate medic growing in Tunisia was measured after inoculation on leaves and roots of M. truncatula. The ability of one isolate to cause disease on M. sativa (alfalfa, Cicer arietinum (chickpea, Pisum sativum (pea, Lens culinaris (lentil and Phaseolus vulgaris (common bean was also tested. The pathogen caused dark lesions that enlarged and coalesced causing yellowing and premature abscission of leaves, resulting in decreased shoot fresh weight in barrel medic plants. All P. medicaginis isolates infected barrel medic roots causing collar rot, brown root discoloration, yellowing of cotyledons and reduced shoot and root development. The pathogen colonized the cortex and the stele of plants and produced fertile pycnidia on infected roots. Symptoms on leaves allowed for greater discrimination in aggressiveness among isolates in comparison to symptoms on roots. No correlations were observed between the parameters measured on leaves and roots suggesting organ specialization in this pathogen. Phoma medicaginis infected leaves of alfalfa, pea, common bean and chickpea causing necrosis and tissue yellowing at 15 d post inoculation (dpi. Pycnidium production was observed on dead and dying foliar tissues of alfalfa, pea and common bean, but not on chickpea. The pathogen caused symptoms of collar rot and brown root discoloration on alfalfa, chickpea, pea and common bean, but did not cause symptoms on leaves or roots of lentil at 15 dpi. Phoma medicaginis was more pathogenic on barrel medic, the host of origin, in comparison to the other legumes, suggesting that these species are likely to be secondary hosts for this pathogen.

  16. Oxychlorine Species in Gale Crater and Broader Implications for Mars

    Science.gov (United States)

    Ming, Douglas W.; Sutter, Brad; Morris, Richard V.; Clark, B. C.; Mahaffy, P. H.; Archilles, C.; Wray, J. J.; Fairen, A. G.; Gellert, Ralf; Yen, Albert; hide

    2017-01-01

    Of 15 samples analyzed to date, the Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) has detected oxychlorine compounds (perchlorate or chlorate) in 12 samples. The presence of oxychlorine species is inferred from the release of oxygen at temperatures less than 600degC and HCl between 350-850degC when a sample is heated to 850degC. The O2 release temperature varies with sample, likely caused by different cations, grain size differences, or catalytic effects of other minerals. In the oxychlorine-containing samples, perchlorate abundances range from 0.06 +/- 0.03 to 1.15 +/- 0.5 wt% Cl2O7 equivalent. Comparing these results to the elemental Cl concentration measured by the Alpha Particle X-ray Spectrometer (APXS) instrument, oxychlorine species account for 5-40% of the total Cl present. The variation in oxychlorine abundance has implications for their production and preservation over time. For example, the John Klein (JK) and Cumberland (CB) samples were acquired within a few meters of each other and CB contained approximately1.2 wt% Cl2O7 equivalent while JK had approximately 0.1 wt%. One difference between the two samples is that JK has a large number of veins visible in the drill hole wall, indicating more post-deposition alteration and removal. Finally, despite Cl concentrations similar to previous samples, the last three Murray formation samples (Oudam, Marimba, and Quela) had no detectable oxygen released during pyrolysis. This could be a result of oxygen reacting with other species in the sample during pyrolysis. Lab work has shown this is likely to have occurred in SAM but it is unlikely to have consumed all the O2 released. Another explanation is that the Cl is present as chlorides, which is consistent with data from the ChemCam (Chemical Camera) and CheMin (Chemistry and Mineralogy) instruments on MSL. For example, the Quela sample has approximately1 wt% elemental Cl detected by APXS, had no detectable O2 released, and halite

  17. Oxychlorine species in Gale Crater and broader implications for Mars

    Science.gov (United States)

    Archer, Paul Douglas; Hogancamp, Joanna C.; Ming, Douglas W.; Sutter, Brad; Morris, Richard V.; Clark, Benton; Mahaffy, Paul R.; Achilles, Cherie; Wray, James J.; Gellert, Ralf; Yen, Albert; Blake, David F.; Vaniman, David T.; Glavin, Daniel P.; Eigenbrode, Jennifer L.; Trainer, Melissa G.; Navarro-González, Rafael; McKay, Christopher P.; Freissinet, Caroline; Martin, Peter

    2017-10-01

    Of 15 samples analyzed to date, the Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) has detected oxychlorine compounds (perchlorate or chlorate) in 12 samples. The presence of oxychlorine species is inferred from the release of oxygen at temperatures <600 °C and HCl between 350-850 °C when a sample is heated to 850 °C. The O2 release temperature varies with sample, likely caused by different cations, grain size differences, or catalytic effects of other minerals. In the oxychlorine-containing samples, perchlorate abundances range from 0.06 ± 0.03 to 1.15 ± 0.5 wt% Cl2O7 equivalent. Comparing these results to the elemental Cl concentration measured by the Alpha Particle X-ray Spectrometer (APXS) instrument, oxychlorine species account for 5-40% of the total Cl present.The variation in oxychlorine abundance has implications for their production and preservation over time. For example, the John Klein (JK) and Cumberland (CB) samples were acquired within a few meters of each other and CB contained ~1.2 wt% Cl2O7 equivalent while JK had ~0.1 wt%. One difference between the two samples is that JK has a large number of veins visible in the drill hole wall, indicating more post-deposition alteration and removal.Finally, despite Cl concentrations similar to previous samples, the last three Murray formation samples (Oudam, Marimba, and Quela) had no detectable oxygen released during pyrolysis. This could be a result of oxygen reacting with other species in the sample during pyrolysis. Lab work has shown this is likely to have occurred in SAM but it is unlikely to have consumed all the O2 released. Another explanation is that the Cl is present as chlorides, which is consistent with data from the ChemCam (Chemical Camera) and CheMin (Chemistry and Mineralogy) instruments on MSL. For example, the Quela sample has ~1 wt% elemental Cl detected by APXS, had no detectable O2 released, and halite (NaCl) has been tentatively identified in CheMin X

  18. Genetics of host-plant preference in the comma butterfly Polygonia c-album (Nymphalidae), and evolutionary implications

    NARCIS (Netherlands)

    Nylin, S.; Nygren, G.H.; Windig, J.J.; Janz, N.; Bergstrom, A.

    2005-01-01

    In the Lepidoptera, sex-linked genes have been found to be of importance for species differences in, for example, hostplant preference, and have been implicated in ecological speciation. Variation within species is typically not sexlinked. However, in the comma butterfly Polygonia c-album

  19. Colonization behaviors of mountain pine beetle on novel hosts: Implications for range expansion into northeastern North America.

    Science.gov (United States)

    Rosenberger, Derek W; Venette, Robert C; Maddox, Mitchell P; Aukema, Brian H

    2017-01-01

    As climates change, thermal limits may no longer constrain some native herbivores within their historical ranges. The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a tree-killing bark beetle native to western North America that is currently expanding its range. Continued eastward expansion through the newly invaded and novel jack pine (Pinus banksiana Lamb.) trees of the Canadian boreal forest could result in exposure of several species of novel potential host pines common in northeastern North America to this oligophagous herbivore. Due to the tightly co-evolved relationship between mountain pine beetle and western pine hosts, in which the insect utilizes the defensive chemistry of the host to stimulate mass attacks, we hypothesized that lack of co-evolutionary association would affect the host attraction and acceptance behaviors of this insect among novel hosts, particularly those with little known historical association with an aggressive stem-infesting insect. We studied how beetle behavior differed among the various stages of colonization on newly cut logs of four novel potential pine host species; jack, red (P. resinosa Ait.), eastern white (P. strobus L.) and Scots (P. sylvestris L.) pines, as well as two historical hosts, ponderosa (P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm.) and lodgepole (P. contorta Dougl. var. latifolia Engelm.) pines. Overall, we found that beetle colonization behaviors at each stage in the colonization process differ between pine hosts, likely due to differing chemical and physical bark traits. Pines without co-evolved constitutive defenses against mountain pine beetle exhibited reduced amounts of defensive monoterpenoid chemicals; however, such patterns also reduced beetle attraction and colonization. Neither chemical nor physical defenses fully defended trees against the various stages of host procurement that can result in tree colonization and death.

  20. Schistosomes of small mammals from the Lake Victoria Basin, Kenya: new species, familiar species, and implications for schistosomiasis control.

    Science.gov (United States)

    Hanelt, B; Mwangi, I N; Kinuthia, J M; Maina, G M; Agola, L E; Mutuku, M W; Steinauer, M L; Agwanda, B R; Kigo, L; Mungai, B N; Loker, E S; Mkoji, G M

    2010-06-01

    Recent schistosomiasis control efforts in sub-Saharan Africa have focused nearly exclusively on treatment of humans with praziquantel. However, the extent to which wild mammals act as reservoirs for Schistosoma mansoni and therefore as sources of renewed transmission following control efforts is poorly understood. With the objective to study the role of small mammals as reservoir hosts, 480 animals belonging to 9 rodent and 1 insectivore species were examined for infection with schistosomes in Kisumu, in the Lake Victoria Basin, Kenya. Animals were collected from 2 sites: near the lakeshore and from Nyabera Marsh draining into the lake. A total of 6.0% of the animals captured, including 5 murid rodent species and 1 species of shrew (Crocidura olivieri) were infected with schistosomes. Four schistosome species were recovered and identified using cox1 DNA barcoding: S. mansoni, S. bovis, S. rodhaini and S. kisumuensis, the latter of which was recently described from Nyabera Marsh. Schistosoma mansoni and S. rodhaini were found infecting the same host individual (Lophuromys flavopunctatus), suggesting that this host species could be responsible for the production of hybrid schistosomes found in the area. Although the prevalence of S. mansoni infection in these reservoir populations was low (1.5%), given their potentially vast population size, their impact on transmission needs further study. Reservoir hosts could perpetuate snail infections and favour renewed transmission to humans once control programmes have ceased.

  1. Description and host interactions of a new species of Exetasis Walker (Diptera: Acroceridae), with a key to species of the genus.

    Science.gov (United States)

    Barneche, Jorge Adrian; Gillung, Jéssica Paula; González, Alda

    2013-01-01

    Exetasis jujuyensis Gillung sp. nov. (Acroceridae) is described from Argentina and a dichotomous key to species of Exetasis Walker is provided. Detailed observations are presented on the effect of fly larval development on the behavior of the host spider (Acanthoscurria sternalis Pocock (Theraphosidae)).

  2. Wild plant species growing closely connected in a subalpine meadow host distinct root-associated bacterial communities

    Directory of Open Access Journals (Sweden)

    Kristin Aleklett

    2015-02-01

    Full Text Available Plant roots are known to harbor large and diverse communities of bacteria. It has been suggested that plant identity can structure these root-associated communities, but few studies have specifically assessed how the composition of root microbiota varies within and between plant species growing under natural conditions. We assessed the community composition of endophytic and epiphytic bacteria through high throughput sequencing using 16S rDNA derived from root tissues collected from a population of a wild, clonal plant (Orange hawkweed–Pilosella aurantiaca as well as two neighboring plant species (Oxeye daisy–Leucanthemum vulgare and Alsike clover–Trifolium hybridum. Our first goal was to determine if plant species growing in close proximity, under similar environmental conditions, still hosted unique root microbiota. Our results showed that plants of different species host distinct bacterial communities in their roots. In terms of community composition, Betaproteobacteria (especially the family Oxalobacteraceae were found to dominate in the root microbiota of L. vulgare and T. hybridum samples, whereas the root microbiota of P. aurantiaca had a more heterogeneous distribution of bacterial abundances where Gammaproteobacteria and Acidobacteria occupied a larger portion of the community. We also explored the extent of individual variance within each plant species investigated, and found that in the plant species thought to have the least genetic variance among individuals (P. aurantiaca still hosted just as diverse microbial communities. Whether all plant species host their own distinct root microbiota and plants more closely related to each other share more similar bacterial communities still remains to be fully explored, but among the plants examined in this experiment there was no trend that the two species belonging to the same family shared more similarities in terms of bacterial community composition.

  3. Chlorella species as hosts for genetic engineering and expression of heterologous proteins: Progress, challenge and perspective.

    Science.gov (United States)

    Yang, Bo; Liu, Jin; Jiang, Yue; Chen, Feng

    2016-10-01

    The species of Chlorella represent a highly specialized group of green microalgae that can produce high levels of protein. Many Chlorella strains can grow rapidly and achieve high cell density under controlled conditions and are thus considered to be promising protein sources. Many advances in the genetic engineering of Chlorella have occurred in recent years, with significant developments in successful expression of heterologous proteins for various applications. Nevertheless, a lot of obstacles remain to be addressed, and a sophisticated and stable Chlorella expression system has yet to emerge. This review provides a brief summary of current knowledge on Chlorella and an overview of recent progress in the genetic engineering of Chlorella, and highlights the advances in the development of a genetic toolbox of Chlorella for heterologous protein expression. Research directions to further exploit the Chlorella expression system with respect to both challenges and perspectives are also discussed. This paper serves as a comprehensive literature review for the Chlorella community and will provide valuable insights into future exploration of Chlorella as a promising host for heterologous protein expression. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Role of dung beetle feeding mechanisms in limiting the suitability of species as hosts for the nematode Spirocerca lupi

    DEFF Research Database (Denmark)

    du Toit, C. A.; Holter, P.; Lutermann, H.

    2012-01-01

    Various species of dung beetle serve as intermediate hosts after ingesting the embryonated eggs (1115 x 3037 mu m) of Spirocerca lupi (Spirurida: Spirocercidae) in dog faeces. The feeding mechanisms of coprophagous dung beetles restrict the size of the food particles they can ingest and hence may...

  5. A new black Aspergillus species, A. vadensis, is a promising host for homologous and heterologous protein production

    DEFF Research Database (Denmark)

    de Vries, R.P.; Burgers, K.; van de Vondervoort, P.J.I

    2004-01-01

    A new species of the group of black aspergilli, Aspergillus vadensis, was analyzed for its potential as a host for homologous and heterologous protein production. Unlike the other black aspergilli, this strain does not acidify the culture medium when nitrate is the nitrogen source and only produces...

  6. Widespread host-dependent hybrid unfitness in the pea aphid species complex.

    Science.gov (United States)

    Peccoud, Jean; de la Huerta, Manon; Bonhomme, Joël; Laurence, Cindy; Outreman, Yannick; Smadja, Carole M; Simon, Jean-Christophe

    2014-10-01

    Linking adaptive divergence to hybrid unfitness is necessary to understand the ecological factors contributing to reproductive isolation and speciation. To date, this link has been demonstrated in few model systems, most of which encompass ecotypes that occupy relatively early stages in the speciation process. Here we extend these studies by assessing how host-plant adaptation conditions hybrid fitness in the pea aphid, Acyrthosiphon pisum. We made crosses between and within five pea aphid biotypes adapted to different host plants and representing various stages of divergence within the complex. Performance of F1 hybrids and nonhybrids was assessed on a "universal" host that is favorable to all pea aphid biotypes in laboratory conditions. Although hybrids performed equally well as nonhybrids on the universal host, their performance was much lower than nonhybrids on the natural hosts of their parental populations. Hence, hybrids, rather than being intrinsically deficient, are maladapted to their parents' hosts. Interestingly, the impact of this maladaptation was stronger in certain hybrids from crosses involving the most divergent biotype, suggesting that host-dependent postzygotic isolation has continued to evolve late in divergence. Even though host-independent deficiencies are not excluded, hybrid maladaptation to parental hosts supports the hypothesis of ecological speciation in this complex. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  7. Using the Pathogen-Host Interactions database (PHI-base to investigate plant pathogen genomes and genes implicated in virulence

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    Martin eUrban

    2015-08-01

    Full Text Available New pathogen-host interaction mechanisms can be revealed by integrating mutant phenotype data with genetic information. PHI-base is a multi-species manually curated database combining peer-reviewed published phenotype data from plant and animal pathogens and gene/protein information in a single database.

  8. Analysis of Genetic Variation in Brevipalpus yothersi (Acari: Tenuipalpidae) Populations from Four Species of Citrus Host Plants.

    Science.gov (United States)

    Salinas-Vargas, Delfina; Santillán-Galicia, Ma Teresa; Guzmán-Franco, Ariel W; Hernández-López, Antonio; Ortega-Arenas, Laura D; Mora-Aguilera, Gustavo

    2016-01-01

    We studied species diversity and genetic variation among populations of Brevipalpus mites from four species of citrus host plants. We sampled mites on orange, lime, grapefruit and mandarin trees from orchards at six localities distributed in the five most important citrus producing states in Mexico. Genetic variation among citrus host plants and localities were assessed by analysis of nucleotide sequence data from fragments of the mitochondrial cytochrome oxidase subunit I (COI). Both Brevipalpus yothersi and B. californicus were found at these sites, and B. yothersi was the most abundant species found on all citrus species and in all localities sampled. B. californicus was found mainly on orange and mandarin and only in two of the states sampled. AMOVA and haplotype network analyses revealed no correlation between B. yothersi genetic population structure and geographical origin or citrus host plant species. Considering that a previous study reported greater genetic diversity in B. yothersi populations from Brazil than we observed in Mexico, we discuss the possibility that the Mexican populations may have originated in the southern region of America.

  9. Helminth infracommunity structure of Leptodactylus melanonotus (Anura) in Tres Palos, Guerrero, and other records for this host species in Mexico.

    Science.gov (United States)

    Mata-López, Rosario; León-Règagnon, Virginia; García-Prieto, Luis

    2013-06-01

    The amphibian genus Leptodactylus includes around 50 species, of which only 2 are distributed in Mexico; the helminth fauna of these 2 species is poorly known. As part of a research program on amphibian parasites in Mexico from 1997 to 2005, 281 sabinal frogs Leptodactylus melanonotus from 42 localities in 11 Mexican states were examined from a helminthological perspective. A total of 20 taxa of helminths-7 digeneans (5 adults, 2 larvae) and 13 nematodes (8 adults, 5 larvae)-was found to infect this amphibian host species. These data represent 105 new locality records, and 11 taxa are recorded in L. melanonotus for the first time. Infracommunity analyses of the sabinal frogs from Tres Palos indicated that these hosts are depauperate. The helminth community is dominated by specialist species, with Cosmocerca podicipinus the most common in almost 50% of the infracommunities. Percutaneous infection and predator-prey interactions were the 2 most common infection routes by helminths in frogs from Tres Palos, with 79% of the parasites recruited via skin penetration. Finally, our results show that the helminth fauna parasitizing L. melanonotus throughout Mexico has low similarity with the helminth fauna of leptodactylids studied comprehensively in South America, with only 2 digeneans and 3 nematodes being shared by hosts from both regions. As a result of our survey, the number of helminth species parasitizing L. melanonotus increased to 34. Considering its native distribution range, this number is now 36 with the inclusion of the nematodes Oswaldocruzia costaricensis and Cruzia empera in Costa Rica.

  10. Examining the Link between Biofilm Formation and the Ability of Pathogenic Salmonella Strains to Colonize Multiple Host Species

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    MacKenzie, Keith D.; Palmer, Melissa B.; Köster, Wolfgang L.; White, Aaron P.

    2017-01-01

    Salmonella are important pathogens worldwide and a predominant number of human infections are zoonotic in nature. The ability of strains to form biofilms, which is a multicellular behavior characterized by the aggregation of cells, is predicted to be a conserved strategy for increased persistence and survival. It may also contribute to the increasing number of infections caused by ingestion of contaminated fruits and vegetables. There is a correlation between biofilm formation and the ability of strains to colonize and replicate within the intestines of multiple host species. These strains predominantly cause localized gastroenteritis infections in humans. In contrast, there are salmonellae that cause systemic, disseminated infections in a select few host species; these “invasive” strains have a narrowed host range, and most are unable to form biofilms. This includes host-restricted Salmonella serovar Typhi, which are only able to infect humans, and atypical gastroenteritis strains associated with the opportunistic infection of immunocompromised patients. From the perspective of transmission, biofilm formation is advantageous for ensuring pathogen survival in the environment. However, from an infection point of view, biofilm formation may be an anti-virulence trait. We do not know if the capacity to form biofilms prevents a strain from accessing the systemic compartments within the host or if loss of the biofilm phenotype reflects a change in a strain’s interaction with the host. In this review, we examine the connections between biofilm formation, Salmonella disease states, degrees of host adaptation, and how this might relate to different transmission patterns. A better understanding of the dynamic lifecycle of Salmonella will allow us to reduce the burden of livestock and human infections caused by these important pathogens. PMID:29159172

  11. Powdery mildew of Chrysanthemum × morifolium: phylogeny and taxonomy in the context of Golovinomyces species on Asteraceae hosts.

    Science.gov (United States)

    Bradshaw, Michael; Braun, Uwe; Götz, Monika; Meeboon, Jamjan; Takamatsu, Susumu

    2017-01-01

    The taxonomic history of the common powdery mildew of Chrysanthemum × morifolium (chrysanthemum, florist's daisy), originally described in Germany as Oidium chrysanthemi, is discussed. The position of O. chrysanthemi was investigated on the basis of morphological traits and molecular phylogenetic analyses. Based on the results of this study, this species, which is closely related to Golovinomyces artemisae, was reassessed and reallocated to Golovinomyces. The phylogenetic analysis and taxonomic reassessment of the chrysanthemum powdery mildew is supplemented by a morphological description, a summary of its worldwide distribution data, and a brief discussion of the introduction of this fungus to North America. G. chrysanthemi differs from true G. artemisiae in that it has much longer conidiophores, is not constricted at the base, and has much larger and most importantly longer conidia. The close affinity of Golovinomyces to Artemisia and Chrysanthemum species signifies a coevolutionary event between the powdery mildews concerned and their host species in the subtribe Artemisiinae (Asteraceae tribe Anthemideae). This conclusion is fully supported by the current phylogeny and taxonomy of the host plant genera and the coevolution that occurred with the host and pathogen. The following powdery mildew species, which are associated with hosts belonging to the tribe Anthemideae of the Asteraceae, are epitypified: Alphitomorpha depressa β artemisiae (≡ Alphitomorpha artemisiae), Erysiphe artemisiae, and Oidium chrysanthemi. Erysiphe macrocarpa is neotypified. Their sequences were retrieved from the epitype collections and have been added to the phylogenetic tree. Golovinomyces orontii, an additional powdery mildew species on Chrysanthemum ×morifolium, is reported. This species is rarely found as a spontaneous infection and was obtained from inoculation experiments.

  12. Effects of host species and population density on Anoplophora glabripennis flight propensity

    Science.gov (United States)

    Joseph A. Francese; David R. Lance; Baode Wang; Zhichun Xu; Alan J. Sawyer; Victor C. Mastro

    2007-01-01

    Anoplophora glabripennis Motschulsky (Coleoptera: Cerambycidae), the Asian longhorned beetle (ALB) is a pest of hardwoods in its native range of China. While the host range of this pest has been studied extensively, its mechanisms for host selection are still unknown. Our goal was to study the factors influencing movement and orientation of adult ALB...

  13. Evolution of the M gene of the influenza A virus in different host species: large-scale sequence analysis

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    Kamigaki Taro

    2009-05-01

    Full Text Available Abstract Background Influenza A virus infects not only humans, but also other species including avian and swine. If a novel influenza A subtype acquires the ability to spread between humans efficiently, it could cause the next pandemic. Therefore it is necessary to understand the evolutionary processes of influenza A viruses in various hosts in order to gain better knowledge about the emergence of pandemic virus. The virus has segmented RNA genome and 7th segment, M gene, encodes 2 proteins. M1 is a matrix protein and M2 is a membrane protein. The M gene may be involved in determining host tropism. Besides, novel vaccines targeting M1 or M2 protein to confer cross subtype protection have been under development. We conducted the present study to investigate the evolution of the M gene by analyzing its sequence in different species. Results Phylogenetic tree revealed host-specific lineages and evolution rates were different among species. Selective pressure on M2 was stronger than that on M1. Selective pressure on M1 for human influenza was stronger than that for avian influenza, as well as M2. Site-by-site analyses identified one site (amino acid position 219 in M1 as positively selected in human. Positions 115 and 121 in M1, at which consensus amino acids were different between human and avian, were under negative selection in both hosts. As to M2, 10 sites were under positive selection in human. Seven sites locate in extracellular domain. That might be due to host's immune pressure. One site (position 27 positively selected in transmembrane domain is known to be associated with drug resistance. And, two sites (positions 57 and 89 locate in cytoplasmic domain. The sites are involved in several functions. Conclusion The M gene of influenza A virus has evolved independently, under different selective pressure on M1 and M2 among different hosts. We found potentially important sites that may be related to host tropism and immune responses. These

  14. Evolution of the M gene of the influenza A virus in different host species: large-scale sequence analysis.

    Science.gov (United States)

    Furuse, Yuki; Suzuki, Akira; Kamigaki, Taro; Oshitani, Hitoshi

    2009-05-29

    Influenza A virus infects not only humans, but also other species including avian and swine. If a novel influenza A subtype acquires the ability to spread between humans efficiently, it could cause the next pandemic. Therefore it is necessary to understand the evolutionary processes of influenza A viruses in various hosts in order to gain better knowledge about the emergence of pandemic virus. The virus has segmented RNA genome and 7th segment, M gene, encodes 2 proteins. M1 is a matrix protein and M2 is a membrane protein. The M gene may be involved in determining host tropism. Besides, novel vaccines targeting M1 or M2 protein to confer cross subtype protection have been under development. We conducted the present study to investigate the evolution of the M gene by analyzing its sequence in different species. Phylogenetic tree revealed host-specific lineages and evolution rates were different among species. Selective pressure on M2 was stronger than that on M1. Selective pressure on M1 for human influenza was stronger than that for avian influenza, as well as M2. Site-by-site analyses identified one site (amino acid position 219) in M1 as positively selected in human. Positions 115 and 121 in M1, at which consensus amino acids were different between human and avian, were under negative selection in both hosts. As to M2, 10 sites were under positive selection in human. Seven sites locate in extracellular domain. That might be due to host's immune pressure. One site (position 27) positively selected in transmembrane domain is known to be associated with drug resistance. And, two sites (positions 57 and 89) locate in cytoplasmic domain. The sites are involved in several functions. The M gene of influenza A virus has evolved independently, under different selective pressure on M1 and M2 among different hosts. We found potentially important sites that may be related to host tropism and immune responses. These sites may be important for evolutional process in different

  15. Screening low fire blight susceptible Crataegus species for host suitability to hawthorn leaf-curling aphids (Dysaphis spp.).

    Science.gov (United States)

    Bribosia, E; Bylemans, D; Van Impe, G; Migon, M

    2002-01-01

    The group of hawthorn leaf-curling aphids (Dysaphis spp.) hosted by the common hawthorn Crataegus monogyna Jacq. may play an important role in the biological control of the rosy apple aphid, Dysaphis plantaginea (Passerini), by increasing reproduction opportunities for the indigenous hymenopteran parasitoid Ephedrus persicae Froggatt. Unfortunately, most fruitgrowers hesitate to introduce the common hawthorn in their orchards because they fear fire blight infections which may be transmitted by this highly susceptible hawthron species. This potential hazard led us to investigate the suitability to leaf-curling aphids of alternative Crataegus species. As representative for these closely-related aphids, the species Dysaphis apiifolia petroselini (Börner) was used in the trials. Ten Crataegus species characterized by their very low susceptibility to fire blight were examined from two angles. Firstly, aphid sexuals were introduced in autumn onto the different species to verify whether egg laying could take place. Secondly, the development of fundatrices and gall formation were followed the next spring. Although eggs and mature fundatrices could be obtained on almost all species, no fundatrice-hosting galls were recorded in spring. The possible causes of these negative results with respect to the geographical origin of the particular Crataegus species involved in this work are discussed.

  16. Multilocus sequence typing of a global collection of Pasteurella multocida isolates from cattle and other host species demonstrates niche association

    Directory of Open Access Journals (Sweden)

    Lainson F Alex

    2011-05-01

    Full Text Available Abstract Background Pasteurella multocida causes disease in many host species throughout the world. In bovids, it contributes to bovine respiratory disease (BRD and causes haemorrhagic septicaemia (HS. Previous studies have suggested that BRD-associated P. multocida isolates are of limited diversity. A multilocus sequence typing (MLST scheme for P. multocida was used to determine whether the low levels of diversity reported are due to the limited discriminatory power of the typing method used, restricted sample selection or true niche association. Bovine respiratory isolates of P. multocida (n = 133 from the UK, the USA and France, collected between 1984 and 2008 from both healthy and clinically affected animals, were typed using MLST. Isolates of P. multocida from cases of HS, isolates from other host species and data from the MLST database were used as comparison. Results Bovine respiratory isolates were found to be clonal (ISA 0.45 with 105/128 belonging to clonal complex 13 (CC13. HS isolates were not related to bovine respiratory isolates. Of the host species studied, the majority had their own unique sequence types (STs, with few STs being shared across host species, although there was some cross over between porcine and bovine respiratory isolates. Avian, ovine and porcine isolates showed greater levels of diversity compared to cattle respiratory isolates, despite more limited geographic origins. Conclusions The homogeneity of STs of bovine respiratory P. multocida observed, and the differences between these and P. multocida subpopulations from bovine non-respiratory isolates and non-bovine hosts may indicate niche association.

  17. Heavy metals in five Sabellidae species (Annelida, Polychaeta): ecological implications.

    Science.gov (United States)

    Giangrande, Adriana; Licciano, Margherita; Del Pasqua, Michela; Fanizzi, Francesco Paolo; Migoni, Danilo; Stabili, Loredana

    2017-02-01

    The present work analyzed three hard-bottom and two soft-bottom species of sabellid polychaetes to determine the content of several heavy metals in their branchial crown and body. The highest concentrations of heavy metals were recorded in the hard-bottom species Branchiomma bairdi, a recent Mediterranean introduction. Differences in the metal concentrations were most notable in the high trace metal levels of the branchial crown for all the studied species. Statistical analysis showed that the Mediterranean hard-bottom species were similar each other in their heavy metal content in the body as well as in the branchial crown and appeared separated from all the other species. Arsenic and vanadium hyperaccumulation in the branchial crowns of the considered sabellid species probably acts as a deterrent for predation. The observed differences among the examined species were discussed not only at the light of habitat colonization but also in terms of the phylogeny.

  18. Comparative expression profiling of Leishmania: modulation in gene expression between species and in different host genetic backgrounds.

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    Daniel P Depledge

    2009-07-01

    Full Text Available Genome sequencing of Leishmania species that give rise to a range of disease phenotypes in the host has revealed highly conserved gene content and synteny across the genus. Only a small number of genes are differentially distributed between the three species sequenced to date, L. major, L. infantum and L. braziliensis. It is not yet known how many of these genes are expressed in the disease-promoting intracellular amastigotes of these species or whether genes conserved between the species are differentially expressed in the host.We have used customised oligonucleotide microarrays to confirm that all of the differentially distributed genes identified by genome comparisons are expressed in intracellular amastigotes, with only a few of these subject to regulation at the RNA level. In the first large-scale study of gene expression in L. braziliensis, we show that only approximately 9% of the genes analysed are regulated in their RNA expression during the L. braziliensis life cycle, a figure consistent with that observed in other Leishmania species. Comparing amastigote gene expression profiles between species confirms the proposal that Leishmania transcriptomes undergo little regulation but also identifies conserved genes that are regulated differently between species in the host. We have also investigated whether host immune competence influences parasite gene expression, by comparing RNA expression profiles in L. major amastigotes derived from either wild-type (BALB/c or immunologically compromised (Rag2(-/- gamma(c (-/- mice. While parasite dissemination from the site of infection is enhanced in the Rag2(-/- gamma(c (-/- genetic background, parasite RNA expression profiles are unperturbed.These findings support the hypothesis that Leishmania amastigotes are pre-adapted for intracellular survival and undergo little dynamic modulation of gene expression at the RNA level. Species-specific parasite factors contributing to virulence and pathogenicity

  19. Host species and environmental effects on bacterial communities associated with Drosophila in the laboratory and in the natural environment.

    Directory of Open Access Journals (Sweden)

    Fabian Staubach

    Full Text Available The fruit fly Drosophila is a classic model organism to study adaptation as well as the relationship between genetic variation and phenotypes. Although associated bacterial communities might be important for many aspects of Drosophila biology, knowledge about their diversity, composition, and factors shaping them is limited. We used 454-based sequencing of a variable region of the bacterial 16S ribosomal RNA gene to characterize the bacterial communities associated with wild and laboratory Drosophila isolates. In order to specifically investigate effects of food source and host species on bacterial communities, we analyzed samples from wild Drosophila melanogaster and D. simulans collected from a variety of natural substrates, as well as from adults and larvae of nine laboratory-reared Drosophila species. We find no evidence for host species effects in lab-reared flies; instead, lab of origin and stochastic effects, which could influence studies of Drosophila phenotypes, are pronounced. In contrast, the natural Drosophila-associated microbiota appears to be predominantly shaped by food substrate with an additional but smaller effect of host species identity. We identify a core member of this natural microbiota that belongs to the genus Gluconobacter and is common to all wild-caught flies in this study, but absent from the laboratory. This makes it a strong candidate for being part of what could be a natural D. melanogaster and D. simulans core microbiome. Furthermore, we were able to identify candidate pathogens in natural fly isolates.

  20. Host Species and Environmental Effects on Bacterial Communities Associated with Drosophila in the Laboratory and in the Natural Environment

    Science.gov (United States)

    Staubach, Fabian; Baines, John F.; Künzel, Sven; Bik, Elisabeth M.; Petrov, Dmitri A.

    2013-01-01

    The fruit fly Drosophila is a classic model organism to study adaptation as well as the relationship between genetic variation and phenotypes. Although associated bacterial communities might be important for many aspects of Drosophila biology, knowledge about their diversity, composition, and factors shaping them is limited. We used 454-based sequencing of a variable region of the bacterial 16S ribosomal RNA gene to characterize the bacterial communities associated with wild and laboratory Drosophila isolates. In order to specifically investigate effects of food source and host species on bacterial communities, we analyzed samples from wild Drosophila melanogaster and D. simulans collected from a variety of natural substrates, as well as from adults and larvae of nine laboratory-reared Drosophila species. We find no evidence for host species effects in lab-reared flies; instead, lab of origin and stochastic effects, which could influence studies of Drosophila phenotypes, are pronounced. In contrast, the natural Drosophila–associated microbiota appears to be predominantly shaped by food substrate with an additional but smaller effect of host species identity. We identify a core member of this natural microbiota that belongs to the genus Gluconobacter and is common to all wild-caught flies in this study, but absent from the laboratory. This makes it a strong candidate for being part of what could be a natural D. melanogaster and D. simulans core microbiome. Furthermore, we were able to identify candidate pathogens in natural fly isolates. PMID:23967097

  1. Reproductive isolation between two populations of Diatraea saccharalis (F.) (Lepidoptera: Crambidae) from different host plant species and regions in Argentina.

    Science.gov (United States)

    Fogliata, S V; Vera, A; Gastaminza, G; Cuenya, M I; Zucchi, M I; Willink, E; Castagnaro, A P; Murúa, M G

    2016-10-01

    The sugarcane borer, Diatraea saccharalis (F.), has a widespread distribution throughout the Western Hemisphere and is a pest of many crop plants including sugarcane, corn, sorghum and rice. The use of Bacillus thuringiensis (Bt) corn has been the primary tool for managing this species in corn fields. Sugarcane borer control has been recently threatened by observations of susceptibility and/or resistance to certain varieties of Bt corn and the protein used in many newer varieties. This has led to increased interest in understanding sugarcane borer genetic diversity and gene flow within and among its populations and the consequent exchange of alleles between geographically distant populations. The objective of this study was to examine reproductive compatibility between host-associated geographic populations of D. saccharalis in Argentina and to determine whether this pest represents a complex of host-associated cryptic species rather than a wide ranging generalist species. Intra and inter-population crosses revealed that D. saccharalis populations from the northwestern and Pampas regions presented evidence of prezygotic and postzygotic incompatibility. Such a result is likely to be the product of an interruption of gene flow produced by either geographic or host plant associated isolation, suggesting that Tucumán (northwestern) and Buenos Aires (Pampas) populations of D. saccharalis are a distinct genotype and possibly an incipient species.

  2. Quantification of ant manure deposition in a tropical agroecosystem: Implications for host plant nitrogen acquisition

    DEFF Research Database (Denmark)

    Pinkalski, Christian Alexander Stidsen; Damgaard, Christian; Jensen, Karl-Martin Vagn

    2015-01-01

    of ant manure may augment the host plants’ acquisition of nitrogen. In this study, we quantified the manure deposited by colonies of the Asian weaver ant Oecophylla smaragdina. We developed a method to estimate the amount of manure deposited in host trees (Mangifera indica) based on the trail activity...

  3. Taxonomy, host specificity and dietary implications of Hurleytrematoides (Digenea: Monorchiidae) from chaetodontid fishes on the Great Barrier Reef.

    Science.gov (United States)

    McNamara, M K A; Cribb, T H

    2011-09-01

    Five new and five previously described species of Hurleytrematoides are reported from 19 of 34 chaetodontid species examined from the Great Barrier Reef; new species are H. faliexae n. sp., H. galzini n. sp., H. loi n. sp., H. morandi n. sp., and H. sasali n. sp. Previously described species are H. coronatum, H. fijiensis, H. prevoti, H. bartolii, and H. zebrasomae. The genus is rediagnosed in the light of morphological variation of the new species; the degree of spination and shape of the terminal genitalia distinguish individual species. Species of Hurleytrematoides infect almost every clade of the family Chaetodontidae found on the Great Barrier Reef, but obligate corallivores are not infected. All ten species were found at Heron Island on the southern Great Barrier Reef, but only six at Lizard Island on the northern Great Barrier Reef. For three of the four species not present at Lizard Island, the absence appears to be statistically significant. Although all species are apparently restricted to chaetodontids on the GBR, specificity within the family varies from oioxenous to euryxenous; a core/satellite host paradigm explains the distribution of several species. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Host specificity of Oschmarinella rochebruni and Brachycladium atlanticum (Digenea: Brachycladiidae) in five cetacean species from western Mediterranean waters.

    Science.gov (United States)

    Mateu, P; Raga, J A; Aznar, F J

    2011-03-01

    We investigated patterns of specificity of liver flukes (fam. Brachycladiidae) in a community of cetaceans from the western Mediterranean. The liver and pancreas of 103 striped dolphins, Stenella coeruleoalba, 18 Risso's dolphins, Grampus griseus, 14 bottlenose dolphins, Tursiops truncatus, 8 common dolphins, Delphinus delphis, and 5 long-finned pilot whales, Globicephala melas, were analysed for brachycladiid species. Two species were found: Oschmarinella rochebruni in striped dolphins (prevalence (P): 61.2%; mean intensity (MI) (95% CI): 34.2 (25.7-45.6)), and Brachycladium atlanticum in striped dolphins (P: 39.8%; MI: 7.1 (4.8-13.1)) and a single individual of common dolphin (P: 12.5%; intensity: 19), which represents a new host record. A molecular analysis using the internal transcribed spacer 2 (ITS2) region of the rDNA gene confirmed that specimens of B. atlanticum were conspecific regardless of host species. Available dietary data suggest that Risso's dolphins, bottlenose dolphins and long-finned pilot whales would contact rarely, if at all, the infective stages of O. rochebruni and B. atlanticum. Neither the prevalence nor the mean abundance of B. atlanticum differed significantly between striped and common dolphins, but a principal component analysis using seven morphometric variables indicated that specimens collected from the common dolphin were stunted. These worms also had fewer eggs compared with specimens typically found in striped dolphins, although the size of the eggs was similar in both host species. Dwarfism and low fecundity have typically been found in helminths infecting unusual host species, and might reflect the lower compatibility of B. atlanticum for common dolphins. In summary, both O. rochebruni and B. atlanticum appear to exhibit a narrow specificity for striped dolphins in the western Mediterranean.

  5. Network analysis of host-virus communities in bats and rodents reveals determinants of cross-species transmission.

    Science.gov (United States)

    Luis, Angela D; O'Shea, Thomas J; Hayman, David T S; Wood, James L N; Cunningham, Andrew A; Gilbert, Amy T; Mills, James N; Webb, Colleen T

    2015-08-24

    Bats are natural reservoirs of several important emerging viruses. Cross-species transmission appears to be quite common among bats, which may contribute to their unique reservoir potential. Therefore, understanding the importance of bats as reservoirs requires examining them in a community context rather than concentrating on individual species. Here, we use a network approach to identify ecological and biological correlates of cross-species virus transmission in bats and rodents, another important host group. We show that given our current knowledge the bat viral sharing network is more connected than the rodent network, suggesting viruses may pass more easily between bat species. We identify host traits associated with important reservoir species: gregarious bats are more likely to share more viruses and bats which migrate regionally are important for spreading viruses through the network. We identify multiple communities of viral sharing within bats and rodents and highlight potential species traits that can help guide studies of novel pathogen emergence. © 2015 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  6. Molecular phylogenetics, systematics and host-plant associations of the Bruchidius albosparsus (Fåhraeus) species group (Coleoptera, Chrysomelidae, Bruchinae) with the description of four new species.

    Science.gov (United States)

    Delobel, Alex; Le Ru, Bruno; Genson, Gwenaëlle; Musyoka, Boaz K; Kergoat, Gael J

    2015-03-16

    Bruchidius Schilsky is a large paraphyletic genus of seed beetles (Coleoptera: Chrysomelidae: Bruchinae) which consists of multiple lineages that are usually associated with narrow sets of host-plants. In this study we focus on a group that mostly develops on wattle trees (acacias) belonging to the genus Vachellia Wight & Arn. This group originally included nine species and was designated as the Bruchidius centromaculatus (Allard) species group, but recent phylogenetic analyses revealed that these species belong to a much wider group of species with similar morphologies. For reasons of anteriority we call this enlarged group Bruchidius albosparsus (Fåhraeus). Here we review the morphology of species in this group and provide new diagnoses and ecological data for 10 species. The following combinations and synonymies are proposed: Bruchidius tanaensis (Pic, 1921) (= Bruchus tanaensis Pic, 1921) comb. nov. and Bruchidius albosparsus (Fåhraeus, 1839) (= Bruchus spadiceus Fåhraeus, 1839) syn. nov. Four new species are also described: B. eminingensis sp. nov., B. gerrardiicola sp. nov., B. glomeratus sp. nov. and B. haladai sp. nov. Finally we carried out molecular phylogenetic analyses on a multi-marker dataset of 59 specimens and 35 species, including 14 species from the group. The resulting trees allow us to confirm the monophyly of the group of interest and provide a more detailed picture of their evolutionary relationships.

  7. Differences in two-component signal transduction proteins among the genus Brucella: implications for host preference and pathogenesis

    DEFF Research Database (Denmark)

    Binnewies, Tim Terence; Ussery, David; Lavín, JL

    2010-01-01

    Two-component systems (TCSs) are the predominant bacterial signal transduction mechanisms. Species of the genus Brucella are genetically highly related and differ mainly in mammalian host adaptation and pathogenesis. In this study, TCS proteins encoded in the available genome sequences of Brucella...... species have been identified using bioinformatic methods. All the Brucella species share an identical set of TCS proteins, and the number of TCS proteins in the closely related opportunistic human pathogen Ochrobactrum anthropi was higher than in Brucella species as expected from its lifestyle. O....... anthropi lacks orthologs of the Brucella TCSs NodVW, TceSR and TcfSR, suggesting that these TCS proteins could be necessary for the adaptation of Brucella as an intracellular pathogen. This genomic analysis revealed the presence of a differential distribution of TCS pseudogenes among Brucella species...

  8. Cultural Keystone Species: Implications for Ecological Conservation and Restoration

    Directory of Open Access Journals (Sweden)

    Ann Garibaldi

    2004-12-01

    Full Text Available Ecologists have long recognized that some species, by virtue of the key roles they play in the overall structure and functioning of an ecosystem, are essential to its integrity; these are known as keystone species. Similarly, in human cultures everywhere, there are plants and animals that form the contextual underpinnings of a culture, as reflected in their fundamental roles in diet, as materials, or in medicine. In addition, these species often feature prominently in the language, ceremonies, and narratives of native peoples and can be considered cultural icons. Without these "cultural keystone species," the societies they support would be completely different. An obvious example is western red-cedar (Thuja plicata for Northwest Coast cultures of North America. Often prominent elements of local ecosystems, cultural keystone species may be used and harvested in large quantities and intensively managed for quality and productivity. Given that biological conservation and ecological restoration embody human cultures as crucial components, one approach that may improve success in overall conservation or restoration efforts is to recognize and focus on cultural keystone species. In this paper, we explore the concept of cultural keystone species, describe similarities to and differences from ecological keystone species, present examples from First Nations cultures of British Columbia, and discuss the application of this concept in ecological restoration and conservation initiatives.

  9. From the Atlantic Forest to the borders of Amazonia: species richness, distribution, and host association of ectoparasitic flies (Diptera: Nycteribiidae and Streblidae) in northeastern Brazil.

    Science.gov (United States)

    Barbier, Eder; Bernard, Enrico

    2017-11-01

    Better knowledge of the geographical distribution of parasites and their hosts can contribute to clarifying aspects of host specificity, as well as on the interactions among hosts, parasites, and the environment in which both exist. Ectoparasitic flies of the Nycteribiidae and Streblidae families are highly specialized hematophagous parasites of bats, whose distributional patterns, species richness, and associations with hosts remain underexplored and poorly known in Brazil. Here, we used information available in the literature and unpublished data to verify if the occurrence of bat hosts in a given environment influences the occurrence and distribution of nycteribiid and streblid flies in different ecoregions in the northeastern Brazil. We evaluate species richness and similarity between ecoregions and tested correlations between species richness and the number of studies in each ecoregion and federative unit. We recorded 50 species and 15 genera of bat ectoparasitic flies on 36 species and 27 genera of bat hosts. The Atlantic Forest had the highest fly species richness (n = 31; 62%), followed by Caatinga (n = 27; 54%). We detected the formation of distinct groups, with low species overlap between ecoregions for both flies and bats. Fly species richness was correlated with host species richness and with the number of studies in each federative unit, but not with the number of studies by ecoregion. Due to the formation of distinct groups with low species overlap for both groups, host availability is likely to be one of the factors that most influence the occurrence of highly specific flies. We also discuss host specificity for some species, produced an updated list of species and distribution for both nycteribiid and streblid flies with information on interaction networks, and conclude by presenting recommendations for more effective inventories of bat ectoparasites in the future.

  10. A new species and new host records of the quill mites (Acari: Syringophilidae) associated with sunbirds (Passeriformes: Nectariniidae).

    Science.gov (United States)

    Klimovičová, Miroslava; Smoľák, Radoslav; Njoroge, Peter; Hromada, Martin

    2014-06-01

    Neoaulonastus cinnyris sp. nov. (Acari: Prostigmata: Syringophilidae) parasitising Cinnyris mediocris (Passeriformes: Nectariniidae) from Tanzania is described. Additionally, Picobia oritis Skoracki et al. 2009 was recorded on four new hosts belonging to the family Nectariniidae from Ethiopian region: Cinnyris oustaleti (Bocage) from Angola, Cinnyris venustus (Shaw) from West Somalia, Cinnyris talatala Smith from Botswana and Zambia and Cinnyris erythrocercus (Hartlaub) from Uganda. All known quill mite species from family Nectariniidae are summarized in table.

  11. The role of diet on intestinal microbiota metabolism: downstream impacts on host immune function and health, and therapeutic implications.

    Science.gov (United States)

    Goldsmith, Jason R; Sartor, R Balfour

    2014-05-01

    Dietary impacts on health may be one of the oldest concepts in medicine; however, only in recent years have technical advances in mass spectroscopy, gnotobiology, and bacterial sequencing enabled our understanding of human physiology to progress to the point where we can begin to understand how individual dietary components can affect specific illnesses. This review explores the current understanding of the complex interplay between dietary factors and the host microbiome, concentrating on the downstream implications on host immune function and the pathogenesis of disease. We discuss the influence of the gut microbiome on body habitus and explore the primary and secondary effects of diet on enteric microbial community structure. We address the impact of consumption of non-digestible polysaccharides (prebiotics and fiber), choline, carnitine, iron, and fats on host health as mediated by the enteric microbiome. Disease processes emphasized include non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, IBD, and cardiovascular disease/atherosclerosis. The concepts presented in this review have important clinical implications, although more work needs to be done to develop fully and validate potential therapeutic approaches. Specific dietary interventions offer exciting potential for nontoxic, physiologic ways to alter enteric microbial structure and metabolism to benefit the natural history of many intestinal and systemic disorders.

  12. Development and optimization of cocktail-ELISA for a unified surveillance of zoonotic schistosomiasis in multiple host species.

    Science.gov (United States)

    Moendeg, Kharleezelle J; Angeles, Jose Ma M; Goto, Yasuyuki; Leonardo, Lydia R; Kirinoki, Masashi; Villacorte, Elena A; Rivera, Pilarita T; Inoue, Noboru; Chigusa, Yuichi; Kawazu, Shin-ichiro

    2015-03-01

    The zoonotic characteristic of the human parasite Schistosoma japonicum infecting a significant number of wild and domestic animals highlights the need to develop a unified surveillance in multiple host species for a strengthened schistosomiasis control. It has been shown in several studies that water buffaloes and dogs are considered important reservoirs in the transmission of the schistosome parasite to humans. Recombinant antigens like thioredoxin peroxidase-1 (SjTPx-1) and tandem repeat proteins (Sj1TR, Sj7TR) have been shown to be good diagnostic antigens individually in humans, water buffaloes, and dogs in previous studies. Mixing these antigens together in a cocktail-ELISA might not only improve their diagnostic potentials but rather produce a multi-host species detection means for zoonotic schistosomiasis. In this study, we aimed to develop and optimize cocktail-ELISA by testing different combinations of these recombinant antigens in humans, water buffaloes, and dogs. As compared with the diagnostic potential calculated for each of the three recombinant antigens used, their combination has presented improved specificities, positive predictive values, and kappa values. Using samples collected from various endemic areas in the Philippines, results showed that the combination of SjTPx-1/Sj7TR/Sj1TR has the highest sensitivity in humans (84.1 %), water buffaloes, and dogs (80 %) and specificity (100 %) in all host species. This study therefore suggests the use of cocktail-ELISA in improving the zoonotic surveillance in schistosomiasis endemic areas.

  13. Association between host species choice and morphological characters of main sensory structures of Culicoides in the Palaeartic region

    Directory of Open Access Journals (Sweden)

    Denis Augot

    2017-07-01

    Full Text Available Culicoides (Diptera: Ceratopogonidae serve as vectors of several mammalian and avian diseases, including bluetongue, Schmallenberg, African horse sickness, avian malaria and Oropouche. Host preference investigations are necessary to assess the transmission routes of vector-borne diseases and to inform mitigation strategies. A recent study examining the main sensory structures (palps and antennae of Culicoides species suggests that they be classified as ornithophilic or mammalophilic according to their feeding habits. We analyzed Culicoides host preferences according to the literature and carried out a multiple correspondence analysis linking these preferences with morphological data. Seven out of 12 variables were found to be reliable predictors of host preference in Culicoides species: Antenna Flagellomer-Sensilla Coeloconica-Number: (7–10 and (11–13; Antenna Flagellomer-Sensilla Coeloconica IV–X: presence; Palpus-size: wide and/or narrow opening and shallow pit; Palpus-Shape: strongly swollen; Antenna-Short sensilla trichodea-distal part segment IV to X-Number: 2 seta each. Our results demonstrate that the presence of sensilla coeloconica and the maxillary palpus can be used to separate ornithophilic and mammalophilic or ornithophilic/mammalophilic species.

  14. Roles of Host Species, Geographic Separation, and Isolation in the Seroprevalence of Jamestown Canyon and Snowshoe Hare Viruses in Newfoundland

    Science.gov (United States)

    Whitney, Hugh

    2012-01-01

    California serogroup viruses, including Jamestown Canyon virus (JCV) and snowshoe hare virus (SSHV), are mosquito-borne members of the Bunyaviridae family and are endemic across North America. These arboviruses are potential pathogens which occasionally cause neuroinvasive disease in humans and livestock. A neutralization assay was used to document JCV and SSHV seroprevalence using blood collected from a variety of domestic and wildlife host species. These species were sampled in an island setting, Newfoundland, which contains diverse ecoregions, ecological landscapes, and habitats. Seroprevalence rates for each virus differed significantly among host species and within certain species across different geographic areas. JCV was significantly associated with large mammals, and SSHV was significantly associated with snowshoe hares. Seroprevalence rates in the 5 species of animals tested for prior exposure to JCV ranged from 0% in snowshoe hares to 64% in horses. Seroprevalence rates for SSHV ranged from less than 1% in bovines to 55% in all snowshoe hares. The seroprevalence of SSHV differed significantly (P Newfoundland was associated with significantly lower JCV seroprevalence (P < 0.01) than that for cattle which had lived off-island. PMID:22798366

  15. The influence of host ecology and biogeography on the helminth species richness of freshwater fishes in Mexico.

    Science.gov (United States)

    Garrido-Olvera, L; Arita, H T; Pérez-Ponce De León, G

    2012-10-01

    Freshwater fish helminths, the most well known Mexican vertebrate parasites, include approximately 260 species (platyhelminthes, acanthocephalans, nematodes, and hirudineans). The distribution patterns of adult helminth diversity (throughout parasite and host groups and hydrological regions) are described and the effects of host traits and environmental and geographical factors on diversity are evaluated. Adult helminths include 160 species, parasitizing 149 fish species of 23 families distributed in 21 regions. Nematoda was the most species-rich (>50 species). Cichlidae harboured rich helminth assemblages, with widespread parasites. By contrast, Atherinopsidae and Goodeidae showed relatively poor helminth assemblages, including specific parasites with narrow distribution. Helminth richness in southeastern Mexico was higher than northern or central regions. Non-parametric richness estimators were used to avoid confusion in comparisons with unequal sampling efforts. Bootstrap values, the method with the best performance, indicated that estimated richness shows the same distribution pattern that observed richness. Non-phylogenetic and phylogenetic analyses were used to determine the role of different factors in the parasite diversification. The distribution range was the most important richness predictor (widespread fishes harbour richer parasite assemblages), although interactions between this variable and others such as trophic level, latitude, habitat temperature and precipitation are also important. Likewise, biogeographical factors can also affect parasite diversity.

  16. Virulent Burkholderia species mimic host actin polymerases to drive actin-based motility.

    Science.gov (United States)

    Benanti, Erin L; Nguyen, Catherine M; Welch, Matthew D

    2015-04-09

    Burkholderia pseudomallei and B. mallei are bacterial pathogens that cause melioidosis and glanders, whereas their close relative B. thailandensis is non-pathogenic. All use the trimeric autotransporter BimA to facilitate actin-based motility, host cell fusion, and dissemination. Here, we show that BimA orthologs mimic different host actin-polymerizing proteins. B. thailandensis BimA activates the host Arp2/3 complex. In contrast, B. pseudomallei and B. mallei BimA mimic host Ena/VASP actin polymerases in their ability to nucleate, elongate, and bundle filaments by associating with barbed ends, as well as in their use of WH2 motifs and oligomerization for activity. Mechanistic differences among BimA orthologs resulted in distinct actin filament organization and motility parameters, which affected the efficiency of cell fusion during infection. Our results identify bacterial Ena/VASP mimics and reveal that pathogens imitate the full spectrum of host actin-polymerizing pathways, suggesting that mimicry of different polymerization mechanisms influences key parameters of infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Host adaptation in the anther smut fungus Ustilago violacea (Microbotryum violaceum): Infection success, spore production and alteration of floral traits on two host species and their F1-hybrid

    NARCIS (Netherlands)

    Biere, A.; Honders, S.C.

    1996-01-01

    It is often assumed that host specialization is promoted by trade-offs in the performance of parasites on different host species, but experimental evidence for such trade-offs is scant. We studied differences in performance among strains of the anther smut fungus Ustilago violacea from two closely

  18. The application of species criteria in avian taxonomy and its implications for the debate over species concepts.

    Science.gov (United States)

    Sangster, George

    2014-02-01

    The debate over species concepts has produced a huge body of literature on how species can, may or should be delimited. By contrast, very few studies have documented how species taxa are delimited in practice. The aims of the present study were to (i) quantify the use of species criteria in taxonomy, (ii) discuss its implications for the debate over species concepts and (iii) assess recent claims about the impact of different species concepts on taxonomic stability and the 'nature' of species. The application of six species criteria was examined in taxonomic studies of birds published between 1950 and 2009. Three types of taxonomic studies were included: descriptions of new species (N = 329), proposals to change the taxonomic rank of species and subspecies (N = 808) and the taxonomic recommendations of the American Ornithologists' Union Committee on Classification and Nomenclature (N = 176). In all three datasets, diagnosability was the most frequently applied criterion, followed by reproductive isolation and degree of difference. This result is inconsistent with the popular notion that the Biological Species Concept is the dominant species concept in avian taxonomy. Since the 1950s, avian species-level taxonomy has become increasingly pluralistic and eclectic. This suggests that taxonomists consider different criteria as complementary rather than as rival approaches to species delimitation. Application of diagnosability more frequently led to the elevation of subspecies to species rank than application of reproductive isolation, although the difference was small. Hypotheses based on diagnosability and reproductive isolation were equally likely to be accepted in a mainstream checklist. These findings contradict recent claims that application of the Phylogenetic Species Concept causes instability and that broader application of the Biological Species Concept can stabilise taxonomy. The criteria diagnosability and monophyly, which are commonly associated

  19. Host Phylogeny Constrains Cross-Species Emergence and Establishment of Rabies Virus in Bats

    National Research Council Canada - National Science Library

    Daniel G. Streicker; Amy S. Turmelle; Maarten J. Vonhof; Ivan V. Kuzmin; Gary F. McCracken; Charles E. Rupprecht

    2010-01-01

    .... Using a data set of hundreds of rabies viruses sampled from 23 North American bat species, we present a general framework to quantify per capita rates of cross-species transmission and reconstruct...

  20. Host response signature to Staphylococcus aureus alpha-hemolysin implicates pulmonary Th17 response.

    Science.gov (United States)

    Frank, Karen M; Zhou, Tong; Moreno-Vinasco, Liliana; Hollett, Brian; Garcia, Joe G N; Bubeck Wardenburg, Juliane

    2012-09-01

    Staphylococcus aureus pneumonia causes significant morbidity and mortality. Alpha-hemolysin (Hla), a pore-forming cytotoxin of S. aureus, has been identified through animal models of pneumonia as a critical virulence factor that induces lung injury. In spite of considerable molecular knowledge of how this cytotoxin injures the host, the precise host response to Hla in the context of infection remains poorly understood. We employed whole-genome expression profiling of infected lungs to define the host response to wild-type S. aureus compared with the response to an Hla-deficient isogenic mutant in experimental pneumonia. These data provide a complete expression profile at 4 and at 24 h postinfection, revealing a unique response to the toxin-expressing strain. Gene ontogeny analysis revealed significant differences in the extracellular matrix and cardiomyopathy pathways, both of which govern cellular interactions in the tissue microenvironment. Evaluation of individual transcript responses to Hla-secreting staphylococci was notable for upregulation of host cytokine and chemokine genes, including the p19 subunit of interleukin-23. Consistent with this observation, the cellular immune response to infection was characterized by a prominent Th17 response to the wild-type pathogen. These findings define specific host mRNA responses to Hla-producing S. aureus, coupling the pulmonary Th17 response to the secretion of this cytotoxin. Expression profiling to define the host response to a single virulence factor proved to be a valuable tool in identifying pathways for further investigation in S. aureus pneumonia. This approach may be broadly applicable to the study of bacterial toxins, defining host pathways that can be targeted to mitigate toxin-induced disease.

  1. Host-Parasite Interactions in Human Malaria: Clinical Implications of Basic Research.

    Science.gov (United States)

    Acharya, Pragyan; Garg, Manika; Kumar, Praveen; Munjal, Akshay; Raja, K D

    2017-01-01

    The malaria parasite, Plasmodium, is one of the oldest parasites documented to infect humans and has proven particularly hard to eradicate. One of the major hurdles in designing an effective subunit vaccine against the malaria parasite is the insufficient understanding of host-parasite interactions within the human host during infections. The success of the parasite lies in its ability to evade the human immune system and recruit host responses as physiological cues to regulate its life cycle, leading to rapid acclimatization of the parasite to its immediate host environment. Hence understanding the environmental niche of the parasite is crucial in developing strategies to combat this deadly infectious disease. It has been increasingly recognized that interactions between parasite proteins and host factors are essential to establishing infection and virulence at every stage of the parasite life cycle. This review reassesses all of these interactions and discusses their clinical importance in designing therapeutic approaches such as design of novel vaccines. The interactions have been followed from the initial stages of introduction of the parasite under the human dermis until asexual and sexual blood stages which are essential for transmission of malaria. We further classify the interactions as "direct" or "indirect" depending upon their demonstrated ability to mediate direct physical interactions of the parasite with host factors or their indirect manipulation of the host immune system since both forms of interactions are known to have a crucial role during infections. We also discuss the many ways in which this understanding has been taken to the field and the success of these strategies in controlling human malaria.

  2. Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species

    Directory of Open Access Journals (Sweden)

    Gaasenbeek Cor

    2009-09-01

    Full Text Available Abstract Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.

  3. Ecosystem services from transborder migratory species: Implications for conservation governance

    Science.gov (United States)

    Lopez-Hoffman, Laura; Chester, Charles C.; Semmens, Darius J.; Thogmartin, Wayne E.; Rodriguez-McGoffin, M. Sofia; Merideth, Robert; Diffendorfer, Jay E.

    2017-01-01

    This article discusses the conservation challenges of volant migratory transborder species and conservation governance primarily in North America. Many migratory species provide ecosystem service benefits to society. For example, insectivorous bats prey on crop pests and reduce the need for pesticides; birds and insects pollinate food plants; and birds afford recreational opportunities to hunters and birdwatchers. Migration is driven by the seasonal availability of resources; as resources in one area become seasonally scarce, individuals move to locations where resources have become seasonally abundant. The separation of the annual lifecycle means that species management and governance is often fractured across international borders. Because migratory species depend on habitat in different locations, their ability to provide ecosystem services in one area depends on the spatial subsidies, or support, provided by habitat and ecological processes in other areas. This creates telecouplings, or interconnections across geographic space, of areas such that impacts to the habitat of a migratory species in one location will affect the benefits enjoyed by people in other locations. Information about telecoupling and spatial subsidies can be used to craft new governance arrangements such as Payment for Ecosystem Services programs that target specific stakeholder groups and locations. We illustrate these challenges and opportunities with three North American case studies: the Duck Stamp Program, Mexican free-tailed bats (Tadarida brasiliensis mexicana), and monarch butterflies (Danaus plexippus).

  4. North American tree squirrels and ground squirrels with overlapping ranges host different Cryptosporidium species and genotypes

    Czech Academy of Sciences Publication Activity Database

    Stenger, B.L.S.; Clark, M.E.; Kváč, Martin; Khan, E.; Giddings, C.W.; Prediger, Jitka; McEvoy, J.M.

    2015-01-01

    Roč. 36, 2015-Dec (2015), s. 287-293 ISSN 1567-1348 R&D Projects: GA ČR GA15-01090S Institutional support: RVO:60077344 Keywords : Cryptosporidium * Tree squirrels * Ground squirrels * Host specificity * Zoonotic Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.591, year: 2015

  5. New Raffaelea species (Ophiostomatales) from the USA and Taiwan associated with ambrosia beetles and plant hosts

    Science.gov (United States)

    D. Rabern Simmons; Z. Wilhelm de Beer; Yin-Tse Huang; Craig Bateman; Alina S. Campbell; Tyler J. Dreaden; You Li; Randy C. Ploetz; Adam Black; Hou-Feng Li; Chi-Yu Chen; Michael J. Wingfield; Jiri Hulcr

    2016-01-01

    Raffaelea (Ophiostomatales) is a genus of more than 20 ophiostomatoid fungi commonly occurring in symbioses with wood-boring ambrosia beetles. We examined ambrosia beetles and plant hosts in the USA and Taiwan for the presence of these mycosymbionts and found 22 isolates representing known and undescribed lineages in ...

  6. Checklist of available generic names for Microsporidia with type species and type host

    Science.gov (United States)

    The science of microsporidiology encompasses a diverse assemblage of pathogens from a large and varied group of hosts. Many members of this group have been studied and exploited for their role in the control of insect pests and vectors as well as their detrimental impact on vertebrates including ma...

  7. Species Diversity, Abundance, and Host Preferences of Mosquitoes (Diptera: Culicidae) in Two Different Ecotypes of Madagascar With Recent RVFV Transmission.

    Science.gov (United States)

    Jean Jose Nepomichene, Thiery Nirina; Elissa, Nohal; Cardinale, Eric; Boyer, Sebastien

    2015-09-01

    Mosquito diversity and abundance were examined in six Madagascan villages in either arid (Toliary II district) or humid (Mampikony district) ecotypes, each with a history of Rift Valley fever virus transmission. Centers for Disease Control and Prevention light traps without CO2 (LT) placed near ruminant parks and animal-baited net trap (NT) baited with either zebu or sheep/goat were used to sample mosquitoes, on two occasions between March 2011 and October 2011. Culex tritaeniorhynchus (Giles) was the most abundant species, followed by Culex antennatus (Becker) and Anopheles squamosus/cydippis (Theobald/de Meillon). These three species comprised more than half of all mosquitoes collected. The NT captured more mosquitoes in diversity and in abundance than the LT, and also caught more individuals of each species, except for An. squamosus/cydippis. Highest diversity and abundance were observed in the humid and warm district of Mampikony. No host preference was highlighted, except for Cx. tritaeniorhynchus presenting a blood preference for zebu baits. The description of species diversity, abundance, and host preference described herein can inform the development of control measures to reduce the risk of mosquito-borne diseases in Madagascar. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Terpenes of Salvia species leaf oils: chemosystematic implications

    OpenAIRE

    Coassini Lokar, Laura; Moneghini, Mariarosa

    2017-01-01

    Wild specimens of Salvia L. were collected in three different moments of anthesis and their volatile leaf oils were analyzed by GC/GCMS. The quantitative terpene composition is very variable with the anthesis. S. bertolonii is the richest species in a-thujone. S. officinalis is characterized by high percentages of 1,8 cineole, 4-terpineol, isorboneol and a -bisabolol. In S. verticillata high percentages of borneol and {3-cariophyllene are present. In the three species a-thujone was always mor...

  9. Plant species richness and abundance in residential yards across a tropical watershed: implications for urban sustainability

    Directory of Open Access Journals (Sweden)

    Cristina P. Vila-Ruiz

    2014-09-01

    Full Text Available Green spaces within residential areas provide important contributions to the sustainability of urban systems. Therefore, studying the characteristics of these areas has become a research priority in cities worldwide. This project evaluated various aspects of the plant biodiversity of residential yards (i.e., front yards and back yards within the Río Piedras watershed in the San Juan metropolitan area of Puerto Rico. Our work included gathering information on vegetation composition and abundance of woody species (i.e., trees, shrubs, palms, ferns and large herbs (>2 m height, species origin (native vs. introduced, and species uses (ornamental, food, and medicinal plants. A total of 424 yards were surveyed within an area of 187,191 m². We found 383 woody species, with shrubs being the most abundant plant habitat. As expected, residential yards hosted a disproportionate amount of introduced species (69.5%. The most common shrub species were all non-native ornamentals, whereas the most common tree species included food trees as well as ornamental plants and two native species. Front yards hosted more ornamental species per unit area than backyards, while the latter had more food plants. The high amount of introduced species may present a challenge in terms of implementation of plant conservation initiatives if there is no clear definition of urban conservation goals. On the other hand, the high frequency of yards containing food plants may facilitate the development of residential initiatives that could provide future adaptive capacity to food shortages.

  10. A comparative genomic analysis of putative pathogenicity genes in the host-specific sibling species Colletotrichum graminicola and Colletotrichum sublineola.

    Science.gov (United States)

    Buiate, E A S; Xavier, K V; Moore, N; Torres, M F; Farman, M L; Schardl, C L; Vaillancourt, L J

    2017-01-10

    Colletotrichum graminicola and C. sublineola cause anthracnose leaf and stalk diseases of maize and sorghum, respectively. In spite of their close evolutionary relationship, the two species are completely host-specific. Host specificity is often attributed to pathogen virulence factors, including specialized secondary metabolites (SSM), and small-secreted protein (SSP) effectors. Genes relevant to these categories were manually annotated in two co-occurring, contemporaneous strains of C. graminicola and C. sublineola. A comparative genomic and phylogenetic analysis was performed to address the evolutionary relationships among these and other divergent gene families in the two strains. Inoculation of maize with C. sublineola, or of sorghum with C. graminicola, resulted in rapid plant cell death at, or just after, the point of penetration. The two fungal genomes were very similar. More than 50% of the assemblies could be directly aligned, and more than 80% of the gene models were syntenous. More than 90% of the predicted proteins had orthologs in both species. Genes lacking orthologs in the other species (non-conserved genes) included many predicted to encode SSM-associated proteins and SSPs. Other common groups of non-conserved proteins included transporters, transcription factors, and CAZymes. Only 32 SSP genes appeared to be specific to C. graminicola, and 21 to C. sublineola. None of the SSM-associated genes were lineage-specific. Two different strains of C. graminicola, and three strains of C. sublineola, differed in no more than 1% percent of gene sequences from one another. Efficient non-host recognition of C. sublineola by maize, and of C. graminicola by sorghum, was observed in epidermal cells as a rapid deployment of visible resistance responses and plant cell death. Numerous non-conserved SSP and SSM-associated predicted proteins that could play a role in this non-host recognition were identified. Additional categories of genes that were also highly

  11. Interaction of Bovine Peripheral Blood Polymorphonuclear Cells and Leptospira Species; Innate Responses in the Natural Bovine Reservoir Host

    Science.gov (United States)

    Wilson-Welder, Jennifer H.; Frank, Ami T.; Hornsby, Richard L.; Olsen, Steven C.; Alt, David P.

    2016-01-01

    Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and Leptospira interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia, and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs) and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2) was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of Leptospira strains

  12. Parasites of two abundant sympatric rodent species in relation to host phylogeny and ecology.

    Science.gov (United States)

    Klimpel, Sven; Förster, Maike; Schmahl, Günter

    2007-03-01

    In the present study, two abundant sympatric rodent species (27 Apodemus flavicollis and 33 A. sylvaticus) were studied for their endo- and ectoparasite fauna. The rodents were trapped in Dormagen, a city in North Rhine-Westphalia, Germany. A total of 20 different parasites species were identified, 13 endoparasite (2 Digenea, 5 Cestoda and 7 Nematoda) and 7 ectoparasite (5 Insecta and 2 Arachnida) species. Thirteen parasite species were found inhabiting both rodent species. The predominant endoparasite species in both rodents was the nematode Pelodera strongyloides, followed by the nematode Heligmosomoides polygyrus and a Syphacia species. The flea Ctenophthalmus agyrtes was the dominant ectoparasite in both rodent species. A. flavicollis usually carried 1-7 ecto-/endoparasite species (mean 4.0), whereas A. sylvaticus were mostly infested with 1-9 (mean 4.4). The parasite diversity of A. flavicollis (H' = 0.268, J = 0.097) was marginal lower in comparison to A. sylvaticus (H' = 0.319, J = 0.110). The two rodent species examined show remarkable similarities in the composition of their endo- and ectoparasite fauna being directly related to their similar pattern of living in the investigated area.

  13. Cestodes change the isotopic signature of brine shrimp, Artemia, hosts: implications for aquatic food webs.

    Science.gov (United States)

    Sánchez, Marta I; Varo, Nico; Matesanz, Cristina; Ramo, Cristina; Amat, Juan A; Green, Andy J

    2013-01-01

    To reach the final host (greater flamingos), the cestode Flamingolepis liguloides alters the behaviour of its intermediate host, the brine shrimp, Artemia parthenogenetica, causing it to spend more time close to the water surface. During summer 2010, we showed that the prevalence of this cestode was consistently higher at the top of the water column in the Odiel salt pans in south-western Spain. We used stable nitrogen (N) and carbon (C) isotopic analysis to test the hypothesis that cestodes also alter resource use by Artemia. In early summer, we compared stable isotopes in infected hosts at the surface with those from uninfected hosts at the bottom of the water column. In late summer, we compared infected and uninfected Artemia from the bottom. δ(15)N was consistently enriched in infected individuals compared with uninfected hosts, especially in Artemia with multiple infections of F. liguloides (family Hymenolepididae) and those with mixed infections of F. liguloides and cestodes of the family Dilepididae. Infected individuals from the surface were enriched in δ(13)C compared with uninfected ones from the bottom, but the opposite was found when comparing uninfected and infected Artemia from the same depth. This may be caused by the increase in lipid concentration in infected Artemia. Isolated cysticercoids of F. liguloides were significantly enriched in δ(13)C compared with cysticercoids in infected hosts, but surprisingly were not enriched in N. Our findings illustrate the way cestodes can alter food webs and highlight the importance of considering the parasitic status of prey in studies of trophic ecology in saline wetlands. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  14. Tailoring biomaterial surface properties to modulate host-implant interactions: implication in cardiovascular and bone therapy.

    Science.gov (United States)

    Pacelli, Settimio; Manoharan, Vijayan; Desalvo, Anna; Lomis, Nikita; Jodha, Kartikeya Singh; Prakash, Satya; Paul, Arghya

    Host body response to a foreign medical device plays a critical role in defining its fate post implantation. It is thus important to control host-material interactions by designing innovative implant surfaces. In the recent years, biochemical and topographical features have been explored as main target to produce this new type of bioinert or bioresponsive implants. The review discusses specific biofunctional materials and strategies to achieve a precise control over implant surface properties and presents possible solutions to develop next generation of implants, particularly in the fields of bone and cardiovascular therapy.

  15. Molecular biology of human herpesvirus 8: novel functions and virus-host interactions implicated in viral pathogenesis and replication.

    Science.gov (United States)

    Cousins, Emily; Nicholas, John

    2014-01-01

    Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), is the second identified human gammaherpesvirus. Like its relative Epstein-Barr virus, HHV-8 is linked to B-cell tumors, specifically primary effusion lymphoma and multicentric Castleman's disease, in addition to endothelial-derived KS. HHV-8 is unusual in its possession of a plethora of "accessory" genes and encoded proteins in addition to the core, conserved herpesvirus and gammaherpesvirus genes that are necessary for basic biological functions of these viruses. The HHV-8 accessory proteins specify not only activities deducible from their cellular protein homologies but also novel, unsuspected activities that have revealed new mechanisms of virus-host interaction that serve virus replication or latency and may contribute to the development and progression of virus-associated neoplasia. These proteins include viral interleukin-6 (vIL-6), viral chemokines (vCCLs), viral G protein-coupled receptor (vGPCR), viral interferon regulatory factors (vIRFs), and viral antiapoptotic proteins homologous to FLICE (FADD-like IL-1β converting enzyme)-inhibitory protein (FLIP) and survivin. Other HHV-8 proteins, such as signaling membrane receptors encoded by open reading frames K1 and K15, also interact with host mechanisms in unique ways and have been implicated in viral pathogenesis. Additionally, a set of micro-RNAs encoded by HHV-8 appear to modulate expression of multiple host proteins to provide conditions conducive to virus persistence within the host and could also contribute to HHV-8-induced neoplasia. Here, we review the molecular biology underlying these novel virus-host interactions and their potential roles in both virus biology and virus-associated disease.

  16. Feline immunodeficiency virus cross-species transmission: Implications for emergence of new lentiviral infections

    Science.gov (United States)

    Lee, Justin; Malmberg, Jennifer L.; Wood, Britta A.; Hladky, Sahaja; Troyer, Ryan; Roelke, Melody; Cunningham, Mark W.; McBride, Roy; Vickers, Winston; Boyce, Walter; Boydston, Erin E.; Serieys, Laurel E.K.; Riley, Seth P D; Crooks, Kevin R.; VandeWoude, Sue

    2016-01-01

    Owing to a complex history of host-parasite coevolution, lentiviruses exhibit a high degree of species specificity. Given the well-documented viral archeology of HIV emergence following human exposures to SIV, understanding processes that promote successful cross-species lentiviral transmissions is highly relevant. We have previously reported natural cross-species transmission of a subtype of feline immunodeficiency virus, puma lentivirus A (PLVA), between bobcats (Lynx rufus) and mountain lions (Puma concolor) in a small number of animals in California and Florida. In this study we investigate host-specific selection pressures, within-host viral fitness, and inter- vs. intra-species transmission patterns among a larger collection of PLV isolates from free-ranging bobcats and mountain lions. Analysis of proviral and viral RNA levels demonstrates that PLVA fitness is severely restricted in mountain lions compared to bobcats. We document evidence of diversifying selection in three of six PLVA genomes from mountain lions, but did not detect selection among twenty PLVA isolates from bobcats. These findings support that PLVA is a bobcat-adapted virus, which is less fit in mountain lions and under intense selection pressure in the novel host. Ancestral reconstruction of transmission events reveals intraspecific PLVA transmission has occurred among panthers (Puma concolor coryi) in Florida following initial cross-species infection from bobcats. In contrast, interspecific transmission from bobcats to mountain lions predominates in California. These findings document outcomes of cross-species lentiviral transmission events among felids that compare to emergence of HIV from nonhuman primates.IMPORTANCE Cross-species transmission episodes can be singular, dead-end events or can result in viral replication and spread in the new species. The factors that determine which outcome will occur are complex, and the risk of new virus emergence is therefore difficult to predict. Here

  17. Independent and competing disease risks : Implications for host Populations in variable environments

    NARCIS (Netherlands)

    Jolles, AE; Etienne, RS; Olff, H; Jolles, Anna E.; DeAngelis, Donald L.; Michalakis, Yannis

    Disease models usually assume disease to act independently of other mortality- and morbidity-causing factors. Alternatively, disease may function as a competing risk factor, for example, killing already moribund hosts. Using tuberculosis (TB) in African buffalo as a model system, we explore

  18. Earthworms as phoretic hosts for Steinernema carpocapsae and Beauveria bassiana: Implications for enhanced biological control

    Science.gov (United States)

    Prior research indicated that earthworms may serve as phoretic hosts to entomopathogenic nematodes. Therefore, we hypothesized that biocontrol efficacy of nematodes could be enhanced in the presence of earthworms based on increased nematode dispersal through the soil. We also hypothesized that ear...

  19. Comparing resource allocation and life history in closely related aphid parasitoid species sharing the same host.

    NARCIS (Netherlands)

    Le Lann, C.; Visser, B.; van Baaren, J.; van Alphen, J.J.M.; Ellers, J.

    2012-01-01

    Species belonging to the same guild (i. e. sharing the same resources) can reduce the negative effects of resource competition through niche partitioning. Coexisting species may differ in their resource exploitation and in the associated allocation of nutrients, depending on their resource niche.

  20. Novel Paraconiothyrium species on stone fruit trees and other woody hosts

    NARCIS (Netherlands)

    Damm, U.; Verkley, G.J.M.; Crous, P.W.; Fourie, P.H.; Haegi, A.; Riccioni, L.

    2008-01-01

    Coniothyrium-like fungi are common wood and soil inhabitants and hyperparasites on other fungi. They belong to different fungal genera within the Pleosporales. Several isolates were obtained on wood of different Prunus species (plum, peach and nectarine) from South Africa, on Actinidia species from

  1. Novel Paraconiothyrium species on stone fruit trees and other woody hosts

    NARCIS (Netherlands)

    Damm, U; Verkley, G J M; Crous, P W; Fourie, P H; Haegi, A; Riccioni, L

    Coniothyrium-like fungi are common wood and soil inhabitants and hyperparasites on other fungi. They belong to different fungal genera within the Pleosporales. Several isolates were obtained on wood of different Prunus species (plum, peach and nectarine) from South Africa, on Actinidia species from

  2. A retrospective analysis of pollen host plant use by stable and declining bumble bee species

    NARCIS (Netherlands)

    Kleijn, D.; Raemakers, I.P.

    2008-01-01

    Understanding population declines has been the objective of a wide range of ecological studies. When species have become rare such studies are complicated because particular behavior or life history traits may be the cause but also the result of the decline of a species. We approached this problem

  3. Possible Influence of MLP Regulators in Foliage of Host Species on Invasion of Phyllophagous Insects

    Directory of Open Access Journals (Sweden)

    Vasiliy I. Ponomarev

    2010-01-01

    Full Text Available On the northern border of the Gypsy moth area (Lymantria dispar L., 1758, caterpillars are reorient to exogenous regulators of membrane lipid peroxidation in connection with repeated cold periods during feeding. In case of an introduction of host plants with high contents of exogenous regulators of MLP (e.g. Fe2+ in foliage in these areas that may affect diapause duration, the boundaries of spreading and intensity of outbreaks may change.

  4. Meloidogyne species in cucurbit crops : characterization and quantification of the host-parasite relationship

    OpenAIRE

    López Gómez, Manuel Francisco

    2015-01-01

    The infection process of Meloidogyne arenaria, M. incognita and M. javanica was compared on zucchini squash, cucumber, melon, pumpkin and watermelon in a growth chamber. All cucurbits were susceptible to the three isolates although M. javanica showed higher invasion rates, faster development and egg production than M. arenaria. Differences among cucurbits were primarily due to root invasion rates and formation of egg masses. Cucumber and melon were better hosts for nematode invasion and repro...

  5. Influence of temperature and host species on the development of Cryptocaryon irritans.

    Science.gov (United States)

    Diggles, B K; Lester, R J

    1996-02-01

    The course of infection of the parasitic ciliate Cryptocaryon irritans was followed on Lates calcarifer and Macquaria novemaculeata at 20 and 25 C. The parasite was originally isolated from locally caught Acanthopagrus australis. At 20 C trophonts stayed on the fish longer, tomonts took longer to excyst, and the resulting theronts were larger than at 25 C. On L. calcarifer at 20 C, trophonts grew slowly at first but eventually became significantly larger (mean tomont diameter 466 x 400 microns) than at 25 C (mean diameter 373 x 320 microns). On M. novemaculeata, trophonts never grew as large as on L. calcarifer and at 20 C they grew poorly. The number of theronts produced per tomont was directly related to the size of the tomont but was not influenced by incubation temperature. The tomont incubation period was not related to the diameter of the tomont but was significantly influenced by the host origin of the tomont. Theront size was also significantly affected by the host origin of the tomont but not the diameter of the tomont. These results show that C. irritans exhibits variability in morphometrics on different hosts and under different temperature conditions. This variability needs to be taken into account if utilizing morphometric data for separating strains of C. irritans.

  6. The Glycoproteins of All Filovirus Species Use the Same Host Factors for Entry into Bat and Human Cells but Entry Efficiency Is Species Dependent.

    Directory of Open Access Journals (Sweden)

    Markus Hoffmann

    Full Text Available Ebola and marburgviruses, members of the family Filoviridae, can cause severe hemorrhagic fever in humans. The ongoing Ebola virus (EBOV disease epidemic in Western Africa claimed more than 11,300 lives and was associated with secondary cases outside Africa, demonstrating that filoviruses pose a global health threat. Bats constitute an important natural reservoir of filoviruses, including viruses of the recently identified Cuevavirus genus within the Filoviridae family. However, the interactions of filoviruses with bat cells are incompletely understood. Here, we investigated whether filoviruses employ different strategies to enter human and bat cells. For this, we examined host cell entry driven by glycoproteins (GP from all filovirus species into cell lines of human and fruit bat origin. We show that all GPs were able to mediate entry into human and most fruit bat cell lines with roughly comparable efficiency. In contrast, the efficiency of entry into the cell line EidNi/41 derived from a straw-colored fruit bat varied markedly between the GPs of different filovirus species. Furthermore, inhibition studies demonstrated that filoviruses employ the same host cell factors for entry into human, non-human primate and fruit bat cell lines, including cysteine proteases, two pore channels and NPC1 (Niemann-Pick C1 molecule. Finally, processing of GP by furin and the presence of the mucin-like domain in GP were dispensable for entry into both human and bat cell lines. Collectively, these results show that filoviruses rely on the same host cell factors for entry into human and fruit bat cells, although the efficiency of the usage of these factors might differ between filovirus species.

  7. Host preference and species richness of wood-inhabiting aphyllophoraceous fungi in a cool temperate area of Japan.

    Science.gov (United States)

    Yamashita, Satoshi; Hattori, Tsutomu; Abe, Hisashi

    2010-01-01

    We examined the species richness and host utilization patterns of wood-inhabiting aphyllophoraceous fungi (polypores and related fungi) in an old-growth beech and oak forest in a cool, temperate area of Japan. Coarse woody debris (CWD) > or = 20 cm diam within a 6 ha plot was surveyed in Sep 2002. Tree genus, diameter, decay class and tree part of CWD samples were recorded. Fruiting bodies of aphyllophoraceous fungi that arose from the CWD were surveyed three times and identified to species. In total 256 CWD samples from 12 tree genera were surveyed with Quercus being the most frequent followed by Castanea and Fagus. From 196 CWD samples we recorded 436 wood-inhabiting fungi belonging to 63 species. Fifteen fungal species had at least 10 records, with Hymenochaete rubiginosa, Daedalea dickinsii, Xylobolus frustulatus, Rigidoporus cinereus and the small form of Fomes fomentarius being the most frequent. The number of fungal species that appeared on Fagus was significantly larger than that on Castanea, when the number of fruiting bodies collected was at least 50. The occurrences of the 15 dominant fungal species, except Trametes versicolor, were related to traits of the CWD. Tree genus was a predictor variable that affected the appearance of 11 of the 15 species of wood-inhabiting fungi. Only the tree part was selected for the models of Rigidoporus eminens, Schizopora flavipora and Stereum ostrea. Our results suggest that tree genus and tree part are important factors determining fungal community structure because these were selected as complementary predictor variables. Both oak and beech appear to be the most important tree genera for maintaining wood-inhabiting fungal species richness because the fungal flora formed on oak CWD is nearly complementary to those on chestnut, with low fungal species richness.

  8. Host specificity and genealogy of the louse Polyplax serrata on field mice, Apodemus species: a case of parasite duplication or colonisation?

    Science.gov (United States)

    Stefka, Jan; Hypsa, Václav

    2008-05-01

    The genealogy, population structure and population dynamics of the sucking louse Polyplax serrata were analysed across four host species of the genus Apodemus. An analysis of 126 sequences of cytochrome c oxidase subunit I using phylogenetic approaches and haplotype networking revealed a clear structure of European samples, forming three distinct and genetically distant clades with different host specificities. Although a clear connection was detected between the host and parasite genealogies/phylogenies, a uniform pattern of co-speciation was not found. For example, a dramatic shift in the degree of host specificity was demonstrated for two related louse lineages living in sympatry and sharing one of their host species. While one of the louse lineages frequently parasitised two different host taxa (Apodemus sylvaticus and Apodemus flavicollis), the other louse lineage was strictly specific to A. flavicollis. The estimate of divergence time between the two louse lineages indicates that they may have arisen due to parasite duplication on A. flavicollis.

  9. Microarray for Identification of the Chiropteran Host Species of Rabies Virus in Canada

    Directory of Open Access Journals (Sweden)

    Tara Furukawa-Stoffer

    2013-05-01

    Full Text Available Species identification through genetic barcoding can augment traditional taxonomic methods, which rely on morphological features of the specimen. Such approaches are especially valuable when specimens are in poor condition or comprise very limited material, a situation that often applies to chiropteran (bat specimens submitted to the Canadian Food Inspection Agency for rabies diagnosis. Coupled with phenotypic plasticity of many species and inconclusive taxonomic keys, species identification using only morphological traits can be challenging. In this study, a microarray assay with associated PCR of the mitochondrial cytochrome c oxidase subunit I (COI gene was developed for differentiation of 14 bat species submitted to the Canadian Food Inspection Agency from 1985–2012 for rabies diagnosis. The assay was validated with a reference collection of DNA from 153 field samples, all of which had been barcoded previously. The COI gene from 152 samples which included multiple specimens of each target species were successfully amplified by PCR and accurately identified by the microarray. One sample that was severely decomposed failed to amplify with PCR primers developed in this study, but amplified weakly after switching to alternate primers and was accurately typed by the microarray. Thus, the chiropteran microarray was able to accurately differentiate between the 14 species of Canadian bats targeted. This PCR and microarray assay would allow unequivocal identification to species of most, if not all, bat specimens submitted for rabies diagnosis in Canada.

  10. Reconstructing geographical movements and host species transitions of foot-and-mouth disease virus serotype SAT 2.

    Science.gov (United States)

    Hall, Matthew D; Knowles, Nick J; Wadsworth, Jemma; Rambaut, Andrew; Woolhouse, Mark E J

    2013-10-22

    Of the three foot-and-mouth-disease virus SAT serotypes mainly confined to sub-Saharan Africa, SAT 2 is the strain most often recorded in domestic animals and has caused outbreaks in North Africa and the Middle East six times in the last 25 years, with three apparently separate events occurring in 2012. This study updates the picture of SAT 2 phylogenetics by using all available sequences for the VP1 section of the genome available at the time of writing and uses phylogeographic methods to trace the origin of all outbreaks occurring north of the Sahara since 1990 and identify patterns of spread among countries of endemicity. Transitions between different host species are also enumerated. Outbreaks in North Africa appear to have origins in countries immediately south of the Sahara, whereas those in the Middle East are more often from East Africa. The results of the analysis of spread within sub-Saharan Africa are consistent with it being driven by relatively short-distance movements of animals across national borders, and the analysis of host species transitions supports the role of the African buffalo (Syncerus caffer) as an important natural reservoir. Foot-and-mouth disease virus is a livestock pathogen of major economic importance, with seven distinct serotypes occurring globally. The SAT 2 serotype, endemic in sub-Saharan Africa, has caused a number of outbreaks in North Africa and the Middle East during the last decades, including three separate incidents in 2012. A comprehensive analysis of all available RNA sequences for SAT 2 has not been published for some years. In this work, we performed this analysis using all previously published sequences and 49 newly determined examples. We also used phylogenetic methods to infer the source country for all outbreaks occurring outside sub-Saharan Africa since 1990 and to reconstruct the spread of viral lineages between countries where it is endemic and movements between different host species.

  11. Oxychlorine Species on Mars: Implications from Gale Crater Samples

    Science.gov (United States)

    Archer, P. Douglas, Jr.; Ming, Douglas W.; Sutter, Brad; Morris, Richard V.; Clark, B. C.; Mahaffy, P. H.; Wray, J. J.; Fairen, A. G.; Gellert, Ralf; Yen, Albert; hide

    2016-01-01

    Evidence of oxychlorine species such as perchlorates or chlorates have been detected in nearly every acquired sample analyzed on the surface of Mars. Perchlorates were first discovered by the Wet Chemistry Laboratory (WCL) instrument on the Phoenix lander in 2008. The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) has analyzed twelve samples from Gale Crater (as of July 2016), nine drilled samples and three scooped samples. After delivery to SAM, samples are heated to approximately 850 C and evolved gases are measured by a quadrupole mass spectrometer.

  12. Molecular phylogenetics of geographically restricted Acropora species: implications for threatened species conservation.

    Science.gov (United States)

    Richards, Z T; Miller, D J; Wallace, C C

    2013-12-01

    To better understand the underlying causes of rarity and extinction risk in Acropora (staghorn coral), we contrast the minimum divergence ages and nucleotide diversity of an array of species with different range sizes and levels of threat. Time-calibrated Bayesian analyses based upon concatenated nuclear and mitochondrial sequence data implied contemporary range size and vulnerability are linked to species age. However, contrary to previous hypotheses that suggest geographically restricted Acropora species evolved in the Plio-Pleistocene, the molecular phylogeny depicts some Indo-Australian species have greater antiquity, diverging in the Miocene. Species age is not related to range size as a simple positive linear function and interpreting the precise tempo of evolution in this genus is greatly complicated by morphological homoplasy and a sparse fossil record. Our phylogenetic reconstructions provide new examples of how morphology conceals cryptic evolutionary relationships in this keystone genus, and offers limited support for the species groupings currently used in Acropora systematics. We hypothesize that in addition to age, other mechanisms (such as a reticulate ancestry) delimit the contemporary range of some Acropora species, as evidenced by the complex patterns of allele sharing and paraphyly we uncover. Overall, both new and ancient evolutionary information may be lost if geographically restricted and threatened Acropora species are forced to extinction. In order to protect coral biodiversity and resolve the evolutionary history of staghorn coral, further analyses based on comprehensive and heterogeneous morphological and molecular data utilizing reticulate models of evolution are needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Darwin and Darwinism: the (alleged) social implications of the origin of species.

    Science.gov (United States)

    Orr, H Allen

    2009-11-01

    Most scientific theories, even revolutionary ones, change the practice of a particular science but have few consequences for culture or society at large. But Darwinism, it has often been said, is different in this respect. Since the publication of The Origin of Species, many have claimed that Darwinism has a number of profound social implications. Here, I briefly consider three of these: the economic, the political, and the religious. I suggest that, for the most part, these supposed implications have been misconstrued or exaggerated. Indeed, it is reasonably clear that the chain of implication sometimes primarily ran in the opposite direction-from, for instance, economics and political theory to Darwinism.

  14. Darwin and Darwinism: The (Alleged) Social Implications of The Origin of Species

    Science.gov (United States)

    Orr, H. Allen

    2009-01-01

    Most scientific theories, even revolutionary ones, change the practice of a particular science but have few consequences for culture or society at large. But Darwinism, it has often been said, is different in this respect. Since the publication of The Origin of Species, many have claimed that Darwinism has a number of profound social implications. Here, I briefly consider three of these: the economic, the political, and the religious. I suggest that, for the most part, these supposed implications have been misconstrued or exaggerated. Indeed, it is reasonably clear that the chain of implication sometimes primarily ran in the opposite direction—from, for instance, economics and political theory to Darwinism. PMID:19933232

  15. Ammonia Bearing Species on Ceres: Implication on Origin and Evolution

    Science.gov (United States)

    De Sanctis, M. C.; Ammannito, E.; Raponi, A.; Marchi, S.; Ciarniello, M.; McSween, H. Y., Jr.; McCord, T. B.; Capaccioni, F.; Capria, M. T.; Carrorro, F. G.; Longobardo, A.; Tosi, F.; Fonte, S.; Giardino, M.; Palomba, E.; Magni, G.; Zambon, F.; Pieters, C. M.; McFadden, L. A.; Raymond, C. A.

    2015-12-01

    The Visible and Infrared Mapping Spectrometer (VIR) on board the Dawn spacecraft observed Ceres' surface acquiring spectra since January 2015. Here we report the average Ceres spectrum, including the spectral range previously precluded from telescopic measurements due to telluric atmospheric absorptions. The data indicate that the surface is very dark: average albedo of 0.090 ±0.006 at 0.55 µm, consistent with HST data (Li et al., 2006). Ceres' average spectrum is characterized by a prominent absorption band at 2.7 micron. Weaker absorption bands are observed between 3.05-3.1, 3.3-3.4 and 3.9-4 micron; the visible and near-IR ranges lack prominent bands. We modelled the spectra of Ceres using Hapke theory. Results of the spectral modelling indicate that extensive water ice is not present in surface spectra acquired so far. The best fit is obtained with a mixture of ammoniated phyllosilicates mixed with other clays, Mg-carbonates, and dark material, like magnetite (De Sanctis et al. 2015, submitted). The presence of ammonia bearing materials across the surface has implications for the origin of Ceres and its internal structure and evolution. Higher spatial resolution spectra are being acquired to address the small scale mineralogy across this dwarf planet. References: Li, et al., Photometric analysis of 1 Ceres and surface mapping from HST observations. Icarus 182, 143-160 (2006). De Sanctis et al., Ammoniated phyllosilicates on dwarf planet Ceres reveal an outer solar system origin, Nature submitted, (2015). This work is supported the Italian Space Agencies, NASA, and from the German Space Agency. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged.

  16. Type VI secretion system contributes to Enterohemorrhagic Escherichia coli virulence by secreting catalase against host reactive oxygen species (ROS).

    Science.gov (United States)

    Wan, Baoshan; Zhang, Qiufen; Ni, Jinjing; Li, Shuxian; Wen, Donghua; Li, Jun; Xiao, Haihan; He, Ping; Ou, Hong-Yu; Tao, Jing; Teng, Qihui; Lu, Jie; Wu, Wenjuan; Yao, Yu-Feng

    2017-03-01

    Enterohemorrhagic Escherichia coli (EHEC) is one major type of contagious and foodborne pathogens. The type VI secretion system (T6SS) has been shown to be involved in the bacterial pathogenicity and bacteria-bacteria competition. Here, we show that EHEC could secrete a novel effector KatN, a Mn-containing catalase, in a T6SS-dependent manner. Expression of katN is promoted by RpoS and OxyR and repressed by H-NS, and katN contributes to bacterial growth under oxidative stress in vitro. KatN could be secreted into host cell cytosol after EHEC is phagocytized by macrophage, which leads to decreased level of intracellular reactive oxygen species (ROS) and facilitates the intramacrophage survival of EHEC. Finally, animal model results show that the deletion mutant of T6SS was attenuated in virulence compared with the wild type strain, while the deletion mutant of katN had comparable virulence to the wild type strain. Taken together, our findings suggest that EHEC could sense oxidative stress in phagosome and decrease the host cell ROS by secreting catalase KatN to facilitate its survival in the host cells.

  17. Patterns of bacteria-host associations suggest different ecological strategies between two reef building cold-water coral species

    Science.gov (United States)

    Meistertzheim, Anne.-Leila; Lartaud, Franck; Arnaud-Haond, Sophie; Kalenitchenko, Dimitri; Bessalam, Manon; Le Bris, Nadine; Galand, Pierre E.

    2016-08-01

    Cold-water corals (CWC) are main ecosystem engineers of the deep sea, and their reefs constitute hot-spots of biodiversity. However, their ecology remains poorly understood, particularly, the nature of the holobiont formed by corals with their associated bacterial communities. Here, we analyzed Madrepora oculata and Lophelia pertusa samples, collected from one location in a Mediterranean canyon in two different seasons (autumn and spring), in order to test for species specificity and temporal stability of the host-bacteria associations. The 16S rRNA sequencing revealed host-specific patterns of bacterial communities associated with L. pertusa and M. oculata, both in terms of community composition and diversity. All analyzed M. oculata polyps exhibited temporally and spatially similar bacterial communities dominated by haplotypes homologous to the known cnidarians-associated genus Endozoicomonas. In contrast, the bacterial communities associated with L. pertusa varied among polyps from the same colony, as well as among distinct colonies and between seasons. While the resilient consortium formed by M. oculata and its bacterial community fit the definition of holobiont, the versatility of the L. pertusa microbiome suggests that this association is more influenced by the environmental conditions or nutritional status. Our results thus highlight distinct host/microbes association strategies for these two closely related Scleractinians sharing the same habitat, suggesting distinct sensitivity to environmental change.

  18. Type VI secretion system contributes to Enterohemorrhagic Escherichia coli virulence by secreting catalase against host reactive oxygen species (ROS.

    Directory of Open Access Journals (Sweden)

    Baoshan Wan

    2017-03-01

    Full Text Available Enterohemorrhagic Escherichia coli (EHEC is one major type of contagious and foodborne pathogens. The type VI secretion system (T6SS has been shown to be involved in the bacterial pathogenicity and bacteria-bacteria competition. Here, we show that EHEC could secrete a novel effector KatN, a Mn-containing catalase, in a T6SS-dependent manner. Expression of katN is promoted by RpoS and OxyR and repressed by H-NS, and katN contributes to bacterial growth under oxidative stress in vitro. KatN could be secreted into host cell cytosol after EHEC is phagocytized by macrophage, which leads to decreased level of intracellular reactive oxygen species (ROS and facilitates the intramacrophage survival of EHEC. Finally, animal model results show that the deletion mutant of T6SS was attenuated in virulence compared with the wild type strain, while the deletion mutant of katN had comparable virulence to the wild type strain. Taken together, our findings suggest that EHEC could sense oxidative stress in phagosome and decrease the host cell ROS by secreting catalase KatN to facilitate its survival in the host cells.

  19. Lack of adaptation to a new host in a generalist herbivore: implications for host plant resistance to twospotted spider mites in cotton.

    Science.gov (United States)

    Miyazaki, Junji; Wilson, Lewis J; Stiller, Warwick N

    2015-04-01

    The twospotted spider mite (Tetranychus urticae Koch) is an important pest of cotton. This pest has a broad host range, but when changing between hosts an initial decline in fitness often occurs. This is usually followed by an increase in fitness after rapid adaptation to the new host, usually within five generations. The generality of this adaptive response was tested by assessing elements of fitness when mites were reared on a host to which they were adapted (Gossypium hirsutum L. cv. Sicot 71) or on a new host, Gossypium arboreum L. (accession BM13H). In a first experiment, mites reared on the new host for ten generations showed declining immature survival compared with those reared on the adapted host. In a second experiment, the intrinsic capacity for increase of mites cultured on the new host for six generations was significantly lower than that of mites cultured on the adapted host for six generations and then transferred to the new host. Hence, exposure to the new host for six or ten generations resulted in declining fitness. This 'negative adaptation' indicates robust antibiosis traits in G. arboreum accession BM13H, which therefore have value in developing mite-resistant G. hirsutum cultivars. © 2014 Society of Chemical Industry.

  20. First Introduction of Two Australian Temnocephalan Species into Africa with an Alien Host: Double Trouble.

    Science.gov (United States)

    Tavakol, Sareh; Luus-Powell, Wilmien J; Smit, Willem J; Baker, Chantélle; Hoffman, Andre; Halajian, Ali

    2016-12-01

    The redclaw crayfish, Cherax quadricarinatus (Decapoda: Parastacidae), is native to Australia but has been introduced to South Africa as a warm-water aquaculture species. In a South African natural waterbody, examined crayfish had high-intensity infections of 3 temnocephalan species on their body surfaces and within the branchial chambers. Temnocephalans were characterized using light and scanning electron microscopy and identified as Craspedella pedum, Diceratocephala boschmai, and Didymorchis sp. This is the first report of the introduction of Australian temnocephalans, C. pedum and Didymorchis sp., to Africa and expands the known distribution of these species beyond their presumptive native range. The present study also documents a naturalized population of C. quadricarinatus from a natural water body in South Africa, comprising a new geographical locality record.

  1. Ticks (Acarina: Ixodida) infesting five reptile species in Sri Lanka with sixteen new host records.

    Science.gov (United States)

    Liyanaarachchi, Dilrukshi R; Rajakaruna, Rupika S; Dikkumbura, Anil W; De Silva, Anslem; Rajapakse, R P V Jayantha

    2015-05-29

    The first study on ticks on reptiles of Sri Lanka dates back to Seneviratna (1965) who reported ticks from five reptiles. Later studies were either limited to one reptile (Fernando & Fernando 2012), or captive animals in zoos (Fernando & Randeniaya 2009) and household pets (Nathanael et al. 2004). According to the current classification (Guglielmone et al. 2010), all the tick species previously recorded on reptiles belong to five species of Amblyomma: A. clypeolatum Neumann, A. gervaisi (Lucas), A. pattoni (Neumann), A. trimaculatum (Lucas) and A. varanense (Supino). Some of the species listed by Seneviratna (1965) were either synonyms or invalid in respect to the present classification. For example Amblyomma laeve sensu Warburton (1910) is a junior synonym of A. pattoni and A. gervaisii var. lucasi is considered a junior synonym of A. varanense (Guglielmone et al. 2010; D. Apanaskevich pers. comm.).

  2. A new method for estimating species age supports the coexistence of malaria parasites and their Mammalian hosts.

    Science.gov (United States)

    Silva, Joana C; Egan, Amy; Arze, Cesar; Spouge, John L; Harris, David G

    2015-05-01

    Species in the genus Plasmodium cause malaria in humans and infect a variety of mammals and other vertebrates. Currently, estimated ages for several mammalian Plasmodium parasites differ by as much as one order of magnitude, an inaccuracy that frustrates reliable estimation of evolutionary rates of disease-related traits. We developed a novel statistical approach to dating the relative age of evolutionary lineages, based on Total Least Squares regression. We validated this lineage dating approach by applying it to the genus Drosophila. Using data from the Drosophila 12 Genomes project, our approach accurately reconstructs the age of well-established Drosophila clades, including the speciation event that led to the subgenera Drosophila and Sophophora, and age of the melanogaster species subgroup. We applied this approach to hundreds of loci from seven mammalian Plasmodium species. We demonstrate the existence of a molecular clock specific to individual Plasmodium proteins, and estimate the relative age of mammalian-infecting Plasmodium. These analyses indicate that: 1) the split between the human parasite Plasmodium vivax and P. knowlesi, from Old World monkeys, occurred 6.1 times earlier than that between P. falciparum and P. reichenowi, parasites of humans and chimpanzees, respectively; and 2) mammalian Plasmodium parasites originated 22 times earlier than the split between P. falciparum and P. reichenowi. Calibrating the absolute divergence times for Plasmodium with eukaryotic substitution rates, we show that the split between P. falciparum and P. reichenowi occurred 3.0-5.5 Ma, and that mammalian Plasmodium parasites originated over 64 Ma. Our results indicate that mammalian-infecting Plasmodium evolved contemporaneously with their hosts, with little evidence for parasite host-switching on an evolutionary scale, and provide a solid timeframe within which to place the evolution of new Plasmodium species. © The Author 2015. Published by Oxford University Press on

  3. The Cotesia sesamiae story: insight into host-range evolution in a Hymenoptera parasitoid and implication for its use in biological control programs.

    Science.gov (United States)

    Kaiser, L; Dupas, S; Branca, A; Herniou, E A; Clarke, C W; Capdevielle Dulac, C; Obonyo, J; Benoist, R; Gauthier, J; Calatayud, P A; Silvain, J F; Le Ru, B P

    2017-12-01

    This review covers nearly 20 years of studies on the ecology, physiology and genetics of the Hymenoptera Cotesia sesamiae, an African parasitoid of Lepidoptera that reduces populations of common maize borers in East and South Africa. The first part of the review presents studies based on sampling of C. sesamiae from maize crops in Kenya. From this agrosystem including one host plant and three main host borer species, studies revealed two genetically differentiated populations of C. sesamiae species adapted to their local host community, and showed that their differentiation involved the joint evolution of virulence genes and sensory mechanisms of host acceptance, reinforced by reproductive incompatibility due to Wolbachia infection status and natural inbreeding. In the second part, we consider the larger ecosystem of wild Poales plant species hosting many Lepidoptera stem borer species that are potential hosts for C. sesamiae. The hypothesis of other host-adapted C. sesamiae populations was investigated based on a large sampling of stem borer larvae on various Poales across sub-Saharan Africa. The sampling provided information on the respective contribution of local hosts, biogeography and Wolbachia in the genetic structure of C. sesamiae populations. Molecular evolution analyses highlighted that several bracovirus genes were under positive selection, some of them being under different selection pressure in C. sesamiae populations adapted to different hosts. This suggests that C. sesamiae host races result from co-evolution acting at the local scale on different bracovirus genes. The third part considers the mechanisms driving specialization. C. sesamiae host races are more or less host-specialized. This character is crucial for efficient and environmentally-safe use of natural enemies for biological control of pests. One method to get an insight in the evolutionary stability of host-parasite associations is to characterize the phylogenetic relationships between

  4. Quantitative analysis of commensal Escherichia coli populations reveals host-specific enterotypes at the intra-species level.

    Science.gov (United States)

    Smati, Mounira; Clermont, Olivier; Bleibtreu, Alexandre; Fourreau, Frédéric; David, Anthony; Daubié, Anne-Sophie; Hignard, Cécile; Loison, Odile; Picard, Bertrand; Denamur, Erick

    2015-08-01

    The primary habitat of the Escherichia coli species is the gut of warm-blooded vertebrates. The E. coli species is structured into four main phylogenetic groups A, B1, B2, and D. We estimated the relative proportions of these phylogroups in the feces of 137 wild and domesticated animals with various diets living in the Ile de France (Paris) region by real-time PCR. We distinguished three main clusters characterized by a particular abundance of two or more phylogroups within the E. coli animal commensal populations, which we called "enterocolitypes" by analogy with the enterotypes defined in the human gut microbiota at the genus level. These enterocolitypes were characterized by a dominant (>50%) B2, B1, or A phylogroup and were associated with different host species, diets, and habitats: wild and herbivorous species (wild rabbits and deer), domesticated herbivorous species (domesticated rabbits, horses, sheep, and cows), and omnivorous species (boar, pigs, and chickens), respectively. By analyzing retrospectively the data obtained using the same approach from 98 healthy humans living in Ile de France (Smati et al. 2013, Appl. Environ. Microbiol. 79, 5005-5012), we identified a specific human enterocolitype characterized by the dominant and/or exclusive (>90%) presence of phylogroup B2. We then compared B2 strains isolated from animals and humans, and revealed that human and animal strains differ regarding O-type and B2 subgroup. Moreover, two genes, sfa/foc and clbQ, were associated with the exclusive character of strains, observed only in humans. In conclusion, a complex network of interactions exists at several levels (genus and intra-species) within the intestinal microbiota. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  5. Coral Symbiodinium Community Composition Across the Belize Mesoamerican Barrier Reef System is Influenced by Host Species and Thermal Variability.

    Science.gov (United States)

    Baumann, J H; Davies, S W; Aichelman, H E; Castillo, K D

    2017-11-02

    Reef-building corals maintain a symbiotic relationship with dinoflagellate algae of the genus Symbiodinium, and this symbiosis is vital for the survival of the coral holobiont. Symbiodinium community composition within the coral host has been shown to influence a coral's ability to resist and recover from stress. A multitude of stressors including ocean warming, ocean acidification, and eutrophication have been linked to global scale decline in coral health and cover in recent decades. Three distinct thermal regimes (highTP, modTP, and lowTP) following an inshore-offshore gradient of declining average temperatures and thermal variation were identified on the Belize Mesoamerican Barrier Reef System (MBRS). Quantitative metabarcoding of the ITS-2 locus was employed to investigate differences and similarities in Symbiodinium genetic diversity of the Caribbean corals Siderastrea siderea, S. radians, and Pseudodiploria strigosa between the three thermal regimes. A total of ten Symbiodinium lineages were identified across the three coral host species. S. siderea was associated with distinct Symbiodinium communities; however, Symbiodinium communities of its congener, S. radians and P. strigosa, were more similar to one another. Thermal regime played a role in defining Symbiodinium communities in S. siderea but not S. radians or P. strigosa. Against expectations, Symbiodinium trenchii, a symbiont known to confer thermal tolerance, was dominant only in S. siderea at one sampled offshore site and was rare inshore, suggesting that coral thermal tolerance in more thermally variable inshore habitats is achieved through alternative mechanisms. Overall, thermal parameters alone were likely not the only primary drivers of Symbiodinium community composition, suggesting that environmental variables unrelated to temperature (i.e., light availability or nutrients) may play key roles in structuring coral-algal communities in Belize and that the relative importance of these

  6. Pacific oysters and parasites: Species invasions and their impact on parasite-host interactions

    NARCIS (Netherlands)

    Goedknegt, M.A.

    2017-01-01

    Human-aided introductions of species affect natural communities and ecosystems worldwide. These biological invasions can be considered to be ‘experiments in nature’ to study general ecological and evolutionary processes at large spatial and temporal scales.Studies on biological

  7. Pacific oysters and parasites Species invasions and their impact on parasite-host interactions

    NARCIS (Netherlands)

    Goedknegt, M.A.

    2017-01-01

    Human-aided introductions of species affect natural communities and ecosystems worldwide. These biological invasions can be considered to be ‘experiments in nature’ to study general ecological and evolutionary processes at large spatial and temporal scales.Studies on biological

  8. Foot and mouth disease virus in different host species; the effect of vaccination on transmission

    NARCIS (Netherlands)

    Orsel, K.

    2007-01-01

    Foot and mouth disease (FMD) is a contagious disease, affecting important livestock species like cattle, sheep and pigs. Therefore, FMD is listed as a notifiable disease to the Office International des Epizooties. The outbreaks of FMD in Europe in 2001 triggered the discussion about the use of

  9. Lipid Bodies: Inflammatory Organelles Implicated in Host-Trypanosoma cruzi Interplay during Innate Immune Responses

    Directory of Open Access Journals (Sweden)

    Heloisa D'Avila

    2012-01-01

    Full Text Available The flagellated protozoa Trypanosoma cruzi is the causal agent of Chagas' disease, a significant public health issue and still a major cause of morbidity and mortality in Latin America. Acute Chagas' disease elicits a strong inflammatory response. In order to control the parasite multiplication, cells of the monocytic lineage are highly mobilized. Monocyte differentiation leads to the formation of phagocytosing macrophages, which are strongly activated and direct host defense. A distinguishing feature of Chagas' disease-triggered macrophages is the presence of increased numbers of distinct cytoplasmic organelles termed lipid bodies or lipid droplets. These organelles are actively formed in response to the parasite and are sites for synthesis and storage of inflammatory mediators. This review covers current knowledge on lipid bodies elicited by the acute Chagas' disease within inflammatory macrophages and discusses the role of these organelles in inflammation. The increased knowledge of lipid bodies in pathogenic mechanisms of infections may not only contribute to the understanding of pathogen-host interactions but may also identify new targets for intervention.

  10. Neuro-immune interactions in inflammation and host defense: Implications for transplantation.

    Science.gov (United States)

    Chavan, Sangeeta S; Ma, Pingchuan; Chiu, Isaac M

    2017-09-23

    Sensory and autonomic neurons of the peripheral nervous system (PNS) play a critical role in regulating the immune system during tissue inflammation and host defense. Recent studies have identified the molecular mechanisms underlying the bidirectional communication between the nervous system and the immune system. Here, we highlight the studies that demonstrate the importance of the neuro-immune interactions in health and disease. Nociceptor sensory neurons detect immune mediators to produce pain, and release neuropeptides that act on the immune system to regulate inflammation. In parallel, neural reflex circuits including the vagus nerve-based inflammatory reflex are physiological regulators of inflammatory responses and cytokine production. In transplantation, neuro-immune communication could significantly impact the processes of host-pathogen defense, organ rejection, and wound healing. Emerging approaches to target the PNS such as bioelectronics could be useful in improving the outcome of transplantation. Therefore, understanding how the nervous system shapes the immune response could have important therapeutic ramifications for transplantation medicine. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  11. Manganese dosimetry: species differences and implications for neurotoxicity.

    Science.gov (United States)

    Aschner, Michael; Erikson, Keith M; Dorman, David C

    2005-01-01

    Manganese (Mn) is an essential mineral that is found at low levels in food, water, and the air. Under certain high-dose exposure conditions, elevations in tissue manganese levels can occur. Excessive manganese accumulation can result in adverse neurological, reproductive, and respiratory effects in both laboratory animals and humans. In humans, manganese-induced neurotoxicity (manganism) is the overriding concern since affected individuals develop a motor dysfunction syndrome that is recognized as a form of parkinsonism. This review primarily focuses on the essentiality and toxicity of manganese and considers contemporary studies evaluating manganese dosimetry and its transport across the blood-brain barrier, and its distribution within the central nervous system (CNS). These studies have dramatically improved our understanding of the health risks posed by manganese by determining exposure conditions that lead to increased concentrations of this metal within the CNS and other target organs. Most individuals are exposed to manganese by the oral and inhalation routes of exposure; however, parenteral injection and other routes of exposure are important. Interactions between manganese and iron and other divalent elements occur and impact the toxicokinetics of manganese, especially following oral exposure. The oxidation state and solubility of manganese also influence the absorption, distribution, metabolism, and elimination of manganese. Manganese disposition is influenced by the route of exposure. Rodent inhalation studies have shown that manganese deposited within the nose can undergo direct transport to the brain along the olfactory nerve. Species differences in manganese toxicokinetics and response are recognized with nonhuman primates replicating CNS effects observed in humans while rodents do not. Potentially susceptible populations, such as fetuses, neonates, individuals with compromised hepatic function, individuals with suboptimal manganese or iron intake, and

  12. Éclair—a web service for unravelling species origin of sequences sampled from mixed host interfaces

    Science.gov (United States)

    Rudd, Stephen; Tetko, Igor V.

    2005-01-01

    The identification of the genes that participate at the biological interface of two species remains critical to our understanding of the mechanisms of disease resistance, disease susceptibility and symbiosis. The sequencing of complementary DNA (cDNA) libraries prepared from the biological interface between two organisms provides an inexpensive way to identify the novel genes that may be expressed as a cause or consequence of compatible or incompatible interactions. Sequence classification and annotation of species origin typically use an orthology-based approach and require access to large portions of either genome, or a close relative. Novel species- or clade-specific sequences may have no counterpart within existing databases and remain ambiguous features. Here we present a web-service, Éclair, which utilizes support vector machines for the classification of the origin of expressed sequence tags stemming from mixed host cDNA libraries. In addition to providing an interface for the classification of sequences, users are presented with the opportunity to train a model to suit their preferred species pair. Éclair is freely available at . PMID:15980572

  13. The life cycle of Prosorhynchoides carvajali (Trematoda: Bucephalidae) involving species of bivalve and fish hosts in the intertidal zone of central Chile.

    Science.gov (United States)

    Muñoz, G; Valdivia, I; López, Z

    2015-09-01

    We describe the life cycle of the bucephalid Prosorhynchoides carvajali from the intertidal rocky zone of central Chile. To elucidate the life cycle of this digenean, two mytilid bivalves, Semimytilus algosus and Perumytilus purpuratus, and ten intertidal fish species belonging to the families Blenniidae, Tripterygiidae, Labrisomidae, Kyphosidae and Gobiesocidae were analysed for natural infections. In addition, experimental infections of fish were undertaken and molecular analyses were performed of several developmental stages of the digeneans in various host species. Experimental infections of fish were made from infected mytilids to determine which fish species were suitable for the metacercarial stage of Prosorhynchoides. We also determined the abundance and prevalence of metacercariae in natural infections in fish and found that they were lower than in the experimental infections. A molecular analysis showed that sporocysts from S. algosus were identical to metacercariae from five fish species and P. carvajali adults. Sporocysts isolated from P. purpuratus were similar to metacercaria found in one fish species only (G. laevifrons) but were different from P. carvajali, with 1.9-2.0% genetic divergence. Therefore, the complete life cycle of P. carvajali consists of the mytilid species S. algosus as the first intermediate host, at least five intertidal fish species as second intermediate hosts (Scartichthys viridis, Auchenionchus microcirrhis, Hypsoblennius sordidus, Helcogrammoides chilensis and Gobiesox marmoratus), two carnivorous fish as definitive hosts (Auchenionchus microcirrhis and A. variolosus) and one occasional definitive host (Syciases sanguineus). This is the second description of a life cycle of a marine digenean from Chile.

  14. New host record of five Flavobacterium species associated with tropical fresh water farmed fishes from North India

    Directory of Open Access Journals (Sweden)

    Dev Kumar Verma

    2015-12-01

    Full Text Available Abstract Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38 of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18% were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6 grouped with F. suncheonense, two strains (Fl6I2, Fl6I3 with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1 clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.

  15. Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species

    Science.gov (United States)

    Magrach, Ainhoa; Senior, Rebecca A.; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F.; Santamaria, Luis; Edwards, David P.

    2016-01-01

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’. PMID:26936241

  16. Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

    Science.gov (United States)

    Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

    2016-03-16

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. © 2016 The Author(s).

  17. Geographic distribution and host plants of Raoiella indica and associated mite species in northern Venezuela.

    Science.gov (United States)

    Vásquez, Carlos; de Moraes, Gilberto J

    2013-05-01

    The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive pest in the New World, where it is currently considered a serious threat to coconut and banana crops. It was first reported from northern Venezuela in 2007. To determine its current distribution in this country, surveys were carried out from October 2008 to April 2010 on coconut (Cocos nucifera L.), banana (Musa spp.), ornamental plants and weeds in northern Venezuela. Higher population levels of RPM were registered on commercial coconut farms in Falcón and Sucre states but also on other plant species naturally growing along the coastal line in Anzoategui, Aragua, Carabobo, Monagas and Nueva Esparta states. Out of 34 botanical species evaluated, all RPM stages were observed only on eight arecaceous, one musaceous and one streliziaceous species, indicating that the pest developed and reproduced only on these plants. Mite specimens found on weeds were considered spurious events, as immature stages of the pest were never found on these. Amblyseius largoensis (Muma) (Acari: Phytoseiidae) was the most frequent predatory mite associated with RPM in all sampling sites. The results indicate that RPM has spread to extensive areas of northern Venezuela since its initial detection in Güiria, Sucre state. Considering the report of this pest mite in northern Brazil in the late 2009, additional samplings in southern Venezuela should be carried out, to evaluate the possible presence of RPM also in that region.

  18. Host response to Foot- and Mouth Disease infection in cattle; possible implications for the development of “carriers”

    DEFF Research Database (Denmark)

    Stenfeldt, Carolina; Heegaard, Peter M. H.

    Foot-and-mouth disease (FMD) is a viral disease with severe financial implications for agricultural industries and the trade of animal products in affected countries. Any cloven hoofed animal species may become infected, and ruminants, especially cattle and buffalo, may develop into persistently...... infected “carriers” shedding low amounts of virus for several years after exposure to the disease. FMD in ruminants involves initial viral replication in pharyngeal epithelia, from where the virus spreads systemically. Mortality rates are low in adult animals but the morbidity is very high and the disease...... in persistence of FMD in cattle are not fully known. A series of animal experiments, with the aim of investigating the innate immune response, and possible implications for the development of persistently infected FMD carrier-animals in cattle has been performed. Bull calves of 4-5 months of age were infected...

  19. The adaptive response of bacterial food-borne pathogens in the environment, host and food: Implications for food safety.

    Science.gov (United States)

    Alvarez-Ordóñez, Avelino; Broussolle, Véronique; Colin, Pierre; Nguyen-The, Christophe; Prieto, Miguel

    2015-11-20

    Bacteria are constantly faced to stress situations in their ecological niches, the food and the host gastrointestinal tract. The capacity to detect and respond to surrounding changes is crucial for bacterial pathogens to survive or grow in changing environments. To this purpose, cells have evolved various sophisticated networks designed to protect against stressors or repair damage caused by them. Challenges can occur during production of foods when subjected to processing, and after food ingestion when confronted with host defensive barriers. Some pathogenic bacteria have shown the capacity to develop stable resistance against extreme conditions within a defined genomic context and a limited number of generations. On the other hand, bacteria can also respond to adverse conditions in a transient manner, through the so-called stress tolerance responses. Bacterial stress tolerance responses include both structural and physiological modifications in the cell and are mediated by complex genetic regulatory machinery. Major aspects in the adaptive response are the sensing mechanisms, the characterization of cell defensive systems, such as the operation of regulatory proteins (e.g. RpoS), the induction of homeostatic and repair systems, the synthesis of shock response proteins, and the modifications of cell membranes, particularly in their fatty acid composition and physical properties. This article reviews certain strategies used by food-borne bacteria to respond to particular stresses (acid, cold stress, extreme pressure) in a permanent or transient manner and discusses the implications that such adaptive responses pose for food safety. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Interaction of bovine peripheral blood polymorphonuclear cells and Leptospira species; innate responses in the natural bovine reservoir host.

    Directory of Open Access Journals (Sweden)

    Jennifer H Wilson-Welder

    2016-07-01

    Full Text Available Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and L. interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2 was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of

  1. Genetic Variation of the Host Plant Species Matters for Interactions with Above- and Belowground Herbivores

    Directory of Open Access Journals (Sweden)

    Dinesh Kafle

    2014-08-01

    Full Text Available Plants are challenged by both above- and belowground herbivores which may indirectly interact with each other via herbivore-induced changes in plant traits; however, little is known about how genetic variation of the host plant shapes such interactions. We used two genotypes (M4 and E9 of Solanum dulcamara (Solanaceae with or without previous experience of aboveground herbivory by Spodoptera exigua (Noctuidae to quantify its effects on subsequent root herbivory by Agriotes spp. (Elateridae. In the genotype M4, due to the aboveground herbivory, shoot and root biomass was significantly decreased, roots had a lower C/N ratio and contained significantly higher levels of proteins, while the genotype E9 was not affected. However, aboveground herbivory had no effects on weight gain or mortality of the belowground herbivores. Root herbivory by Agriotes increased the nitrogen concentration in the roots of M4 plants leading to a higher weight gain of conspecific larvae. Also, in feeding bioassays, Agriotes larvae tended to prefer roots of M4 over E9, irrespective of the aboveground herbivore treatment. Fourier-Transform Infrared Spectroscopy (FT-IR documented differences in metabolic profiles of the two plant genotypes and of the roots of M4 plants after aboveground herbivory. Together, these results demonstrate that previous aboveground herbivory can have genotype-specific effects on quantitative and qualitative root traits. This may have consequences for belowground interactions, although generalist root herbivores might not be affected when the root biomass offered is still sufficient for growth and survival.

  2. Macroparasite fauna of alien grey squirrels (Sciurus carolinensis: composition, variability and implications for native species.

    Directory of Open Access Journals (Sweden)

    Claudia Romeo

    Full Text Available Introduced hosts populations may benefit of an "enemy release" through impoverishment of parasite communities made of both few imported species and few acquired local ones. Moreover, closely related competing native hosts can be affected by acquiring introduced taxa (spillover and by increased transmission risk of native parasites (spillback. We determined the macroparasite fauna of invasive grey squirrels (Sciurus carolinensis in Italy to detect any diversity loss, introduction of novel parasites or acquisition of local ones, and analysed variation in parasite burdens to identify factors that may increase transmission risk for native red squirrels (S. vulgaris. Based on 277 grey squirrels sampled from 7 populations characterised by different time scales in introduction events, we identified 7 gastro-intestinal helminths and 4 parasite arthropods. Parasite richness is lower than in grey squirrel's native range and independent from introduction time lags. The most common parasites are Nearctic nematodes Strongyloides robustus (prevalence: 56.6% and Trichostrongylus calcaratus (6.5%, red squirrel flea Ceratophyllus sciurorum (26.0% and Holarctic sucking louse Neohaematopinus sciuri (17.7%. All other parasites are European or cosmopolitan species with prevalence below 5%. S. robustus abundance is positively affected by host density and body mass, C. sciurorum abundance increases with host density and varies with seasons. Overall, we show that grey squirrels in Italy may benefit of an enemy release, and both spillback and spillover processes towards native red squirrels may occur.

  3. Three-way interactions between Fusarium species, their plant hosts and biocontrol organisms

    DEFF Research Database (Denmark)

    Kosawang, Chatchai

    severity in comparison with the wild-type strain, whereas the C. rosea IK726 wild type provided complete protection against both F. graminearum strains. This suggested that ZEA detoxification is important for successful mycoparasitism of IK726. Furthermore, we generated DON- and ZEA-induced cDNA libraries...... are responsible for xenobiotic transport in many organisms, suggesting that the expansion of ABC transporters might be reflected in resistance to broad xenobiotics in C. rosea, while the contraction of subfamily C in T. reesei and T. atroviridae may be reflected in distinct lifestyles in these latter species....

  4. Three-way interactions between Fusarium species, their plant hosts and biocontrol organisms

    DEFF Research Database (Denmark)

    Kosawang, Chatchai

    Deoxynivalenol (DON) and Zearalenone (ZEA) are among the most predominant mycotoxins produced by Fusarium head blight pathogens. DON is a potent protein inhibitor while ZEA is a potent estrogenic metabolite. The toxins are known to inhibit growth and development of fungi with the exception...... of the mycoparasitic fungus Clonostachys rosea IK726, which is effective in controlling mycotoxin-producing Fusarium species. This thesis reports on aspects regarding (I) detoxification of ZEA in connection to biocontrol activities of the IK726, (II) mechanisms conferring resistance to DON and ZEA and (III) evolution...

  5. Chrysomelids American diabroticines Hosts and natural enemies. Biology-feasibility for control of pest species (Crisomelidos Diabroticinos americanos Hospederos y enemigos naturales Biologia y factibili manejo especies plagas

    Science.gov (United States)

    The chrysomelids in the Diabroticites include some of the most important pest species of the American continent. The chemical and management techniques used to date to control them are: crop rotation to prevent re-infection of host crops, especially in the species that display an egg diapause; insec...

  6. Geography and host species shape the evolutionary dynamics of U genogroup infectious hematopoietic necrosis virus

    Science.gov (United States)

    Black, Allison; Breyta, Rachel; Bedford, Trevor; Kurath, Gael

    2016-01-01

    Infectious hematopoietic necrosis virus (IHNV) is a negative-sense RNA virus that infects wild and cultured salmonids throughout the Pacific Coastal United States and Canada, from California to Alaska. Although infection of adult fish is usually asymptomatic, juvenile infections can result in high mortality events that impact salmon hatchery programs and commercial aquaculture. We used epidemiological case data and genetic sequence data from a 303 nt portion of the viral glycoprotein gene to study the evolutionary dynamics of U genogroup IHNV in the Pacific Northwestern United States from 1971 to 2013. We identified 114 unique genotypes among 1,219 U genogroup IHNV isolates representing 619 virus detection events. We found evidence for two previously unidentified, broad subgroups within the U genogroup, which we designated ‘UC’ and ‘UP’. Epidemiologic records indicated that UP viruses were detected more frequently in sockeye salmon (Oncorhynchus nerka) and in coastal waters of Washington and Oregon, whereas UC viruses were detected primarily in Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) in the Columbia River Basin, which is a large, complex watershed extending throughout much of interior Washington, Oregon, and Idaho. These findings were supported by phylogenetic analysis and by FST. Ancestral state reconstruction indicated that early UC viruses in the Columbia River Basin initially infected sockeye salmon but then emerged via host shifts into Chinook salmon and steelhead trout sometime during the 1980s. We postulate that the development of these subgroups within U genogroup was driven by selection pressure for viral adaptation to Chinook salmon and steelhead trout within the Columbia River Basin.

  7. Microhabitat preference of Anisakis simplex in 3 salmonid species: Immunological Implications

    DEFF Research Database (Denmark)

    Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt

    in inflammatory tissue in connection with the worms. CD8+ cells were detected in all three species but MHC II bearing cells were only found associated with encapsulated Anisakis in rainbow trout and brown trout, but not in Baltic salmon. In this study we have shown that Anisakis nematodes show a site predilection......Third stage larvae of Anisakis simplex nematodes are considered to have a low host-specificity and are able to infect a wide range of fish species. However, the physiological and immunological status of the fish species may affect the fate of the worm following infection. We selected three...... already at day 21 post infection. Immunohistochemical studies using monoclonal antibodies raised against IgT, IgM, CD8 and MHCII were used to detect the presence of immune cells around the infecting nematodes. None of the three fish species showed positive reactions for IgT and IgM bearing cells...

  8. Comparative Genomics of the Bacterial Genus Streptococcus Illuminates Evolutionary Implications of Species Groups

    Science.gov (United States)

    Gao, Xiao-Yang; Zhi, Xiao-Yang; Li, Hong-Wei; Klenk, Hans-Peter; Li, Wen-Jun

    2014-01-01

    Members of the genus Streptococcus within the phylum Firmicutes are among the most diverse and significant zoonotic pathogens. This genus has gone through considerable taxonomic revision due to increasing improvements of chemotaxonomic approaches, DNA hybridization and 16S rRNA gene sequencing. It is proposed to place the majority of streptococci into “species groups”. However, the evolutionary implications of species groups are not clear presently. We use comparative genomic approaches to yield a better understanding of the evolution of Streptococcus through genome dynamics, population structure, phylogenies and virulence factor distribution of species groups. Genome dynamics analyses indicate that the pan-genome size increases with the addition of newly sequenced strains, while the core genome size decreases with sequential addition at the genus level and species group level. Population structure analysis reveals two distinct lineages, one including Pyogenic, Bovis, Mutans and Salivarius groups, and the other including Mitis, Anginosus and Unknown groups. Phylogenetic dendrograms show that species within the same species group cluster together, and infer two main clades in accordance with population structure analysis. Distribution of streptococcal virulence factors has no obvious patterns among the species groups; however, the evolution of some common virulence factors is congruous with the evolution of species groups, according to phylogenetic inference. We suggest that the proposed streptococcal species groups are reasonable from the viewpoints of comparative genomics; evolution of the genus is congruent with the individual evolutionary trajectories of different species groups. PMID:24977706

  9. Interaction between Plasmodium Glycosylphosphatidylinositol and the Host Protein Moesin Has No Implication in Malaria Pathology.

    Science.gov (United States)

    Dunst, Josefine; Azzouz, Nahid; Liu, Xinyu; Tsukita, Sachiko; Seeberger, Peter H; Kamena, Faustin

    2017-01-01

    Glycosylphosphatidylinositol (GPI) anchor of Plasmodium falciparum origin is considered an important toxin leading to severe malaria pathology through stimulation of pro-inflammatory responses from innate immune cells. Even though the GPI-induced immune response is widely described to be mediated by pattern recognition receptors such as TLR2 and TLR4, previous studies have revealed that these two receptors are dispensable for the development of severe malaria pathology. Therefore, this study aimed at the identification of potential alternative Plasmodium GPI receptors. Herein, we have identified the host protein moesin as an interaction partner of Plasmodium GPI in vitro. Given previous reports indicating the relevance of moesin especially in the LPS-mediated induction of pro-inflammatory responses, we have conducted a series of in vitro and in vivo experiments to address the physiological relevance of the moesin-Plasmodium GPI interaction in the context of malaria pathology. We report here that although moesin and Plasmodium GPI interact in vitro, moesin is not critically involved in processes leading to Plasmodium-induced pro-inflammatory immune responses or malaria-associated cerebral pathology.

  10. A Compartmental Comparison of Major Lipid Species in a Coral-Symbiodinium Endosymbiosis: Evidence that the Coral Host Regulates Lipogenesis of Its Cytosolic Lipid Bodies.

    Directory of Open Access Journals (Sweden)

    Hung-Kai Chen

    Full Text Available The lipid body (LB formation in the host coral gastrodermal cell cytoplasm is a hallmark of the coral-Symbiodinium endosymbiosis, and such lipid-based entities are not found in endosymbiont-free cnidarian cells. Therefore, the elucidation of lipogenesis regulation in LBs and how it is related to the lipid metabolism of the host and endosymbiont could provide direct insight to understand the symbiosis mechanism. Herein, the lipid composition of host cells of the stony coral Euphyllia glabrescens, as well as that of their cytoplasmic LBs and in hospite Symbiodinium populations, was examined by high performance liquid chromatography (HPLC and gas chromatography/mass spectrometry (GC/MS, and six major lipid species were identified: wax esters, sterol esters, triacylglycerols, cholesterols, free fatty acids, and phospholipids. Their concentrations differed significantly between host coral cells, LBs, and Symbiodinium, suggesting compartmental regulation. WE were only present in the host coral and were particularly highly concentrated in LBs. Amongst the four species of WE, the monoene R = C18:1/R = C16 was found to be LB-specific and was not present in the host gastrodermal cell cytoplasm. Furthermore, the acyl pool profiles of the individual LB lipid species were more similar, but not equal to, those of the host gastrodermal cells in which they were located, indicating partially autonomous lipid metabolism in these LBs. Nevertheless, given the overall similarity in the host gastrodermal cell and LB lipid profiles, these data suggest that a significant portion of the LB lipids may be of host coral origin. Finally, lipid profiles of the in hospite Symbiodinium populations were significantly distinct from those of the cultured Symbiodinium, potentially suggesting a host regulation effect that may be fundamental to lipid metabolism in endosymbiotic associations involving clade C Symbiodinium.

  11. A Compartmental Comparison of Major Lipid Species in a Coral-Symbiodinium Endosymbiosis: Evidence that the Coral Host Regulates Lipogenesis of Its Cytosolic Lipid Bodies.

    Science.gov (United States)

    Chen, Hung-Kai; Song, Shin-Ni; Wang, Li-Hsueh; Mayfield, Anderson B; Chen, Yi-Jyun; Chen, Wan-Nan U; Chen, Chii-Shiarng

    2015-01-01

    The lipid body (LB) formation in the host coral gastrodermal cell cytoplasm is a hallmark of the coral-Symbiodinium endosymbiosis, and such lipid-based entities are not found in endosymbiont-free cnidarian cells. Therefore, the elucidation of lipogenesis regulation in LBs and how it is related to the lipid metabolism of the host and endosymbiont could provide direct insight to understand the symbiosis mechanism. Herein, the lipid composition of host cells of the stony coral Euphyllia glabrescens, as well as that of their cytoplasmic LBs and in hospite Symbiodinium populations, was examined by high performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS), and six major lipid species were identified: wax esters, sterol esters, triacylglycerols, cholesterols, free fatty acids, and phospholipids. Their concentrations differed significantly between host coral cells, LBs, and Symbiodinium, suggesting compartmental regulation. WE were only present in the host coral and were particularly highly concentrated in LBs. Amongst the four species of WE, the monoene R = C18:1/R = C16 was found to be LB-specific and was not present in the host gastrodermal cell cytoplasm. Furthermore, the acyl pool profiles of the individual LB lipid species were more similar, but not equal to, those of the host gastrodermal cells in which they were located, indicating partially autonomous lipid metabolism in these LBs. Nevertheless, given the overall similarity in the host gastrodermal cell and LB lipid profiles, these data suggest that a significant portion of the LB lipids may be of host coral origin. Finally, lipid profiles of the in hospite Symbiodinium populations were significantly distinct from those of the cultured Symbiodinium, potentially suggesting a host regulation effect that may be fundamental to lipid metabolism in endosymbiotic associations involving clade C Symbiodinium.

  12. Trichinella infections in different host species of an endemic district of Serbia.

    Science.gov (United States)

    Zivojinovic, M; Sofronic-Milosavljevic, Lj; Cvetkovic, J; Pozio, E; Interisano, M; Plavsic, B; Radojicic, S; Kulisic, Z

    2013-05-20

    Trichinella infections are endemic in the Balkan region of Europe. Though trichinellosis and agents thereof are serious problems for human health and animal husbandry, only a limited number of Trichinella isolates from Serbia have been identified at the species level so far. The aim of the present study was the surveillance and monitoring of Trichinella in domestic pigs and wild animals from the endemic district of Branicevo. Investigations performed during the 2009-2010 period revealed Trichinella infections in 344 out of 282,960 (0.12%) domestic pigs. Among wildlife, Trichinella infections were detected in 11 out of 94 (11.7%) wild boars (Sus scrofa), 7 out of 57 (12.3%) red foxes (Vulpes vulpes), 7 out of 13 (53.8%) golden jackals (Canis aureus), and in all three examined wolves (Canis lupus). Trichinella spiralis and Trichinella britovi were the only two species identified. T. britovi was identified in 31% of isolates from wildlife of the Branicevo district and T. spiralis was found in 53% of wild animals; mixed infections were observed in 16% of the animals examined. Findings form the basis of an information campaign for veterinary services, pig owners and the hunter's associations about the risk of the transmission of these zoonotic agents. The application of control programs as established at the Veterinary Specialist Institute of Pozarevac resulted in a decline in Trichinella infections among domestic pigs and the absence of human trichinellosis in the last three years in the Branicevo district. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Differential effect of Agaricus host species on the population development of Megaselia halterata (Diptera: Phoridae).

    Science.gov (United States)

    Smith, J E; Challen, M P; White, P F; Edmondson, R N; Chandler, D

    2006-12-01

    Twelve isolates from the genus Agaricus (Fungi, Basidiomycota) were investigated for their ability to support development of the phorid fly, Megaselia halterata (Wood), which is an important pest of the commercial white button mushroom Agaricus bisporus. Combined effects of oviposition of adult female M. halterata and larval development in mushroom compost inoculated with Agaricus mycelium were determined using bioassays. The numbers of M. halterata offspring that developed were affected by the Agaricus isolate used, and there was a significant separation between resistant and susceptible isolates. In a bioassay where the female phorids had a choice of all 12 isolates for oviposition, three isolates produced >200 adults per 100 g compost pot while the remaining nine isolates had 100 adults per 100 g compost pot while the remainder resulted in <4 adults per pot. With the susceptible isolates, there was a positive correlation between increasing concentration of mycelium in the substrate and phorid development until the concentration exceeded 40% after which numbers of emerging phorids declined. Genetic identity of Agaricus isolates was determined using ITS sequencing and phylogenetic methods, which revealed two major cluster groups. Isolates supporting the development of large populations of M. halterata were located in one of these clusters (group I), and were either Agaricus bisporus or other species from the same Agaricus section Duploannulatae. Isolates that did not support the development of M. halterata populations were located in a different cluster (group II) and were more genetically distant from A. bisporus, e.g. Agaricus sections Arvenses, Minores and Xanthodermatei. Species of Agaricus with resistance to M. halterata could have significant potential for the breeding and cultivation of phorid-free mushrooms.

  14. Host specificity in phylogenetic and geographic space.

    Science.gov (United States)

    Poulin, Robert; Krasnov, Boris R; Mouillot, David

    2011-08-01

    The measurement of host specificity goes well beyond counting how many host species can successfully be used by a parasite. In particular, specificity can be assessed with respect to how closely related the host species are, or whether a parasite exploits the same or different hosts across its entire geographic range. Recent developments in the measurement of biodiversity offer a new set of analytical tools that can be used to quantify the many aspects of host specificity. We describe here the multifaceted nature of host specificity, summarize the indices available to measure its different facets one at a time or in combination, and discuss their implications for parasite evolution and disease epidemiology. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. When history repeats itself: exploring the genetic architecture of host-plant adaptation in two closely related lepidopteran species.

    Directory of Open Access Journals (Sweden)

    Hermine Alexandre

    Full Text Available The genus Ostrinia includes two allopatric maize pests across Eurasia, namely the European corn borer (ECB, O. nubilalis and the Asian corn borer (ACB, O. furnacalis. A third species, the Adzuki bean borer (ABB, O. scapulalis, occurs in sympatry with both the ECB and the ACB. The ABB mostly feeds on native dicots, which probably correspond to the ancestral host plant type for the genus Ostrinia. This situation offers the opportunity to characterize the two presumably independent adaptations or preadaptations to maize that occurred in the ECB and ACB. In the present study, we aimed at deciphering the genetic architecture of these two adaptations to maize, a monocot host plant recently introduced into Eurasia. To this end, we performed a genome scan analysis based on 684 AFLP markers in 12 populations of ECB, ACB and ABB. We detected 2 outlier AFLP loci when comparing French populations of the ECB and ABB, and 9 outliers when comparing Chinese populations of the ACB and ABB. These outliers were different in both countries, and we found no evidence of linkage disequilibrium between any two of them. These results suggest that adaptation or preadaptation to maize relies on a different genetic architecture in the ECB and ACB. However, this conclusion must be considered in light of the constraints inherent to genome scan approaches and of the intricate evolution of adaptation and reproductive isolation in the Ostrinia spp. complex.

  16. Radiation of the red algal parasite Congracilaria babae onto a secondary host species, Hydropuntia sp. (Gracilariaceae, Rhodophyta.

    Directory of Open Access Journals (Sweden)

    Poh-Kheng Ng

    Full Text Available Congracilaria babae was first reported as a red alga parasitic on the thallus of Gracilaria salicornia based on Japanese materials. It was circumscribed to have deep spermatangial cavities, coloration similar to its host and the absence of rhizoids. We observed a parasitic red alga with morphological and anatomical features suggestive of C. babae on a Hydropuntia species collected from Sabah, East Malaysia. We addressed the taxonomic affinities of the parasite growing on Hydropuntia sp. based on the DNA sequence of molecular markers from the nuclear, mitochondrial and plastid genomes (nuclear ITS region, mitochondrial cox1 gene and plastid rbcL gene. Phylogenetic analyses based on all genetic markers also implied the monophyly of the parasite from Hydropuntia sp. and C. babae, suggesting their conspecificity. The parasite from Hydropuntia sp. has a DNA signature characteristic to C. babae in having plastid rbcL gene sequence identical to G. salicornia. C. babae is likely to have evolved directly from G. salicornia and subsequently radiated onto a secondary host Hydropuntia sp. We also recommend the transfer of C. babae to the genus Gracilaria and propose a new combination, G. babae, based on the anatomical observations and molecular data.

  17. When history repeats itself: exploring the genetic architecture of host-plant adaptation in two closely related lepidopteran species.

    Science.gov (United States)

    Alexandre, Hermine; Ponsard, Sergine; Bourguet, Denis; Vitalis, Renaud; Audiot, Philippe; Cros-Arteil, Sandrine; Streiff, Réjane

    2013-01-01

    The genus Ostrinia includes two allopatric maize pests across Eurasia, namely the European corn borer (ECB, O. nubilalis) and the Asian corn borer (ACB, O. furnacalis). A third species, the Adzuki bean borer (ABB, O. scapulalis), occurs in sympatry with both the ECB and the ACB. The ABB mostly feeds on native dicots, which probably correspond to the ancestral host plant type for the genus Ostrinia. This situation offers the opportunity to characterize the two presumably independent adaptations or preadaptations to maize that occurred in the ECB and ACB. In the present study, we aimed at deciphering the genetic architecture of these two adaptations to maize, a monocot host plant recently introduced into Eurasia. To this end, we performed a genome scan analysis based on 684 AFLP markers in 12 populations of ECB, ACB and ABB. We detected 2 outlier AFLP loci when comparing French populations of the ECB and ABB, and 9 outliers when comparing Chinese populations of the ACB and ABB. These outliers were different in both countries, and we found no evidence of linkage disequilibrium between any two of them. These results suggest that adaptation or preadaptation to maize relies on a different genetic architecture in the ECB and ACB. However, this conclusion must be considered in light of the constraints inherent to genome scan approaches and of the intricate evolution of adaptation and reproductive isolation in the Ostrinia spp. complex.

  18. Development of species-specific primers for identification of Biomphalaria arabica, the intermediate host of Schistosoma mansoni in Saudi Arabia.

    Science.gov (United States)

    Al-Quraishy, Saleh A; Bin Dajem, Saad M; Mostafa, Osama M; Ibrahim, Essam H; Al-Qahtani, Ahmed

    2014-01-01

    Schistosoma mansoni is mediated through the intermediate host Biomphalaria arabica which lives in Saudi Arabia. Molecular characterization and identification of this intermediate host are important for epidemiological studies of schistosomiasis. The present work aimed to determine the molecular variations among the populations of B. arabica found in Southern part of Saudi Arabia, and to develop species-specific primers for identification of these snails as a first step in the development of multiplex PCR for simultaneously identifying the snails and diagnosing its infections in a single step. Five populations of Saudi B. arabica snails were collected from freshwater bodies. Three populations were collected from Asser and two populations were collected from AL-Baha. Genomic DNA was extracted from snails and was amplified using five different RAPD-PCR primers. The banding patterns of amplified materials by primers P1 and P5 were identical in all populations. However, the rest primers displayed intra-specific differences among populations with variable degrees. Largest sizes of RAPD-PCR products were cloned into TA cloning vector as a preparatory step for DNA sequence analysis. After sequencing, similarity searches of obtained DNA sequences revealed that there are no similar sequences submitted to genebank data bases and its associated banks. The results obtained will be helpful in the development of simultaneous identification of B. arabica snails and diagnosis of S. mansoni infection within it in a single step by an implementation of multiplex PCR.

  19. The New World Gibbobruchus Pic (Coleoptera, Chrysomelidae, Bruchinae): description of a new species and phylogenetic insights into the evolution of host associations and biogeography.

    Science.gov (United States)

    Manfio, Daiara; Jorge, Isaac R; Morse, Geoffrey E; Ribeiro-Costa, Cibele S

    2016-04-18

    The seed beetle Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. is described from the Amazon basin in Brazil (Acre) and Ecuador (Napo), and is included in an updated key to the species of Gibbobruchus Pic. This new species and the recently described G. bergamini Manfio & Ribeiro-Costa are incorporated into a phylogenetic reanalysis of the genus and into a comparative analysis of host plant use and biogeography. Species groups previously proposed were supported and the evolutionary history in host plant-use shows Gibbobruchus conserved at tribe level, Cercideae (Caesalpinioideae), with coordination between biogeographic expansion and host genus shifts. Both species, Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. and G. bergamini, were placed within the group scurra (G. tridentatus (G. scurra (G. cavillator+G. bolivianus+G. bergamini))) and supported by one synapomorphy. Additionally, we update geographic distributions and host plant records. Two hosts, Bauhinia argentinensis Burkart and B. tarapotensis Benth. are recorded for the first time as hosts for the genus and for the subfamily.

  20. Peptide-Recombinant VP6 Protein Based Enzyme Immunoassay for the Detection of Group A Rotaviruses in Multiple Host Species.

    Directory of Open Access Journals (Sweden)

    Naveen Kumar

    Full Text Available We developed a novel enzyme immunoassay for the detection of group A rotavirus (RVA antigen in fecal samples of multiple host species. The assay is based on the detection of conserved VP6 protein using anti-recombinant VP6 antibodies as capture antibodies and anti-multiple antigenic peptide (identified and constructed from highly immunodominant epitopes within VP6 protein antibodies as detector antibodies. The clinical utility of the assay was evaluated using a panel of 914 diarrhoeic fecal samples from four different host species (bovine, porcine, poultry and human collected from diverse geographical locations in India. Using VP6- based reverse transcription-polymerase chain reaction (RT-PCR as the gold standard, we found that the diagnostic sensitivity (DSn and specificity (DSp of the new assay was high [bovine (DSn = 94.2% & DSp = 100%; porcine (DSn = 94.6% & DSp = 93.3%; poultry (DSn = 74.2% & DSp = 97.7% and human (DSn = 82.1% & DSp = 98.7%]. The concordance with RT-PCR was also high [weighted kappa (k = 0.831-0.956 at 95% CI = 0.711-1.0] as compared to RNA-polyacrylamide gel electrophoresis (RNA-PAGE. The performance characteristics of the new immunoassay were comparable to those of the two commercially available ELISA kits. Our results suggest that this peptide-recombinant protein based assay may serve as a preliminary assay for epidemiological surveillance of RVA antigen and for evaluation of vaccine effectiveness especially in low and middle income settings.

  1. Addressing potential local adaptation in species distribution models: implications for conservation under climate change

    Science.gov (United States)

    Hällfors, Maria Helena; Liao, Jishan; Dzurisin, Jason D. K.; Grundel, Ralph; Hyvärinen, Marko; Towle, Kevin; Wu, Grace C.; Hellmann, Jessica J.

    2016-01-01

    Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs to treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account, may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted, however. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate MaxEnt models, one considering the species as a single population and two of disjunct populations. PCA analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species versus population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

  2. Metatranscriptome analysis reveals host-microbiome interactions in traps of carnivorous Genlisea species

    Directory of Open Access Journals (Sweden)

    Hieu X. Cao

    2015-07-01

    Full Text Available In the carnivorous plant genus Genlisea a unique lobster pot trapping mechanism supplements nutrition in nutrient-poor habitats. A wide spectrum of microbes frequently occurs in Genlisea’s leaf-derived traps without clear relevance for Genlisea carnivory. We sequenced the metatranscriptomes of subterrestrial traps versus the aerial chlorophyll-containing leaves of G. nigrocaulis and of G. hispidula. Ribosomal RNA assignment revealed soil-borne microbial diversity in Genlisea traps, with 92 genera of 19 phyla present in more than one sample. Microbes from 16 of these phyla including proteobacteria, green algae, amoebozoa, fungi, ciliates and metazoans, contributed additionally short-lived mRNA to the metatranscriptome. Furthermore, transcripts of 438 members of hydrolases (e.g. proteases, phosphatases, lipases, mainly resembling those of metazoans, ciliates and green algae, were found. Compared to aerial leaves, Genlisea traps displayed a transcriptional up-regulation of endogenous NADH oxidases generating reactive oxygen species as well as of acid phosphatases for prey digestion. A leaf-versus-trap transcriptome comparison reflects that carnivory provides inorganic P- and different forms of N-compounds (ammonium, nitrate, amino acid, oligopeptides and implies the need to protect trap cells against oxidative stress. The analysis elucidates a complex food web inside the Genlisea traps, and suggests ecological relationships between this plant genus and its entrapped microbiome.

  3. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus as a Potential Reservoir Host Species for Monkeypox Virus.

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    Christina L Hutson

    Full Text Available Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s. In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4 or West African (W-MPXV: n = 4; an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV between 3 and 27 days post infection (p.i. (up to 1X108 pfu/ml, with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  4. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus.

    Science.gov (United States)

    Hutson, Christina L; Nakazawa, Yoshinori J; Self, Joshua; Olson, Victoria A; Regnery, Russell L; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L; Rocke, Tonie E; Osorio, Jorge E; Damon, Inger K; Carroll, Darin S

    2015-01-01

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  5. [Distribution diversity of integrins and calcium channels on major human and mouse host cells of Leptospira species].

    Science.gov (United States)

    Li, Cheng-xue; Zhao, Xin; Qian, Jing; Yan, Jie

    2012-07-01

    To determine the distribution of integrins and calcium channels on major human and mouse host cells of Leptospira species. The expression of β1, β2 and β3 integrins was detected with immunofluorescence assay on the surface of human monocyte line THP-1, mouse mononuclear-macrophage-like cell line J774A.1, human vascular endothelial cell line HUVEC, mouse vascular endothelial cell EOMA, human hepatocyte line L-02, mouse hepatocyte line Hepa1-6, human renal tubular epithelial cell line HEK-293, mouse glomerular membrane epithelial cell line SV40-MES13, mouse collagen blast line NIH/3T3, human and mouse platelets. The distribution of voltage gate control calcium channels Cav3.1, Cav3.2, Cav3.3 and Cav2.3, and receptor gate calcium channels P(2)X(1), P(2)2X(2), P(2)X(3), P(2)X(4), P(2)X(5), P(2)X(6) and P(2)X(7) were determined with Western blot assay. β1 integrin proteins were positively expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, L-02, Hepa1-6 and HEK-239 cells as well as human and mouse platelets. β2 integrin proteins were expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, and NIH/3T3 cells. β3 integrin proteins were expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, Hepa1-6, HEK-239 and NIH/3T3 cells as well as human and mouse platelets. P(2)X(1) receptor gate calcium channel was expressed on the membrane surface of human and mouse platelets, while P(2)X(5) receptor gate calcium channel was expressed on the membrane surface of J774A.1, THP-1, L-02, Hepa1-6, HEK-239 and HUVEC cells. However, the other calcium channels were not detected on the tested cell lines or platelets. There is a large distribution diversity of integrins and calcium channel proteins on the major human and mouse host cells of Leptospira species, which may be associated with the differences of leptospira-induced injury in different host cells.

  6. Asexual propagation of sea anemones that host anemonefishes: implications for the marine ornamental aquarium trade and restocking programs.

    Science.gov (United States)

    Scott, Anna; Hardefeldt, Jannah M; Hall, Karina C

    2014-01-01

    Anemonefishes and their host sea anemones form an iconic symbiotic association in reef environments, and are highly sought after in the marine aquarium trade. This study examines asexual propagation as a method for culturing a geographically widespread and commonly traded species of host sea anemone, Entacmaea quadricolor. Two experiments were done: the first to establish whether size or colour morph influenced survival after cutting into halves or quarters; and the second to see whether feeding was needed to maximise survival and growth after cutting. Survival rates were high in both experiments, with 89.3 and 93.8% of the anemones cut in half, and 62.5 and 80.4% cut in quarters surviving in experiments 1 and 2, respectively. Anemones that were cut in half were larger in size, and healed and grew quicker than those cut in quarters. However, even though survival was lower when the individuals were cut in quarters, this treatment produced the greatest number of anemones. Feeding increased oral disc diameter growth and reduced wet weight loss, but did not significantly influence pedal disc diameter. Given that the anemones took up to 56 d to form an off-centre mouth, it is highly likely that feeding may have produced greater effect if the experiment was run for longer. This low technology method of propagation could be used to produce individuals throughout the year and the anemones could then be used to supply the aquarium trade or restock depleted habitats, thus supporting biodiversity conservation in coral reef areas.

  7. Feeding and development of the glassy-winged sharpshooter, Homalodisca vitripennis, on Australian native plant species and implications for Australian biosecurity.

    Directory of Open Access Journals (Sweden)

    Anna A Rathé

    Full Text Available In any insect invasion the presence or absence of suitable food and oviposition hosts in the invaded range is a key factor determining establishment success. The glassy-winged sharpshooter, Homalodisca vitripennis, is an important insect vector of the xylem-limited bacterial plant pathogen, Xylella fastidiosa, which causes disease in numerous host plants including food and feedstock crops, ornamentals and weeds. Both the pathogen and the vector are native to the Americas and are considered to be highly invasive. Neither has been detected in Australia. Twelve Australian native plant species present in the USA were observed over two years for suitability as H. vitripennis feeding, oviposition and nymph development hosts. Hosts providing evidence of adult or nymph presence were Leptospermum laevigatum, Acacia cowleana, Eremophila divaricata, Eucalyptus wandoo, Hakea laurina, Melaleuca laterita and Swainsona galegifolia. An oviposition-suitability field study was conducted with citrus, a favoured oviposition host, as a positive control. Citrus and L. laevigatum, A. cowleana, B. ericifolia×B. spinulosa, C. pulchella, E. divaricata, E. wandoo, H. laurina, and S. galegifolia were found to be oviposition hosts. Egg parasitism by the mymarid parasitoid Gonatocerus ashmeadi was observed on all Australian plants. A number of Australian plants that may facilitate H. vitripennis invasion have been identified and categorised as 'high risk' due to their ability to support all three life stages (egg, nymph and adult of the insect in the field (L. laevigatum, A. cowleana, E. divaricata, H. laurina, and S. galegifolia. The implications of these host status and natural enemy research findings are discussed and placed in an Australian invasion context.

  8. An updated concept and revised composition for Hamacreadium Linton, 1910 (Opecoelidae: Plagioporinae) clarifies a previously obscured pattern of host-specificity among species.

    Science.gov (United States)

    Martin, Storm B; Cutmore, Scott C; Ward, Selina; Cribb, Thomas H

    2017-04-12

    The present concept of the trematode genus Hamacreadium Linton, 1910 encompasses considerable morphological variability and includes species reported from a broad range of fishes. These include herbivores and planktivores, despite the life-cycle of the type-species, Hamacreadium mutabile Linton, 1910, being known to use fishes as intermediate hosts. Reports of H. mutabile are numerous, spanning the west Atlantic, east Pacific and Indo-west Pacific, whereas other nominal species are infrequently reported and several inadequately described. Following a comprehensive review, a strict revised morphological definition is proposed for the genus. Several nominal species are excluded, but, conversely, finer distinctions are recognised among the species concluded to genuinely belong in the genus. Justified records for species retained in the genus are overwhelmingly from fishes of the families Lutjanidae Gill (snappers) and Lethrinidae Bonaparte (emperors), revealing a previously concealed pattern of host-specificity. For H. mutabile, it is argued that only records from western Atlantic lutjanid fishes should be considered genuine; those from plausible Indo-Pacific fishes most likely represent different species. In addition to H. mutabile, eight species are recognised: Hamacreadium cribbi Bray & Justine, 2016, Hamacreadium hainanense Shen, 1990, Hamacreadium interruptum Nagaty, 1941, Hamacreadium lethrini Yamaguti, 1934, Hamacreadium longivesiculum (Yamaguti, 1952) n. comb., Hamacreadium lutiani (Shen, 1990) n. comb., Hamacreadium morgani Baz,1946 and Hamacreadium phyllorchis (Bilqees, 1976) Cribb, 2005. A key to species of Hamacreadium and comprehensive lists of all host-locality records are included.

  9. Climate change risks and conservation implications for a threatened small-range mammal species.

    Science.gov (United States)

    Morueta-Holme, Naia; Fløjgaard, Camilla; Svenning, Jens-Christian

    2010-04-29

    Climate change is already affecting the distributions of many species and may lead to numerous extinctions over the next century. Small-range species are likely to be a special concern, but the extent to which they are sensitive to climate is currently unclear. Species distribution modeling, if carefully implemented, can be used to assess climate sensitivity and potential climate change impacts, even for rare and cryptic species. We used species distribution modeling to assess the climate sensitivity, climate change risks and conservation implications for a threatened small-range mammal species, the Iberian desman (Galemys pyrenaicus), which is a phylogenetically isolated insectivore endemic to south-western Europe. Atlas data on the distribution of G. pyrenaicus was linked to data on climate, topography and human impact using two species distribution modeling algorithms to test hypotheses on the factors that determine the range for this species. Predictive models were developed and projected onto climate scenarios for 2070-2099 to assess climate change risks and conservation possibilities. Mean summer temperature and water balance appeared to be the main factors influencing the distribution of G. pyrenaicus. Climate change was predicted to result in significant reductions of the species' range. However, the severity of these reductions was highly dependent on which predictor was the most important limiting factor. Notably, if mean summer temperature is the main range determinant, G. pyrenaicus is at risk of near total extinction in Spain under the most severe climate change scenario. The range projections for Europe indicate that assisted migration may be a possible long-term conservation strategy for G. pyrenaicus in the face of global warming. Climate change clearly poses a severe threat to this illustrative endemic species. Our findings confirm that endemic species can be highly vulnerable to a warming climate and highlight the fact that assisted migration has

  10. Climate change risks and conservation implications for a threatened small-range mammal species.

    Directory of Open Access Journals (Sweden)

    Naia Morueta-Holme

    Full Text Available BACKGROUND: Climate change is already affecting the distributions of many species and may lead to numerous extinctions over the next century. Small-range species are likely to be a special concern, but the extent to which they are sensitive to climate is currently unclear. Species distribution modeling, if carefully implemented, can be used to assess climate sensitivity and potential climate change impacts, even for rare and cryptic species. METHODOLOGY/PRINCIPAL FINDINGS: We used species distribution modeling to assess the climate sensitivity, climate change risks and conservation implications for a threatened small-range mammal species, the Iberian desman (Galemys pyrenaicus, which is a phylogenetically isolated insectivore endemic to south-western Europe. Atlas data on the distribution of G. pyrenaicus was linked to data on climate, topography and human impact using two species distribution modeling algorithms to test hypotheses on the factors that determine the range for this species. Predictive models were developed and projected onto climate scenarios for 2070-2099 to assess climate change risks and conservation possibilities. Mean summer temperature and water balance appeared to be the main factors influencing the distribution of G. pyrenaicus. Climate change was predicted to result in significant reductions of the species' range. However, the severity of these reductions was highly dependent on which predictor was the most important limiting factor. Notably, if mean summer temperature is the main range determinant, G. pyrenaicus is at risk of near total extinction in Spain under the most severe climate change scenario. The range projections for Europe indicate that assisted migration may be a possible long-term conservation strategy for G. pyrenaicus in the face of global warming. CONCLUSIONS/SIGNIFICANCE: Climate change clearly poses a severe threat to this illustrative endemic species. Our findings confirm that endemic species can be

  11. Native trees of the Northeast Argentine: natural hosts of the Cryptococcus neoformans-Cryptococcus gattii species complex.

    Science.gov (United States)

    Cattana, Maria Emilia; Sosa, María de Los Ángeles; Fernández, Mariana; Rojas, Florencia; Mangiaterra, Magdalena; Giusiano, Gustavo

    2014-01-01

    In Argentina, information about epidemiology and environmental distribution of Cryptococcus is scarce. The city of Resistencia borders with Brazil and Paraguay where this fungus is endemic. All these supported the need to investigate the ecology of the genus and the epidemiology of cryptococcosis in this area. The aim was to investigate the presence of species of Cryptococcus neoformans-Cryptococcus gattii complex and their genotypes in trees of the city of Resistencia. One hundred and five trees were sampled by swabbing technique. The isolates were identified using conventional and commercial methods and genotyped by PCR-RFLP (Restriction Fragment Length Polymorphism). Cryptococcus was found in 7 out of the total trees. 6 out of 7 Cryptococcus isolates were identified as C. neoformans and one as C. gattii. C. gattii was isolated from Grevillea robusta. C. neoformans strains were isolated from Tabebuia avellanedae and Peltophorum dubium. Genotyping showed that all C. neoformans belonged to the VNI type and C. gattii belonged to the VGI type. This represents the first study on the ecology of Cryptococcus spp. associated to trees from northeastern Argentina, and the first report describing Grevillea robusta as a host of members of this fungal genus. Another finding is the isolation of C. neoformans from Tabebuia avellanedae and Peltophorum dubium, both tree species native to northeastern Argentina. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  12. Evidence for potential of managing some African fruit fly species (Diptera: Tephritidae) using the mango fruit fly host-marking pheromone.

    Science.gov (United States)

    Kachigamba, Donald L; Ekesi, Sunday; Ndungu, Mary W; Gitonga, Linus M; Teal, Peter E A; Torto, Baldwyn

    2012-12-01

    We investigated conspecific and heterospecific oviposition host discrimination among four economically important fruit fly pests of mango in Africa (Ceratitis capitata, Wiedemann; C. fasciventris, Bezzi; C. rosa, Karsch, and C. cosyra, Walker) with regard to host-marking behavior and fecal matter aqueous solutions. The objective of the study was to get insight into the potential of managing these pests using the host-marking technique. Observations were done on mango slices marked by the flies and treated with aqueous solutions of fecal matter of the flies, respectively. In both host-marking and fecal matter experiments, C. cosyra, which is the most destructive species of the four on mango, was exceptional. It only discriminated against hosts treated with its fecal matter but with lower sensitivity while C. capitata and C.fasciventris discriminated against hosts marked by it or treated with its fecal matter and with higher sensitivity. Our results provide evidence for potential of managing some of the major fruit fly species infesting mango in Africa using the host-marking pheromone of the mango fruit fly, C. cosyra.

  13. Integrating molecular and morphological approaches for characterizing parasite cryptic species: implications for parasitology.

    Science.gov (United States)

    Nadler, Steven A; DE León, Gerardo Pérez-Ponce

    2011-11-01

    Herein we review theoretical and methodological considerations important for finding and delimiting cryptic species of parasites (species that are difficult to recognize using traditional systematic methods). Applications of molecular data in empirical investigations of cryptic species are discussed from an historical perspective, and we evaluate advantages and disadvantages of approaches that have been used to date. Developments concerning the theory and practice of species delimitation are emphasized because theory is critical to interpretation of data. The advantages and disadvantages of different molecular methodologies, including the number and kind of loci, are discussed relative to tree-based approaches for detecting and delimiting cryptic species. We conclude by discussing some implications that cryptic species have for research programmes in parasitology, emphasizing that careful attention to the theory and operational practices involved in finding, delimiting, and describing new species (including cryptic species) is essential, not only for fully characterizing parasite biodiversity and broader aspects of comparative biology such as systematics, evolution, ecology and biogeography, but to applied research efforts that strive to improve development and understanding of epidemiology, diagnostics, control and potential eradication of parasitic diseases.

  14. Comparative host feeding patterns of the Asian tiger mosquito, Aedes albopictus, in urban and suburban Northeastern USA and implications for disease transmission.

    OpenAIRE

    Ary Faraji; Andrea Egizi; Dina M Fonseca; Isik Unlu; Taryn Crepeau; Sean P Healy; Randy Gaugler

    2014-01-01

    Background Aedes albopictus is an invasive species which continues expanding its geographic range and involvement in mosquito-borne diseases such as chikungunya and dengue. Host selection patterns by invasive mosquitoes are critically important because they increase endemic disease transmission and drive outbreaks of exotic pathogens. Traditionally, Ae. albopictus has been characterized as an opportunistic feeder, primarily feeding on mammalian hosts but occasionally acquiring blood from avia...

  15. Phylogenetic analysis of glucosyltransferases and implications for the coevolution of mutans streptococci with their mammalian hosts.

    Science.gov (United States)

    Argimón, Silvia; Alekseyenko, Alexander V; DeSalle, Rob; Caufield, Page W

    2013-01-01

    Glucosyltransferases (Gtfs) catalyze the synthesis of glucans from sucrose and are produced by several species of lactic-acid bacteria. The oral bacterium Streptococcus mutans produces large amounts of glucans through the action of three Gtfs. GtfD produces water-soluble glucan (WSG), GtfB synthesizes water-insoluble glucans (WIG) and GtfC produces mainly WIG but also WSG. These enzymes, especially those synthesizing WIG, are of particular interest because of their role in the formation of dental plaque, an environment where S. mutans can thrive and produce lactic acid, promoting the formation of dental caries. We sequenced the gtfB, gtfC and gtfD genes from several mutans streptococcal strains isolated from the oral cavity of humans and searched for their homologues in strains isolated from chimpanzees and macaque monkeys. The sequence data were analyzed in conjunction with the available Gtf sequences from other bacteria in the genera Streptococcus, Lactobacillus and Leuconostoc to gain insights into the evolutionary history of this family of enzymes, with a particular emphasis on S. mutans Gtfs. Our analyses indicate that streptococcal Gtfs arose from a common ancestral progenitor gene, and that they expanded to form two clades according to the type of glucan they synthesize. We also show that the clade of streptococcal Gtfs synthesizing WIG appeared shortly after the divergence of viviparous, dentate mammals, which potentially contributed to the formation of dental plaque and the establishment of several streptococci in the oral cavity. The two S. mutans Gtfs capable of WIG synthesis, GtfB and GtfC, are likely the product of a gene duplication event. We dated this event to coincide with the divergence of the genomes of ancestral early primates. Thus, the acquisition and diversification of S. mutans Gtfs predates modern humans and is unrelated to the increase in dietary sucrose consumption.

  16. Phylogenetic analysis of glucosyltransferases and implications for the coevolution of mutans streptococci with their mammalian hosts.

    Directory of Open Access Journals (Sweden)

    Silvia Argimón

    Full Text Available Glucosyltransferases (Gtfs catalyze the synthesis of glucans from sucrose and are produced by several species of lactic-acid bacteria. The oral bacterium Streptococcus mutans produces large amounts of glucans through the action of three Gtfs. GtfD produces water-soluble glucan (WSG, GtfB synthesizes water-insoluble glucans (WIG and GtfC produces mainly WIG but also WSG. These enzymes, especially those synthesizing WIG, are of particular interest because of their role in the formation of dental plaque, an environment where S. mutans can thrive and produce lactic acid, promoting the formation of dental caries. We sequenced the gtfB, gtfC and gtfD genes from several mutans streptococcal strains isolated from the oral cavity of humans and searched for their homologues in strains isolated from chimpanzees and macaque monkeys. The sequence data were analyzed in conjunction with the available Gtf sequences from other bacteria in the genera Streptococcus, Lactobacillus and Leuconostoc to gain insights into the evolutionary history of this family of enzymes, with a particular emphasis on S. mutans Gtfs. Our analyses indicate that streptococcal Gtfs arose from a common ancestral progenitor gene, and that they expanded to form two clades according to the type of glucan they synthesize. We also show that the clade of streptococcal Gtfs synthesizing WIG appeared shortly after the divergence of viviparous, dentate mammals, which potentially contributed to the formation of dental plaque and the establishment of several streptococci in the oral cavity. The two S. mutans Gtfs capable of WIG synthesis, GtfB and GtfC, are likely the product of a gene duplication event. We dated this event to coincide with the divergence of the genomes of ancestral early primates. Thus, the acquisition and diversification of S. mutans Gtfs predates modern humans and is unrelated to the increase in dietary sucrose consumption.

  17. A pox on thee! Manipulation of the host immune system by myxoma virus and implications for viral-host co-adaptation.

    Science.gov (United States)

    Zúñiga, Martha C

    2002-09-01

    The poxviruses have evolved a diverse array of proteins which serve to subvert innate and adaptive host responses that abort or at least limit viral infections. Myxoma virus and its rabbit host are considered to represent an ideal poxvirus-host system in which to study the effects of these immunomodulatory proteins. Studies of laboratory rabbits (Oryctolagus cuniculus) infected with gene knockout variants of myxoma virus have provided compelling evidence that several myxoma virus gene products contribute to the pathogenic condition known as myxomatosis. However, myxomatosis, which is characterized by skin lesions, systemic immunosuppression, and a high mortality rate, does not occur in the virus' natural South American host, Sylvilogus brasiliensis. Moreover, in Australia where myxoma virus was willfully introduced to control populations of O. cuniculus, myxomatosis-resistant rabbits emerged within a year of myxoma virus introduction into the field. In this review I discuss the characterized immunomodulatory proteins of myxoma virus, their biochemical properties, their pathogenic effects in laboratory rabbits, the role of the host immune system in the susceptibility or resistance to myxomatosis, and the evidence that immunomodulatory genes may have been attenuated during the co-adaptation of myxoma virus and O. cuniculus in Australia.

  18. Are gall midge species (Diptera, Cecidomyiidae host-plant specialists? Espécies de moscas galhadoras (Diptera, Cecidomyiidae são especialistas em plantas hospedeiras?

    Directory of Open Access Journals (Sweden)

    Marco Antonio A. Carneiro

    2009-01-01

    Full Text Available Despite the speciose fauna of gall-inducing insects in the Neotropical region, little is known about their taxonomy. On the other hand, gall morphotypes associated with host species have been extensively used as a surrogate of the inducer species worldwide. This study reviewed the described gall midges and their galls to test the generalization on the use of gall morphotypes as surrogates of gall midge species in the Brazilian fauna. We compiled taxonomic and biological data for 196 gall midge species recorded on 128 host plant species. Ninety two percent of those species were monophagous, inducing galls on a single host plant species, whereas only 5.6% species were oligophagous, inducing galls on more than one congeneric host plant species. Only four species induced galls on more than one host plant genus. We conclude that gall morphotypes associated with information on the host plant species and attacked organs are reliable surrogates of the gall-inducing species.Apesar do elevado número de espécies da fauna de insetos indutores de galhas na região Neotropical, muito pouco espécies foram descritas. Por outro lado, o morfotipo da galha associado com a espécie da planta hospedeira é em todo o mundo amplamente utilizado como um indicador da espécie de inseto indutor. Este estudo revê as espécies de cecidommídeos descritos e suas galhas para verificar a generalização do uso da morfologia da galha como indicador da espécie de cecidomíideo na fauna brasileira. Nós compilamos dados biológicos e taxonômicos de 196 espécies de cecidomiídeos em 128 espécies de plantas no Brasil. Noventa e dois porcento destas espécies foram monófagas, induzindo galhas em uma única espécie de planta hospedeira, enquanto somente 5,6% das espécies foram oligófagas, induzindo galhas em mais de uma espécie de planta do mesmo gênero. Somente quatro espécies induzem galhas em espécies de plantas de gêneros diferentes. Nós concluímos que o morfo

  19. Plasmalogen enrichment in exosomes secreted by a nematode parasite versus those derived from its mouse host: implications for exosome stability and biology

    Directory of Open Access Journals (Sweden)

    Fabio Simbari

    2016-07-01

    Full Text Available Extracellular vesicles (EVs mediate communication between cells and organisms across all 3 kingdoms of life. Several reports have demonstrated that EVs can transfer molecules between phylogenetically diverse species and can be used by parasites to alter the properties of the host environment. Whilst the concept of vesicle secretion and uptake is broad reaching, the molecular composition of these complexes is expected to be diverse based on the physiology and environmental niche of different organisms. Exosomes are one class of EVs originally defined based on their endocytic origin, as these derive from multivesicular bodies that then fuse with the plasma membrane releasing them into the extracellular environment. The term exosome has also been used to describe any small EVs recovered by high-speed ultracentrifugation, irrespective of origin since this is not always well characterized. Here, we use comparative global lipidomic analysis to examine the composition of EVs, which we term exosomes, that are secreted by the gastrointestinal nematode, Heligmosomoides polygyrus, in relation to exosomes secreted by cells of its murine host. Ultra-performance liquid chromatography – tandem mass spectrometry (UPLC-MS/MS analysis reveals a 9- to 62-fold enrichment of plasmalogens, as well as other classes of ether glycerophospholipids, along with a relative lack of cholesterol and sphingomyelin (SM in the nematode exosomes compared with those secreted by murine cells. Biophysical analyses of the membrane dynamics of these exosomes demonstrate increased rigidity in those from the nematode, and parallel studies with synthetic vesicles support a role of plasmalogens in stabilizing the membrane structure. These results suggest that nematodes can maintain exosome membrane structure and integrity through increased plasmalogens, compensating for diminished levels of other lipids, including cholesterol and SM. This work also illuminates the prevalence of

  20. A host-plant specialist, Helicoverpa assulta, is more tolerant to capsaicin from Capsicum annuum than other noctuid species.

    Science.gov (United States)

    Ahn, Seung-Joon; Badenes-Pérez, Francisco R; Heckel, David G

    2011-09-01

    Plant secondary compounds not only play an important role in plant defense, but have been a driving force for host adaptation by herbivores. Capsaicin (8-methyl-N-vanillyl-6-nonenamide), an alkaloid found in the fruit of Capsicum spp. (Solanaceae), is responsible for the pungency of hot pepper fruits and is unique to the genus. The oriental tobacco budworm, Helicoverpa assulta (Lepidoptera: Noctuidae), is a specialist herbivore feeding on solanaceous plants including Capsicum annuum, and is one of a very few insect herbivores worldwide capable of feeding on hot pepper fruits. To determine whether this is due in part to an increased physiological tolerance of capsaicin, we compared H. assulta with another specialist on Solanaceae, Heliothis subflexa, and four generalist species, Spodoptera frugiperda, Heliothis virescens, Helicoverpa armigera, and Helicoverpa zea, all belonging to the family Noctuidae. When larvae were fed capsaicin-spiked artificial diet for the entire larval period, larval mortality increased in H. subflexa and H. zea but decreased in H. assulta. Larval growth decreased on the capsaicin-spiked diet in four of the species, was unaffected in H. armigera and increased in H. assulta. Food consumption and utilization experiments showed that capsaicin decreased relative consumption rate (RCR), relative growth rate (RGR) and approximate digestibility (AD) in H. zea, and increased AD and the efficiency of conversion of ingested food (ECI) in H. armigera; whereas it did not significantly change any of these nutritional indices in H. assulta. The acute toxicity of capsaicin measured by injection into early fifth instar larvae was less in H. assulta than in H. armigera and H. zea. Injection of high concentrations produced abdominal paralysis and self-cannibalism. Injection of sub-lethal doses of capsaicin resulted in reduced pupal weights in H. armigera and H. zea, but not in H. assulta. The results indicate that H. assulta is more tolerant to capsaicin than

  1. Asexual propagation of sea anemones that host anemonefishes: implications for the marine ornamental aquarium trade and restocking programs.

    Directory of Open Access Journals (Sweden)

    Anna Scott

    Full Text Available Anemonefishes and their host sea anemones form an iconic symbiotic association in reef environments, and are highly sought after in the marine aquarium trade. This study examines asexual propagation as a method for culturing a geographically widespread and commonly traded species of host sea anemone, Entacmaea quadricolor. Two experiments were done: the first to establish whether size or colour morph influenced survival after cutting into halves or quarters; and the second to see whether feeding was needed to maximise survival and growth after cutting. Survival rates were high in both experiments, with 89.3 and 93.8% of the anemones cut in half, and 62.5 and 80.4% cut in quarters surviving in experiments 1 and 2, respectively. Anemones that were cut in half were larger in size, and healed and grew quicker than those cut in quarters. However, even though survival was lower when the individuals were cut in quarters, this treatment produced the greatest number of anemones. Feeding increased oral disc diameter growth and reduced wet weight loss, but did not significantly influence pedal disc diameter. Given that the anemones took up to 56 d to form an off-centre mouth, it is highly likely that feeding may have produced greater effect if the experiment was run for longer. This low technology method of propagation could be used to produce individuals throughout the year and the anemones could then be used to supply the aquarium trade or restock depleted habitats, thus supporting biodiversity conservation in coral reef areas.

  2. Oviposition Preference of Pea Weevil, Bruchus pisorum L. Among Host and Non-host Plants and its Implication for Pest Management.

    Science.gov (United States)

    Mendesil, Esayas; Rämert, Birgitta; Marttila, Salla; Hillbur, Ylva; Anderson, Peter

    2015-01-01

    The pea weevil, Bruchus pisorum L. is a major insect pest of field pea, Pisum sativum L. worldwide and current control practices mainly depend on the use of chemical insecticides that can cause adverse effects on environment and human health. Insecticides are also unaffordable by many small-scale farmers in developing countries, which highlights the need for investigating plant resistance traits and to develop alternative pest management strategies. The aim of this study was to determine oviposition preference of pea weevil among P. sativum genotypes with different level of resistance (Adet, 32410-1 and 235899-1) and the non-host leguminous plants wild pea (Pisum fulvum Sibth. et Sm.) and grass pea (Lathyrus sativus L.), in no-choice and dual-choice tests. Pod thickness and micromorphological traits of the pods were also examined. In the no-choice tests significantly more eggs were laid on the susceptible genotype Adet than on the other genotypes. Very few eggs were laid on P. fulvum and L. sativus. In the dual-choice experiments Adet was preferred by the females for oviposition. Furthermore, combinations of Adet with either 235899-1 or non-host plants significantly reduced the total number of eggs laid by the weevil in the dual-choice tests. Female pea weevils were also found to discriminate between host and non-host plants during oviposition. The neoplasm (Np) formation on 235899-1 pods was negatively correlated with oviposition by pea weevil. Pod wall thickness and trichomes might have influenced oviposition preference of the weevils. These results on oviposition behavior of the weevils can be used in developing alternative pest management strategies such as trap cropping using highly attractive genotype and intercropping with the non-host plants.

  3. Oviposition preference of pea weevil, Bruchus pisorum L. among host and non-host plants and its implication for pest management

    Directory of Open Access Journals (Sweden)

    Esayas Mendesil eAmosa

    2016-01-01

    Full Text Available The pea weevil, Bruchus pisorum L. is a major insect pest of field pea, Pisum sativum L. worldwide and current control practices mainly depend on the use of chemical insecticides that can cause adverse effects on environment and human health. Insecticides are also unaffordable by many small-scale farmers in developing countries, which highlights the need for investigating plant resistance traits and to develop alternative pest management strategies. The aim of this study was to determine oviposition preference of pea weevil among P. sativum genotypes with different level of resistance (Adet, 32410-1 and 235899-1 and the non-host leguminous plants wild pea (Pisum fulvum Sibth. et Sm. and grass pea (Lathyrus sativus L., in no-choice and dual-choice tests. Pod thickness and micromorphological traits of the pods were also examined. In the no-choice tests significantly more eggs were laid on the susceptible genotype Adet than on the other genotypes. Very few eggs were laid on P. fulvum and L. sativus. In the dual-choice experiments Adet was preferred by the females for oviposition. Furthermore, combinations of Adet with either 235899-1 or non-host plants significantly reduced the total number of eggs laid by the weevil in the dual-choice tests. Female pea weevils were also found to discriminate between host and non-host plants during oviposition. The neoplasm (Np formation on 235899-1 pods was negatively correlated with oviposition by pea weevil. Pod wall thickness and trichomes might have influenced oviposition preference of the weevils. These results on oviposition behavior the weevils can be used in developing alternative pest management strategies such as trap cropping using highly attractive genotype and intercropping with the non-host plants.

  4. Adaptation of Borna disease virus to new host species attributed to altered regulation of viral polymerase activity.

    Science.gov (United States)

    Ackermann, Andreas; Staeheli, Peter; Schneider, Urs

    2007-08-01

    Borna disease virus (BDV) can persistently infect the central nervous system of a broad range of mammalian species. Mice are resistant to infections with primary BDV isolates, but certain laboratory strains can be adapted to replicate in mice. We determined the molecular basis of adaptation by studying mutations acquired by a cDNA-derived BDV strain during one brain passage in rats and three passages in mice. The adapted virus propagated efficiently in mouse brains and induced neurological disease. Its genome contained seven point mutations, three of which caused amino acid changes in the L polymerase (L1116R and N1398D) and in the polymerase cofactor P (R66K). Recombinant BDV carrying these mutations either alone or in combination all showed enhanced multiplication speed in Vero cells, indicating improved intrinsic viral polymerase activity rather than adaptation to a mouse-specific factor. Mutations R66K and L1116R, but not N1398D, conferred replication competence of recombinant BDV in mice if introduced individually. Virus propagation in mouse brains was substantially enhanced if both L mutations were present simultaneously, but infection remained mostly nonsymptomatic. Only if all three amino acid substitutions were combined did BDV replicate vigorously and induce early disease in mice. Interestingly, the virulence-enhancing effect of the R66K mutation in P could be attributed to reduced negative regulation of polymerase activity by the viral X protein. Our data demonstrate that BDV replication competence in mice is mediated by the polymerase complex rather than the viral envelope and suggest that altered regulation of viral gene expression can favor adaptation to new host species.

  5. Zoosporic tolerance to pH stress and its implications for Phytophthora species in aquatic ecosystems.

    Science.gov (United States)

    Kong, Ping; Moorman, Gary W; Lea-Cox, John D; Ross, David S; Richardson, Patricia A; Hong, Chuanxue

    2009-07-01

    Phytophthora species, a group of destructive plant pathogens, are commonly referred to as water molds, but little is known about their aquatic ecology. Here we show the effect of pH on zoospore survival of seven Phytophthora species commonly isolated from irrigation reservoirs and natural waterways and dissect zoospore survival strategy. Zoospores were incubated in a basal salt liquid medium at pH 3 to 11 for up to 7 days and then plated on a selective medium to determine their survival. The optimal pHs differed among Phytophthora species, with the optimal pH for P. citricola at pH 9, the optimal pH for P. tropicalis at pH 5, and the optimal pH for the five other species, P. citrophthora, P. insolita, P. irrigata, P. megasperma, and P. nicotianae, at pH 7. The greatest number of colonies was recovered from zoospores of all species plated immediately after being exposed to different levels of pH. At pH 5 to 11, the recovery rate decreased sharply (P exposure for five of the seven species. In contrast, no change occurred (P > or = 0.1125) in the recovery of any species even after a 7-day exposure at pH 3. Overall, P. megasperma and P. citricola survived longer at higher rates in a wider range of pHs than other species did. These results are generally applicable to field conditions as indicated by additional examination of P. citrophthora and P. megasperma in irrigation water at different levels of pH. These results challenge the notion that all Phytophthora species inhabit aquatic environments as water molds and have significant implications in the management of plant diseases resulting from waterborne microbial contamination.

  6. Commensal Bacteroides species induce colitis in host-genotype-specific fashion in a mouse model of inflammatory bowel disease

    Science.gov (United States)

    Bloom, Seth M.; Bijanki, Vinieth N.; Nava, Gerardo M.; Sun, Lulu; Malvin, Nicole P.; Donermeyer, David L.; Dunne, W. Michael; Allen, Paul M.; Stappenbeck, Thaddeus S.

    2011-01-01

    SUMMARY The intestinal microbiota is important for induction of inflammatory bowel disease (IBD). IBD is associated with complex shifts in microbiota composition, but it is unclear whether specific bacterial subsets induce IBD and, if so, whether their proportions in the microbiota are altered during disease. Here we fulfilled Koch’s postulates in host-genotype-specific fashion using a mouse model of IBD with human-relevant disease-susceptibility mutations. From screening experiments we isolated common commensal Bacteroides species, introduced them into antibiotic-pretreated mice, and quantitatively re-isolated them in culture. The bacteria colonized IBD-susceptible and non-susceptible mice equivalently, but induced disease exclusively in susceptible animals. Conversely, commensal Enterobacteriaceae were >100-fold enriched during spontaneous disease but an Enterobacteriaceae isolate failed to induce disease in antibiotic-pretreated mice despite robust colonization. We thus demonstrate that IBD-associated microbiota alterations do not necessarily reflect underlying disease etiology. These findings establish important experimental criteria and a conceptual framework for understanding microbial contributions to IBD. PMID:21575910

  7. A new and distinct species in the genus Caulimovirus exists as an endogenous plant pararetroviral sequence in its host, Dahlia variabilis.

    Science.gov (United States)

    Pahalawatta, Vihanga; Druffel, Keri; Pappu, Hanu

    2008-07-05

    Viruses in certain genera in family Caulimoviridae were shown to integrate their genomic sequences into their host genomes and exist as endogenous pararetroviral sequences (EPRV). However, members of the genus Caulimovirus remained to be the exception and are known to exist only as episomal elements in the infected cell. We present evidence that the DNA genome of a new and distinct Caulimovirus species, associated with dahlia mosaic, is integrated into its host genome, dahlia (Dahlia variabilis). Using cloned viral genes as probes, Southern blot hybridization of total plant DNA from dahlia seedlings showed the presence of viral DNA in the host DNA. Fluorescent in situ hybridization using labeled DNA probes from the D10 genome localized the viral sequences in dahlia chromosomes. The natural integration of a Caulimovirus genome into its host and its existence as an EPRV suggests the co-evolution of this plant-virus pathosystem.

  8. Genetic and morphological diversity of Trisetacus species (Eriophyoidea: Phytoptidae) associated with coniferous trees in Poland: phylogeny, barcoding, host and habitat specialization.

    Science.gov (United States)

    Lewandowski, Mariusz; Skoracka, Anna; Szydło, Wiktoria; Kozak, Marcin; Druciarek, Tobiasz; Griffiths, Don A

    2014-08-01

    Eriophyoid species belonging to the genus Trisetacus are economically important as pests of conifers. A narrow host specialization to conifers and some unique morphological characteristics have made these mites interesting subjects for scientific inquiry. In this study, we assessed morphological and genetic variation of seven Trisetacus species originating from six coniferous hosts in Poland by morphometric analysis and molecular sequencing of the mitochondrial cytochrome oxidase subunit I gene and the nuclear D2 region of 28S rDNA. The results confirmed the monophyly of the genus Trisetacus as well as the monophyly of five of the seven species studied. Both DNA sequences were effective in discriminating between six of the seven species tested. Host-dependent genetic and morphological variation in T. silvestris and T. relocatus, and habitat-dependent genetic and morphological variation in T. juniperinus were detected, suggesting the existence of races or even distinct species within these Trisetacus taxa. This is the first molecular phylogenetic analysis of the Trisetacus species. The findings presented here will stimulate further investigations on the evolutionary relationships of Trisetacus as well as the entire Phytoptidae family.

  9. Phylogeny and host-plant relationships of the Australian Myrtaceae leafmining moth genus Pectinivalva (Lepidoptera, Nepticulidae), with new subgenera and species

    Science.gov (United States)

    Hoare, Robert J.B.; van Nieukerken, Erik J.

    2013-01-01

    Abstract The phylogeny of the mainly Australian nepticulid genus Pectinivalva Scoble, 1983 is investigated on the basis of morphology, and a division into three monophyletic subgenera is proposed on the basis of these results. These subgenera (Pectinivalva, Casanovula Hoare, subgen. n. and Menurella Hoare, subgen. n. ) are described and diagnosed, the described species of Pectinivalva are assigned to them, and representative new species are described in each: Pectinivalva (Pectinivalva) mystaconota Hoare, sp. n., Pectinivalva (Casanovula) brevipalpa Hoare, sp. n., Pectinivalva (Casanovula) minotaurus Hoare, sp. n., Pectinivalva (Menurella) scotodes Hoare, sp. n., Pectinivalva (Menurella) acmenae Hoare, sp. n., Pectinivalva (Menurella) xenadelpha Van Nieukerken & Hoare, sp. n., Pectinivalva (Menurella) quintiniae Hoare & Van Nieukerken, sp. n., and Pectinivalva (Menurella) tribulatrix Van Nieukerken & Hoare, sp. n. Pectinivalva (Menurella) quintiniae (from Quintinia verdonii, Paracryphiaceae) is the first known member of the genus with a host-plant not belonging to Myrtaceae. Pectinivalva (Menurella) xenadelpha from Mt Gunung Lumut, Kalimantan, Borneo, is the first pectinivalvine reported from outside Australia. Keys to the subgenera of Nepticulidae known from Australia, based on adults, male and female genitalia, and larvae, are presented. Host-plant relationships of Pectinivalva are discussed with relation to the phylogeny, and a list of known host-plants of Pectinivalva, including hosts of undescribed species, is presented. DNA barcodes are provided for most of the new and several unnamed species. PMID:23794827

  10. Phylogeny and host-plant relationships of the Australian Myrtaceae leafmining moth genus Pectinivalva (Lepidoptera, Nepticulidae, with new subgenera and species

    Directory of Open Access Journals (Sweden)

    Robert Hoare

    2013-03-01

    Full Text Available The phylogeny of the mainly Australian nepticulid genus Pectinivalva Scoble, 1983 is investigated on the basis of morphology, and a division into three monophyletic subgenera is proposed on the basis of these results. These subgenera (Pectinivalva, Casanovula Hoare, subgen. n. and Menurella Hoare, subgen. n. are described and diagnosed, the described species of Pectinivalva are assigned to them, and representative new species are described in each: P. (P. mystaconota Hoare, sp. n., P. (C. brevipalpa Hoare, sp. n., P. (C. minotaurus Hoare, sp. n., P. (M. scotodes Hoare, sp. n., P. (M. acmenae Hoare, sp. n., P. (M. xenadelpha Van Nieukerken & Hoare, sp. n., P. (M. quintiniae Hoare & Van Nieukerken, sp. n., and P. (M. tribulatrix Van Nieukerken & Hoare, sp. n. Pectinivalva (Menurella quintiniae (from Quintinia verdonii, Paracryphiaceae is the first known member of the genus with a host-plant not belonging to Myrtaceae. P. (M. xenadelpha from Mt Gunung Lumut, Kalimantan, Borneo, is the first pectinivalvine reported from outside Australia. Keys to the subgenera of Nepticulidae known from Australia, based on adults, male and female genitalia, and larvae, are presented. Host-plant relationships of Pectinivalva are discussed with relation to the phylogeny, and a list of known host-plants of Pectinivalva, including hosts of undescribed species, is presented. DNA barcodes are provided for most of the new and several unnamed species.

  11. Effect of host tree species on cellulase activity and bacterial community composition in the gut of larval Asian longhorned beetle.

    Science.gov (United States)

    Geib, Scott M; Jimenez-Gasco, Maria Del Mar; Carlson, John E; Tien, Ming; Hoover, Kelli

    2009-06-01

    Anoplophora glabripennis, the Asian longhorned beetle, is a wood-boring insect that can develop in a wide range of healthy deciduous hosts and requires gut microbes to aid in wood degradation and digestion. Here we show that larval A. glabripennis harbor a diverse gut bacterial community, and this community can be extremely variable when reared in different host trees. A. glabripennis reared in a preferred host (Acer saccharum) had the highest gut bacterial diversity compared with larvae reared either in a secondary host (Quercus palustris), a resistant host (Pyrus calleryana), or on artificial diet. The gut microbial community of larval A. glabripennis collected from field populations on Brooklyn, NY, showed the highest degree of complexity among all samples in this study. Overall, when larvae fed on a preferred host, they harbored a broad diversity of gut bacteria spanning the alpha-, beta-, gamma-Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Cellulase activities (beta-1,4-endoglucanase, beta-1,4-exoglucanase, and beta-1,4-glucosidase) in the guts of larvae fed in a preferred host (A. saccharum) or a secondary host (Q. palustris) were significantly higher than that of artificial diet fed larvae. Larvae that fed on wood from a resistant host (P. calleryana) showed suppressed total gut cellulase activity. Results show that the host tree can impact both gut microbial community complexity and cellulase activity in A. glabripennis.

  12. The Microbiome of Field-Caught and Laboratory-Adapted Australian Tephritid Fruit Fly Species with Different Host Plant Use and Specialisation.

    Science.gov (United States)

    Morrow, J L; Frommer, M; Shearman, D C A; Riegler, M

    2015-08-01

    Tephritid fruit fly species display a diversity of host plant specialisation on a scale from monophagy to polyphagy. Furthermore, while some species prefer ripening fruit, a few are restricted to damaged or rotting fruit. Such a diversity of host plant use may be reflected in the microbial symbiont diversity of tephritids and their grade of dependency on their microbiomes. Here, we investigated the microbiome of six tephritid species from three genera, including species that are polyphagous pests (Bactrocera tryoni, Bactrocera neohumeralis, Bactrocera jarvisi, Ceratitis capitata) and a monophagous specialist (Bactrocera cacuminata). These were compared with the microbiome of a non-pestiferous but polyphagous tephritid species that is restricted to damaged or rotting fruit (Dirioxa pornia). The bacterial community associated with whole fruit flies was analysed by 16S ribosomal DNA (rDNA) amplicon pyrosequencing to detect potential drivers of taxonomic composition. Overall, the dominant bacterial families were Enterobacteriaceae and Acetobacteraceae (both Proteobacteria), and Streptococcaceae and Enterococcaceae (both Firmicutes). Comparisons across species and genera found different microbial composition in the three tephritid genera, but limited consistent differentiation between Bactrocera species. Within Bactrocera species, differentiation of microbial composition seemed to be influenced by the environment, possibly including their diets; beyond this, tephritid species identity or ecology also had an effect. The microbiome of D. pornia was most distinct from the other five species, which may be due to its ecologically different niche of rotting or damaged fruit, as opposed to ripening fruit favoured by the other species. Our study is the first amplicon pyrosequencing study to compare the microbiomes of tephritid species and thus delivers important information about the turnover of microbial diversity within and between fruit fly species and their potential

  13. Host and parasite life history interplay to yield divergent population genetic structures in two ectoparasites living on the same bat species.

    Science.gov (United States)

    van Schaik, J; Dekeukeleire, D; Kerth, G

    2015-05-01

    Host-parasite interactions are ubiquitous in nature. However, how parasite population genetic structure is shaped by the interaction between host and parasite life history remains understudied. Studies comparing multiple parasites infecting a single host can be used to investigate how different parasite life history traits interplay with host behaviour and life history. In this study, we used 10 newly developed microsatellite loci to investigate the genetic structure of a parasitic bat fly (Basilia nana). Its host, the Bechstein's bat (Myotis bechsteinii), has a social system and roosting behaviour that restrict opportunities for parasite transmission. We compared fly genetic structure to that of the host and another parasite, the wing-mite, Spinturnix bechsteini. We found little spatial or temporal genetic structure in B. nana, suggesting a large, stable population with frequent genetic exchange between fly populations from different bat colonies. This contrasts sharply with the genetic structure of the wing-mite, which is highly substructured between the same bat colonies as well as temporally unstable. Our results suggest that although host and parasite life history interact to yield similar transmission patterns in both parasite species, the level of gene flow and eventual spatiotemporal genetic stability is differentially affected. This can be explained by the differences in generation time and winter survival between the flies and wing-mites. Our study thus exemplifies that the population genetic structure of parasites on a single host can vary strongly as a result of how their individual life history characteristics interact with host behaviour and life history traits. © 2015 John Wiley & Sons Ltd.

  14. Invasive species threat: parasite phylogenetics reveals patterns and processes of host-switching between non-native and native captive freshwater turtles.

    Science.gov (United States)

    Verneau, O; Palacios, C; Platt, T; Alday, M; Billard, E; Allienne, J-F; Basso, C; DU Preez, L H

    2011-11-01

    One of the major threats to biodiversity involves biological invasions with direct consequences on the stability of ecosystems. In this context, the role of parasites is not negligible as it may enhance the success of invaders. The red-eared slider, Trachemys scripta elegans, has been globally considered among the worst invasive species. Since its introduction through the pet trade, T. s. elegans is now widespread and represents a threat for indigenous species. Because T. s. elegans coexists with Emys orbicularis and Mauremys leprosa in Europe, it has been suggested it may compete with the native turtle species and transmit pathogens. We examined parasite transfer from American captive to the two native species that co-exist in artificial pools of a Turtle Farm in France. As model parasite species we used platyhelminth worms of the family Polystomatidae (Monogenea) because polystomes have been described from American turtles in their native range. Phylogenetic relationships among polystomes parasitizing chelonian host species that are geographically widespread show patterns of diversification more complex than expected. Using DNA barcoding to identify species from adult and/or polystome eggs, several cases of host switching from exotic to indigenous individuals were illustrated, corroborating that parasite transmission is important when considering the pet trade and in reintroduction programmes to reinforce wild populations of indigenous species.

  15. A remarkable new species of Liparis (Orchidaceae from China and its phylogenetic implications.

    Directory of Open Access Journals (Sweden)

    Lin Li

    Full Text Available In the present study, we formally describe Liparis pingxiangensis as a new species from Guangxi, China on the basis of morphological and molecular phylogenetic analyses. It is easily distinguished from closely related species by strongly curved column without column wings, and broadly rhombic-elliptic lip with 2 uncinate calli at the base. In particular, it differs most markedly from its congeners in possessing two pollinia attached by long and prominent caudicles (not stipes, to a distinct sticky disc. This type of pollinarium, as far as we know, is not found in any other species of Liparis, and is also unique among the orchids with waxy pollinia. We then proceeded to a phylogenetic analysis to ascertain the systematic position of this enigmatic species. Molecular study based on nuclear ribosomal ITS and plastid matK DNA sequence data supports L. pingxiangensis as a distinct species, which forms an independent lineage sister to L. nervosa and its allies (93% BS, 1.00 BPP. In the light of previous work, the findings have important implications for a better understanding of the well-supported pattern mainly based on vegetative features in Malaxideae.

  16. Prognostic Implication of Human Papillomavirus Types and Species in Cervical Cancer Patients Undergoing Primary Treatment

    OpenAIRE

    Yat Ming Lau; Tak Hong Cheung; Winnie Yeo; Frankie Mo; Mei Yung Yu; Kun Min Lee; Ho, Wendy C. S.; Yeung, Apple C. M.; Priscilla T. Y. Law; Chan, Paul K. S.

    2015-01-01

    High-risk human papillomavirus (HPV) types are associated with cervical cancer. It is well established that individual HPV types vary in oncogenicity, but current data on their prognostic implication remain controversial. We examined the association between HPV types/species and the survival of 236 Chinese women aged 26-87 (mean 54.4) years after receiving primary treatment for cervical cancer. Overall, 45.8% were of FIGO stage I, 41.9% stage II, and 12.3% stage III. The four most prevalent t...

  17. Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

    DEFF Research Database (Denmark)

    Zhang, Gui-Fen; Lövei, Gabor L; Hu, Man

    2014-01-01

    BACKGROUND: The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co-occur on their host plants. The effect of host plant occupation by one species on later-arriving conspecific individuals or on the other competing species was examined....... RESULTS: Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario....... However, resource preoccupied by T. vaporariorum had only minor detrimental effectsonthe performanceof later-arriving B. tabaci MEAM1.In theopposite colonisation sequence, previous occupation by B. tabaci MEAM1 had no significant effects on the life history parameters of later-arriving conspecifics...

  18. A test of the nest sanitation hypothesis for the evolution of foreign egg rejection in an avian brood parasite rejecter host species

    Science.gov (United States)

    Luro, Alec B.; Hauber, Mark E.

    2017-04-01

    Hosts of avian brood parasites have evolved diverse defenses to avoid the costs associated with raising brood parasite nestlings. In egg ejection, the host recognizes and removes foreign eggs laid in its nest. Nest sanitation, a behavior similar in motor pattern to egg ejection, has been proposed repeatedly as a potential pre-adaptation to egg ejection. Here, we separately placed blue 3D-printed, brown-headed cowbird ( Molothrus ater) eggs known to elicit interindividual variation in ejection responses and semi-natural leaves into American robins' ( Turdus migratorius) nests to test proximate predictions that (1) rejecter hosts should sanitize debris from nests more frequently and consistently than accepter hosts and (2) hosts that sanitize their nests of debris prior to the presentation of a foreign egg will be more likely to eject the foreign egg. Egg ejection responses were highly repeatable within individuals yet variable between them, but were not influenced by prior exposure to debris, nor related to sanitation tendencies as a whole, because nearly all individuals sanitized their nests. Additionally, we collected published data for eight different host species to test for a potential positive correlation between sanitation and egg ejection. We found no significant correlation between nest sanitation and egg ejection rates; however, our comparative analysis was limited to a sample size of 8, and we advise that more data from additional species are necessary to properly address interspecific tests of the pre-adaptation hypothesis. In lack of support for the nest sanitation hypothesis, our study suggests that, within individuals, foreign egg ejection is distinct from nest sanitation tendencies, and sanitation and foreign egg ejection may not correlate across species.

  19. Distribution of Pholeter gastrophilus (Digenea) within the stomach of four odontocete species: the role of the diet and digestive physiology of hosts.

    Science.gov (United States)

    Aznar, F J; Fognani, P; Balbuena, J A; Pietrobelli, M; Raga, J A

    2006-09-01

    We compared the distribution of the digenean Pholeter gastrophilus in the stomach of 27 harbour porpoises, Phocoena phocoena, 27 striped dolphins, Stenella coeruleoalba, 18 bottlenose dolphins, Tursiops truncatus, and 100 long-finned pilot whales, Globicephala melas. The stomach of these species is composed of 4 chambers of different size, structure and function. In all species, P. gastrophilus was largely restricted to the glandular region of the stomach, but the parasite tended to favour the fundic chamber in bottlenose dolphins and harbour porpoises, the pyloric chamber in pilot whales, and none in striped dolphins. However, predictability at infrapopulation level was generally low, suggesting a weak preference of P. gastrophilus for any of the chambers. Three hypotheses were tested to investigate a common cause for the distribution of P. gastrophilus in all host species, namely, colonization of chambers was (1) sequential, (2) dependent on chamber size, or (3) dependent on the passage time of food through the whole stomach. The latter hypothesis was indirectly tested by assuming, based on previous evidence from other vertebrates, that the greater the size of the stomach and/or the energy content of prey, the greater the delay of food passage. We found no compelling evidence that chamber colonization was sequential, or related to chamber size in any species. However, the distribution of P. gastrophilus was significantly more anteriad when the host species had larger stomachs and, particularly, when hosts fed on prey with higher caloric content. Accordingly, the stomach distribution of P. gastrophilus at this scale seems to be passively driven by features of the diet and digestive physiology of each host species. This study provides a general framework to formulate null hypotheses in future studies on microhabitat choice by parasites.

  20. Analysis of plant leaf metabolites reveals no common response to insect herbivory by Pieris rapae in three related host-plant species.

    Science.gov (United States)

    Riach, A C; Perera, M V L; Florance, H V; Penfield, S D; Hill, J K

    2015-05-01

    Studying the biochemical responses of different plant species to insect herbivory may help improve our understanding of the evolution of defensive metabolites found in host plants and their role in plant-herbivore interactions. Untargeted metabolic fingerprints measured as individual mass features were used to compare metabolite reactions in three Brassicales host-plant species (Cleome spinosa, Brassica oleracea, and Lunaria annua) to larval herbivore attack (Pieris rapae; Lepidoptera). Principal component analyses of metabolic fingerprints were able to distinguish among the three plant species and between uneaten control plants and plants that had been eaten. A large number of mass features (1186, 13% of mass features measured in control plants) were common to the three plant species. However, there were few similarities in the mass features that were induced (i.e. changed in abundance) following herbivory. Of the 87 and 68 induced mass features in B. oleracea and C. spinosa, respectively, there were only three that were induced in both plant species. By contrast, L. annua only had one mass feature induced by herbivory, and this was not induced in the other two plant species. The growth of the P. rapae larvae was poorer on the host plant L. annua than on B. oleracea and C. spinosa. The absence of common metabolites among the plants meant these induced responses could not be related to the performance of the herbivore. Thus, the response to herbivory by the same herbivore in these three host plants has evolved to be idiosyncratic in terms of the specific metabolites induced. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  1. Transposable element-assisted evolution and adaptation to host plant within the Leptosphaeria maculans-Leptosphaeria biglobosa species complex of fungal pathogens.

    Science.gov (United States)

    Grandaubert, Jonathan; Lowe, Rohan G T; Soyer, Jessica L; Schoch, Conrad L; Van de Wouw, Angela P; Fudal, Isabelle; Robbertse, Barbara; Lapalu, Nicolas; Links, Matthew G; Ollivier, Bénédicte; Linglin, Juliette; Barbe, Valérie; Mangenot, Sophie; Cruaud, Corinne; Borhan, Hossein; Howlett, Barbara J; Balesdent, Marie-Hélène; Rouxel, Thierry

    2014-10-12

    Many plant-pathogenic fungi have a tendency towards genome size expansion, mostly driven by increasing content of transposable elements (TEs). Through comparative and evolutionary genomics, five members of the Leptosphaeria maculans-Leptosphaeria biglobosa species complex (class Dothideomycetes, order Pleosporales), having different host ranges and pathogenic abilities towards cruciferous plants, were studied to infer the role of TEs on genome shaping, speciation, and on the rise of better adapted pathogens. L. maculans 'brassicae', the most damaging species on oilseed rape, is the only member of the species complex to have a TE-invaded genome (32.5%) compared to the other members genomes (<4%). These TEs had an impact at the structural level by creating large TE-rich regions and are suspected to have been instrumental in chromosomal rearrangements possibly leading to speciation. TEs, associated with species-specific genes involved in disease process, also possibly had an incidence on evolution of pathogenicity by promoting translocations of effector genes to highly dynamic regions and thus tuning the regulation of effector gene expression in planta. Invasion of L. maculans 'brassicae' genome by TEs followed by bursts of TE activity allowed this species to evolve and to better adapt to its host, making this genome species a peculiarity within its own species complex as well as in the Pleosporales lineage.

  2. Host-derived pentapeptide affecting adhesion, proliferation, and local pH in biofilm communities composed of Streptococcus and Actinomyces species

    DEFF Research Database (Denmark)

    Drobni, M.; Li, T.; Krüger, C.

    2006-01-01

    Salivary proline-rich proteins (PRPs) attach commensal Actinomyces and Streptococcus species to teeth. Here, gel filtration, mass spectrometry and Edman degradation were applied to show the release of a pentapeptide, RGRPQ, from PRP-1 upon proteolysis by Streptococcus gordonii. Moreover, syntheti...... of a host-bacterium interaction in which a host peptide released by bacterial proteolysis affects key properties in biofilm formation....... RGRPQ and derivatives were used to investigate associated innate properties and responsible motifs. The RGRPQ peptide increased 2.5-fold the growth rate of S. gordonii via a Q-dependent sequence motif and selectively stimulated oral colonization of this organism in a rat model in vivo. In contrast...

  3. Egg morphology, laying behavior and record of the host plants of Ricania speculum (Walker, 1851), a new alien species for Europe (Hemiptera: Ricaniidae).

    Science.gov (United States)

    Rossi, Elisabetta; Stroiński, Adam; Lucchi, Andrea

    2015-11-17

    The exotic planthopper, Ricania speculum (Ricaniidae) was recently detected in Liguria, in northern Italy, and recorded as a first alert for Europe. The first morphological description of eggs and laying behavior are given. Eggs are inserted into the woody tissue of a wide range of different host plants in such a unique manner among native and alien planthoppers of Italy that it can be used to describe the prevalence and diffusion of the species in new environments, though in the absence of juveniles and/or adults. In addition, the paper lists the host plants utilized for egg laying and describes the eggs.

  4. Biogeochemical implications of the ubiquitous colonization of marine habitats and redox gradients by Marinobacter species

    Directory of Open Access Journals (Sweden)

    Kim Marie Handley

    2013-05-01

    Full Text Available The Marinobacter genus comprises widespread marine bacteria, found in localities as diverse as the deep ocean, coastal seawater and sediment, hydrothermal settings, oceanic basalt, sea-ice, sand, solar salterns, and oil fields. Terrestrial sources include saline soil and wine-barrel-decalcification wastewater. The genus was designated in 1992 for the Gram-negative, hydrocarbon-degrading bacterium Marinobacter hydrocarbonoclasticus. Since then, a further 31 type strains have been designated. Nonetheless, the metabolic range of many Marinobacter species remains largely unexplored. Most species have been classified as aerobic heterotrophs, and assessed for limited anaerobic pathways (fermentation or nitrate reduction, whereas studies of low-temperature hydrothermal sediments, basalt at oceanic spreading centers, and phytoplankton have identified species that possess a respiratory repertoire with significant biogeochemical implications. Notable physiological traits include nitrate-dependent Fe(II-oxidation, arsenic and fumarate redox cycling, and Mn(II oxidation. There is also evidence for Fe(III reduction, and metal(loid resistance. Considering the ubiquity and metabolic capabilities of the genus, Marinobacter species may perform an important and underestimated role in the biogeochemical cycling of organics and metals in varied marine habitats, and spanning aerobic-to-anoxic redox gradients.

  5. Spatial patterns of soil pathogens in declining Mediterranean forests: implications for tree species regeneration.

    Science.gov (United States)

    Gómez-Aparicio, Lorena; Ibáñez, Beatriz; Serrano, María S; De Vita, Paolo; Avila, José M; Pérez-Ramos, Ignacio M; García, Luis V; Esperanza Sánchez, M; Marañón, Teodoro

    2012-06-01

    Soil-borne pathogens are a key component of the belowground community because of the significance of their ecological and socio-economic impacts. However, very little is known about the complexity of their distribution patterns in natural systems. Here, we explored the patterns, causes and ecological consequences of spatial variability in pathogen abundance in Mediterranean forests affected by oak decline. We used spatially explicit neighborhood models to predict the abundance of soil-borne pathogen species (Phytophthora cinnamomi, Pythium spiculum and Pythium spp.) as a function of local abiotic conditions (soil texture) and the characteristics of the tree and shrub neighborhoods (species composition, size and health status). The implications of pathogen abundance for tree seedling performance were explored by conducting a sowing experiment in the same locations in which pathogen abundance was quantified. Pathogen abundance in the forest soil was not randomly distributed, but exhibited spatially predictable patterns influenced by both abiotic and, particularly, biotic factors (tree and shrub species). Pathogen abundance reduced seedling emergence and survival, but not in all sites or tree species. Our findings suggest that heterogeneous spatial patterns of pathogen abundance at fine spatial scale can be important for the dynamics and restoration of declining Mediterranean forests. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  6. Hearing sensitivity in context: Conservation implications for a highly vocal endangered species

    Directory of Open Access Journals (Sweden)

    Megan A. Owen

    2016-04-01

    Full Text Available Hearing sensitivity is a fundamental determinant of a species’ vulnerability to anthropogenic noise, however little is known about the hearing capacities of most conservation dependent species. When audiometric data are integrated with other aspects of species’ acoustic ecology, life history, and characteristic habitat topography and soundscape, predictions can be made regarding probable vulnerability to the negative impacts of different types of anthropogenic noise. Here we used an adaptive psychoacoustic technique to measure hearing thresholds in the endangered giant panda; a species that uses acoustic communication to coordinate reproduction. Our results suggest that giant pandas have functional hearing into the ultrasonic range, with good sensitivity between 10.0 and 16.0 kHz, and best sensitivity measured at 12.5–14.0 kHz. We estimated the lower and upper limits of functional hearing as 0.10 and 70.0 kHz respectively. While these results suggest that panda hearing is similar to that of some other terrestrial carnivores, panda hearing thresholds above 14.0 kHz were significantly lower (i.e., more sensitive than those of the polar bear, the only other bear species for which data are available. We discuss the implications of this divergence, as well as the relationship between hearing sensitivity and the spectral parameters of panda vocalizations. We suggest that these data, placed in context, can be used towards the development of a sensory-based model of noise disturbance for the species.

  7. Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

    KAUST Repository

    An, Ran

    2018-01-24

    Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

  8. Identifying the Achilles heel of multi-host pathogens: the concept of keystone ‘host’ species illustrated by Mycobacterium ulcerans transmission

    Science.gov (United States)

    Roche, Benjamin; Benbow, M. Eric; Merritt, Richard; Kimbirauskas, Ryan; McIntosh, Mollie; Small, Pamela L. C.; Williamson, Heather; Guégan, Jean-François

    2013-12-01

    Pathogens that use multiple host species are an increasing public health issue due to their complex transmission, which makes them difficult to mitigate. Here, we explore the possibility of using networks of ecological interactions among potential host species to identify the particular disease-source species to target to break down transmission of such pathogens. We fit a mathematical model on prevalence data of Mycobacterium ulcerans in western Africa and we show that removing the most abundant taxa for this category of pathogen is not an optimal strategy to decrease the transmission of the mycobacterium within aquatic ecosystems. On the contrary, we reveal that the removal of some taxa, especially Oligochaeta worms, can clearly reduce rates of pathogen transmission, and these should be considered as keystone organisms for its transmission because they lead to a substantial reduction in pathogen prevalence regardless of the network topology. Besides their potential application for the understanding of M. ulcerans ecology, we discuss how networks of species interactions can modulate transmission of multi-host pathogens.

  9. Genetic differentiation among Maruca vitrata F. (Lepidoptera: Crambidae populations on cultivated cowpea and wild host plants: implications for insect resistance management and biological control strategies.

    Directory of Open Access Journals (Sweden)

    Tolulope A Agunbiade

    Full Text Available Maruca vitrata Fabricius (Lepidoptera: Crambidae is a polyphagous insect pest that feeds on a variety of leguminous plants in the tropics and subtropics. The contribution of host-associated genetic variation on population structure was investigated using analysis of mitochondrial cytochrome oxidase 1 (cox1 sequence and microsatellite marker data from M. vitrata collected from cultivated cowpea (Vigna unguiculata L. Walp., and alternative host plants Pueraria phaseoloides (Roxb. Benth. var. javanica (Benth. Baker, Loncocarpus sericeus (Poir, and Tephrosia candida (Roxb.. Analyses of microsatellite data revealed a significant global FST estimate of 0.05 (P≤0.001. The program STRUCTURE estimated 2 genotypic clusters (co-ancestries on the four host plants across 3 geographic locations, but little geographic variation was predicted among genotypes from different geographic locations using analysis of molecular variance (AMOVA; among group variation -0.68% or F-statistics (FSTLoc = -0.01; P = 0.62. These results were corroborated by mitochondrial haplotype data (φSTLoc = 0.05; P = 0.92. In contrast, genotypes obtained from different host plants showed low but significant levels of genetic variation (FSTHost = 0.04; P = 0.01, which accounted for 4.08% of the total genetic variation, but was not congruent with mitochondrial haplotype analyses (φSTHost = 0.06; P = 0.27. Variation among host plants at a location and host plants among locations showed no consistent evidence for M. vitrata population subdivision. These results suggest that host plants do not significantly influence the genetic structure of M. vitrata, and this has implications for biocontrol agent releases as well as insecticide resistance management (IRM for M. vitrata in West Africa.

  10. Taxonomy, host-plant associations and phylogeny of African Crotalaria-feeding seed beetles (Coleoptera, Chrysomelidae, Bruchinae): the Conicobruchus strangulatus (Fåhraeus) species group.

    Science.gov (United States)

    Le Ru, Bruno P; Delobel, Alex; György, Zoltán; Genson, Gwenaëlle; Kergoat, Gael J

    2014-12-15

    A small group of six morphologically related seed beetles (Coleoptera: Chrysomelidae: Bruchinae) belonging to the Conicobruchus genus is reviewed. Species in this group for which host-plants are known feed on various species of Crotalaria (Fabaceae, Crotalarieae). Here we provide diagnoses and a dichotomous key for all six species. The following synonymies are proposed: Conicobruchus cicatricosus (Fåhraeus, 1839) (= Bruchus cicatricosus pallidioripennis Pic, 1941) syn. nov.; Conicobruchus strangulatus (Fåhraeus, 1839) (= Bruchus hargreavesi Pic, 1933) syn. nov. The corresponding Conicobruchus strangulatus species group is hereby designated. New host-plant data are also included, which correspond to the results of recent collections of legume pods in East Africa. In addition we carried out molecular phylogenetic analyses on a representative sampling of Conicobruchus species (including the six species of interest). The latter allow us to assess the monophyly of the group of interest and to unravel their evolutionary relationships. Molecular phylogenetic analyses also indicate that at least two lineages of Conicobruchus successfully shifted toward Crotalarieae during the course of their diversification. 

  11. Plant-soil feedbacks in declining forests: implications for species coexistence.

    Science.gov (United States)

    Gómez-Aparicio, Lorena; Domínguez-Begines, Jara; Kardol, Paul; Ávila, José M; Ibáñez, Beatriz; García, Luis V

    2017-07-01

    Plant-soil feedbacks (PSFs) play a relevant role as drivers of species abundance, coexistence, and succession in plant communities. However, the potential contribution of PSFs to community dynamics in changing forest ecosystems affected by global change drivers is still largely unexplored. We measured the direction, strength and nature (biological vs. chemical) of PSFs experienced by coexisting tree species in two types of declining Quercus suber forests of southwestern Spain (open woodland vs. closed forest) invaded by the exotic soil pathogen Phytophthora cinnamomi. To test PSFs in a realistic community context, we focused not only on individual PSFs (i.e., comparing the growth of a tree species on conspecific vs. heterospecific soil) but also calculated net-pairwise PSFs by comparing performance of coexisting tree species on their own and each other's soils. We hypothesized that the decline and death of Q. suber would alter the direction and strength of individual and net-pairwise PSFs due to the associated changes in soil nutrients and microbial communities, with implications for recruitment dynamics and species coexistence. In support of our hypothesis, we found that the decline of Q. suber translated into substantial alterations of individual and net-pairwise PSFs, which shifted from mostly neutral to significantly positive or negative, depending on the forest type. In both cases however the identified PSFs benefited other species more than Q. suber (i.e., heterospecific positive PSF in the open woodland, conspecific negative PSF in the closed forest). Our results supported PSFs driven by changes in chemical soil properties (mainly phosphorus) and arbuscular mycorrhizal fungi, but not in pathogen abundance. Overall, our study suggests that PSFs might reinforce the loss of dominance of Q. suber in declining forests invaded by P. cinnamomi by promoting the relative performance of non-declining coexisting species. More generally, our results indicate an

  12. Multivariate discrimination among cryptic mites of the genus Androlaelaps (Acari: Mesostigmata: Laelapidae) parasitic of sympatric akodontine rodents (Cricetidae: Sigmodontinae) in northeastern Argentina: possible evidence of host switch followed by speciation, with the description of two new species.

    Science.gov (United States)

    Lareschi, Marcela; Galliari, Carlos

    2014-12-01

    Laelapids are among the most common ectoparasites of rodents. Currently, it is under discussion whether there is a single polixenous species that parasites a variety of hosts, or whether there are cryptic species highly host specific. Herein, multivariate morphometric analyses of cryptic sympatric laelapids of the genus Androlaelaps allowed us to identify different species. These species are specific of their akodontine hosts, Akodon montensis and Thaptomys nigrita, in localities situated in northeastern Argentina. In addition, we analyzed similar laelapids associated with the akodontines Deltamys kempi and Akodon cursor. Using principle component analyses we differentiated four laelapid species, each one host specific, independent of sympatry of the hosts, and without geographical variation. From these four species, we described two new species (Androlaelaps navonae n. sp. and Androlaelaps wingei n. sp.). We determined the four species based on a range of variations in several characters, mainly size. These four laelapid species belong to the Androlaelaps rotundus species group, specific to akodontines. These species are very similar among them but differ from the remainder species of the group by their small size, distance between j6 setae similar to the distance between the z5 setae, strong ventral setae, opisthogaster with 13 pairs of strong setae (one close to the distal margin of epigynal shield), and anal shield wider than long. Further studies will elucidate whether they constitute a new laelapid genus. Phylogenetic and ecological factors influencing host-specificity are discussed, and we propose that host colonization could have taken place by host switching of a single laelapid species among rodent species, followed by speciation.

  13. Plant Host Species and Geographic Distance Affect the Structure of Aboveground Fungal Symbiont Communities, and Environmental Filtering Affects Belowground Communities in a Coastal Dune Ecosystem.

    Science.gov (United States)

    David, Aaron S; Seabloom, Eric W; May, Georgiana

    2016-05-01

    Microbial symbionts inhabit tissues of all plants and animals. Their community composition depends largely on two ecological processes: (1) filtering by abiotic conditions and host species determining the environments that symbionts are able to colonize and (2) dispersal-limitation determining the pool of symbionts available to colonize a given host and community spatial structure. In plants, the above- and belowground tissues represent such distinct habitats for symbionts that we expect different effects of filtering and spatial structuring on their symbiont communities. In this study, we characterized above- and belowground communities of fungal endophytes--fungi living asymptomatically within plants--to understand the contributions of filtering and spatial structure to endophyte community composition. We used a culture-based approach to characterize endophytes growing in leaves and roots of three species of coastal beachgrasses in dunes of the USA Pacific Northwest. For leaves, endophyte isolation frequency and OTU richness depended primarily on plant host species. In comparison, for roots, both isolation frequency and OTU richness increased from the nutrient-poor front of the dune to the higher-nutrient backdune. Endophyte community composition in leaves exhibited a distance-decay relationship across the region. In a laboratory assay, faster growth rates and lower spore production were more often associated with leaf- than root-inhabiting endophytes. Overall, our results reveal a greater importance of biotic filtering by host species and dispersal-limitation over regional geographic distances for aboveground leaf endophyte communities and stronger effects of abiotic environmental filtering and locally patchy distributions for belowground root endophyte communities.

  14. Correlative microscopy of the constituents of a dinosaur rib fossil and hosting mudstone: Implications on diagenesis and fossil preservation

    National Research Council Canada - National Science Library

    Jung-Kyun Kim; Yong-Eun Kwon; Sang-Gil Lee; Chang-Yeon Kim; Jin-Gyu Kim; Min Huh; Eunji Lee; Youn-Joong Kim

    2017-01-01

    We have applied correlative microscopy to identify the key constituents of a dorsal rib fossil from Koreanosaurus boseongensis and its hosting mudstone discovered at the rich fossil site in Boseong...

  15. The abundance and host-seeking behavior of culicine species (Diptera: Culicidae and Anopheles sinensis in Yongcheng city, people's Republic of China

    Directory of Open Access Journals (Sweden)

    Liu Xiao-Bo

    2011-11-01

    Full Text Available Abstract Background The knowledge of mosquito species diversity and the level of anthropophily exhibited by each species in a region are of great importance to the integrated vector control. Culicine species are the primary vectors of Japanese encephalitis (JE virus and filariasis in China. Anopheles sinensis plays a major role in the maintenance of Plasmodium vivax malaria transmission in China. The goal of this study was to compare the abundance and host-seeking behavior of culicine species and An. sinensis in Yongcheng city, a representative region of P. vivax malaria. Specifically, we wished to determine the relative attractiveness of different animal baits versus human bait to culicine species and An. sinensis. Results Culex tritaeniorhynchus was the most prevalent mosquito species and An. sinensis was the sole potential vector of P. vivax malaria in Yongcheng city. There were significant differences (P An. sinensis and Cx. tritaeniorhynchus collected in distinct baited traps. The relative attractiveness of animal versus human bait was similar towards both An. sinensis and Cx. tritaeniorhynchus. The ranking derived from the mean number of mosquitoes per bait indicated that pigs, goats and calves frequently attracted more mosquitoes than the other hosts tested (dogs, humans, and chickens. These trends were similar across all capture nights at three distinct villages. The human blood index (HBI of female An. sinensis was 2.94% when computed with mixed meals while 3.70% computed with only the single meal. 19:00~21:00 was the primary peak of host-seeking female An. sinensis while 4:00~5:00 was the smaller peak at night. There was significant correlation between the density of female An. sinensis and the average relative humidity (P Conclusions Pigs, goats and calves were more attractive to An. sinensis and Cx. tritaeniorhynchus than dogs, humans, and chickens. Female An. sinensis host-seeking activity mainly occurred from 19:00 to 21:00. Thus

  16. Morphological Properties of the Species Thymus pulegioides L. subsp. effusus Host and Plantago media L. Growing upon Dolomite and Limestone Rocks

    Directory of Open Access Journals (Sweden)

    Nina Janjić

    2008-01-01

    Full Text Available The study focused on investigating the effect of geological parent material on morphological properties of the weed species Thymus pulegioides L. subsp. effusus Host and Plantago media L. The investigation was carried out at two sites on Mount Manjača. Thefirst one, Kadina Voda, has a limestone rock for parent material, while the other, Stričići, has a dolomite rock. Morphology of the species studied is characterized by adaptibility to unfavourable conditions that exist in dolomite rocks, which is evident from their stunted growth, smaller leaves and prominent xeromorphic character.

  17. Maintenance of host leukocytes in peripheral immune compartments following lethal irradiation and bone marrow reconstitution: implications for graft versus host disease.

    Science.gov (United States)

    Staley, Elizabeth M; Tanner, Scott M; Daft, Joseph G; Stanus, Andrea L; Martin, Steven M; Lorenz, Robin G

    2013-03-01

    Bone marrow reconstitution is utilized as a tool for disease treatment and as a research technique to elucidate the function of bone marrow derived cells. Clinically successful engraftment is indicated by the development of a functioning immune repertoire. In research, reconstitution is considered successful if >85% of splenic leukocytes are of donor origins. Previous work suggests that splenic reconstitution may not be indicative of reconstitution in the mucosa. We sought to evaluate mucosal reconstitution in animals following a standard bone marrow eradication and reconstitution technique. Bone marrow was harvested from adult B6.SJL donor mice (CD45.1) and injected via either the retro-orbital or intraperitoneal route into lethally irradiated B6 (CD45.2) adult or neonatal recipients respectively. The expression of CD45 by flow cytometry was used to calculate reconstitution with respect to immune compartment and cell type. In reconstituted adult animals 93.2±1.5% of splenic leukocytes expressed the donor CD45.1 antigen thus meeting the standard definition of reconstitution, however only 58.6±13.6% of intestinal lamina propria lymphocytes and 52.4±16.0% of intestinal intraepithelial lymphocytes were of donor origin, confirming splenic reconstitution fails to represent peripheral immune reconstitution. T-cells in the gastrointestinal tract are the most poorly reconstituted, while B-cells appear to be almost universally replaced by donor cells. The inadequate mucosal reconstitution was not corrected by evaluating later time points or by performing the bone marrow transfer during the neonatal period. This demonstration that substantial host T-cells remain in the intestinal mucosa after a "successful" bone marrow transplantation should cause a re-evaluation of data from research bone marrow chimera experiments, as well as the mechanisms for complications after clinical bone marrow transplantation. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Genetic characterization of oropharyngeal trichomonad isolates from wild birds indicates that genotype is associated with host species, diet and presence of pathognomonic lesions.

    Science.gov (United States)

    Martínez-Herrero, M C; Sansano-Maestre, J; López Márquez, I; Obón, E; Ponce, C; González, J; Garijo-Toledo, M M; Gómez-Muñoz, M T

    2014-01-01

    Oropharyngeal trichomonad isolates of wild birds from Spain were studied. A total of 1688 samples (1214 of predator birds and 474 of prey species) from wildlife recovery centres and scientific bird-ringing campaigns were analysed from 2011 to 2013. The overall infection prevalence was 20.3% (11.4% in predator birds and 43.3% in prey species). Pathognomonic lesions were present in 26% of the infected birds (57.3% in predator birds and 4.9% in prey species). The most commonly parasitized species were the goshawk (Accipiter gentilis, 74.5%) and the rock pigeon (Columba livia, 79.4%). Host species in which the parasite has not been previously analysed by polymerase chain reaction and sequencing in Spain are also reported: Columba palumbus, Streptopelia turtur, Pica pica, A. gentilis, Accipiter nisus, Asio otus, Bubo bubo, Buteo buteo, Circus aeruginosus, Circus cyaneus, Falco naumanni, Falco peregrinus, Neophron percnopterus, Otus scops, Pernis apivorus and Strix aluco. Sequence analysis of the ITS1/5.8S/ITS2 region revealed five different genotypes and also some mixed infections. A relationship between genotype and host species was observed, but only two genotypes (ITS-OBT-Tg-1and ITS-OBT-Tg-2) were widely distributed. Genotype ITS-OBT-Tg-1 was most frequently found in predator birds and statistically associated with pathognomonic lesions. Non-strict ornithophagous species were at higher risk to develop disease than ornithophagous ones. Genotypes ITS-OBT-Tcl-1 and ITS-OBT-Tcl-2 are new reports, and ITS-OBT-Tvl-5 is reported for the first time in Spain. They showed higher genetic homology to Trichomonas canistomae and Trichomonas vaginalis than to Trichomonas gallinae, indicating the possibility of new species within this genus.

  19. Species Richness and Community Structure on a High Latitude Reef: Implications for Conservation and Management

    Directory of Open Access Journals (Sweden)

    Wayne Houston

    2011-07-01

    Full Text Available In spite of the wealth of research on the Great Barrier Reef, few detailed biodiversity assessments of its inshore coral communities have been conducted. Effective conservation and management of marine ecosystems begins with fine-scale biophysical assessments focused on diversity and the architectural species that build the structural framework of the reef. In this study, we investigate key coral diversity and environmental attributes of an inshore reef system surrounding the Keppel Bay Islands near Rockhampton in Central Queensland, Australia, and assess their implications for conservation and management. The Keppels has much higher coral diversity than previously found. The average species richness for the 19 study sites was ~40 with representatives from 68% of the ~244 species previously described for the southern Great Barrier Reef. Using scleractinian coral species richness, taxonomic distinctiveness and coral cover as the main criteria, we found that five out of 19 sites had particularly high conservation value. A further site was also considered to be of relatively high value. Corals at this site were taxonomically distinct from the others (representatives of two families were found here but not at other sites and a wide range of functionally diverse taxa were present. This site was associated with more stressful conditions such as high temperatures and turbidity. Highly diverse coral communities or biodiversity ‘hotspots’ and taxonomically distinct reefs may act as insurance policies for climatic disturbance, much like Noah’s Arks for reefs. While improving water quality and limiting anthropogenic impacts are clearly important management initiatives to improve the long-term outlook for inshore reefs, identifying, mapping and protecting these coastal ‘refugia’ may be the key for ensuring their regeneration against catastrophic climatic disturbance in the meantime.

  20. Prevalence of viral haemorrhagic septicaemia virus in Danish marine fishes and its occurrence in new host species

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Mellergaard, Stig

    2005-01-01

    to 1997. In total, 16 655 fish were examined virologically as 3569 samples. Forty fish species and 3 invertebrate species were represented. VHSV was isolated from 133 samples representing 8 species: herring Clupea harengus, sprat Sprattus sprattus, dab Limanda limanda, flounder Platichthys flesus, plaice...

  1. Response of brown-headed cowbirds and three host species to thinning treatments in low-elevation ponderosa pine forests along the northern Colorado Front Range

    Science.gov (United States)

    Keeley, W.H.; Germaine, Stephen S.; Stanley, Thomas R.; Spaulding, Sarah A.; Wanner, C.E.

    2013-01-01

    Thinning ponderosa pine (Pinus ponderosa) forests to achieve desired ecological conditions remains a priority in the North American west. In addition to reducing the risk of high-severity wildfires in unwanted areas, stand thinning may increase wildlife and plant diversity and provide increased opportunity for seedling recruitment. We initiated conservative (i.e. minimal removal of trees) ponderosa stand thinning treatments with the goals of reducing fire risk and improving habitat conditions for native wildlife and flora. We then compared site occupancy of brown-headed cowbirds (Molothrus ater), chipping sparrows (Spizella passerina), plumbeous vireos (Vireo plumbeus), and western wood-pewees (Contopus sordidulus) in thinned and unthinned (i.e., control) forest stands from 2007 to 2009. Survey stations located in thinned stands had 64% fewer trees/ha, 25% less canopy cover, and 23% less basal area than stations in control stands. Occupancy by all three host species was negatively associated with tree density, suggesting that these species respond favorably to forest thinning treatments in ponderosa pine forests. We also encountered plumbeous vireos more frequently in plots closer to an ecotonal (forest/grassland) edge, an association that may increase their susceptibility to edge-specialist, brood parasites like brown-headed cowbirds. Occupancy of brown-headed cowbirds was not related to forest metrics but was related to occupancy by plumbeous vireos and the other host species in aggregate, supporting previous reports on the affiliation between these species. Forest management practices that promote heterogeneity in forest stand structure may benefit songbird populations in our area, but these treatments may also confer costs associated with increased cowbird occupancy. Further research is required to understand more on the complex relationships between occupancy of cowbirds and host species, and between cowbird occupancy and realized rates of nest parasitism.

  2. Host seeking parasitic nematodes use specific odors to assess host resources.

    Science.gov (United States)

    Baiocchi, Tiffany; Lee, Grant; Choe, Dong-Hwan; Dillman, Adler R

    2017-07-24

    Entomopathogenic nematodes (EPNs) are insect parasites used as biological control agents. Free-living infective juveniles (IJs) of EPNs employ host-seeking behaviors to locate suitable hosts for infection. We found that EPNs can differentiate between naïve and infected hosts, and that host attractiveness changes over time in a species-specific manner. We used solid-phase microextraction and gas chromatography/mass spectrometry to identify volatile chemical cues that may relay information about a potential host's infection status and resource availability. Among the chemicals identified from the headspace of infected hosts, 3-Methyl-2-buten-1-ol (prenol) and 3-Hydroxy-2-butanone (AMC) were selected for further behavioral assays due to their temporal correlation with the behavioral changes of IJs towards the infected hosts. Both compounds were repulsive to IJs of Steinernema glaseri and S. riobrave in a dose-dependent manner when applied on an agar substrate. Furthermore, the repulsive effects of prenol were maintained when co-presented with the uninfected host odors, overriding attraction to uninfected hosts. Prenol was attractive to dauers of some free-living nematodes and insect larvae. These data suggest that host-associated chemical cues may have several implications in EPN biology, not only as signals for avoidance and dispersal of conspecifics, but also as attractants for new potential hosts.

  3. Prognostic implication of human papillomavirus types and species in cervical cancer patients undergoing primary treatment.

    Directory of Open Access Journals (Sweden)

    Yat Ming Lau

    Full Text Available High-risk human papillomavirus (HPV types are associated with cervical cancer. It is well established that individual HPV types vary in oncogenicity, but current data on their prognostic implication remain controversial. We examined the association between HPV types/species and the survival of 236 Chinese women aged 26-87 (mean 54.4 years after receiving primary treatment for cervical cancer. Overall, 45.8% were of FIGO stage I, 41.9% stage II, and 12.3% stage III. The four most prevalent types found were HPV-16 (60.2%, HPV-18 (21.6%, HPV-52 (11.9%, and HPV-58 (9.3%. Overall, 19.5% of patients had multiple-type infections, 78.4% harboured one or more alpha-9 species, and 28.8% harboured one or more alpha-7 species. After a median follow-up of 8.0 years, 156 (66.1% patients survived. The 3-year overall survival rate was 75.5%. Factors independently associated with a poorer 3-year overall survival were age >60 years, tumour size >4 cm, lymph node involvement and treatment with radiotherapy+/-chemotherapy. Univariate analysis showed HPV-16 single-type infection was associated with a marginally poorer disease-specific survival (71.6% vs. 87.0%, HR: 1.71, 95% CI = 1.01-2.90, whereas non-HPV-16 alpha-9 species was associated with a better disease-specific survival (90.0% vs. 76.2%, HR: 0.36, 95% CI = 0.16-0.79. However, on multivariate analysis, HPV infection status irrespective of different grouping methods, including individual types, species, single-type or co-infection, did not carry any significant prognostic significance. In conclusion, we did not observe any association between infection with a particular HPV type/species and survival. An HPV type-based stratification in treatment and follow-up plan could not be recommended.

  4. Prognostic implication of human papillomavirus types and species in cervical cancer patients undergoing primary treatment.

    Science.gov (United States)

    Lau, Yat Ming; Cheung, Tak Hong; Yeo, Winnie; Mo, Frankie; Yu, Mei Yung; Lee, Kun Min; Ho, Wendy C S; Yeung, Apple C M; Law, Priscilla T Y; Chan, Paul K S

    2015-01-01

    High-risk human papillomavirus (HPV) types are associated with cervical cancer. It is well established that individual HPV types vary in oncogenicity, but current data on their prognostic implication remain controversial. We examined the association between HPV types/species and the survival of 236 Chinese women aged 26-87 (mean 54.4) years after receiving primary treatment for cervical cancer. Overall, 45.8% were of FIGO stage I, 41.9% stage II, and 12.3% stage III. The four most prevalent types found were HPV-16 (60.2%), HPV-18 (21.6%), HPV-52 (11.9%), and HPV-58 (9.3%). Overall, 19.5% of patients had multiple-type infections, 78.4% harboured one or more alpha-9 species, and 28.8% harboured one or more alpha-7 species. After a median follow-up of 8.0 years, 156 (66.1%) patients survived. The 3-year overall survival rate was 75.5%. Factors independently associated with a poorer 3-year overall survival were age >60 years, tumour size >4 cm, lymph node involvement and treatment with radiotherapy+/-chemotherapy. Univariate analysis showed HPV-16 single-type infection was associated with a marginally poorer disease-specific survival (71.6% vs. 87.0%, HR: 1.71, 95% CI = 1.01-2.90), whereas non-HPV-16 alpha-9 species was associated with a better disease-specific survival (90.0% vs. 76.2%, HR: 0.36, 95% CI = 0.16-0.79). However, on multivariate analysis, HPV infection status irrespective of different grouping methods, including individual types, species, single-type or co-infection, did not carry any significant prognostic significance. In conclusion, we did not observe any association between infection with a particular HPV type/species and survival. An HPV type-based stratification in treatment and follow-up plan could not be recommended.

  5. Spinocellular carcinoma from warts in a HPV infection natural history lasting 49 years. Virus strategy or host choice? Implications for researches and therapeutic vaccines.

    Science.gov (United States)

    Criscione, S M

    2011-11-01

    ), to prolong its own survival (balance with the virus), to avoid the risk of producing uncontrolled cells (dangerous outcomes). Finally, the postulated negative implications for therapeutic vaccines in cervical cancer, as they really seem to not work till now might be ascribed just to the cited host immune-specific state itself, through an activation induced cell death, elicited by recall antigens (E6/E7 in the case of my wife). Also this latter hypothesis, as well as the previous ones may be of some value to better account for clinical behaviors and researches. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Expression of human CD81 differently affects host cell susceptibility to malaria sporozoites depending on the Plasmodium species.

    NARCIS (Netherlands)

    Silvie, O.; Greco, C.; Franetich, J.F.; Dubart-Kupperschmitt, A.; Hannoun, L.; Gemert, G.J.A. van; Sauerwein, R.W.; Levy, S.; Boucheix, C.; Rubinstein, E.; Mazier, D.

    2006-01-01

    Plasmodium sporozoites can enter host cells by two distinct pathways, either through disruption of the plasma membrane followed by parasite transmigration through cells, or by formation of a parasitophorous vacuole (PV) where the parasite further differentiates into a replicative exo-erythrocytic

  7. Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species.

    NARCIS (Netherlands)

    Sprong, H.; Wielinga, P.R.; Fonville, M.; Reusken, C.; Brandenburg, A.H.; Borgsteede, F.H.M.

    2009-01-01

    Background - Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts.

  8. Changes of wood anatomical characters of selected species of Araucaria- during artificial charring - implications for palaeontology

    Directory of Open Access Journals (Sweden)

    Isa Carla Osterkamp

    2017-11-01

    Full Text Available ABSTRACT Charcoal is widely accepted as evidence of the occurrence of palaeo-wildfire. Although fossil charcoal remains have been used in many studies, investigation into the anatomical changes occurring during charring are few. The present study analyses changes in selected anatomical characters during artificial charring of modern wood of three species of the genus Araucaria (i.e. Araucaria angustifolia, Araucaria bidwillii and Araucaria columnaris. Wood samples of the studied species was charred under controlled conditions at varying temperatures. Measurements of anatomical features of uncharred wood and artificial charcoal were statistically analysed. The anatomical changes were statistically correlated with charring temperatures and most of the parameters showed marked decreases with increasing charring temperature. Compared to the intrinsic variability in anatomical features, both within and between growth rings of an individual plant, the changes induced by temperature account only for a comparatively small percentage of the observed variability. Regarding Araucaria charcoal, it seems possible that at least general taxonomic and palaeoenvironmental implications can be drawn from such material. However, it is not clear so far whether these results and interpretations based on only three taxa, can be generalized for the entire family and anatomically similar fossil taxa or not.

  9. Repeatability and reproducibility of Population Viability Analysis (PVA and the implications for threatened species management

    Directory of Open Access Journals (Sweden)

    Clare Morrison

    2016-08-01

    Full Text Available Conservation triage focuses on prioritizing species, populations or habitats based on urgency, biodiversity benefits, recovery potential as well as cost. Population Viability Analysis (PVA is frequently used in population focused conservation prioritizations. The critical nature of many of these management decisions requires that PVA models are repeatable and reproducible to reliably rank species and/or populations quantitatively. This paper assessed the repeatability and reproducibility of a subset of previously published PVA models. We attempted to rerun baseline models from 90 publicly available PVA studies published between 2000-2012 using the two most common PVA modelling software programs, VORTEX and RAMAS-GIS. Forty percent (n = 36 failed, 50% (45 were both repeatable and reproducible, and 10% (9 had missing baseline models. Repeatability was not linked to taxa, IUCN category, PVA program version used, year published or the quality of publication outlet, suggesting that the problem is systemic within the discipline. Complete and systematic presentation of PVA parameters and results are needed to ensure that the scientific input into conservation planning is both robust and reliable, thereby increasing the chances of making decisions that are both beneficial and defensible. The implications for conservation triage may be far reaching if population viability models cannot be reproduced with confidence, thus undermining their intended value.

  10. Host galaxy properties of mergers of stellar binary black holes and their implications for advanced LIGO gravitational wave sources

    Science.gov (United States)

    Cao, Liang; Lu, Youjun; Zhao, Yuetong

    2018-03-01

    Understanding the host galaxy properties of stellar binary black hole (SBBH) mergers is important for revealing the origin of the SBBH gravitational wave sources detected by advanced LIGO and helpful for identifying their electromagnetic counterparts. Here, we present a comprehensive analysis of the host galaxy properties of SBBHs by implementing semi-analytical recipes for SBBH formation and merger into cosmological galaxy formation model. If the time delay between SBBH formation and merger ranges from ≲ Gyr to the Hubble time, SBBH mergers at redshift z ≲ 0.3 occur preferentially in big galaxies with stellar mass M* ≳ 2 × 1010 M⊙ and metallicities Z peaking at ˜0.6 Z⊙. However, the host galaxy stellar mass distribution of heavy SBBH mergers (M•• ≳ 50 M⊙) is bimodal with one peak at ˜109 M⊙ and the other peak at ˜2 × 1010 M⊙. The contribution fraction from host galaxies with Z ≲ 0.2 Z⊙ to heavy mergers is much larger than that to less heavy mergers. If SBBHs were formed in the early Universe (e.g. z > 6), their mergers detected at z ≲ 0.3 occur preferentially in even more massive galaxies with M* > 3 × 1010 M⊙ and in galaxies with metallicities mostly ≳ 0.2 Z⊙ and peaking at Z ˜ 0.6 Z⊙, due to later cosmic assembly and enrichment of their host galaxies. SBBH mergers at z ≲ 0.3 mainly occur in spiral galaxies, but the fraction of SBBH mergers that occur in elliptical galaxies can be significant if those SBBHs were formed in the early Universe; and about two-thirds of those mergers occur in the central galaxies of dark matter haloes. We also present results on the host galaxy properties of SBBH mergers at higher redshift.

  11. Young children's acceptance of within-species variation: Implications for essentialism and teaching evolution.

    Science.gov (United States)

    Emmons, Natalie A; Kelemen, Deborah A

    2015-11-01

    Neglecting within-species variation plays a crucial role in students' misconceptions about adaptation by natural selection. Prior research on the development of this propensity suggests that this neglect is due to a strong early-arising essentialist bias to treat species as invariant. Across two studies, we examined the strength of this bias by exploring 5- and 6-year-olds' and 7- and 8-year-olds' assumptions about variation in contexts similar to those used in a recent early educational intervention teaching adaptation. In Study 1, children heard about fictitious animals' physical and behavioral traits and their beneficial functions. They then judged whether all other species members would vary or be invariant on those traits. Across age groups, children showed a marginal essentialist tendency to reject variation. In Study 2, the same method was used, but all references to beneficial trait functions were removed. The 5- and 6-year-olds' responding did not differ from Study 1, but the 7- and 8-year-olds' acceptance of variation increased to above chance rates. Parental religious and evolution beliefs correlated with younger children's responses but not with older children's responses. Together, the findings suggest that under certain facilitative contexts children display greater abilities to represent variation than assumptions of a robust and inflexible essentialist bias would predict. By 7 to 8 years of age, children displayed autonomy from their parents' beliefs and tended to expect variation. However, priming their teleological intuitions undermined their non-essentialist expectations. Theoretical and educational implications are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Analysis of the long control region of bovine papillomavirus type 1 associated with sarcoids in equine hosts indicates multiple cross-species transmission events and phylogeographical structure.

    Science.gov (United States)

    Trewby, Hannah; Ayele, Gizachew; Borzacchiello, Giuseppe; Brandt, Sabine; Campo, M Saveria; Del Fava, Claudia; Marais, Johan; Leonardi, Leonardo; Vanselow, Barbara; Biek, Roman; Nasir, Lubna

    2014-12-01

    Papillomaviruses are a family of slowly evolving DNA viruses and their evolution is commonly linked to that of their host species. However, whilst bovine papillomavirus-1 (BPV-1) primarily causes warts in its natural host, the cow, it can also cause locally aggressive and invasive skin tumours in equids, known as sarcoids, and thus provides a rare contemporary example of cross-species transmission of a papillomavirus. Here, we describe the first phylogenetic analysis of BPV-1 in equine sarcoids to our knowledge, allowing us to explore the evolutionary history of BPV-1 and investigate its cross-species association with equids. A phylogenetic analysis of the BPV-1 transcriptional promoter region (the long control region or LCR) was conducted on 15 bovine and 116 equine samples from four continents. Incorporating previous estimates for evolutionary rates in papillomavirus implied that the genetic diversity in the LCR variants was ancient and predated domestication of both equids and cattle. The phylogeny demonstrated geographical segregation into an ancestral group (African, South American and Australian samples), and a more recently derived, largely European clade. Whilst our data are consistent with BPV-1 originating in cattle, we found evidence of multiple, probably relatively recent, cross-species transmission events into horses. We also demonstrated the high prevalence of one particular sequence variant (variant 20), and suggest this may indicate that this variant shows a fitness advantage in equids. Although strong host specificity remains the norm in papillomaviruses, our results demonstrate that exceptions to this rule exist and can become epidemiologically relevant. © 2014 The Authors.

  13. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, Lionel [UMR, France; Klonowska, Agnieszka [UMR, France; Caroline, Bournaud [UMR, France; Booth, Kristina [University of Massachusetts; Vriezen, Jan A.C. [University of Massachusetts; Melkonian, Remy [UMR, France; James, Euan [James Hutton Institute, Dundee, United Kingdom; Young, Peter W. [University of York, United Kingdom; Bena, Gilles [UMR, France; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lizotte-Waniewski, Michelle [University of Massachusetts; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Riley, Monica [Woods Hole Oceanographic Institution (WHOI), Woods Hole

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  14. Molecular species delimitation in the Racomitrium canescens complex (Grimmiaceae and implications for DNA barcoding of species complexes in mosses.

    Directory of Open Access Journals (Sweden)

    Michael Stech

    Full Text Available In bryophytes a morphological species concept is still most commonly employed, but delimitation of closely related species based on morphological characters is often difficult. Here we test morphological species circumscriptions in a species complex of the moss genus Racomitrium, the R. canescens complex, based on variable DNA sequence markers from the plastid (rps4-trnT-trnL region and nuclear (nrITS genomes. The extensive morphological variability within the complex has led to different opinions about the number of species and intraspecific taxa to be distinguished. Molecular phylogenetic reconstructions allowed to clearly distinguish all eight currently recognised species of the complex plus a ninth species that was inferred to belong to the complex in earlier molecular analyses. The taxonomic significance of intraspecific sequence variation is discussed. The present molecular data do not support the division of the R. canescens complex into two groups of species (subsections or sections. Most morphological characters, albeit being in part difficult to apply, are reliable for species identification in the R. canescens complex. However, misidentification of collections that were morphologically intermediate between species questioned the suitability of leaf shape as diagnostic character. Four partitions of the molecular markers (rps4-trnT, trnT-trnL, ITS1, ITS2 that could potentially be used for molecular species identification (DNA barcoding performed almost equally well concerning amplification and sequencing success. Of these, ITS1 provided the highest species discrimination capacity and should be considered as a DNA barcoding marker for mosses, especially in complexes of closely related species. Molecular species identification should be complemented by redefining morphological characters, to develop a set of easy-to-use molecular and non-molecular identification tools for improving biodiversity assessments and ecological research

  15. Phytoalexin detoxification genes and gene products: Implication for the evolution of host specific traits for pathogenicity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    VanEtten, H.

    1997-06-01

    The overall objectives of this research were to determine which differences among PDA genes were associated with different levels of virulence on pea and to clone and characterize a MAK gene. The authors also proposed to characterize the pisatin detoxifying system in pea pathogens in addition to N. haematococca to assess whether pathogens of a common host had evolved similar pathogenicity genes.

  16. A new species of Australotaenia (Cestoda: Proteocephalidea) from a snake in Cambodia: host switching or postcyclic parasitism in a distant region?

    Science.gov (United States)

    de Chambrier, Alain; Scholz, Tomás

    2012-12-01

    Australotaenia de Chambrier et de Chambrier, 2010 has been proposed to accommodate two species of proteocephalidean cestodes from hylid frogs (Litoria spp.) in Australia. Recently, apparently congeneric cestode, for which the name A. bunthangi sp. n. is proposed, was found in the homalopsid snake Enhydris enhydris (Schneider) (Serpentes: Homalopsidae) from South-East Asia (Cambodia). This finding indicates a much wider range of definitive hosts of species of this genus, i.e. amphibians and reptiles, which is exceptional among proteocephalideans. Postcyclic parasitism, i.e. predation of the definitive host infected with sexually mature parasites, cannot be excluded but does not seem to be probable. In addition, the occurrence of A. bunthangi in the former Indochina extends the range of the geographical distribution of the genus to another zoogeographical region. The new species differs from both species of Australotaenia in the relative size of an apical organ, the diameter of which equals to that of suckers (versus much smaller in the remaining species, in which the width of the apical organ represents less than 2/3 of the diameter of the suckers), much smaller scolex and suckers (width 150 microm and diameter of suckers 50-55 microm versus 245-420 microm and 100-140 microm, respectively), and longer body (224 mm versus 57-121 mm). In addition, A. bunthangi differs from A. hylae (Johnston, 1912) (type-species of the genus) by the number of testes (46-64 versus 74-106 in A. hylae) and by the ovary width/proglottis width ratio (55-65% versus 68-71% in A. hylae). Australotaenia bunthangi differs from A. grobeli de Chambrier et de Chambrier, 2010 by relative size of the cirrus-sac (its length represents 18-24% of the width of the proglottis versus 27-33% in A. grobeli) and by the diameter of the embryophore (25-27 microm versus 18-23 microm in A. grobeli).

  17. Cryptic speciation and host specificity among Mycosphaerella spp. occurring on Australian Acacia species grown as exotics in the tropics

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Pongpanich, K.; Himaman, W.; Arzanlou, M.; Wingfield, M.J.

    2004-01-01

    Species of Mycosphaerella and their anamorphs represent serious pathogens of two phyllodenous species of Acacia, A. mangium and A. crassicarpa. In recent years, these fungi have been collected during surveys in South America and South-East Asia, where these trees are widely planted as exotics. In

  18. Osmia species (Hymenoptera, Megachilidae) from the southeastern United States with modified facial hairs: taxonomy, host plants, and conservation status

    Science.gov (United States)

    We describe females and males of Osmia (Melanosmia) calaminthae, new species, an apparent floral specialist on Calamintha ashei (Lamiaceae). Females of O. calaminthae have short, erect, simple facial hairs. The species is currently only known from sandy scrub at a number of sites in the southern La...

  19. Hepacivirus NS3/4A Proteases Interfere with MAVS Signaling in both Their Cognate Animal Hosts and Humans: Implications for Zoonotic Transmission.

    Science.gov (United States)

    Anggakusuma; Brown, Richard J P; Banda, Dominic H; Todt, Daniel; Vieyres, Gabrielle; Steinmann, Eike; Pietschmann, Thomas

    2016-12-01

    Multiple novel members of the genus Hepacivirus have recently been discovered in diverse mammalian species. However, to date, their replication mechanisms and zoonotic potential have not been explored in detail. The NS3/4A serine protease of hepatitis C virus (HCV) is critical for cleavage of the viral polyprotein. It also cleaves the cellular innate immune adaptor MAVS, thus decreasing interferon (IFN) production and contributing to HCV persistence in the human host. To investigate the conservation of fundamental aspects of the hepaciviral life cycle, we explored if MAVS cleavage and suppression of innate immune signaling represent a common mechanism employed across different clades of the genus Hepacivirus to enhance viral replication. To estimate the zoonotic potential of these nonhuman hepaciviruses, we assessed if their NS3/4A proteases were capable of cleaving human MAVS. NS3/4A proteases of viruses infecting colobus monkeys, rodents, horses, and cows cleaved the MAVS proteins of their cognate hosts and interfered with the ability of MAVS to induce the IFN-β promoter. All NS3/4A proteases from nonhuman viruses readily cleaved human MAVS. Thus, NS3/4A-dependent cleavage of MAVS is a conserved replication strategy across multiple clades within the genus Hepacivirus Human MAVS is susceptible to cleavage by these nonhuman viral proteases, indicating that it does not pose a barrier for zoonotic transmission of these viruses to humans. Virus infection is recognized by cellular sensor proteins triggering innate immune signaling and antiviral defenses. While viruses have evolved strategies to thwart these antiviral programs in their cognate host species, these evasion mechanisms are often ineffective in a novel host, thus limiting viral transmission across species. HCV, the best-characterized member of the genus Hepacivirus within the family Flaviviridae, uses its NS3/4A protease to disrupt innate immune signaling by cleaving the cellular adaptor protein MAVS

  20. New species of leaf-mining Nepticulidae (Lepidoptera) from the Neotropical and Ando-Patagonian regions, with new data on host plants.

    Science.gov (United States)

    Stonis, Jonas R; Remeikis, Andrius; Diškus, Arūnas; Megoran, Nick

    2017-05-26

    The paper treats fifteen species of leaf-mining pygmy moths (Insecta, Lepidoptera, Nepticulidae) discovered in the Neotropics (British Virgin Islands, Belize, Costa Rica, Venezuela, and Ecuador), and Ando-Patagonian region (Argentina and Chile). Except for two species, all belong to Stigmella Schrank. Twelve species are new, and are named and described in the current paper: Stigmella apicibrunella Diškus & Stonis, sp. nov.; S. decora Diškus & Stonis, sp. nov.; S. unicaudata Remeikis & Stonis, sp. nov.; S. sanmartini Remeikis & Stonis, sp. nov.; S. patula Remeikis & Stonis, sp. nov.; S. torosa Remeikis & Stonis, sp. nov.; S. monstrata Remeikis & Stonis, sp. nov.; S. huahumi Remeikis & Stonis, sp. nov.; S. venezuelica Remeikis & Stonis, sp. nov.; S. virginica Remeikis & Stonis, sp. nov.; Fomoria miranda Diškus & Stonis, sp. nov.; and Hesperolyra robinsoni Stonis, sp. n. Newly discovered variation of male genitalia of the Andean Stigmella rudis Puplesis & Robinson, 2000 is briefly discussed, and the formerly poorly understood Stigmella hylomaga (Meyrick, 1931) is redescribed and documented with photographs for the first time. We also present more photographs and add some addtional information on Stigmella gallicola van Nieukerken & Nishida, a recently described gall-maker from Costa Rica.The paper also provides new host-plant data: some of the described (or redescribed) species are reported for the first time as leaf-miners on plants belonging to Euphorbiaceae (Acalypha padifolia Kunth), Salicaceae (Azara microphylla Hook. f.), Fabaceae (Inga spectabilis (Vahl) Willd. or I. edulis Mart.), Rhamnaceae (Colletia spinosissima J. F. Gmel.), Geraniaceae or Vivianiaceae (Rhynchotheca spinosa Ruiz & Pav.), and Asteraceae (Mutisia decurrens Cav.). All species treated in the paper are illustrated with photographs of the adults and genitalia, a distribution map, and also photographs of the leaf-mines and host plants when available.

  1. A review of the early stages and host plants of the genera Eumerus and Merodon (Diptera: Syrphidae, with new data on four species.

    Directory of Open Access Journals (Sweden)

    Antonio Ricarte

    Full Text Available The genera Eumerus and Merodon (Diptera: Syrphidae have a high taxonomic diversity (300+ species altogether, but life histories of most species are unknown. In addition, these hoverfly genera are recognised to be pests (ornamental plants and vegetable crops. In this paper, early stages of four hoverfly species are described, Eumerus hungaricus Szilády, 1940, Eumerus nudus Loew, 1848 and Merodon geniculatus Strobl, 1909, from Spain, and Eumerus strigatus Walker, 1859, from California, USA. Larvae of E. nudus were obtained from swollen roots of Asphodelus cerasiferus J. Gay. Larvae of E. hungaricus were found in bulbs of Narcissus confusus Pugsley. The host plant of the examined specimen of Eumerus strigatus is unknown. Larvae of M. geniculatus were reared from bulbs of different species of Narcissus L. Scanning electron microscope imaging was used to study and illustrate the anterior respiratory processes, pupal spiracles and posterior respiratory processes of the new early stages. A compilation of all available information on the early stages and host plants of Eumerus (21 spp. and Merodon (15 spp is provided, as well as an identification key to all known larvae/puparia of these genera. Eumerus elavarensis Séguy, 1961 is proposed as a new synonym of E. hungaricus and first data of this species are reported from Austria, Bulgaria, Spain and Turkey. In Eumerus, larvae are alleged to rely on the previous presence of decay organisms, but in the larvae of E. nudus the sclerotisation and size of the mandibular hooks suggest that this larva can generate decay from intact plant tissue.

  2. A review of the early stages and host plants of the genera Eumerus and Merodon (Diptera: Syrphidae), with new data on four species.

    Science.gov (United States)

    Ricarte, Antonio; Souba-Dols, Gabriel J; Hauser, Martin; Marcos-García, Mª Ángeles

    2017-01-01

    The genera Eumerus and Merodon (Diptera: Syrphidae) have a high taxonomic diversity (300+ species altogether), but life histories of most species are unknown. In addition, these hoverfly genera are recognised to be pests (ornamental plants and vegetable crops). In this paper, early stages of four hoverfly species are described, Eumerus hungaricus Szilády, 1940, Eumerus nudus Loew, 1848 and Merodon geniculatus Strobl, 1909, from Spain, and Eumerus strigatus Walker, 1859, from California, USA. Larvae of E. nudus were obtained from swollen roots of Asphodelus cerasiferus J. Gay. Larvae of E. hungaricus were found in bulbs of Narcissus confusus Pugsley. The host plant of the examined specimen of Eumerus strigatus is unknown. Larvae of M. geniculatus were reared from bulbs of different species of Narcissus L. Scanning electron microscope imaging was used to study and illustrate the anterior respiratory processes, pupal spiracles and posterior respiratory processes of the new early stages. A compilation of all available information on the early stages and host plants of Eumerus (21 spp.) and Merodon (15 spp) is provided, as well as an identification key to all known larvae/puparia of these genera. Eumerus elavarensis Séguy, 1961 is proposed as a new synonym of E. hungaricus and first data of this species are reported from Austria, Bulgaria, Spain and Turkey. In Eumerus, larvae are alleged to rely on the previous presence of decay organisms, but in the larvae of E. nudus the sclerotisation and size of the mandibular hooks suggest that this larva can generate decay from intact plant tissue.

  3. The role of diet on intestinal microbiota metabolism: Downstream impacts on host immune function and health, and therapeutic implications

    OpenAIRE

    Goldsmith, Jason R.; Sartor, Balfour

    2014-01-01

    Dietary impacts on health may be one of the oldest concepts in medicine; however, only in recent years have technical advances in mass spectroscopy, gnotobiology, and bacterial sequencing enabled our understanding of human physiology to progress to the point where we can begin to understand how individual dietary components can affect specific illnesses. This review explores the current understanding of the complex interplay between dietary factors and the host microbiome, concentrating on th...

  4. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    Science.gov (United States)

    Graves, David B.

    2012-07-01

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well.

  5. Phylogeography of two parthenogenetic sawfly species (Hymenoptera: Tenthredinidae): relationship of population genetic differentiation to host plant distribution

    NARCIS (Netherlands)

    Müller, C.; Barker, A.; Boevé, J.L.; Jong, de P.W.; Vos, de H.; Brakefield, P.M.

    2004-01-01

    This study compares the population genetic structure of two obligate parthenogenetic sawfly species, Aneugmenus padi (L.) Zhelochovtsev and Eurhadinoceraea ventralis (Panzer) Enslin (Hymenoptera: Tenthredinidae). Allozymes were used to detect genetic differences in larvae collected at different

  6. Comparative pan genome analysis of oral Prevotella species implicated in periodontitis.

    Science.gov (United States)

    Ibrahim, Maziya; Subramanian, Ahalyaa; Anishetty, Sharmila

    2017-02-24

    Prevotella is part of the oral bacterial community implicated in periodontitis. Pan genome analyses of eight oral Prevotella species, P. dentalis, P. enoeca, P. fusca, P. melaninogenica, P. denticola, P. intermedia 17, P. intermedia 17-2 and P. sp. oral taxon 299 are presented in this study. Analysis of the Prevotella pan genome revealed features such as secretion systems, resistance to oxidative stress and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems that enable the bacteria to adapt to the oral environment. We identified the presence of type VI secretion system (T6SS) in P. fusca and P. intermedia strains. For some VgrG and Hcp proteins which were not part of the core T6SS loci, we used gene neighborhood analysis and identified putative effector proteins and putative polyimmunity loci in P. fusca and polymorphic toxin systems in P. intermedia strains. Earlier studies have identified the presence of Por secretion system (PorSS) in P. gingivalis, P. melaninogenica and P. intermedia. We noted the presence of their homologs in six other oral Prevotella studied here. We suggest that in Prevotella, PorSS is used to secrete cysteine proteases such as interpain and C-terminal domain containing proteins with a "Por_secre_tail" domain. We identified subtype I-B CRISPR-Cas system in P. enoeca. Putative CRISPR-Cas system subtypes for 37 oral Prevotella and 30 non-oral Prevotella species were also predicted. Further, we performed a BLASTp search of the Prevotella proteins which are also conserved in the red-complex pathogens, against the human proteome to identify potential broad-spectrum drug targets. In summary, the use of a pan genome approach enabled identification of secretion systems and defense mechanisms in Prevotella that confer adaptation to the oral cavity.

  7. Toxicity of zinc and copper to Brassica species: Implications for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbs, S.D.; Kochian, L.V. [Cornell Univ., Ithaca, NY (United States)

    1997-05-01

    The toxicity of Zn and Cu in three species from the genus Brassica was examined to determine if these plants showed sufficient tolerance and metal accumulation to be used to phytoremediate a site contaminated with these two heavy metals. Hydroponically grown 12-d-old plants of Brassica juncea, B. rapa, and B. napus were grown for an additional 14 d in the presence of either elevated Zn (6.5 mg L{sup {minus}1}), Cu (0.32 mg L{sup {minus}1}), or Zn+Cu to quantify the toxic effects of these metals on several different growth parameters. With few exceptions, both root and shoot dry weight for all three species decreased significantly in the presence of heavy metals. Cu inhibited lateral root elongation in B. rapa, B. napus, and, to a lesser extent, B. juncea, while Zn tended to decrease only lateral root diameter. Both metals reduced shoot Fe and Mn concentrations in all three Brassica spp. to levels associated with Fe and Mn deficiencies. These deficiencies, however, did not correlate with observed patterns of leaf chlorosis. Nonetheless, heavy metal-induced inhibition of Fe and Mn accumulation may have been a significant factor in reducing plant growth. In terms of heavy metal removal, the Brassica spp, were more effective at removing Zn from the nutrient solution than Cu. The extent of Zn and Cu removal was reduced in the presence of both metals, as compared to the single heavy metal treatments. The implications of these results for phytoremediation are discussed. 20 refs., 6 figs., 1 tab.

  8. Species-specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress

    DEFF Research Database (Denmark)

    Abrego, David; Ulstrup, Karin E; Willis, Bette L

    2008-01-01

    The impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different Symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. Here we compare the functionality and physiological properties...... and a potential role for host factors in determining the physiological performance of reef corals....... of juvenile corals when experimentally infected with one of two homologous Symbiodinium types and exposed to combined heat and light stress. A suite of physiological indicators including chlorophyll a fluorescence, oxygen production and respiration, as well as pigment concentration consistently demonstrated...

  9. HOST PLANTS AND CLIMATIC PREFERENCES OF THE INVASIVE SPECIES METCALFA PRUINOSA (SAY 1830 (HEMIPTERA: FLATIDAE IN SOME PLACES FROM SOUTHERN ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniela Barbuceanu

    2015-12-01

    Full Text Available Observations carried out in May-September 2015 in two sites of Southern Romania reveal a rich spectrum of host plants for Metcalfa pruinosa, which consists of 204 species in 56 families. The species it is noticed on weeds and cultivated plants. The remarkable polyphagia of this species, the lack of natural enemies, and the climatic conditions of 2015 - warm and dry summer, had lead to an invasion of M. pruinosa, in the researched areas; the highest numerical abundances are noticed in shady habitats. Furthermore, on herbs, such as Levisticum officinale, Artemisia dracunculus, Ocimum basilicum, Mentha spp., usually avoided by pests, were observed colonies of the species. It is recorded high numerical abundance on fruit trees and shrubs: Hippophaë rhamnoides, Juglans regia, Prunus cerasus, Vitis vinifera, Rubus idaeus. The harmful effect occurs on apple trees Romus 1 variety as a result of the association with another pest of American origin, Eriosoma lanigerum, situation that favors the attack of the Erwinia amylovora bacteria, causing the collapse of the tree. It is found that altitudes higher than 200 m do not represent a limitative factor in the spreading of species, one of the investigated sites being located at 304 m altitude.

  10. A key to American genus Merobruchus Bridwell (Coleoptera: Chrysomelidae: Bruchinae) with descriptions of species and two new host plant records for the subfamily.

    Science.gov (United States)

    Manfio, Daiara; Ribeiro-Costa, Cibele Stramare

    2016-02-09

    Merobruchus Bridwell is placed in the group Merobruchus of Acanthoscelidina (Bruchini) being distinguished from all bruchines mainly by the apical projections in the last abdominal ventrite of females and some males. All 25 species of Merobruchus are distributed in the New World, mainly in the Neotropical Region, feeding on seeds of Mimosoideae (Acacieae, Ingeae and Mimoseae). As well as some other bruchine genera, Merobruchus shows considerable morphological variation both in external and in internal (male genitalia) characters. Moreover, some species are very similar to each other in their colour and distribution pattern of pubescence on the dorsal surface, sometimes making species recognition difficult. Thus, the main objective of this paper is to provide a key including coloured illustrations for Merobruchus species to facilitate the process of identification and to avoid misunderstandings. Images of dorsal habitus, male and female pygidium and male genitalia are provided for all species. In addition, M. machadoi sp. nov. (Holotype male deposited in DZUP: Brazil, Rio Grande do Sul State) is described; M. bicoloripes (Pic) and M. pickeli (Pic) are redescribed; and a new synonymy is proposed: Pseudopachymerus pickeli Pic, 1927 = Pseudopachymerus pickeli var. subnotatus Pic, 1927 syn. nov. Two new host plants are recorded for Bruchinae: Parapiptadenia rigida (Benth.) Brenan (Mimosoideae) and Pterogyne nitens Tul. (Caesalpinioideae).

  11. Unravelling the riddle of Radix: DNA barcoding for species identification of freshwater snail intermediate hosts of zoonotic digeneans and estimating their inter-population evolutionary relationships.

    Science.gov (United States)

    Lawton, Scott P; Lim, Rivka M; Dukes, Juliet P; Kett, Stephen M; Cook, Richard T; Walker, Anthony J; Kirk, Ruth S

    2015-10-01

    Radix spp. are intermediate host snails for digenean parasites of medical and veterinary importance. Within this genus, species differentiation using shell and internal organ morphology can result in erroneous species identification, causing problems when trying to understand the population biology of Radix. In the present study, DNA barcoding, using cox1 and ITS2 sequences, identified populations of Radix auricularia and Radix balthica from specimens originally morphologically identified as Radix peregra from the UK. Assessment of cox1 and ITS2 as species identification markers showed that, although both markers differentiated species, cox1 possessed greater molecular diversity and higher phylogenetic resolution. Cox1 also proved useful for gaining insights into the evolutionary relationships of Radix species populations. Phylogenetic analysis and haplotype networks of cox1 indicated that R. auricularia appeared to have invaded the UK several times; some haplotypes forming a distinct UK specific clade, whilst others are more akin to those found on mainland Europe. This was in contrast to relationships between R. balthica populations, which had low molecular diversity and no distinct UK specific haplotypes, suggesting recent and multiple invasions from mainland Europe. Molecular techniques therefore appear to be crucial for distinguishing Radix spp., particularly using cox1. This barcoding marker also enables the population biology of Radix spp. to be explored, and is invaluable for monitoring the epidemiology of fluke diseases especially in the light of emerging diseases and food security. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Key to Holarctic species of Epitrix flea beetles (Coleoptera: Chrysomelidae: Galerucinae: Alticini) with review of their distribution, host plants and history of invasions.

    Science.gov (United States)

    Bieńkowski, Andrzej O; Orlova-Bienkowskaja, Marina J

    2016-10-17

    The genus Epitrix Foudras, 1860a has a worldwide distribution. Some species of Epitrix are major pests of potato, tomato, eggplant, tobacco and other plants in North America and Europe. Some pest species have been inadvertently introduced from North America to Europe, from Europe to North America and from both continents to some islands in Atlantic and Pacific oceans. Therefore, a key for the identification of all Holarctic species is necessary for plant quarantine and protection services. We have compiled the key for distinguishing Epitrix from genera that could be confused with it and a key for all Holarctic species of Epitrix with the figures of spermathecae and aedeagi and the checklist with a review of the geographical distribution, host plants and history of invasions. The following species are included: E. abeillei (Bauduer), E. allardii (Wollaston), E. atropae Foudras, E. brevis Schwarz, E. caucasica (Heikertinger), E. cucumeris (Harris), E. dieckmanni (Mohr), E. ermischi (Mohr), E. fasciata Blatchley, E. flavotestacea Horn, E. fuscula Crotch, E. hirtipennis (Melsheimer), E. humeralis Dury, E. intermedia Foudras, E. krali Döberl, E. lobata Crotch, E. muehlei Döberl, E. priesneri (Heikertinger), E. pubescens (Koch), E. ogloblini (Iablokov-Khnzorian), E. robusta Jacoby, E. setosella (Fairmaire), E. similaris Gentner, E. solani (Blatchley), E. subcrinita (LeConte), E. tuberis Gentner, E. warchalowskii (Mohr) and E. papa Orlova-Bienkowskaja.

  13. Guild-specific patterns of species richness and host specialization in plant-herbivore food webs from a tropical forest.

    Science.gov (United States)

    Novotny, Vojtech; Miller, Scott E; Baje, Leontine; Balagawi, Solomon; Basset, Yves; Cizek, Lukas; Craft, Kathleen J; Dem, Francesca; Drew, Richard A I; Hulcr, Jiri; Leps, Jan; Lewis, Owen T; Pokon, Rapo; Stewart, Alan J A; Samuelson, G Allan; Weiblen, George D

    2010-11-01

    1. The extent to which plant-herbivore feeding interactions are specialized is key to understand the processes maintaining the diversity of both tropical forest plants and their insect herbivores. However, studies documenting the full complexity of tropical plant-herbivore food webs are lacking. 2. We describe a complex, species-rich plant-herbivore food web for lowland rain forest in Papua New Guinea, resolving 6818 feeding links between 224 plant species and 1490 herbivore species drawn from 11 distinct feeding guilds. By standardizing sampling intensity and the phylogenetic diversity of focal plants, we are able to make the first rigorous and unbiased comparisons of specificity patterns across feeding guilds. 3. Specificity was highly variable among guilds, spanning almost the full range of theoretically possible values from extreme trophic generalization to monophagy. 4. We identify guilds of herbivores that are most likely to influence the composition of tropical forest vegetation through density-dependent herbivory or apparent competition. 5. We calculate that 251 herbivore species (48 of them unique) are associated with each rain forest tree species in our study site so that the ∼200 tree species coexisting in the lowland rain forest community are involved in ∼50,000 trophic interactions with ∼9600 herbivore species of insects. This is the first estimate of total herbivore and interaction number in a rain forest plant-herbivore food web. 6. A comprehensive classification of insect herbivores into 24 guilds is proposed, providing a framework for comparative analyses across ecosystems and geographical regions. © 2010 The Authors. Journal compilation © 2010 British Ecological Society.

  14. Native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses.

    Science.gov (United States)

    Long, Hoang Hoa; Schmidt, Dominik D; Baldwin, Ian T

    2008-07-16

    All plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. Changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (PGP) rhizobacteria which can decrease ethylene (ET) levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC) deaminase or produce indole acetic acid (IAA). Whether these common PGP mechanisms work similarly for different plant species has not been rigorously tested. We isolated bacterial endophytes from field-grown Solanum nigrum; characterized PGP traits (ACC deaminase activity, IAA production, phosphate solubilization and seedling colonization); and determined their effects on their host, S. nigrum, as well as on another Solanaceous native plant, Nicotiana attenuata. In S. nigrum, a majority of isolates that promoted root growth were associated with ACC deaminase activity and IAA production. However, in N. attenuata, IAA but not ACC deaminase activity was associated with root growth. Inoculating N. attenuata and S. nigrum with known PGP bacteria from a culture collection (DSMZ) reinforced the conclusion that the PGP effects are not highly conserved. We conclude that natural endophytic bacteria with PGP traits do not have general and predictable effects on the growth and fitness of all host plants, although the underlying mechanisms are conserved.

  15. Native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses.

    Directory of Open Access Journals (Sweden)

    Hoang Hoa Long

    Full Text Available BACKGROUND: All plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. Changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (PGP rhizobacteria which can decrease ethylene (ET levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC deaminase or produce indole acetic acid (IAA. Whether these common PGP mechanisms work similarly for different plant species has not been rigorously tested. METHODOLOGY/PRINCIPAL FINDINGS: We isolated bacterial endophytes from field-grown Solanum nigrum; characterized PGP traits (ACC deaminase activity, IAA production, phosphate solubilization and seedling colonization; and determined their effects on their host, S. nigrum, as well as on another Solanaceous native plant, Nicotiana attenuata. In S. nigrum, a majority of isolates that promoted root growth were associated with ACC deaminase activity and IAA production. However, in N. attenuata, IAA but not ACC deaminase activity was associated with root growth. Inoculating N. attenuata and S. nigrum with known PGP bacteria from a culture collection (DSMZ reinforced the conclusion that the PGP effects are not highly conserved. CONCLUSIONS/SIGNIFICANCE: We conclude that natural endophytic bacteria with PGP traits do not have general and predictable effects on the growth and fitness of all host plants, although the underlying mechanisms are conserved.

  16. Species limits, quarantine risk and the intrigue of a polyphagous invasive pest with highly restricted host relationships in its area of invasion.

    Science.gov (United States)

    Rafter, Michelle A; Hereward, James P; Walter, Gimme H

    2013-12-01

    Scirtothrips aurantii is a generalist horticultural pest in its native African range and recently established quite widely in Australia on the invasive succulent weed Bryophyllum delagoense. Paradoxically, this thrips is not polyphagous in its incursive range. The issue is principally one of quarantine. Will the thrips in Australia shift, perhaps adaptively, to citrus, and should the primary focus be on containment around Australian citrus, or does the real quarantine risk exist offshore with thrips present on citrus in Africa? We examined the phylogenetic relationships between Bryophyllum-associated thrips populations in Australia and populations sampled from various host plant species in South Africa (including Bryophyllum) using both CO1 and 28s markers. Eight variable microsatellite markers were developed to assess the extent of gene flow between the thrips on different hosts in South Africa. The COI phylogeny resolved S. aurantii into three distinct clades with samples collected from B. delagoense in South Africa and Australia representing a single clade, a second clade associated with Gloriosa lilies and the third with horticultural hosts. The microsatellite analysis confirmed that the populations associated with citrus and Bryophyllum do not hybridize with one another in sympatry. We conclude that the citrus-damaging thrips are not currently present in Australia and remain a serious quarantine concern in relation to Australian horticulture.

  17. Additions to the Encyrtidae and Mymaridae (Chalcidoidea of India with new distribution and host records for some species

    Directory of Open Access Journals (Sweden)

    A. Rameshkumar

    2015-06-01

    Results and conclusions. A total of 961 specimens were collected, from which 883 COI sequences were obtained. The sequences generated corresponded to 289 barcoding species and 30 identified genera. The most speciose genera were Heterospilus Haliday (170 spp., Ecphylus Förster (19 spp., Allorhogas Gahan (15 spp. and Callihormius Ashmead (14 spp.. Addition of previously collected material increased the diversity of the subfamily in the region to 34 genera and 290 species. Paraphyly of Heterospilus with respect to Neoheterospilus and Heterospathius was again recovered. Twenty new species and two new genera (Sabinita Belokobylskij, Zaldívar-Riverón et Martínez, Ficobolus Martínez, Belokobylskij et Zaldívar-Riverón have been described so far from the material collected in this work.

  18. Comparative Evaluation of DNA Extraction Methods from Feces of Multiple Host Species for Downstream Next-Generation Sequencing.

    Directory of Open Access Journals (Sweden)

    Marcia L Hart

    Full Text Available The gastrointestinal tract contains a vast community of microbes that to this day remain largely unculturable, making studies in this area challenging. With the newly affordable advanced sequencing technology, important breakthroughs in this exciting field are now possible. However, standardized methods of sample collection, handling, and DNA extraction have yet to be determined. To help address this, we investigated the use of 5 common DNA extraction methods on fecal samples from 5 different species. Our data show that the method of DNA extraction impacts DNA concentration and purity, successful NGS amplification, and influences microbial communities seen in NGS output dependent on the species of fecal sample and the DNA extraction method used. These data highlight the importance of careful consideration of DNA extraction method used when designing and interpreting data from cross species studies.

  19. Woody Species Diversity in Traditional Agroforestry Practices of Dellomenna District, Southeastern Ethiopia: Implication for Maintaining Native Woody Species

    Directory of Open Access Journals (Sweden)

    Abiot Molla

    2015-01-01

    Full Text Available The major impact of humans on forest ecosystems including loss of forest area, habitat fragmentation, and soil degradation leads to losses of biodiversity. These problems can be addressed by integration of agriculture with forests and maintaining the existing forests. This study was initiated to assess woody species diversity of traditional agroforestry practices. Three study sites (Burkitu, Chire, and Erba were selected based on the presence of agroforestry practice. Forty-eight (48 sample quadrants having an area of 20 m × 20 m, 16 sample quadrants in each study site, were systematically laid using four transect lines at different distance. The diversity of woody species was analyzed by using different diversity indices. A total of 55 woody species belonging to 31 families were identified and documented. There were significantly different (P<0.05 among the study Kebeles (peasant associations. Mangifera indica, Entada abyssinica, and Croton macrostachyus were found to have the highest Important Value Index. The results confirmed that traditional agroforestry plays a major role in the conservation of native woody species. However, threats to woody species were observed. Therefore, there is a need to undertake conservation practices before the loss of species.

  20. Nestedness of ectoparasite-vertebrate host networks.

    Directory of Open Access Journals (Sweden)

    Sean P Graham

    2009-11-01

    Full Text Available Determining the structure of ectoparasite-host networks will enable disease ecologists to better understand and predict the spread of vector-borne diseases. If these networks have consistent properties, then studying the structure of well-understood networks could lead to extrapolation of these properties to others, including those that support emerging pathogens. Borrowing a quantitative measure of network structure from studies of mutualistic relationships between plants and their pollinators, we analyzed 29 ectoparasite-vertebrate host networks--including three derived from molecular bloodmeal analysis of mosquito feeding patterns--using measures of nestedness to identify non-random interactions among species. We found significant nestedness in ectoparasite-vertebrate host lists for habitats ranging from tropical rainforests to polar environments. These networks showed non-random patterns of nesting, and did not differ significantly from published estimates of nestedness from mutualistic networks. Mutualistic and antagonistic networks appear to be organized similarly, with generalized ectoparasites interacting with hosts that attract many ectoparasites and more specialized ectoparasites usually interacting with these same "generalized" hosts. This finding has implications for understanding the network dynamics of vector-born pathogens. We suggest that nestedness (rather than random ectoparasite-host associations can allow rapid transfer of pathogens throughout a network, and expand upon such concepts as the dilution effect, bridge vectors, and host switching in the context of nested ectoparasite-vertebrate host networks.

  1. Discovery of intermediate hosts for two species of blood flukes Cardicola orientalis and Cardicola forsteri (Trematoda: Aporocotylidae) infecting Pacific bluefin tuna in Japan.

    Science.gov (United States)

    Shirakashi, Sho; Tani, Kazuki; Ishimaru, Katsuya; Shin, Sang Phil; Honryo, Tomoki; Uchida, Hiro'omi; Ogawa, Kazuo

    2016-04-01

    Fish blood flukes (Aporocotylidae) are important pathogens of farmed finfish around the world. Among them, Cardicola spp. infecting farmed tuna are considered to be serious threats to tuna farming and have received tremendous attention. We conducted periodical samplings at a tuna farming site in Japan between January and May, 2015 to determine the life cycle of Cardicola spp. We collected over 4700 terebellid polychaetes from ropes, floats and frames of tuna culture cages and found nearly 400 infected worms. Sporocysts and cercariae found in Nicolea gracilibranchis were genetically identified as Cardicola orientalis by 28S and ITS2 ribosomal DNA sequences. This was the first discovery of the intermediate host for this parasite species. Infection prevalence and the abundance of N. gracilibranchis significantly varied between sampling points and the highest number of infected terebellids were collected from ropes. We also demonstrated morphologically and molecularly that asexual stages found in a single Amphitrite sp. (Terebellidae) and adult worms isolated from farmed juvenile tuna were Cardicola forsteri. This is the first report of C. forsteri in Pacific bluefin tuna (PBT) Thunnus orientalis in Japan. Our results demonstrated that all three species of Cardicola orientalis, C. forsteri and Cardicola opisthorchis exist in Japanese farmed PBTs and that they all use terebellid polychaetes as the intermediate hosts. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Effects of tea saponin on growth and development, nutritional indicators, and hormone titers in diamondback moths feeding on different host plant species.

    Science.gov (United States)

    Cai, Hongjiao; Bai, Yan; Wei, Hui; Lin, Shuo; Chen, Yixin; Tian, Houjun; Gu, Xiaojun; Murugan, Kadarkarai

    2016-07-01

    The diamondback moth (DBM) is an important worldwide pest. This insect has been studied for several decades; however, its control remains problematic. Numerous chemical insecticides have become ineffective and chemical residues constitute an important problem. In the present study, we determined the mortality of 3rd instar DBM larvae feeding on three different host plant species and exposed to various concentrations of tea saponin (TS). In addition, we evaluated growth and development parameters, nutritional indicators, and juvenile hormone (JH) and molting hormone (MH) titers in 2nd instar larvae exposed to LC20 and LC50 doses of TS. We found that treatment of DBM larvae with LC20 and LC50 doses of TS led to lower growth rates, decreased feed consumption, reduced frass production, lower pupal weights, reduced percentage pupation, slower adult emergence percentages, and diminished fecundity, but prolonged durations of the larval and pupal periods. The efficiency of conversion of ingested and digested food increased, but the approximate digestibility did not differ significantly between treatments and controls. JH and MH titers were higher after TS treatment; these increases varied according to the host species and TS concentration. Our results indicate that TS represents a potential new alternative insecticide based on its natural origin, low cost, and minimum environmental impact. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Multi-cereal molecular surveys suggest host preference among members of the Fusarium graminearum species complex from southern Brazil

    Science.gov (United States)

    This study aimed to assess the extent and distribution of members of the Fusarium graminearum species complex (FGSC) associated with cereals grown in southern Brazil between 2009 and 2012. The total collection comprised 1,127 isolates, which were divided into four collections obtained from: 1) disea...

  4. Diversity, composition and host-species relationships of epiphytic orchids and ferns in two forest in Nepal

    Czech Academy of Sciences Publication Activity Database

    Adhikari, Y. P.; Fischer, A.; Fischer, H. S.; Rokaya, Maan Bahadur; Bhattarai, P.; Gruppe, A.

    2017-01-01

    Roč. 14, č. 6 (2017), s. 1065-1075 ISSN 1672-6316 Grant - others:European Comission(XE) 212459 Program:FP7 Institutional support: RVO:67985939 Keywords : environmental factors * epiphytes * large trees * indicator species * multivariate and univariate analyses * permutations tests Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.016, year: 2016

  5. Bee species-specific nesting material attracts a generalist parasitoid: implications for co-occurring bees in nest box enhancements.

    Science.gov (United States)

    Macivor, J Scott; Salehi, Baharak

    2014-08-01

    Artificial nests (e.g., nest boxes) for bees are increasingly being used to contribute to nesting habitat enhancement for bees that use preexisting cavities to provision brood. They usually incorporate additional nesting materials that vary by species. Cavity-nesting bees are susceptible to brood parasitoids that recognize their host(s) using visual and chemical cues. Understanding the range of cues that attract parasitoids to bee nests, including human-made analogues, is important if we wish to control parasitism and increase the potential value of artificial nests as habitat-enhancement strategies. In this study, we investigated the cues associated with the orientation of the generalist brood parasitoid Monodontomerus obscurus Westwood (Hymenoptera: Torymidae) to the nests of a common cavity-nesting resin bee Megachile campanulae (Robertson) (Megachilidae). The parasitoids were reared from previously infested M. campanulae brood cells and placed into choice trials where they were presented with pairs of different nest material cues. Among different materials tested, we found that Mo. obscurus was most attracted to fresh resin collected directly from Pinus strobus trees followed by previously used resin collected from the bee nest. The parasitoid also attacked other bee species in the same nest boxes, including those that do not use resin for nesting. Our findings suggest that M. campanulae could act as a magnet, drawing parasites away from other bee hosts co-occurring in nest boxes, or, as an attractant of Mo. obscurus to nest boxes, increasing attacks on co-occurring host bee species, potentially undermining bee diversity enhancement initiatives.

  6. Entamoeba Species in South Africa: Correlations With the Host Microbiome, Parasite Burdens, and First Description of Entamoeba bangladeshi Outside of Asia.

    Science.gov (United States)

    Ngobeni, Renay; Samie, Amidou; Moonah, Shannon; Watanabe, Koji; Petri, William A; Gilchrist, Carol

    2017-12-19

    Diarrhea is frequent in communities without clean water, which include low-income South African populations in Giyani and Pretoria. In these populations, the amount of diarrhea caused by Entamoeba histolytica, inclusive of all ages, sexes, and human immunodeficiency virus status, is uncertain. Infection with E. histolytica can modulate the host microbiota, and a key species indicative of this is the Prevotella copri pathobiont. A cross-sectional study of patients attending gastroenterology clinics was conducted to determine the frequency and burden of 4 Entamoeba species and P. copri. Entamoeba species were present in 27% of patients (129/484), with E. histolytica detected in 8.5% (41), E. dispar in 8% (38), E. bangladeshi in 4.75% (23), and E. moshkovskii in 0%. This is the first description of E. bangladeshi outside Bangladesh. In E. histolytica-positive samples, the levels of both the parasite and P. copri were lower in nondiarrheal samples, validating the results of a study in Bangladesh (P = .0034). By contrast, in E. histolytica-negative samples positive for either of the nonpathogenic species E. dispar or E. bangladeshi, neither P. copri nor Entamoeba levels were linked to gastrointestinal status. Nonmorphologic identification of this parasite is essential. In South Africa, 3 morphologically identical Entamoeba were common, but only E. histolytica was linked to both disease and changes in the microbiota.

  7. Molecular species identification, host preference and detection of myxoma virus in the Anopheles maculipennis complex (Diptera: Culicidae) in southern England, UK.

    Science.gov (United States)

    Brugman, Victor A; Hernández-Triana, Luis M; Prosser, Sean W J; Weland, Chris; Westcott, David G; Fooks, Anthony R; Johnson, Nicholas

    2015-08-15

    Determining the host feeding patterns of mosquitoes by identifying the origin of their blood-meals is an important part of understanding the role of vector species in current and future disease transmission cycles. Collecting large numbers of blood-fed mosquitoes from the field is difficult, therefore it is important to maximise the information obtained from each specimen. This study aimed to use mosquito genome sequence to identify the species within Anopheles maculipennis sensu lato (An. maculipennis s.l.), identify the vertebrate hosts of field-caught blood-fed An. maculipennis s.l. , and to test for the presence of myxoma virus (Poxviridae, genus Leporipoxvirus) in specimens found to have fed on the European rabbit (Oryctolagus cuniculus). Blood-fed An. maculipennis s.l. were collected from resting sites at Elmley Nature Reserve, Kent, between June and September 2013. Hosts that An. maculipennis s.l. had fed on were determined by a PCR-sequencing approach based on the partial amplification of the mitochondrial cytochrome C oxidase subunit I gene. Mosquitoes were then identified to species by sequencing a region of the internal transcribed spacer-2. DNA extracts from all mosquitoes identified as having fed on rabbits were subsequently screened using PCR for the presence of myxoma virus. A total of 94 blood-fed Anopheles maculipennis s.l. were collected, of which 43 (46%) provided positive blood-meal identification results. Thirty-six of these specimens were identified as Anopheles atroparvus, which had fed on rabbit (n = 33, 92%) and cattle (n = 3, 8%). Seven mosquitoes were identified as Anopheles messeae, which had fed on cattle (n = 6, 86%) and dog (n = 1, 14%). Of the 33 An. atroparvus that contained rabbit blood, nine (27%) were positive for myxoma virus. Results demonstrate that a single DNA extract from a blood-fed mosquito can be successfully used for molecular identification of members of the An. maculipennis complex, blood

  8. The Schistosoma indicum species group in Nepal: presence of a new lineage of schistosome and use of the Indoplanorbis exustus species complex of snail hosts.

    Science.gov (United States)

    Devkota, Ramesh; Brant, Sara V; Loker, Eric S

    2015-11-01

    From 2007-2014, 19,360 freshwater snails from the Terai and Hilly regions of Nepal were screened for cercariae of mammalian schistosomes. Based on analysis of mitochondrial cytochrome oxidase I, 12S, 16S and 28S sequences (3,675bp) of the cercariae recovered, we provide, to our knowledge, the first report of the Schistosoma indicum species group in Nepal. Five samples of Schistosoma nasale, nine of Schistosoma spindale and 17 of Schistosoma sp. were recovered, all from the snail Indoplanorbis exustus. The last-mentioned lineage failed to group in any of our analyses with S. nasale, S. spindale or S. indicum. It diverged in cox1 sequence from them by 16%, 13% and 13%, respectively, levels of difference comparable to well-studied species pairs of Schistosoma. Analysis of cox1, 16S and internal transcribed spacer 1 sequences (1,874bp) for Nepalese specimens of I. exustus was also surprising in revealing the presence of four genetically distinct clades. They diverged from one another at levels comparable to those noted for species pairs in the sister genus Bulinus. There was no obvious pattern of use by Nepalese Schistosoma of the Indoplanorbis clades. We found high support for a close relationship between S. indicum and Schistosoma haematobium groups, but failed to retrieve support for a clean separation of the two, with a tendency for S. nasale to fall as the most basal representative. If this pattern holds, hypotheses for the origin of the Asian Indoplanorbis-transmitted S. indicum group from the Bulinus-transmitted S. haematobium group may require modification, including consideration of more contemporaneous origins of the two groups. The Indian subcontinent is under-studied with respect to schistosome diversity and our current knowledge of the S. indicum and I. exustus species groups is inadequate. Further study is warranted given the ability of indicum group species to cause veterinary problems and cercarial dermatitis, with a worrisome potential in the future to

  9. Population distribution, host-switching, and chemical sensing in the symbiotic shrimp Lysmata pederseni: implications for its mating system in a changing reef seascape

    Science.gov (United States)

    Baeza, J. Antonio; Guéron, Rodrigo; Simpson, Lunden; Ambrosio, Louis J.

    2016-12-01

    Lysmata pederseni, a protandric simultaneously hermaphroditic shrimp that inhabits the tube sponge Callyspongia vaginalis, is monogamous in the central and southeastern Caribbean Sea. We tested the null hypothesis of monogamy in a northern Caribbean population. In the Florida Keys, shrimps did not inhabit host individuals in pairs with a frequency greater than expected by chance alone. Hermaphrodites inhabited sponges solitarily and often brooded embryos. Hermaphrodites do not store sperm and need to be inseminated shortly after molting to fertilize a new batch of eggs. Thus, males and/or other hermaphrodites are likely switching among host individuals in search of sexual partners. Field experiments demonstrated low shrimp host fidelity. Host residence time was 2 times shorter for males than for hermaphrodites. We inferred a polygynandrous mating system in L. pederseni from the Florida Keys, with male-role and young hermaphrodites often moving among sponges in search of older, more sedentary, female-role hermaphrodites. We expected shrimps to use water-borne chemical cues originating from conspecifics or sponges to locate sexual partners. Experiments demonstrated that shrimps were attracted to water-borne cues originating from sponges but not conspecifics. We have described the mating system of a reef-associated shrimp in a fast-pace shifting seascape increasingly dominated by sponges and vanishing stony corals. In the central and southeastern Caribbean Sea, with greater coral cover and lower sponge abundance than in the Florida Keys, the same species is monogamous. Whether or not similar shifts in the social organization of other coral reef-dwelling marine organisms are occurring due to contemporary changes in seascapes is a relevant topic that deserves further attention.

  10. A new species of Smicromorpha (Hymenoptera, Chalcididae from Vietnam, with notes on the host association of the genus

    Directory of Open Access Journals (Sweden)

    Chris Darling

    2009-09-01

    Full Text Available Smicromorpha masneri Darling, sp. n. is described from Bach Ma National Park, Thua Thien-Hue Province, Vietnam. This is the first confirmed record for the genus on mainland southeast Asia. It is generally accepted that species of Smicromorpha are parasitoids of green tree or weaver ants, Oecophylla smaragdina (Fabricius but this is first rearing record of these parasitoids from the nests of weaver ants.

  11. Diversity, composition and host-species relationships of epiphytic orchids and ferns in two forests in Nepal

    Czech Academy of Sciences Publication Activity Database

    Adhikari, Y. P.; Fischer, A.; Fischer, H. S.; Rokaya, Maan Bahadur; Bhattarai, P.; Gruppe, A.

    2017-01-01

    Roč. 14, č. 6 (2017), s. 1065-1075 ISSN 1672-6316 R&D Projects: GA ČR GB14-36098G Institutional support: RVO:86652079 Keywords : vascular epiphytes * kathmandu valley * managed forests * dry forest * land-use * richness * conservation * biodiversity * assemblages * preferences * Environmental factors * Epiphytes * Large trees * Indicator species * Multivariate and univariate analyses * Permutations tests Subject RIV: EH - Ecology, Behaviour Impact factor: 1.016, year: 2016

  12. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus

    OpenAIRE

    Christina L. Hutson; Nakazawa, Yoshinori J; Joshua Self; Olson, Victoria A.; Regnery, Russell L.; Zachary Braden; Sonja Weiss; Jean Malekani; Eddie Jackson; Mallory Tate; Karem, Kevin L.; Tonie E Rocke; Osorio, Jorge E; Inger K. Damon; Carroll, Darin S.

    2015-01-01

    Abstract Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricet...

  13. Host response to Foot- and Mouth Disease infection in cattle; possible implications for the development of “carriers”

    DEFF Research Database (Denmark)

    Stenfeldt, Carolina; Heegaard, Peter M. H.; Tjørnehøj, Kirsten

    activation of the innate immune response, with activation and recruitment of effector-cells, and subsequent activation of T- and B-cells, leading to the production of circulating antibodies, as well as activation of cytotoxic T-cells. Previous experiments have indicated that the site of persistent......, as well as samples of lymphoid tissue derived from staged post mortems were analysed for the presence of viral proteins through indirect immunoflourescence. These samples have also been analysed for the presence of specific populations of immune cells such as CD8+ T-cells and Dendritic cells. Biopsy...... replication of FMDV is located in pharyngeal lymphoid tissue, as well as the basal epithelia of the dorsal soft palate. A series of animal experiments, with the aim of investigating the host immune response, and sites of viral replication at different time points during both acute and persistent phases...

  14. Host-response to foot-and-mouth disease in cattle; possible implications for the development of persistently infected "carriers"

    DEFF Research Database (Denmark)

    Stenfeldt, Anna Carolina

    General purpose and objectives Foot-and-mouth disease (FMD) is a viral infection of implicit financial importance for countries, such as Denmark, which rely on a significant trade in agricultural products. The disease is highly contagious with rapid spread amongst susceptible animals, causing...... for effective disease control. The main purpose of this PhD-project has been to investigate the host response to FMD infection in cattle, with further objectives of elucidating any detectable differences in the measured immune response between animals that developed into FMDV carriers and those that did not...... manuscript contains results from measurements of mRNA levels of inflammatory cytokines IFNα- and –β as well as tumor necrosis factor –α (TNF-α), in collected biopsy samples. The type 1 interferon response in the analyzed tissue samples is discussed in relation to the previously reported systemic interferon...

  15. Correlative microscopy of the constituents of a dinosaur rib fossil and hosting mudstone: Implications on diagenesis and fossil preservation.

    Science.gov (United States)

    Kim, Jung-Kyun; Kwon, Yong-Eun; Lee, Sang-Gil; Kim, Chang-Yeon; Kim, Jin-Gyu; Huh, Min; Lee, Eunji; Kim, Youn-Joong

    2017-01-01

    We have applied correlative microscopy to identify the key constituents of a dorsal rib fossil from Koreanosaurus boseongensis and its hosting mudstone discovered at the rich fossil site in Boseong, South Korea, to investigate the factors that likely contributed to diagenesis and the preservation of fossil bone. Calcite and illite were the commonly occurring phases in the rib bone, hosting mudstone, and the boundary region in-between. The boundary region may have contributed to bone preservation once it fully formed by acting as a protective shell. Fluorapatite crystals in the rib bone matrix signified diagenetic alteration of the original bioapatite crystals. While calcite predominantly occupied vascular channels and cracks, platy illite crystals widely occupied miniscule pores throughout the bone matrix. Thorough transmission electron microscopy (TEM) study of illite within the bone matrix indicated the solid-state transformation of 1M to 2M without composition change, which was more evident from the lateral variation of 1M to 2M within the same layer. The high level of lattice disordering of 2M illite suggested an early stage of 1M to 2M transformation. Thus, the diagenetic alteration of both apatite and illite crystals within the bone matrix may have increased its overall density, as the preferred orientation of apatite crystals from moderate to strong degrees was evident despite the poor preservation of osteohistological features. The combined effects of rapid burial, formation of a boundary region, and diagenesis of illite and apatite within the bone matrix may have contributed to the rib bone preservation.

  16. Novel IgG-Degrading Enzymes of the IgdE Protease Family Link Substrate Specificity to Host Tropism of Streptococcus Species.

    Science.gov (United States)

    Spoerry, Christian; Hessle, Pontus; Lewis, Melanie J; Paton, Lois; Woof, Jenny M; von Pawel-Rammingen, Ulrich

    2016-01-01

    Recently we have discovered an IgG degrading enzyme of the endemic pig pathogen S. suis designated IgdE that is highly specific for porcine IgG. This protease is the founding member of a novel cysteine protease family assigned C113 in the MEROPS peptidase database. Bioinformatical analyses revealed putative members of the IgdE protease family in eight other Streptococcus species. The genes of the putative IgdE family proteases of S. agalactiae, S. porcinus, S. pseudoporcinus and S. equi subsp. zooepidemicus were cloned for production of recombinant protein into expression vectors. Recombinant proteins of all four IgdE family proteases were proteolytically active against IgG of the respective Streptococcus species hosts, but not against IgG from other tested species or other classes of immunoglobulins, thereby linking the substrate specificity to the known host tropism. The novel IgdE family proteases of S. agalactiae, S. pseudoporcinus and S. equi showed IgG subtype specificity, i.e. IgdE from S. agalactiae and S. pseudoporcinus cleaved human IgG1, while IgdE from S. equi was subtype specific for equine IgG7. Porcine IgG subtype specificities of the IgdE family proteases of S. porcinus and S. pseudoporcinus remain to be determined. Cleavage of porcine IgG by IgdE of S. pseudoporcinus is suggested to be an evolutionary remaining activity reflecting ancestry of the human pathogen to the porcine pathogen S. porcinus. The IgG subtype specificity of bacterial proteases indicates the special importance of these IgG subtypes in counteracting infection or colonization and opportunistic streptococci neutralize such antibodies through expression of IgdE family proteases as putative immune evasion factors. We suggest that IgdE family proteases might be valid vaccine targets against streptococci of both human and veterinary medical concerns and could also be of therapeutic as well as biotechnological use.

  17. Sea lamprey mark type, marking rate, and parasite-host relationships for lake trout and other species in Lake Ontario

    Science.gov (United States)

    Lantry, Brian F.; Adams, Jean V.; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce

    2015-01-01

    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  18. Whipworm genome and dual-species transcriptome analyses provide molecular insights into an intimate host-parasite interaction.

    Science.gov (United States)

    Foth, Bernardo J; Tsai, Isheng J; Reid, Adam J; Bancroft, Allison J; Nichol, Sarah; Tracey, Alan; Holroyd, Nancy; Cotton, James A; Stanley, Eleanor J; Zarowiecki, Magdalena; Liu, Jimmy Z; Huckvale, Thomas; Cooper, Philip J; Grencis, Richard K; Berriman, Matthew

    2014-07-01

    Whipworms are common soil-transmitted helminths that cause debilitating chronic infections in man. These nematodes are only distantly related to Caenorhabditis elegans and have evolved to occupy an unusual niche, tunneling through epithelial cells of the large intestine. We report here the whole-genome sequences of the human-infective Trichuris trichiura and the mouse laboratory model Trichuris muris. On the basis of whole-transcriptome analyses, we identify many genes that are expressed in a sex- or life stage-specific manner and characterize the transcriptional landscape of a morphological region with unique biological adaptations, namely, bacillary band and stichosome, found only in whipworms and related parasites. Using RNA sequencing data from whipworm-infected mice, we describe the regulated T helper 1 (TH1)-like immune response of the chronically infected cecum in unprecedented detail. In silico screening identified numerous new potential drug targets against trichuriasis. Together, these genomes and associated functional data elucidate key aspects of the molecular host-parasite interactions that define chronic whipworm infection.

  19. Combining a Climatic Niche Model of an Invasive Fungus with Its Host Species Distributions to Identify Risks to Natural Assets: Puccinia psidii Sensu Lato in Australia

    Science.gov (United States)

    Kriticos, Darren J.; Morin, Louise; Leriche, Agathe; Anderson, Robert C.; Caley, Peter

    2013-01-01

    Puccinia psidii sensu lato (s.l.) is an invasive rust fungus threatening a wide range of plant species in the family Myrtaceae. Originating from Central and South America, it has invaded mainland USA and Hawai'i, parts of Asia and Australia. We used CLIMEX to develop a semi-mechanistic global climatic niche model based on new data on the distribution and biology of P. psidii s.l. The model was validated using independent distribution data from recently invaded areas in Australia, China and Japan. We combined this model with distribution data of its potential Myrtaceae host plant species present in Australia to identify areas and ecosystems most at risk. Myrtaceaeous species richness, threatened Myrtaceae and eucalypt plantations within the climatically suitable envelope for P. psidii s.l in Australia were mapped. Globally the model identifies climatically suitable areas for P. psidii s.l. throughout the wet tropics and sub-tropics where moist conditions with moderate temperatures prevail, and also into some cool regions with a mild Mediterranean climate. In Australia, the map of species richness of Myrtaceae within the P. psidii s.l. climatic envelope shows areas where epidemics are hypothetically more likely to be frequent and severe. These hotspots for epidemics are along the eastern coast of New South Wales, including the Sydney Basin, in the Brisbane and Cairns areas in Queensland, and in the coastal region from the south of Bunbury to Esperance in Western Australia. This new climatic niche model for P. psidii s.l. indicates a higher degree of cold tolerance; and hence a potential range that extends into higher altitudes and latitudes than has been indicated previously. The methods demonstrated here provide some insight into the impacts an invasive species might have within its climatically suited range, and can help inform biosecurity policies regarding the management of its spread and protection of valued threatened assets. PMID:23704988

  20. Combining a climatic niche model of an invasive fungus with its host species distributions to identify risks to natural assets: Puccinia psidii Sensu Lato in Australia.

    Directory of Open Access Journals (Sweden)

    Darren J Kriticos

    Full Text Available Puccinia psidii sensu lato (s.l. is an invasive rust fungus threatening a wide range of plant species in the family Myrtaceae. Originating from Central and South America, it has invaded mainland USA and Hawai'i, parts of Asia and Australia. We used CLIMEX to develop a semi-mechanistic global climatic niche model based on new data on the distribution and biology of P. psidii s.l. The model was validated using independent distribution data from recently invaded areas in Australia, China and Japan. We combined this model with distribution data of its potential Myrtaceae host plant species present in Australia to identify areas and ecosystems most at risk. Myrtaceaeous species richness, threatened Myrtaceae and eucalypt plantations within the climatically suitable envelope for P. psidii s.l in Australia were mapped. Globally the model identifies climatically suitable areas for P. psidii s.l. throughout the wet tropics and sub-tropics where moist conditions with moderate temperatures prevail, and also into some cool regions with a mild Mediterranean climate. In Australia, the map of species richness of Myrtaceae within the P. psidii s.l. climatic envelope shows areas where epidemics are hypothetically more likely to be frequent and severe. These hotspots for epidemics are along the eastern coast of New South Wales, including the Sydney Basin, in the Brisbane and Cairns areas in Queensland, and in the coastal region from the south of Bunbury to Esperance in Western Australia. This new climatic niche model for P. psidii s.l. indicates a higher degree of cold tolerance; and hence a potential range that extends into higher altitudes and latitudes than has been indicated previously. The methods demonstrated here provide some insight into the impacts an invasive species might have within its climatically suited range, and can help inform biosecurity policies regarding the management of its spread and protection of valued threatened assets.

  1. Combining a climatic niche model of an invasive fungus with its host species distributions to identify risks to natural assets: Puccinia psidii Sensu Lato in Australia.

    Science.gov (United States)

    Kriticos, Darren J; Morin, Louise; Leriche, Agathe; Anderson, Robert C; Caley, Peter

    2013-01-01

    Puccinia psidii sensu lato (s.l.) is an invasive rust fungus threatening a wide range of plant species in the family Myrtaceae. Originating from Central and South America, it has invaded mainland USA and Hawai'i, parts of Asia and Australia. We used CLIMEX to develop a semi-mechanistic global climatic niche model based on new data on the distribution and biology of P. psidii s.l. The model was validated using independent distribution data from recently invaded areas in Australia, China and Japan. We combined this model with distribution data of its potential Myrtaceae host plant species present in Australia to identify areas and ecosystems most at risk. Myrtaceaeous species richness, threatened Myrtaceae and eucalypt plantations within the climatically suitable envelope for P. psidii s.l in Australia were mapped. Globally the model identifies climatically suitable areas for P. psidii s.l. throughout the wet tropics and sub-tropics where moist conditions with moderate temperatures prevail, and also into some cool regions with a mild Mediterranean climate. In Australia, the map of species richness of Myrtaceae within the P. psidii s.l. climatic envelope shows areas where epidemics are hypothetically more likely to be frequent and severe. These hotspots for epidemics are along the eastern coast of New South Wales, including the Sydney Basin, in the Brisbane and Cairns areas in Queensland, and in the coastal region from the south of Bunbury to Esperance in Western Australia. This new climatic niche model for P. psidii s.l. indicates a higher degree of cold tolerance; and hence a potential range that extends into higher altitudes and latitudes than has been indicated previously. The methods demonstrated here provide some insight into the impacts an invasive species might have within its climatically suited range, and can help inform biosecurity policies regarding the management of its spread and protection of valued threatened assets.

  2. The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai-G. agassizii group.

    Science.gov (United States)

    Edwards, Taylor; Karl, Alice E; Vaughn, Mercy; Rosen, Philip C; Torres, Cristina Meléndez; Murphy, Robert W

    2016-01-01

    Desert tortoises (Testudines; Testudinidae; Gopherus agassizii group) have an extensive distribution throughout the Mojave, Colorado, and Sonoran desert regions. Not surprisingly, they exhibit a tremendous amount of ecological, behavioral, morphological and genetic variation. Gopherus agassizii was considered a single species for almost 150 years but recently the species was split into the nominate form and Morafka's desert tortoise, Gopherus morafkai, the latter occurring south and east of the Colorado River. Whereas a large body of literature focuses on tortoises in the United States, a dearth of investigations exists for Mexican animals. Notwithstanding, Mexican populations of desert tortoises in the southern part of the range of Gopherus morafkai are distinct, particularly where the tortoises occur in tropical thornscrub and tropical deciduous forest. Recent studies have shed light on the ecology, morphology and genetics of these southern 'desert' tortoises. All evidence warrants recognition of this clade as a distinctive taxon and herein we describe it as Gopherus evgoodei sp. n. The description of the new species significantly reduces and limits the distribution of Gopherus morafkai to desertscrub habitat only. By contrast, Gopherus evgoodei sp. n. occurs in thornscrub and tropical deciduous forests only and this leaves it with the smallest range of the three sister species. We present conservation implications for the newly described Gopherus evgoodei, which already faces impending threats.

  3. The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai–G. agassizii group

    Science.gov (United States)

    Edwards, Taylor; Karl, Alice E.; Vaughn, Mercy; Rosen, Philip C.; Torres, Cristina Meléndez; Murphy, Robert W.

    2016-01-01

    Abstract Desert tortoises (Testudines; Testudinidae; Gopherus agassizii group) have an extensive distribution throughout the Mojave, Colorado, and Sonoran desert regions. Not surprisingly, they exhibit a tremendous amount of ecological, behavioral, morphological and genetic variation. Gopherus agassizii was considered a single species for almost 150 years but recently the species was split into the nominate form and Morafka’s desert tortoise, Gopherus morafkai, the latter occurring south and east of the Colorado River. Whereas a large body of literature focuses on tortoises in the United States, a dearth of investigations exists for Mexican animals. Notwithstanding, Mexican populations of desert tortoises in the southern part of the range of Gopherus morafkai are distinct, particularly where the tortoises occur in tropical thornscrub and tropical deciduous forest. Recent studies have shed light on the ecology, morphology and genetics of these southern ‘desert’ tortoises. All evidence warrants recognition of this clade as a distinctive taxon and herein we describe it as Gopherus evgoodei sp. n. The description of the new species significantly reduces and limits the distribution of Gopherus morafkai to desertscrub habitat only. By contrast, Gopherus evgoodei sp. n. occurs in thornscrub and tropical deciduous forests only and this leaves it with the smallest range of the three sister species. We present conservation implications for the newly described Gopherus evgoodei, which already faces impending threats. PMID:27006625

  4. Review of the largest species group of the New World seed beetle genus Sennius Bridwell (Coleoptera: Chrysomelidae), with host plant associations.

    Science.gov (United States)

    Viana, Jéssica Herzog; Ribeiro-Costa, Cibele Stramare

    2013-11-15

    Sennius Bridwell is a New World genus of Bruchinae. Most species are placed in eight groups. In this study the species of the S. abbreviatus group are reviewed based on characters of the external morphology and the male genitalia. The group includes 14 species, two of which are new: Sennius abbreviatus (Say, 1824), S. bondari (Pic, 1929), S. durangensis Johnson & Kingsolver, 1973, S. lawrencei Johnson, 1977, S. lebasi (Fåhraeus, 1839), S. leucostauros Johnson & Kingsolver, 1973, S. lojaensis (Pic, 1933), S. medialis (Sharp, 1885), S. nappi Ribeiro-Costa & Reynaud, 1998, S. rufomaculatus (Motschulsky, 1874), S. transversesignatus (Fåhraeus, 1839), S. trinotaticollis (Pic, 1930), S. vivi sp. nov. and S. flinte sp. nov. The S. abbreviatus group differs from other groups by the pattern of sclerites and the shape of the internal sac of the male genitalia, and has three subgroups, defined here. The lectotype of S. lebasi is designated. New host plant records are presented for S. lojaensis and S. transversesignatus, and new distribution records for S. lawrencei, S. lojaensis and S. trinotaticollis. 

  5. Detection of Trypanosoma brucei in field-captured tsetse flies and identification of host species fed on by the infected flies.

    Science.gov (United States)

    Konnai, Satoru; Mekata, Hirohisa; Odbileg, Raadan; Simuunza, Martin; Chembensof, Mwelwa; Witola, William Harold; Tembo, Mwase Enala; Chitambo, Harrison; Inoue, Noboru; Onuma, Misao; Ohashi, Kazuhiko

    2008-08-01

    The prevalence of trypanosome infections in tsetse flies in the Chiawa area of Lower Zambezi in Zambia, with endemic trypanosomosis, was determined by a polymerase chain reaction (PCR) method that allowed the detection of trypanosome DNA and determination of the type of animal host fed on by the tsetse fly Glossina pallidipes, using tsetse-derived DNA extracts as templates. Ninety G. pallidipes (82 females and 8 males; 18.3%) of the 492 flies captured by baited biconical traps tested positive for the presence of Trypanosoma brucei species genomic DNA. Of the 90 T. brucei-positive flies, 47 (52.2%) also tested positive for vertebrate mitochondrial DNA. Sequence analysis of the vertebrate mitochondrial DNA amplicons established that they originated from 8 different vertebrate species, namely, human (Homo sapiens), African elephant (Loxodonta cyclotis), African buffalo (Syncerus caffer), waterbuck (Kobus ellipsiprymnus), roan antelope (Hippotragus equinus), greater kudu (Tragelaphus strepsiceros), warthog (Phacochoerus africanus), and goat (Capra hircus). Furthermore, to investigate the prevalence of trypanosome infections in domestic goats in the same area where trypanosomes had been detected in tsetse files, a total of 86 goats were randomly selected from 6 different herds. Among the selected goats, 36 (41.9%) were found to be positive for T. brucei species. This combined detection method would be an ideal approach not only for mass screening for infection prevalence in tsetse populations, but also for the prediction of natural reservoirs in areas endemic for trypanosomosis.

  6. Host-specificity of myxoma virus: Pathogenesis of South American and North American strains of myxoma virus in two North American lagomorph species.

    Science.gov (United States)

    Silvers, L; Barnard, D; Knowlton, F; Inglis, B; Labudovic, A; Holland, M K; Janssens, P A; van Leeuwen, B H; Kerr, P J

    2010-03-24

    The pathogenesis of South American and North American myxoma viruses was examined in two species of North American lagomorphs, Sylvilagus nuttallii (mountain cottontail) and Sylvilagus audubonii (desert cottontail) both of which have been shown to have the potential to transmit the South American type of myxoma virus. Following infection with the South American strain (Lausanne, Lu), S. nuttallii developed both a local lesion and secondary lesions on the skin. They did not develop the classical myxomatosis seen in European rabbits (Oryctolagus cuniculus). The infection at the inoculation site did not resolve during the 20-day time course of the trial and contained transmissible virus titres at all times. In contrast, S. audubonii infected with Lu had very few signs of disseminated infection and partially controlled virus replication at the inoculation site. The prototype Californian strain of myxoma virus (MSW) was able to replicate at the inoculation site of both species but did not induce clinical signs of a disseminated infection. In S. audubonii, there was a rapid response to MSW characterised by a massive T lymphocyte infiltration of the inoculation site by day 5. MSW did not reach transmissible titres at the inoculation site in either species. This might explain why the Californian myxoma virus has not expanded its host-range in North America. Crown Copyright 2009. Published by Elsevier B.V. All rights reserved.

  7. Implications of Changing Temperatures on the Growth, Fecundity and Survival of Intermediate Host Snails of Schistosomiasis: A Systematic Review.

    Science.gov (United States)

    Kalinda, Chester; Chimbari, Moses; Mukaratirwa, Samson

    2017-01-13

    Climate change has been predicted to increase the global mean temperature and to alter the ecological interactions among organisms. These changes may play critical roles in influencing the life history traits of the intermediate hosts (IHs). This review focused on studies and disease models that evaluate the potential effect of temperature rise on the ecology of IH snails and the development of parasites within them. The main focus was on IH snails of schistosome parasites that cause schistosomiasis in humans. A literature search was conducted on Google Scholar, EBSCOhost and PubMed databases using predefined medical subject heading terms, Boolean operators and truncation symbols in combinations with direct key words. The final synthesis included nineteen published articles. The studies reviewed indicated that temperature rise may alter the distribution, optimal conditions for breeding, growth and survival of IH snails which may eventually increase the spread and/or transmission of schistosomiasis. The literature also confirmed that the life history traits of IH snails and their interaction with the schistosome parasites are affected by temperature and hence a change in climate may have profound outcomes on the population size of snails, parasite density and disease epidemiology. We concluded that understanding the impact of temperature on the growth, fecundity and survival of IH snails may broaden the knowledge on the possible effects of climate change and hence inform schistosomiasis control programmes.

  8. Implications of Changing Temperatures on the Growth, Fecundity and Survival of Intermediate Host Snails of Schistosomiasis: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Chester Kalinda

    2017-01-01

    Full Text Available Climate change has been predicted to increase the global mean temperature and to alter the ecological interactions among organisms. These changes may play critical roles in influencing the life history traits of the intermediate hosts (IHs. This review focused on studies and disease models that evaluate the potential effect of temperature rise on the ecology of IH snails and the development of parasites within them. The main focus was on IH snails of schistosome parasites that cause schistosomiasis in humans. A literature search was conducted on Google Scholar, EBSCOhost and PubMed databases using predefined medical subject heading terms, Boolean operators and truncation symbols in combinations with direct key words. The final synthesis included nineteen published articles. The studies reviewed indicated that temperature rise may alter the distribution, optimal conditions for breeding, growth and survival of IH snails which may eventually increase the spread and/or transmission of schistosomiasis. The literature also confirmed that the life history traits of IH snails and their interaction with the schistosome parasites are affected by temperature and hence a change in climate may have profound outcomes on the population size of snails, parasite density and disease epidemiology. We concluded that understanding the impact of temperature on the growth, fecundity and survival of IH snails may broaden the knowledge on the possible effects of climate change and hence inform schistosomiasis control programmes.

  9. Possible implication of bacterial infection in acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Shigeo eFuji

    2014-04-01

    Full Text Available Graft-versus-host disease (GVHD is still one of the major causes of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (HSCT. In the pathogenesis of acute GVHD, it has been established that donor-derived T cells activated in the recipient play a major role in GVHD in initiation and maintenance within an inflammatory cascade. To reduce the risk of GVHD, intensification of GVHD prophylaxis like T cell depletion is effective, but it inevitably increases the risk of infectious diseases and abrogates beneficial graft-versus-leukemia effects. Although various cytokines are considered to play an important role in the pathogenesis of GVHD, GVHD initiation is such a complex process that cannot be prevented by means of single inflammatory cytokine inhibition. Thus, efficient methods to control the whole inflammatory milieu both on cellular and humoral view are needed. In this context, infectious diseases can theoretically contribute to an elevation of inflammatory cytokines after allogeneic HSCT and activation of various subtypes of immune effector cells, which might in summary lead to an aggravation of acute GVHD. The appropriate treatments or prophylaxis of bacterial infection during the early phase after allogeneic HSCT might be beneficial to reduce not only infectious-related but also GVHD-related mortality. Here, we aim to review the literature addressing the interactions of bacterial infections and GVHD after allogeneic HSCT.

  10. Evolution and Phylogenetic Diversity of Yam Species (Dioscorea spp.: Implication for Conservation and Agricultural Practices.

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    Marie Florence Sandrine Ngo Ngwe

    Full Text Available Yams (Dioscorea spp. consist of approximately 600 species. Presently, these species are threatened by genetic erosion due to many factors such as pest attacks and farming practices. In parallel, complex taxonomic boundaries in this genus makes it more challenging to properly address the genetic diversity of yam and manage its germplasm. As a first step toward evaluating and preserving the genetic diversity yam species, we use a phylogenetic diversity (PD approach that has the advantage to investigate phylogenetic relationships and test hypotheses of species monophyly while alleviating to the problem of ploidy variation within and among species. The Bayesian phylogenetic analysis of 62 accessions from 7 species from three regions of Cameroon showed that most Dioscorea sections were monophyletic, but species within sections were generally non-monophyletic. The wild species D. praehensilis and cultivated D. cayenensis were the species with the highest PD. At the opposite, D. esculenta has a low PD and future studies should focus on this species to properly address its conservation status. We also show that wild species show a stronger genetic structure than cultivated species, which potentially reflects the management of the yam germplasm by farmers. These findings show that phylogenetic diversity is a promising approach for an initial investigation of genetic diversity in a crop consisting of closely related species.

  11. Host factors do not influence the colonization or infection by fluconazole resistant Candida species in hospitalized patients

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    Ho Yu-Huai

    2008-12-01

    Full Text Available Abstract Nosocomial yeast infections have significantly increased during the past two decades in industrialized countries, including Taiwan. This has been associated with the emergence of resistance to fluconazole and other antifungal drugs. The medical records of 88 patients, colonized or infected with Candida species, from nine of the 22 hospitals that provided clinical isolates to the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY program in 1999 were reviewed. A total of 35 patients contributed fluconazole resistant strains [minimum inhibitory concentrations (MICs ≧ 64 mg/l], while the remaining 53 patients contributed susceptible ones (MICs ≦ 8 mg/l. Fluconazole resistance was more frequent among isolates of Candida tropicalis (46.5% than either C. albicans (36.8% or C. glabrata (30.8%. There was no significant difference in demographic characteristics or underlying diseases among patients contributing strains different in drug susceptibility.

  12. A global phylogenetic analysis in order to determine the host species and geography dependent features present in the evolution of avian H9N2 influenza hemagglutinin

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    Andrew R. Dalby

    2014-10-01

    Full Text Available A complete phylogenetic analysis of all of the H9N2 hemagglutinin sequences that were collected between 1966 and 2012 was carried out in order to build a picture of the geographical and host specific evolution of the hemagglutinin protein. To improve the quality and applicability of the output data the sequences were divided into subsets based upon location and host species.The phylogenetic analysis of hemagglutinin reveals that the protein has distinct lineages between China and the Middle East, and that wild birds in both regions retain a distinct form of the H9 molecule, from the same lineage as the ancestral hemagglutinin. The results add further evidence to the hypothesis that the current predominant H9N2 hemagglutinin lineage might have originated in Southern China. The study also shows that there are sampling problems that affect the reliability of this and any similar analysis. This raises questions about the surveillance of H9N2 and the need for wider sampling of the virus in the environment.The results of this analysis are also consistent with a model where hemagglutinin has predominantly evolved by neutral drift punctuated by occasional selection events. These selective events have produced the current pattern of distinct lineages in the Middle East, Korea and China. This interpretation is in agreement with existing studies that have shown that there is widespread intra-country sequence evolution.

  13. Immature Stages and Hosts of Two Plesiomorphic, Antillean Genera of Membracidae (Hemiptera and a new species of Antillotolania from Puerto Rico

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    Stuart McKamey

    2013-05-01

    Full Text Available The nymphs of Antillotolania Ramos and Deiroderes Ramos are described for the first time, along with the first host record for the genus Antillotolania, represented by A. myricae, sp. n. Nymphal features of both genera, such as a ventrally fused, cylindrical tergum IX (anal tube, the presence of abdominal lamellae, and heads with foliaceous ventrolateral lobes confirm their placement in Membracidae and are consistent with phylogenetic analyses placing them in Stegaspidinae but in conflict with a cladistic analysis showing a closer relationship to Nicomiinae. Head processes and emarginate forewing pads in the last instars of both genera support an earlier estimate, based on nuclear genes, that the two genera form a monophyletic group in Stegaspidinae. Distinguishing features of the four species of Antillotolania are tabulated.

  14. Occurrence, pathways and implications of biological production of reactive oxygen species in natural waters

    Science.gov (United States)

    Zhang, T.; Hansel, C. M.; Voelker, B. M.; Lamborg, C. H.

    2014-12-01

    Reactive oxygen species (ROS), such as superoxide (O2-) and hydrogen peroxide (H2O2) play a critical role in the redox cycling of both toxic (e.g., Hg) and nutrient (e.g., Fe) metals. Despite the discovery of extracellular ROS production in various microbial cultures, including fungi, algae and bacteria, photo-dependent processes are generally considered as the predominant source of ROS in natural waters. Here we show that biological production of ROS is ubiquitous and occurs at a significant rate in freshwater and brackish water environments. Water samples were collected from three freshwater and one brackish water ponds in Cape Cod, Massachusetts, USA, periodically from 2012 to 2014. Production of O2- and H2O2 were measured in dark incubations of natural water using a chemiluminescent and a colorimetric probe, respectively. Rates of biological ROS production were obtained by comparing unfiltered with 0.2-μm filtered samples. The role of biological activity in ROS production was confirmed by the cessation of ROS production upon addition of formaldehyde. In surface water, production rates of O2- ranged from undetectable to 96.0 ± 30.0 nmol L-1 h-1, and production rates of H2O2 varied between 9.9 ± 1.3 nmol L-1 h-1 and 145.6 ± 11.2 nmol L-1 h-1. The maximum production rates of both ROS were observed in mid-summer 2013, which coincides with peak biological activity. ROS production in the water from aphotic zone was greater than in the water from photic zone. Thus, non-light dependent biological processes are likely the major contributors to ROS production in this system. Moreover, O2- production appeared to be enhanced by NADH and inhibited by proteinase-K, suggesting the possible involvement of NADH oxidoreductases in this process. The potential role of different microbial communities in ROS production, and the implications of biological ROS production for mercury speciation will also be discussed.

  15. Complete chloroplast genome of the genus Cymbidium: lights into the species identification, phylogenetic implications and population genetic analyses

    Science.gov (United States)

    2013-01-01

    Background Cymbidium orchids, including some 50 species, are the famous flowers, and they possess high commercial value in the floricultural industry. Furthermore, the values of different orchids are great differences. However, species identification is very difficult. To a certain degree, chloroplast DNA sequence data are a versatile tool for species identification and phylogenetic implications in plants. Different chloroplast loci have been utilized for evaluating phylogenetic relationships at each classification level among plant species, including at the interspecies and intraspecies levels. However, there is no evidence that a short sequence can distinguish all plant species from each other in order to infer phylogenetic relationships. Molecular markers derived from the complete chloroplast genome can provide effective tools for species identification and phylogenetic resolution. Results The complete nucleotide sequences of eight individuals from a total of five Cymbidium species’ chloroplast (cp) genomes were determined using Illumina sequencing technology of the total DNA via a combination of de novo and reference-guided assembly. The length of the Cymbidium cp genome is about 155 kb. The cp genomes contain 123 unique genes, and the IR regions contain 24 duplicates. Although the genomes, including genome structure, gene order and orientation, are similar to those of other orchids, they are not evolutionarily conservative. The cp genome of Cymbidium evolved moderately with more than 3% sequence divergence, which could provide enough information for phylogeny. Rapidly evolving chloroplast genome regions were identified and 11 new divergence hotspot regions were disclosed for further phylogenetic study and species identification in Orchidaceae. Conclusions Phylogenomic analyses were conducted using 10 complete chloroplast genomes from seven orchid species. These data accurately identified the individuals and established the phylogenetic relationships between

  16. Estimation of Species Identification Error: Implications for Raptor Migration Counts and Trend Estimation

    Science.gov (United States)

    J.M. Hull; A.M. Fish; J.J. Keane; S.R. Mori; B.J Sacks; A.C. Hull

    2010-01-01

    One of the primary assumptions associated with many wildlife and population trend studies is that target species are correctly identified. This assumption may not always be valid, particularly for species similar in appearance to co-occurring species. We examined size overlap and identification error rates among Cooper's (Accipiter cooperii...

  17. Foraging behavior of European starlings: implications for mitigating their impact on native species

    Science.gov (United States)

    Kathryn L. Purcell

    2015-01-01

    European starlings (Sturnus vulgaris) are a remarkably successful invasive species known to compete with native bird species for nest sites. The objective of this study was to understand why starlings avoid ungrazed pastures and provide recommendations to help mitigate the impacts of starlings on native bird species. I used aviary trials to examine...

  18. HybriFree: a robust and rapid method for the development of monoclonal antibodies from different host species.

    Science.gov (United States)

    Kivi, Gaily; Teesalu, Kaupo; Parik, Jüri; Kontkar, Elen; Ustav, Mart; Noodla, Liis; Ustav, Mart; Männik, Andres

    2016-01-08

    The production of recombinant monoclonal antibodies in mammalian cell culture is of high priority in research and medical fields. A critical step in this process is the isolation of the antigen-binding domain sequences of antibodies possessing the desired properties. Many different techniques have been described to achieve this goal, but all have shortcomings; most techniques have problems with robustness, are time-consuming and costly, or have complications in the transfer from isolation to production phase. Here, we report a novel HybriFree technology for the development of monoclonal antibodies from different species that is robust, rapid, inexpensive and flexible and can be used for the subsequent production of antibodies in mammalian cell factories. HybriFree technology is illustrated herein via detailed examples of isolating mouse, rabbit and chicken monoclonal antibody sequences from immunized animals. Starting from crude spleen samples, antigen capturing of specific B-cells is performed initially. cDNA of antibody variable domains is amplified from the captured cells and used a source material for simple and rapid restriction/ligation free cloning of expression vector library in order to produce scFv-Fc or intact IgG antibodies. The vectors can be directly used for screening purposes as well as for the subsequent production of the developed monoclonal antibodies in mammalian cell culture. The antibodies isolated by the method have been shown to be functional in different immunoassays, including ELISA, immunofluorescence and Western blot. In addition, we demonstrate that by using a modified method including a negative selection step, we can isolate specific antibodies targeting the desired epitope and eliminate antibodies directed to undesired off-targets. HybriFree can be used for the reliable development of monoclonal antibodies and their subsequent production in mammalian cells. This simple protocol requires neither the culturing of B-cells nor single

  19. Genomic variation of the fibropapilloma-associated marine turtle herpes virus across seven geographic areas and three host species

    Science.gov (United States)

    Greenblatt, R.J.; Quackenbush, S.L.; Casey, R.N.; Rovnak, J.; Balazs, G.H.; Work, Thierry M.; Casey, J.W.; Sutton, C.A.

    2005-01-01

    Fibropapillomatosis (FP) of marine turtles is an emerging neoplastic disease associated with infection by a novel turtle herpesvirus, fibropapilloma-associated turtle herpesvirus (FPTHV). This report presents 23 kb of the genome of an FPTHV infecting a Hawaiian green turtle (Chelonia mydas). By sequence homology, the open reading frames in this contig correspond to herpes simplex virus genes UL23 through UL36. The order, orientation, and homology of these putative genes indicate that FPTHV is a member of the Alphaherpesvirinae. The UL27-, UL30-, and UL34-homologous open reading frames from FPTHVs infecting nine FP-affected marine turtles from seven geographic areas and three turtle species (C. mydas, Caretta caretta, and Lepidochelys olivacea) were compared. A high degree of nucleotide sequence conservation was found among these virus variants. However, geographic variations were also found: the FPTHVs examined here form four groups, corresponding to the Atlantic Ocean, West pacific, mid-Pacific, and east Pacific. Our results indicate that FPTHV was established in marine turtle populations prior to the emergence of FP as it is currently known.

  20. Biomechanics of Riparian Plant Species Common to the Platte River and Implications for Management of Habitat for Endangered Species. (Invited)

    Science.gov (United States)

    Bankhead, N. L.; Thomas, R. E.; Simon, A.

    2010-12-01

    Improving riparian habitat for endangered species in the central Platte River fundamentally relies upon re-creating a dynamic, braided stream channel. The diversion and storage of water for agricultural, municipal and industrial uses has caused significant alteration of the hydrologic regime of the central Platte River, allowing the colonization and proliferation of vegetation that has effectively created semi-permanent islands, narrowed the active channel and reduced available habitat. Attempts to remove vegetation by spraying and disking for the purpose of re-creating a dynamic braided channel are costly and time consuming. Alternative plans to remove vegetation by modifying the hydrologic regime must be based on a fundamental understanding and quantification of the effects of vegetation on in-stream hydraulics, the effects of in-stream hydraulics on vegetation and the effects of the biomechanical properties of the plant on the substrate. This study aims to investigate the resistance of bar-top vegetation to removal by the drag forces exerted on the stems and leaves of partly or completely submerged plants with different rooting depths. In the first phase, we measured the forces required to remove 1 to 2 year-old Phragmites, reed canary grass, cottonwood and sandbar willow plants from sandbars in the Platte River. In addition, root tensile strength tests were carried out for each species and over a range of root diameters. The mean plant pullout or breaking force ranged from 31.9 N for young cottonwood saplings to 156 N for Phragmites. The mean rooting depths of cottonwoods and sandbar willows were 0.14 and 0.12 m, respectively, and during testing it was observed that largely intact rootballs were removed from the substrate. Therefore, it is possible that 1 to 2 year-old cottonwoods and sandbar willows could be removed by flows of sufficient magnitude and duration to scour such depths of sediment. Conversely, Phragmites plants had deep rhizome networks that broke

  1. Temporal Patterns in the Abundance and Species Composition of Spiders on Host Plants of the Invasive Moth Epiphyas postvittana (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Hogg, Brian N; Mills, Nicholas J; Daane, Kent M

    2017-06-01

    Generalist predators such as spiders may help mitigate the spread and impact of exotic herbivores. The lack of prey specificity and long generation times of spiders may allow them to persist when pests are scarce, and to limit the growth of pest populations before they reach damaging levels. We examined whether resident spiders are likely to play a role in maintaining populations of the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), below outbreak levels in California. We surveyed the spider community on two E. postvittana host plants, the ornamental Australian tea tree, Leptospermum laevigatum, and the weed French broom, Genista monspessulana, to characterize spider and larval E. postvittana abundance and spider species composition throughout the year. Spider densities and species composition showed slight seasonal changes. Spiders were present during periods of high and low E. postvittana abundance. Anyphaenid hunting spiders, Anyphaena aperta Banks in Australian tea tree and Anyphaena pacifica Banks in French broom, dominated spider species composition at four of five sampled sites, and underwent only slight seasonal variation in abundance. Adult A. aperta were rare at all times of the year, suggesting that high mortality among juvenile A. aperta limits the potential of this species as a predator of E. postvittana. Nevertheless, the continued presence of spiders throughout the year indicates that the resident spider community is likely to play a key role in reducing E. postvittana populations in California. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  2. Phage-host interactions analysis of newly characterized Oenococcus oeni bacteriophages: Implications for malolactic fermentation in wine.

    Science.gov (United States)

    Costantini, Antonella; Doria, Francesca; Saiz, Juan-Carlos; Garcia-Moruno, Emilia

    2017-04-04

    Nowadays, only few phages infecting Oenococcus oeni, the principal lactic acid bacteria (LAB) species responsible for malolactic fermentation (MLF) in wine, have been characterized. In the present study, to better understanding the factors affecting the lytic activity of Oenococcus phages, fifteen O. oeni bacteriophages have been studied in detail, both with molecular and microbiological methods. No correlations were found between genome sizes, type of integrase genes, or morphology and the lytic activity of the 15 tested phages. Interestingly, though phage attack in a wine at the end of alcoholic fermentation seems not to be a problem, it can indeed represent a risk factor for MLF when the alcohol content is low, feature that may be a key point for choosing the appropriate time for malolactic starter inoculation. Additionally, it was observed that some phages genomes bear 2 or 3 types of integrase genes, which point to horizontal gene transfer between O. oeni bacteriophages. Copyright © 2017. Published by Elsevier B.V.

  3. Comparative host feeding patterns of the Asian tiger mosquito, Aedes albopictus, in urban and suburban Northeastern USA and implications for disease transmission.

    Science.gov (United States)

    Faraji, Ary; Egizi, Andrea; Fonseca, Dina M; Unlu, Isik; Crepeau, Taryn; Healy, Sean P; Gaugler, Randy

    2014-08-01

    Aedes albopictus is an invasive species which continues expanding its geographic range and involvement in mosquito-borne diseases such as chikungunya and dengue. Host selection patterns by invasive mosquitoes are critically important because they increase endemic disease transmission and drive outbreaks of exotic pathogens. Traditionally, Ae. albopictus has been characterized as an opportunistic feeder, primarily feeding on mammalian hosts but occasionally acquiring blood from avian sources as well. However, limited information is available on their feeding patterns in temperate regions of their expanded range. Because of the increasing expansion and abundance of Ae. albopictus and the escalating diagnoses of exotic pathogens in travelers returning from endemic areas, we investigated the host feeding patterns of this species in newly invaded areas to further shed light on its role in disease ecology and assess the public health threat of an exotic arbovirus outbreak. We identified the vertebrate source of 165 blood meals in Ae. albopictus collected between 2008 and 2011 from urban and suburban areas in northeastern USA. We used a network of Biogents Sentinel traps, which enhance Ae. albopictus capture counts, to conduct our collections of blooded mosquitoes. We also analyzed blooded Culex mosquitoes collected alongside Ae. albopictus in order to examine the composition of the community of blood sources. We found no evidence of bias since as expected Culex blood meals were predominantly from birds (n = 149, 93.7%) with only a small proportion feeding on mammals (n = 10, 6.3%). In contrast, Aedes albopictus fed exclusively on mammalian hosts with over 90% of their blood meals derived from humans (n = 96, 58.2%) and domesticated pets (n = 38, 23.0% cats; and n = 24, 14.6% dogs). Aedes albopictus fed from humans significan