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Sample records for grasshopper pathogens differentiated

  1. Effect of temperature on efficacy of insecticides to differential grasshopper (Orthoptera: Acrididae).

    PubMed

    Amarasekare, Kaushalya G; Edelson, J V

    2004-10-01

    The effect of temperature on activity of insecticides for controlling grasshoppers in leafy green vegetables was evaluated. Insecticides evaluated had differing modes of action and included diflubenzuron, azadirachtin, Beauveria bassiana, spinosad, endosulfan, esfenvalerate, and naled. We evaluated these insecticides for efficacy to third instars of differential grasshopper, Melanoplus differentialis (Thomas), at temperatures ranging from 10 to 35 degrees C. In the laboratory, treatment with esfenvalerate resulted in 100% mortality at temperatures of 10 to 35 degrees C, and efficacy was not temperature dependent. Treatment with spinosad resulted in similar mortality as with esfenvalerate at all temperatures except 10 degrees C. The activity of B. bassiana was greatest at 25 degrees C and was adversely affected by high and low temperatures. Treatment with diflubenzuron resulted in increased mortality at high temperatures, and at 35 degrees C its activity was similar to that of esfenvalerate and spinosad. The activity of azadirachtin ranged from 19 to 31% and was not influenced by temperature. In field studies, spinosad, diflubenzuron, and esfenvalerate provided differing levels of mortality both at application and when nymphs were exposed to 1-h-old residues. However, only spinosad and diflubenzuron provided similar levels of mortality when nymphs were exposed to 24-h-old residues. The residual activity of endosulfan, naled, esfenvalerate, and spinosad decreased with increasing time (0-24 h) after exposure to sunlight and high summer temperatures. Compared with other insecticides, naled had a short residual activity period and activity was dependent upon immediate contact with the nymphs or their substrate. B. bassiana was inactive under high temperatures and intense sunlight as occurs in summer. PMID:15568348

  2. Discordant patterns of genetic and phenotypic differentiation in five grasshopper species codistributed across a microreserve network.

    PubMed

    Ortego, Joaquín; García-Navas, Vicente; Noguerales, Víctor; Cordero, Pedro J

    2015-12-01

    Conservation plans can be greatly improved when information on the evolutionary and demographic consequences of habitat fragmentation is available for several codistributed species. Here, we study spatial patterns of phenotypic and genetic variation among five grasshopper species that are codistributed across a network of microreserves but show remarkable differences in dispersal-related morphology (body size and wing length), degree of habitat specialization and extent of fragmentation of their respective habitats in the study region. In particular, we tested the hypothesis that species with preferences for highly fragmented microhabitats show stronger genetic and phenotypic structure than codistributed generalist taxa inhabiting a continuous matrix of suitable habitat. We also hypothesized a higher resemblance of spatial patterns of genetic and phenotypic variability among species that have experienced a higher degree of habitat fragmentation due to their more similar responses to the parallel large-scale destruction of their natural habitats. In partial agreement with our first hypothesis, we found that genetic structure, but not phenotypic differentiation, was higher in species linked to highly fragmented habitats. We did not find support for congruent patterns of phenotypic and genetic variability among any studied species, indicating that they show idiosyncratic evolutionary trajectories and distinctive demographic responses to habitat fragmentation across a common landscape. This suggests that conservation practices in networks of protected areas require detailed ecological and evolutionary information on target species to focus management efforts on those taxa that are more sensitive to the effects of habitat fragmentation. PMID:26475782

  3. Households at Grasshopper Pueblo.

    ERIC Educational Resources Information Center

    Reid, J. Jefferson; Whittlesey, Stephanie M.

    1982-01-01

    Describes the archaeological reconstruction of domestic life in Grasshopper, Arizona, a mogollon pueblo community which began around 1300 A.D. Categories of space and domestic activities are discussed. An analysis of variations in the patterns of household types within the pueblo is included. (AM)

  4. Mechanical Vectors Enhance Fungal Entomopathogen Reduction of the Grasshopper Pest Camnula pellucida (Orthoptera: Acrididae).

    PubMed

    Kistner, Erica J; Saums, Marielle; Belovsky, Gary E

    2015-02-01

    Mounting scientific evidence indicates that pathogens can regulate insect populations. However, limited dispersal and sensitivity to abiotic conditions often restricts pathogen regulation of host populations. While it is well established that arthropod biological vectors increase pathogen incidence in host populations, few studies have examined whether arthropod mechanical vectors (an organism that transmits pathogens but is not essential to the life cycle of the pathogen) influence host-pathogen dynamics. The importance of mechanical dispersal by ant scavengers, Formica fusca (L.), in a grasshopper-fungal entomopathogen system was investigated. We examined the ability of ants to mechanically disperse and transmit the pathogen, Entomophaga grylli (Fresenius) pathotype 1, to its host, the pest grasshopper Camnula pellucida (Scudder), in a series of laboratory experiments. Fungal spores were dispersed either externally on the ant's body surface or internally through fecal deposition. In addition, a third of all grasshoppers housed with fungal-inoculated ants became infected, indicating that ants can act as mechanical vectors of E. grylli. The effect of ant mechanical vectors on E. grylli incidence was also examined in a field experiment. Ant access to pathogen-exposed experimental grasshopper populations was restricted using organic ant repellent, thereby allowing us to directly compare mechanical and natural transmission. Ants increased grasshopper pathogen mortality by 58%, which led to greater pathogen reductions of grasshopper survival than natural transmission. Taken together, our results indicate that ants enhance E. grylli reduction of grasshopper pest numbers. Therefore, mechanical transmission of pathogens may be an important overlooking component of this grasshopper-fungal pathogen system. PMID:26308817

  5. Mechanical Vectors Enhance Fungal Entomopathogen Reduction of the Grasshopper Pest Camnula pellucida (Orthoptera: Acrididae).

    PubMed

    Kistner, Erica J; Saums, Marielle; Belovsky, Gary E

    2015-02-01

    Mounting scientific evidence indicates that pathogens can regulate insect populations. However, limited dispersal and sensitivity to abiotic conditions often restricts pathogen regulation of host populations. While it is well established that arthropod biological vectors increase pathogen incidence in host populations, few studies have examined whether arthropod mechanical vectors (an organism that transmits pathogens but is not essential to the life cycle of the pathogen) influence host-pathogen dynamics. The importance of mechanical dispersal by ant scavengers, Formica fusca (L.), in a grasshopper-fungal entomopathogen system was investigated. We examined the ability of ants to mechanically disperse and transmit the pathogen, Entomophaga grylli (Fresenius) pathotype 1, to its host, the pest grasshopper Camnula pellucida (Scudder), in a series of laboratory experiments. Fungal spores were dispersed either externally on the ant's body surface or internally through fecal deposition. In addition, a third of all grasshoppers housed with fungal-inoculated ants became infected, indicating that ants can act as mechanical vectors of E. grylli. The effect of ant mechanical vectors on E. grylli incidence was also examined in a field experiment. Ant access to pathogen-exposed experimental grasshopper populations was restricted using organic ant repellent, thereby allowing us to directly compare mechanical and natural transmission. Ants increased grasshopper pathogen mortality by 58%, which led to greater pathogen reductions of grasshopper survival than natural transmission. Taken together, our results indicate that ants enhance E. grylli reduction of grasshopper pest numbers. Therefore, mechanical transmission of pathogens may be an important overlooking component of this grasshopper-fungal pathogen system.

  6. Phylogenetic Characterization of Encephalitozoon Romaleae (Microsporidia) from a Grasshopper Host: Relationship to Encephalitozoon spp. Infecting Humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Encephalitozoon species are the most common microsporidian pathogens of humans and domesticated animals. We recently discovered a new microsporidium, Encephalitozoon romaleae, infecting the eastern lubber grasshopper Romalea microptera. To understand its evolutionary relationships, we compared par...

  7. New case of long-term persistence of Paranosema locustae (Microsporidia) in melanopline grasshoppers (Orthoptera: Acrididae: Melanoplinae) of Argentina.

    PubMed

    Lange, Carlos E; Azzaro, Francisco G

    2008-11-01

    We report an additional case of long-term persistence of Paranosema locustae in grasshoppers of Argentina. The pathogen was introduced from North America on rangeland at Loncopué, Neuquén province. Microsporidia were not detected in pre-introduction samples whereas infected grasshoppers were found 11 years after introduction. Affected grasshoppers were the melanoplines Dichroplus elongatus, Dichroplus maculipennis, and Scotussa lemniscata, some of them with high spore loads. The case highlights the ability of P. locustae to recycle in local grasshopper communities by parasitizing susceptible species other than the natural hosts.

  8. Positive interactions between large herbivores and grasshoppers, and their consequences for grassland plant diversity.

    PubMed

    Zhong, Zhiwei; Wang, Deli; Zhu, Hui; Wang, Ling; Feng, Chao; Wang, Zhongnan

    2014-04-01

    Although the influence of positive interactions on plant and sessile communities has been well documented, surprisingly little is known about their role in structuring terrestrial animal communities. We evaluated beneficial interactions between two distantly related herbivore taxa, large vertebrate grazers (sheep) and smaller insect grazers (grasshoppers), using a set of field experiments in eastern Eurasian steppe of China. Grazing by large herbivores caused significantly higher grasshopper density, and this pattern persisted until the end of the experiment. Grasshoppers, in turn, increased the foraging time of larger herbivores, but such response occurred only during the peak of growing season (August). These reciprocal interactions were driven by differential herbivore foraging preferences for plant resources; namely, large herbivores preferred Artemisia forbs, whereas grasshoppers preferred Leymus grass. The enhancement of grasshopper density in areas grazed by large herbivores likely resulted from the selective consumption of Artemisia forbs by vertebrate grazers, which may potentially improve the host finding of grasshoppers. Likewise, grasshoppers appeared to benefit large herbivores by decreasing the cover and density of the dominant grass Leymus chinensis, which hampers large herbivores' access to palatable forbs. Moreover, we found that large herbivores grazing alone may significantly decrease plant diversity, yet grasshoppers appeared to mediate such negative effects when they grazed with large herbivores. Our results suggest that the positive, reciprocal interactions in terrestrial herbivore communities may be more prevalent and complex than previously thought.

  9. [THE IDENTIFICATION AND DIFFERENTIATION OF BACTERIOPHAGES OF HUMAN PATHOGENIC VIBRIO].

    PubMed

    Gaevskaia, N E; Kudriakova, T A; Makedonova, L D; Kachkina, G V

    2015-04-01

    The issue of identification and differentiation of large group of bacteriophages of human pathogenic vibrio is still unresolved. In research and practical applied purposes it is important to consider characteristics of bacteriophages for establishing similarity and differences between them. The actual study was carried out to analyze specimens of DNA-containing bacteriophages of pathogenic vibrio. The overwhelming majority of them characterized by complicated type of symmetry--phages with double-helical DNA and also phages with mono-helical DNA structure discovered recently in vibrio. For the first time, the general framework of identification and differentiation of bacteriophages of pathogenic vibrio was developed. This achievement increases possibility to establish species assignment of phages and to compare with phages registered in the database. "The collection of bacteriophages and test-strains of human pathogenic vibrio" (No2010620549 of 24.09.210).

  10. Epidemiological differentiation of pathogenic strains of Salmonella enteritidis by ribotyping.

    PubMed Central

    Landeras, E; González-Hevia, M A; Alzugaray, R; Mendoza, M C

    1996-01-01

    The usefulness of two-way ribotyping, performed with SphI and PstI, as a genetic marker for a series of pathogenic Salmonella enteritidis strains is reported. Eighteen combined ribotypes were differentiated, a discrimination index of 0.77 was reached, a genetic relationship dendrogram was traced, and the results were applied in an epidemiological study. PMID:8862603

  11. First Record of Fusarium verticillioides as an Entomopathogenic Fungus of Grasshoppers

    PubMed Central

    Pelizza, SA; Stenglein, SA; Cabello, MN; Dinolfo, MI; Lange, CE

    2011-01-01

    Fusarium verticillioides (Saccardo) Nirenberg (Ascomycota: Hypocreales) is the most common fungus reported on infected corn kernels and vegetative tissues, but has not yet been documented as being entomopathogenic for grasshoppers. Grasshoppers and locusts represent a large group of insects that cause economic damage to forage and crops. Tropidacris collaris (Stoll) (Orthoptera: Acridoidea: Romaleidae) is a large and voracious grasshopper that in recent years has become an increasingly recurrent and widespread pest in progressively more greatly extended areas of some of in Argentina's northern provinces, with chemical insecticides being currently the only means of control. During February and March of 2008–09, nymphs and adults of T. collaris were collected with sweep nets in dense woodland vegetation at a site near Tres Estacas in western Chaco Province, Argentina, and kept in screened cages. F. verticillioides was isolated from insects that died within 10 days and was cultured in PGA medium. Pathogenicity tests were conducted and positive results recorded. Using traditional and molecular-biological methods, an isolate of F. verticillioides was obtained from T. collaris, and its pathogenecity in the laboratory was shown against another harmful grasshopper, Ronderosia bergi (Stål) (Acridoidea: Acrididae: Melanoplinae). The mortality caused by F. verticillioides on R. bergi reached 58 ± 6.53% by 10 days after inoculation. This is the first record of natural infection caused by F. verticillioides in grasshoppers. PMID:21867437

  12. Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

    PubMed

    Palková, Zdena; Váchová, Libuše

    2016-09-01

    Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. PMID:27084693

  13. Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

    PubMed

    Palková, Zdena; Váchová, Libuše

    2016-09-01

    Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned.

  14. Ferocious Fighting between Male Grasshoppers

    PubMed Central

    Umbers, Kate D. L.; Tatarnic, Nikolai J.; Holwell, Gregory I.; Herberstein, Marie E.

    2012-01-01

    Contests among individuals over mating opportunities are common across diverse taxa, yet physical conflict is relatively rare. Due to the potentially fatal consequences of physical fighting, most animals employ mechanisms of conflict resolution involving signalling and ritualistic assessment. Here we provide the first evidence of ubiquitous escalated fighting in grasshoppers. The chameleon grasshopper (Kosciuscola tristis) is an Australian alpine specialist, in which males engage in highly aggressive combat over ovipositing females. We describe discrete agonistic behaviours including mandible flaring, mounting, grappling, kicking and biting, and their use depending on the individual’s role as challenger or defender. We show that male role predicts damage, with challengers being more heavily damaged than males defending females (defenders). Challengers also possess wider mandibles than defenders, but are similar in other metrics of body size. Our data suggest that fights escalate between males matched in body size and that mandibles are used as weapons in this species. This system represents an exciting opportunity for future research into the evolution of costly fighting behaviour in an otherwise placid group. PMID:23166725

  15. Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation.

    PubMed

    Meyer, Martin; Fehling, Helena; Matthiesen, Jenny; Lorenzen, Stephan; Schuldt, Kathrin; Bernin, Hannah; Zaruba, Mareen; Lender, Corinna; Ernst, Thomas; Ittrich, Harald; Roeder, Thomas; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

    2016-08-01

    We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1-A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1-B12) derived from a pathogenic isolate HM-1:IMSS-B. "Non-pathogenicity" included the induction of small and quickly resolved lesions while "pathogenicity" comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica. PMID:27575775

  16. Plant functional traits reveal the relative contribution of habitat and food preferences to the diet of grasshoppers.

    PubMed

    Ibanez, Sébastien; Manneville, Olivier; Miquel, Christian; Taberlet, Pierre; Valentini, Alice; Aubert, Serge; Coissac, Eric; Colace, Marie-Pascale; Duparc, Quentin; Lavorel, Sandra; Moretti, Marco

    2013-12-01

    Food preferences and food availability are two major determinants of the diet of generalist herbivores and of their spatial distribution. How do these factors interact and eventually lead to diet differentiation in co-occurring herbivores? We quantified the diet of four grasshopper species co-occurring in subalpine grasslands using DNA barcoding of the plants contained in the faeces of individuals sampled in the field. The food preferences of each grasshopper species were assessed by a choice (cafeteria) experiment from among 24 plant species common in five grassland plots, in which the four grasshoppers were collected, while the habitat was described by the relative abundance of plant species in the grassland plots. Plant species were characterised by their leaf economics spectrum (LES), quantifying their nutrient vs. structural tissue content. The grasshoppers' diet, described by the mean LES of the plants eaten, could be explained by their plant preferences but not by the available plants in their habitat. The diet differed significantly across four grasshopper species pairs out of six, which validates food preferences assessed in standardised conditions as indicators for diet partitioning in nature. In contrast, variation of the functional diversity (FD) for LES in the diet was mostly correlated to the FD of the available plants in the habitat, suggesting that diet mixing depends on the environment and is not an intrinsic property of the grasshopper species. This study sheds light on the mechanisms determining the feeding niche of herbivores, showing that food preferences influence niche position whereas habitat diversity affects niche breadth.

  17. Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation

    PubMed Central

    Lorenzen, Stephan; Schuldt, Kathrin; Bernin, Hannah; Zaruba, Mareen; Lender, Corinna; Ittrich, Harald; Roeder, Thomas; Tannich, Egbert; Lotter, Hannelore; Bruchhaus, Iris

    2016-01-01

    We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1–A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1–B12) derived from a pathogenic isolate HM-1:IMSS-B. “Non-pathogenicity” included the induction of small and quickly resolved lesions while “pathogenicity” comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica. PMID:27575775

  18. Assessment of grasshopper abundance in cereal crops using pan traps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasshoppers and locusts frequently invade cereal crops from adjacent source habitats. To protect the crops from grasshopper damage, areas bordering crop fields may be treated with insecticides. Study of grasshopper dispersal into crops and evaluation of various management alternatives is hindered b...

  19. Influence of Weather Variables and Plant Communities on Grasshopper Density in the Southern Pampas, Argentina

    PubMed Central

    de Wysiecki, María Laura; Arturi, Marcelo; Torrusio, Sandra; Cigliano, María Marta

    2011-01-01

    temperature had no significant effect on total grasshopper density, these weather variables and plant communities had differential influence on the dominant grasshopper species. PMID:22220572

  20. In vitro phenotypic differentiation towards commensal and pathogenic oral biofilms.

    PubMed

    Janus, Marleen M; Keijser, Bart J F; Bikker, Floris J; Exterkate, Rob A M; Crielaard, Wim; Krom, Bastiaan P

    2015-01-01

    Commensal oral biofilms, defined by the absence of pathology-related phenotypes, are ubiquitously present. In contrast to pathological biofilms commensal biofilms are rarely studied. Here, the effect of the initial inoculum and subsequent growth conditions on in vitro oral biofilms was studied. Biofilms were inoculated with saliva and grown anaerobically for up to 21 days in McBain medium with or without fetal calf serum (FCS) or sucrose. Pathology-related phenotypes were quantified and the community composition was determined. Biofilms inoculated with pooled saliva or individual inocula were similar. Denaturing gradient gel electrophoresis (DGGE) analysis allowed differentiation of biofilms grown with sucrose, but not with FCS. Lactate production by biofilms was significantly increased by sucrose and protease activity by FCS. McBain grown biofilms showed low activity for both phenotypes. Three clinically relevant in vitro biofilm models were developed and could be differentiated based on pathology-related phenotypes but not DGGE analysis. These models allow analysis of health-to-disease shifts and the effectiveness of prevention measures.

  1. Differential accumulation of host mRNAs on polyribosomes during obligate pathogen-plant interactions.

    PubMed

    Moeller, Jackson R; Moscou, Matthew J; Bancroft, Tim; Skadsen, Ronald W; Wise, Roger P; Whitham, Steven A

    2012-08-01

    Plant pathogens elicit dramatic changes in the expression of host genes during both compatible and incompatible interactions. Gene expression profiling studies of plant-pathogen interactions have only considered messenger RNAs (mRNAs) present in total RNA, which contains subpopulations of actively translated mRNAs associated with polyribosomes (polysomes) and non-translated mRNAs that are not associated with polysomes. The goal of this study was to enhance previous gene expression analyses by identifying host mRNAs that become differentially associated with polysomes following pathogen inoculation. Total and polysomal RNA were extracted from barley (Hordeum vulgare) plants at 32 h after inoculation with Blumeria graminis f. sp. hordei, and Arabidopsis thaliana plants at 10 days after inoculation with Turnip mosaic virus. Gene expression profiles were obtained for each pathosystem, which represent diverse plant host-obligate pathogen interactions. Using this approach, host mRNAs were identified that were differentially associated with polysomes in response to pathogen treatment. Approximately 18% and 26% of mRNAs represented by probe sets on the Affymetrix Barley1 and Arabidopsis ATH1 GeneChips, respectively, differentially accumulated in the two populations in one or more combinations of treatment and genotype. Gene ontology analysis of mRNAs sharing the same pattern of accumulation in total and polysomal RNA identified gene sets that contained a significant number of functionally related annotations, suggesting both transcript accumulation and recruitment to polyribosomes are coordinately regulated in these systems.

  2. Multilocus sequence typing of Metarhizium anisopliae var acridum isolates as microbial agents for locust and grasshopper control. Genbank Accession numbers FJ787311 to FJ787325

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growing interest in the biological control of locusts and grasshoppers (Acrididae) has led to the development of biopesticides based on naturally occurring pathogens which offers an environmentally safe alternative to chemical pesticides. However, the fungal strains which are being sought for biop...

  3. Organophosphate residues in grasshoppers from sprayed rangelands

    USGS Publications Warehouse

    Stromborg, K.L.; McEwen, L.C.; Lamont, T.

    1984-01-01

    Grasshoppers (Orthoptera) were collected in pastures that had been sprayed with malathion and acephate to estimate the secondary exposure of insectivorous birds to these pesticides. Residues of malathion were below 3 ppm at 30 'and 54 hours after spraying and no malaoxon was detected. In contrast, acephate was found at 8 and 9 ppm 4 hours after spray; 3-5 ppm of the toxic metabolite methamidophos were also detected at that time. By 53 hours postspray, acephate levels declined to 2 ppm and methamidophos to less than 1 ppm. These results suggest that although malathion may not be a hazard to insectivorous species. acephate may be hazardous through metabolic transformation to methamidophos.

  4. Influence of a large late summer precipitation event on food limitation and grasshopper population dynamics in a northern Great Plains grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about the ecological processes that generate grasshopper outbreaks, and the complex ecological interactions between grasshoppers, weather conditions and plants that cause fluctuations in grasshopper populations remain poorly understood. The effects of initial and increasing grasshopp...

  5. An integrated lab-on-chip for rapid identification and simultaneous differentiation of tropical pathogens.

    PubMed

    Tan, Jeslin J L; Capozzoli, Monica; Sato, Mitsuharu; Watthanaworawit, Wanitda; Ling, Clare L; Mauduit, Marjorie; Malleret, Benoît; Grüner, Anne-Charlotte; Tan, Rosemary; Nosten, François H; Snounou, Georges; Rénia, Laurent; Ng, Lisa F P

    2014-01-01

    Tropical pathogens often cause febrile illnesses in humans and are responsible for considerable morbidity and mortality. The similarities in clinical symptoms provoked by these pathogens make diagnosis difficult. Thus, early, rapid and accurate diagnosis will be crucial in patient management and in the control of these diseases. In this study, a microfluidic lab-on-chip integrating multiplex molecular amplification and DNA microarray hybridization was developed for simultaneous detection and species differentiation of 26 globally important tropical pathogens. The analytical performance of the lab-on-chip for each pathogen ranged from 102 to 103 DNA or RNA copies. Assay performance was further verified with human whole blood spiked with Plasmodium falciparum and Chikungunya virus that yielded a range of detection from 200 to 4×105 parasites, and from 250 to 4×107 PFU respectively. This lab-on-chip was subsequently assessed and evaluated using 170 retrospective patient specimens in Singapore and Thailand. The lab-on-chip had a detection sensitivity of 83.1% and a specificity of 100% for P. falciparum; a sensitivity of 91.3% and a specificity of 99.3% for P. vivax; a positive 90.0% agreement and a specificity of 100% for Chikungunya virus; and a positive 85.0% agreement and a specificity of 100% for Dengue virus serotype 3 with reference methods conducted on the samples. Results suggested the practicality of an amplification microarray-based approach in a field setting for high-throughput detection and identification of tropical pathogens.

  6. Twenty-Five Fun Things to Do with Grasshoppers.

    ERIC Educational Resources Information Center

    Dyche, Steven E.

    1981-01-01

    Briefly described are 25 "hands on" classroom activities which require live, freshly killed, or preserved grasshoppers. Topics of activities include predator-prey relationships, feeding habits, locomotion, dissection, anatomy, and population estimates. (DS)

  7. Differential regulation of Sciaenops ocellatus viperin expression by intracellular and extracellular bacterial pathogens.

    PubMed

    Dang, Wei; Zhang, Min; Hu, Yong-hua; Sun, Li

    2010-08-01

    Viperin is an antiviral protein that has been found to exist in diverse vertebrate organisms and is involved in innate immunity against the infection of a wide range of viruses. However, it is largely unclear as to the potential role played by viperin in bacterial infection. In this study, we identified the red drum Sciaenops ocellatus viperin gene (SoVip) and analyzed its expression in relation to bacterial challenge. The complete gene of SoVip is 2570 bp in length and contains six exons and five introns. The open reading frame of SoVip is 1065 bp, which is flanked by a 5'-untranslated region (UTR) of 34 bp and a 3'-UTR of 350 bp. The deduced amino acid sequence of SoVip shares extensive identities with the viperins of several fish species and possesses the conserved domain of the radical S-adenosylmethionine superfamily proteins. Expressional analysis showed that constitutive expression of SoVip was relatively high in blood, muscle, brain, spleen, and liver, and low in kidney, gill, and heart. Experimental challenges with poly(I:C) and bacterial pathogens indicated that SoVip expression in liver was significantly upregulated by poly(I:C) and the fish pathogen Edwardsiella tarda but down-regulated by the fish pathogens Listonella anguillarum and Streptococcus iniae. Similar differential induction patterns were also observed at cellular level with primary hepatocytes challenged with E. tarda, L. anguillarum, and S. iniae. Infection study showed that all three bacterial pathogens could attach to cultured primary hepatocytes but only E. tarda was able to invade into and survive in hepatocytes. Together these results indicate that SoVip is involved in host immune response during bacterial infection and is differentially regulated at transcription level by different bacterial pathogens. PMID:20420911

  8. PCR-restriction fragment length polymorphism analysis using groEL gene to differentiate pathogenic Vibrio species.

    PubMed

    Hossain, Muhammad Tofazzal; Kim, Yu-Ri; Kong, In-Soo

    2014-01-01

    Important pathogenic Vibrio species were differentiated by PCR-restriction fragment length polymorphism analysis. A 1117-bp groEL gene product was amplified using universal primers and digested using the restriction enzymes NruI or XbaI, revealing unique digestion patterns for each of the 10 Vibrio species, of which 7 were pathogenic in humans, along with 2 other species pathogenic in fish.

  9. Oviposition site selection by the grasshoppers Melanoplus borealis and M. sanguinipes (Orthoptera: Acrididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Female grasshoppers can affect the fitness of their offspring through their selection of oviposition sites. Successful embryological development depends on suitable temperature and moisture levels, factors which may vary considerably on a fine scale in natural environments where grasshoppers occur. ...

  10. Immunogenetic Variation and Differential Pathogen Exposure in Free-Ranging Cheetahs across Namibian Farmlands

    PubMed Central

    Castro-Prieto, Aines; Wachter, Bettina; Melzheimer, Joerg; Thalwitzer, Susanne; Hofer, Heribert; Sommer, Simone

    2012-01-01

    Background Genes under selection provide ecologically important information useful for conservation issues. Major histocompatibility complex (MHC) class I and II genes are essential for the immune defence against pathogens from intracellular (e.g. viruses) and extracellular (e.g. helminths) origins, respectively. Serosurvey studies in Namibian cheetahs (Acinonyx juabuts) revealed higher exposure to viral pathogens in individuals from north-central than east-central regions. Here we examined whether the observed differences in exposure to viruses influence the patterns of genetic variation and differentiation at MHC loci in 88 free-ranging Namibian cheetahs. Methodology/Principal Findings Genetic variation at MHC I and II loci was assessed through single-stranded conformation polymorphism (SSCP) analysis and sequencing. While the overall allelic diversity did not differ, we observed a high genetic differentiation at MHC class I loci between cheetahs from north-central and east-central Namibia. No such differentiation in MHC class II and neutral markers were found. Conclusions/Significance Our results suggest that MHC class I variation mirrors the variation in selection pressure imposed by viruses in free-ranging cheetahs across Namibian farmland. This is of high significance for future management and conservation programs of this species. PMID:23145096

  11. Effect of hosts on competition among clones and evidence of differential selection between pathogenic and saprophytic phases in experimental populations of the wheat pathogen Phaeosphaeria nodorum

    PubMed Central

    2011-01-01

    Background Monoculture, multi-cropping and wider use of highly resistant cultivars have been proposed as mechanisms to explain the elevated rate of evolution of plant pathogens in agricultural ecosystems. We used a mark-release-recapture experiment with the wheat pathogen Phaeosphaeria nodorum to evaluate the impact of two of these mechanisms on the evolution of a pathogen population. Nine P. nodorum isolates marked with ten microsatellite markers and one minisatellite were released onto five replicated host populations to initiate epidemics of Stagonospora nodorum leaf blotch. The experiment was carried out over two consecutive host growing seasons and two pathogen collections were made during each season. Results A total of 637 pathogen isolates matching the marked inoculants were recovered from inoculated plots over two years. Genetic diversity in the host populations affected the evolution of the corresponding P. nodorum populations. In the cultivar mixture the relative frequencies of inoculants did not change over the course of the experiment and the pathogen exhibited a low variation in selection coefficients. Conclusions Our results support the hypothesis that increasing genetic heterogeneity in host populations may retard the rate of evolution in associated pathogen populations. Our experiment also provides indirect evidence of fitness costs associated with host specialization in P. nodorum as indicated by differential selection during the pathogenic and saprophytic phases. PMID:21718545

  12. Differential Responses of Pattern Recognition Receptors to Outer Membrane Vesicles of Three Periodontal Pathogens

    PubMed Central

    Lenzo, Jason C.; Holden, James A.; Chen, Yu-Yen; Singleton, William; Gause, Katelyn T.; Yan, Yan; Caruso, Frank; Reynolds, Eric C.

    2016-01-01

    Highly purified outer membrane vesicles (OMVs) of the periodontal pathogens, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were produced using tangential flow ultrafiltration, ultracentrifugation and Optiprep density gradient separation. Cryo-TEM and light scattering showed OMVs to be single lipid-bilayers with modal diameters of 75 to 158 nm. Enumeration of OMVs by nanoparticle flow-cytometry at the same stage of late exponential culture indicated that P. gingivalis was the most prolific OMV producer. P. gingivalis OMVs induced strong TLR2 and TLR4-specific responses and moderate responses in TLR7, TLR8, TLR9, NOD1 and NOD2 expressing-HEK-Blue cells. Responses to T. forsythia OMVs were less than those of P. gingivalis and T. denticola OMVs induced only weak responses. Compositional analyses of OMVs from the three pathogens demonstrated differences in protein, fatty acids, lipopolysaccharide, peptidoglycan fragments and nucleic acids. Periodontal pathogen OMVs induced differential pattern recognition receptor responses that have implications for their role in chronic periodontitis. PMID:27035339

  13. Differential Responses of Pattern Recognition Receptors to Outer Membrane Vesicles of Three Periodontal Pathogens.

    PubMed

    Cecil, Jessica D; O'Brien-Simpson, Neil M; Lenzo, Jason C; Holden, James A; Chen, Yu-Yen; Singleton, William; Gause, Katelyn T; Yan, Yan; Caruso, Frank; Reynolds, Eric C

    2016-01-01

    Highly purified outer membrane vesicles (OMVs) of the periodontal pathogens, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were produced using tangential flow ultrafiltration, ultracentrifugation and Optiprep density gradient separation. Cryo-TEM and light scattering showed OMVs to be single lipid-bilayers with modal diameters of 75 to 158 nm. Enumeration of OMVs by nanoparticle flow-cytometry at the same stage of late exponential culture indicated that P. gingivalis was the most prolific OMV producer. P. gingivalis OMVs induced strong TLR2 and TLR4-specific responses and moderate responses in TLR7, TLR8, TLR9, NOD1 and NOD2 expressing-HEK-Blue cells. Responses to T. forsythia OMVs were less than those of P. gingivalis and T. denticola OMVs induced only weak responses. Compositional analyses of OMVs from the three pathogens demonstrated differences in protein, fatty acids, lipopolysaccharide, peptidoglycan fragments and nucleic acids. Periodontal pathogen OMVs induced differential pattern recognition receptor responses that have implications for their role in chronic periodontitis.

  14. Differential Responses of Pattern Recognition Receptors to Outer Membrane Vesicles of Three Periodontal Pathogens.

    PubMed

    Cecil, Jessica D; O'Brien-Simpson, Neil M; Lenzo, Jason C; Holden, James A; Chen, Yu-Yen; Singleton, William; Gause, Katelyn T; Yan, Yan; Caruso, Frank; Reynolds, Eric C

    2016-01-01

    Highly purified outer membrane vesicles (OMVs) of the periodontal pathogens, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were produced using tangential flow ultrafiltration, ultracentrifugation and Optiprep density gradient separation. Cryo-TEM and light scattering showed OMVs to be single lipid-bilayers with modal diameters of 75 to 158 nm. Enumeration of OMVs by nanoparticle flow-cytometry at the same stage of late exponential culture indicated that P. gingivalis was the most prolific OMV producer. P. gingivalis OMVs induced strong TLR2 and TLR4-specific responses and moderate responses in TLR7, TLR8, TLR9, NOD1 and NOD2 expressing-HEK-Blue cells. Responses to T. forsythia OMVs were less than those of P. gingivalis and T. denticola OMVs induced only weak responses. Compositional analyses of OMVs from the three pathogens demonstrated differences in protein, fatty acids, lipopolysaccharide, peptidoglycan fragments and nucleic acids. Periodontal pathogen OMVs induced differential pattern recognition receptor responses that have implications for their role in chronic periodontitis. PMID:27035339

  15. Caution: Reptile pets shuttle grasshopper allergy and asthma into homes.

    PubMed

    Jensen-Jarolim, Erika; Pali-Schöll, Isabella; Jensen, Sebastian A F; Robibaro, Bruno; Kinaciyan, Tamar

    2015-01-01

    The numbers of reptiles in homes has at least doubled in the last decade in Europe and the USA. Reptile purchases are increasingly triggered by the attempt to avoid potentially allergenic fur pets like dogs and cats. Consequently, reptiles are today regarded as surrogate pets initiating a closer relationship with the owner than ever previously observed. Reptile pets are mostly fed with insects, especially grasshoppers and/or locusts, which are sources for aggressive airborne allergens, best known from occupational insect breeder allergies. Exposure in homes thus introduces a new form of domestic allergy to grasshoppers and related insects. Accordingly, an 8-year old boy developed severe bronchial hypersensitivity and asthma within 4 months after purchase of a bearded dragon. The reptile was held in the living room and regularly fed with living grasshoppers. In the absence of a serological allergy diagnosis test, an IgE immunoblot on grasshopper extract and prick-to-prick test confirmed specific sensitization to grasshoppers. After 4 years of allergen avoidance, a single respiratory exposure was sufficient to trigger a severe asthma attack again in the patient. Based on literature review and the clinical example we conclude that reptile keeping is associated with introducing potent insect allergens into home environments. Patient interviews during diagnostic procedure should therefore by default include the question about reptile pets in homes. PMID:26322151

  16. Caution: Reptile pets shuttle grasshopper allergy and asthma into homes.

    PubMed

    Jensen-Jarolim, Erika; Pali-Schöll, Isabella; Jensen, Sebastian A F; Robibaro, Bruno; Kinaciyan, Tamar

    2015-01-01

    The numbers of reptiles in homes has at least doubled in the last decade in Europe and the USA. Reptile purchases are increasingly triggered by the attempt to avoid potentially allergenic fur pets like dogs and cats. Consequently, reptiles are today regarded as surrogate pets initiating a closer relationship with the owner than ever previously observed. Reptile pets are mostly fed with insects, especially grasshoppers and/or locusts, which are sources for aggressive airborne allergens, best known from occupational insect breeder allergies. Exposure in homes thus introduces a new form of domestic allergy to grasshoppers and related insects. Accordingly, an 8-year old boy developed severe bronchial hypersensitivity and asthma within 4 months after purchase of a bearded dragon. The reptile was held in the living room and regularly fed with living grasshoppers. In the absence of a serological allergy diagnosis test, an IgE immunoblot on grasshopper extract and prick-to-prick test confirmed specific sensitization to grasshoppers. After 4 years of allergen avoidance, a single respiratory exposure was sufficient to trigger a severe asthma attack again in the patient. Based on literature review and the clinical example we conclude that reptile keeping is associated with introducing potent insect allergens into home environments. Patient interviews during diagnostic procedure should therefore by default include the question about reptile pets in homes.

  17. Canalization of freeze tolerance in an alpine grasshopper.

    PubMed

    Hawes, Timothy C

    2015-10-01

    In the Rock and Pillar Range, New Zealand, the alpine grasshopper, Sigaus australis Hutton, survives equilibrium freezing (EF) all-year round. A comparison of freeze tolerance (FT) in grasshoppers over four austral seasons for a 1 year period finds that: (a) the majority (>70%) of the sample population of grasshoppers survive single freeze-stress throughout the year; (b) exposure to increased freeze stress (multiple freeze-stress events) does not lead to a loss of freeze tolerance; and (c) responses to increased freeze stress reveal seasonal tuning of the FT adaptation to environmental temperatures. The Rock and Pillar sample population provides a clear example of the canalization of the FT adaptation. Seasonal variability in the extent of tolerance of multiple freezing events indicates that physiology is modulated to environmental temperatures by phenotypic plasticity - i.e. the FT adaptation is permanent and adjustable. PMID:26210007

  18. Living biointerfaces based on non-pathogenic bacteria support stem cell differentiation

    NASA Astrophysics Data System (ADS)

    Hay, Jake J.; Rodrigo-Navarro, Aleixandre; Hassi, Karoliina; Moulisova, Vladimira; Dalby, Matthew J.; Salmeron-Sanchez, Manuel

    2016-02-01

    Lactococcus lactis, a non-pathogenic bacteria, has been genetically engineered to express the III7-10 fragment of human fibronectin as a membrane protein. The engineered L. lactis is able to develop biofilms on different surfaces (such as glass and synthetic polymers) and serves as a long-term substrate for mammalian cell culture, specifically human mesenchymal stem cells (hMSC). This system constitutes a living interface between biomaterials and stem cells. The engineered biofilms remain stable and viable for up to 28 days while the expressed fibronectin fragment induces hMSC adhesion. We have optimised conditions to allow long-term mammalian cell culture, and found that the biofilm is functionally equivalent to a fibronectin-coated surface in terms of osteoblastic differentiation using bone morphogenetic protein 2 (BMP-2) added to the medium. This living bacteria interface holds promise as a dynamic substrate for stem cell differentiation that can be further engineered to express other biochemical cues to control hMSC differentiation.

  19. Living biointerfaces based on non-pathogenic bacteria support stem cell differentiation

    PubMed Central

    Hay, Jake J.; Rodrigo-Navarro, Aleixandre; Hassi, Karoliina; Moulisova, Vladimira; Dalby, Matthew J.; Salmeron-Sanchez, Manuel

    2016-01-01

    Lactococcus lactis, a non-pathogenic bacteria, has been genetically engineered to express the III7–10 fragment of human fibronectin as a membrane protein. The engineered L. lactis is able to develop biofilms on different surfaces (such as glass and synthetic polymers) and serves as a long-term substrate for mammalian cell culture, specifically human mesenchymal stem cells (hMSC). This system constitutes a living interface between biomaterials and stem cells. The engineered biofilms remain stable and viable for up to 28 days while the expressed fibronectin fragment induces hMSC adhesion. We have optimised conditions to allow long-term mammalian cell culture, and found that the biofilm is functionally equivalent to a fibronectin-coated surface in terms of osteoblastic differentiation using bone morphogenetic protein 2 (BMP-2) added to the medium. This living bacteria interface holds promise as a dynamic substrate for stem cell differentiation that can be further engineered to express other biochemical cues to control hMSC differentiation. PMID:26902619

  20. Living biointerfaces based on non-pathogenic bacteria support stem cell differentiation

    NASA Astrophysics Data System (ADS)

    Hay, Jake J.; Rodrigo-Navarro, Aleixandre; Hassi, Karoliina; Moulisova, Vladimira; Dalby, Matthew J.; Salmeron-Sanchez, Manuel

    2016-02-01

    Lactococcus lactis, a non-pathogenic bacteria, has been genetically engineered to express the III7–10 fragment of human fibronectin as a membrane protein. The engineered L. lactis is able to develop biofilms on different surfaces (such as glass and synthetic polymers) and serves as a long-term substrate for mammalian cell culture, specifically human mesenchymal stem cells (hMSC). This system constitutes a living interface between biomaterials and stem cells. The engineered biofilms remain stable and viable for up to 28 days while the expressed fibronectin fragment induces hMSC adhesion. We have optimised conditions to allow long-term mammalian cell culture, and found that the biofilm is functionally equivalent to a fibronectin-coated surface in terms of osteoblastic differentiation using bone morphogenetic protein 2 (BMP-2) added to the medium. This living bacteria interface holds promise as a dynamic substrate for stem cell differentiation that can be further engineered to express other biochemical cues to control hMSC differentiation.

  1. Red List of grasshoppers of the Wadden Sea area

    NASA Astrophysics Data System (ADS)

    Holst, K.; Grein, G.; Dierking, U.; van Wingerden, W. K. R. E.

    1996-10-01

    In typical coastal habitats of the Wadden Sea, 15 species of grasshoppers are threatened in at least one subregion. Of these, 14 species are threatened in the entire area and are therefore placed on the trilateral Red List. The situation in the Danish part of the Wadden Sea could only be taken into consideration in a limited way due to the latest available data in Denmark from 1969. The status of 2 species of grasshoppers in the entire Wadden Sea area is critical, 4 species are endangered, the status of 3 species is vulnerable and of 5 species susceptible.

  2. Burkholderia cenocepacia Differential Gene Expression during Host–Pathogen Interactions and Adaptation to the Host Environment

    PubMed Central

    O’Grady, Eoin P.; Sokol, Pamela A.

    2011-01-01

    Members of the Burkholderia cepacia complex (Bcc) are important in medical, biotechnological, and agricultural disciplines. These bacteria naturally occur in soil and water environments and have adapted to survive in association with plants and animals including humans. All Bcc species are opportunistic pathogens including Burkholderia cenocepacia that causes infections in cystic fibrosis and chronic granulomatous disease patients. The adaptation of B. cenocepacia to the host environment was assessed in a rat chronic respiratory infection model and compared to that of high cell-density in vitro grown cultures using transcriptomics. The distribution of genes differentially expressed on chromosomes 1, 2, and 3 was relatively proportional to the size of each genomic element, whereas the proportion of plasmid-encoded genes differentially expressed was much higher relative to its size and most genes were induced in vivo. The majority of genes encoding known virulence factors, components of types II and III secretion systems and chromosome 2-encoded type IV secretion system were similarly expressed between in vitro and in vivo environments. Lower expression in vivo was detected for genes encoding N-acyl-homoserine lactone synthase CepI, orphan LuxR homolog CepR2, zinc metalloproteases ZmpA and ZmpB, LysR-type transcriptional regulator ShvR, nematocidal protein AidA, and genes associated with flagellar motility, Flp type pilus formation, and type VI secretion. Plasmid-encoded type IV secretion genes were markedly induced in vivo. Additional genes induced in vivo included genes predicted to be involved in osmotic stress adaptation or intracellular survival, metal ion, and nutrient transport, as well as those encoding outer membrane proteins. Genes identified in this study are potentially important for virulence during host–pathogen interactions and may be associated with survival and adaptation to the host environment during chronic lung infections. PMID:22919581

  3. Population genetics of Mioscirtus wagneri, a grasshopper showing a highly fragmented distribution.

    PubMed

    Ortego, Joaquín; Aguirre, Maria Pilar; Cordero, Pedro J

    2010-02-01

    The genetic consequences of population fragmentation and isolation are major issues in conservation biology. In this study we analyse the genetic variability and structure of the Iberian populations of Mioscirtus wagneri, a specialized grasshopper exclusively inhabiting highly fragmented hypersaline low grounds. For this purpose we have used seven species-specific microsatellite markers to type 478 individuals from 24 localities and obtain accurate estimates of their genetic variability. Genetic diversity was relatively low and we detected genetic signatures suggesting that certain populations of M. wagneri have probably passed through severe demographic bottlenecks. We have found that the populations of this grasshopper show a strong genetic structure even at small geographical scales, indicating that they mostly behave as isolated populations with low levels of gene flow among them. Thus, several populations can be regarded as independent and genetically differentiated units which require adequate conservation strategies to avoid eventual extinctions that in highly isolated localities are not likely to be compensated for with the arrival of immigrants from neighbouring populations. Overall, our results show that these populations probably represent the 'fragments' of a formerly more widespread population and highlight the importance of protecting Iberian hypersaline environments due to the high number of rare and endangered species they sustain. PMID:20051009

  4. Modifications to improve entrance slit thermal stability for grasshopper monochromators

    NASA Astrophysics Data System (ADS)

    Wallace, Daniel J.; Rogers, Gregory C.; Crossley, Sherry L.

    1994-08-01

    As new monochromators are designed for high-flux storage rings, computer modeling and thermal engineering can be done to process increased heat loads and achieve mechanical stability. Several older monochromators, such as the Mark 2 and Mark 5 Grasshopper monochromators, which were designed in 1974, have thermal instabilities in their entrance slit mechanisms. The Grasshoppers operating with narrow slits experience closure of the entrance slit from thermal expansion. In extreme cases, the thermal expansion of the precision components has caused permanent mechanical damage, leaving the slit uncalibrated and/or inoperable. For the Mark 2 and Mark 5 Grasshopper monochromators at the Synchrotron Radiation Center, the original 440 stainless steel entrance slit jaws were retrofitted with an Invar (low expansion Fe, Ni alloy) slit jaw. To transfer the heat from the critical components, two flexible heat straps of Cu were attached. These changes allow safe operation with a 10 μm entrance slit width where the previous limit was 30 μm. After an initial 2 min equilibration, the slit remains stable to 10%, with 100 mA of beam current. Additional improvements in slit thermal stability are planned for a third Grasshopper.

  5. The diversity of caeliferins in American grasshoppers, what possible function?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caeliferins is a new class of compounds recently identified from regurgitant of the American grasshopper (Schistocerca americana)1. Two closely related caeliferins were shown to induce the release of volatiles in corn plants comparable to what earlier has been shown with volicitin and other fatty a...

  6. [Diversity of grasshopper community in lac plantation-farmland ecosystem].

    PubMed

    Li, Qiao; Chen, You-qing; Chen, Yan-lin; Chen, Zhen

    2009-03-01

    The grasshopper communities in the paddy field, dry land, natural forest, and plantation forest of lac plantation-farmland ecosystem in Lvchun County, Yunnan were investigated by sweep netting. A total of 1426 grasshoppers belonging to 33 species, 22 genena, and 5 families were captured. In the paddy field, dry land, natural forest, and plantation forest of the ecosystem, the species richness S were 16.333, 13.000, 11.000, and 12.000, Margalef index was 2.873, 2.266, 2.335, and 2. 137, Shannon-Wiener index was 2.034, 1.976, 1.982, and 1.488, Simpson index was 0.196, 0.189, 0.174, and 0.323, and Pielou index was 0.728, 0.787, 0.829, 0.599, respectively. This ecosystem had a lower diversity of grasshopper communities, and different land use habitats in the ecosystem had different species component and diversity. In paddy field, grasshopper had a higher diversity than in dry land, but its evenness and stability were moderate; in natural forest, the diversity was high and the stability was strong; while in plantation forest, the diversity was low and the stability was weak. There existed species exchange in different land use habitats in the ecosystem.

  7. Pathogenic Naegleria fowleri and non-pathogenic Naegleria lovaniensis exhibit differential adhesion to, and invasion of, extracellular matrix proteins.

    PubMed

    Jamerson, Melissa; da Rocha-Azevedo, Bruno; Cabral, Guy A; Marciano-Cabral, Francine

    2012-03-01

    Naegleria fowleri and Naegleria lovaniensis are closely related free-living amoebae found in the environment. N. fowleri causes primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system, while N. lovaniensis is non-pathogenic. N. fowleri infection occurs when the amoebae access the nasal passages, attach to the nasal mucosa and its epithelial lining, and migrate to the brain. This process involves interaction with components of the host extracellular matrix (ECM). Since the ability to invade tissues can be a characteristic that distinguishes pathogenic from non-pathogenic amoebae, the objective of this study was to assess adhesion to, and invasion of, the ECM by these two related but distinct Naegleria species. N. fowleri exhibited a higher level of adhesion to the ECM components laminin-1, fibronectin and collagen I. Scanning electron microscopy revealed that N. fowleri attached on ECM substrata exhibited a spread-out appearance that included the presence of focal adhesion-like structures. Western immunoblotting revealed two integrin-like proteins for both species, but one of these, with a molecular mass of approximately 70 kDa, was detected at a higher level in N. fowleri. Confocal microscopy indicated that the integrin-like proteins co-localized to the focal adhesion-like structures. Furthermore, anti-integrin antibody decreased adhesion of N. fowleri to ECM components. Finally, N. fowleri disrupted 3D ECM scaffolds, while N. lovaniensis had a minimal effect. Collectively, these results indicate a distinction in adhesion to, and invasion of, ECM proteins between N. fowleri and N. lovaniensis.

  8. Pathogenic Naegleria fowleri and non-pathogenic Naegleria lovaniensis exhibit differential adhesion to, and invasion of, extracellular matrix proteins

    PubMed Central

    Jamerson, Melissa; da Rocha-Azevedo, Bruno; Cabral, Guy A.

    2012-01-01

    Naegleria fowleri and Naegleria lovaniensis are closely related free-living amoebae found in the environment. N. fowleri causes primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system, while N. lovaniensis is non-pathogenic. N. fowleri infection occurs when the amoebae access the nasal passages, attach to the nasal mucosa and its epithelial lining, and migrate to the brain. This process involves interaction with components of the host extracellular matrix (ECM). Since the ability to invade tissues can be a characteristic that distinguishes pathogenic from non-pathogenic amoebae, the objective of this study was to assess adhesion to, and invasion of, the ECM by these two related but distinct Naegleria species. N. fowleri exhibited a higher level of adhesion to the ECM components laminin-1, fibronectin and collagen I. Scanning electron microscopy revealed that N. fowleri attached on ECM substrata exhibited a spread-out appearance that included the presence of focal adhesion-like structures. Western immunoblotting revealed two integrin-like proteins for both species, but one of these, with a molecular mass of approximately 70 kDa, was detected at a higher level in N. fowleri. Confocal microscopy indicated that the integrin-like proteins co-localized to the focal adhesion-like structures. Furthermore, anti-integrin antibody decreased adhesion of N. fowleri to ECM components. Finally, N. fowleri disrupted 3D ECM scaffolds, while N. lovaniensis had a minimal effect. Collectively, these results indicate a distinction in adhesion to, and invasion of, ECM proteins between N. fowleri and N. lovaniensis. PMID:22222499

  9. Spatial genetic structure and mitochondrial DNA phylogeography of Argentinean populations of the grasshopper Dichroplus elongatus.

    PubMed

    Rosetti, Natalia; Remis, Maria Isabel

    2012-01-01

    Many grasshopper species are considered of agronomical importance because they cause damage to pastures and crops. Comprehension of pest population dynamics requires a clear understanding of the genetic diversity and spatial structure of populations. In this study we report on patterns of genetic variation in the South American grasshopper Dichroplus elongatus which is an agricultural pest of crops and forage grasses of great economic significance in Argentina. We use Direct Amplification of Minisatellite Regions (DAMD) and partial sequences of the cytochrome oxydase 1 (COI) mitochondrial gene to investigate intraspecific structure, demographic history and gene flow patterns in twenty Argentinean populations of this species belonging to different geographic and biogeographic regions. DAMD data suggest that, although genetic drift and migration occur within and between populations, measurable relatedness among neighbouring populations declines with distance and dispersal over distances greater than 200 km is not typical, whereas effective gene flow may occur for populations separated by less than 100 km. Landscape analysis was useful to detect genetic discontinuities associated with environmental heterogeneity reflecting the changing agroecosystem. The COI results indicate the existence of strong genetic differentiation between two groups of populations located at both margins of the Paraná River which became separated during climate oscillations of the Middle Pleistocene, suggesting a significant restriction in effective dispersion mediated by females and large scale geographic differentiation. The number of migrants between populations estimated through mitochondrial and DAMD markers suggest that gene flow is low prompting a non-homogeneous spatial structure and justifying the variation through space. Moreover, the genetic analysis of both markers allows us to conclude that males appear to disperse more than females, reducing the chance of the genetic loss

  10. Spatial Genetic Structure and Mitochondrial DNA Phylogeography of Argentinean Populations of the Grasshopper Dichroplus elongatus

    PubMed Central

    Rosetti, Natalia; Remis, Maria Isabel

    2012-01-01

    Many grasshopper species are considered of agronomical importance because they cause damage to pastures and crops. Comprehension of pest population dynamics requires a clear understanding of the genetic diversity and spatial structure of populations. In this study we report on patterns of genetic variation in the South American grasshopper Dichroplus elongatus which is an agricultural pest of crops and forage grasses of great economic significance in Argentina. We use Direct Amplification of Minisatellite Regions (DAMD) and partial sequences of the cytochrome oxydase 1 (COI) mitochondrial gene to investigate intraspecific structure, demographic history and gene flow patterns in twenty Argentinean populations of this species belonging to different geographic and biogeographic regions. DAMD data suggest that, although genetic drift and migration occur within and between populations, measurable relatedness among neighbouring populations declines with distance and dispersal over distances greater than 200 km is not typical, whereas effective gene flow may occur for populations separated by less than 100 km. Landscape analysis was useful to detect genetic discontinuities associated with environmental heterogeneity reflecting the changing agroecosystem. The COI results indicate the existence of strong genetic differentiation between two groups of populations located at both margins of the Paraná River which became separated during climate oscillations of the Middle Pleistocene, suggesting a significant restriction in effective dispersion mediated by females and large scale geographic differentiation. The number of migrants between populations estimated through mitochondrial and DAMD markers suggest that gene flow is low prompting a non-homogeneous spatial structure and justifying the variation through space. Moreover, the genetic analysis of both markers allows us to conclude that males appear to disperse more than females, reducing the chance of the genetic loss

  11. Tracking the evolution of sex chromosome systems in Melanoplinae grasshoppers through chromosomal mapping of repetitive DNA sequences

    PubMed Central

    2013-01-01

    Background The accumulation of repetitive DNA during sex chromosome differentiation is a common feature of many eukaryotes and becomes more evident after recombination has been restricted or abolished. The accumulated repetitive sequences include multigene families, microsatellites, satellite DNAs and mobile elements, all of which are important for the structural remodeling of heterochromatin. In grasshoppers, derived sex chromosome systems, such as neo-XY♂/XX♀ and neo-X1X2Y♂/X1X1X2X2♀, are frequently observed in the Melanoplinae subfamily. However, no studies concerning the evolution of sex chromosomes in Melanoplinae have addressed the role of the repetitive DNA sequences. To further investigate the evolution of sex chromosomes in grasshoppers, we used classical cytogenetic and FISH analyses to examine the repetitive DNA sequences in six phylogenetically related Melanoplinae species with X0♂/XX♀, neo-XY♂/XX♀ and neo-X1X2Y♂/X1X1X2X2♀ sex chromosome systems. Results Our data indicate a non-spreading of heterochromatic blocks and pool of repetitive DNAs (C0t-1 DNA) in the sex chromosomes; however, the spreading of multigene families among the neo-sex chromosomes of Eurotettix and Dichromatos was remarkable, particularly for 5S rDNA. In autosomes, FISH mapping of multigene families revealed distinct patterns of chromosomal organization at the intra- and intergenomic levels. Conclusions These results suggest a common origin and subsequent differential accumulation of repetitive DNAs in the sex chromosomes of Dichromatos and an independent origin of the sex chromosomes of the neo-XY and neo-X1X2Y systems. Our data indicate a possible role for repetitive DNAs in the diversification of sex chromosome systems in grasshoppers. PMID:23937327

  12. Chemical cues from females trigger male courtship behaviour in grasshoppers.

    PubMed

    Finck, Jonas; Kuntze, Janine; Ronacher, Bernhard

    2016-05-01

    Gomphocerine grasshoppers use species-specific calling songs for sex recognition and mate attraction. In two closely related species, Chorthippus biguttulus and C. mollis, acoustic communication is the only experimentally characterized communication channel that elicits male courtship behaviour. However, courtship in these species involves extensive close-range interactions that are likely to be mediated by other signalling modalities, in particular chemical cues. We developed a bioassay to determine if female cuticular hydrocarbons (CHCs) act as chemical cues that induce courtship behaviour, and if males assess variation in CHCs to determine whether or not to court a female. The results of this approach provide evidence that grasshopper males use species- and sex-specific information from CHC signals and respond with a courtship song to the CHC profile of conspecific females but not to the CHC profile of heterospecific females and conspecific males. We conclude that males of C. biguttulus and C. mollis use multimodal channels for mating decisions, based on both acoustic and olfactory cues. We discuss various factors that might favour the evolution of male choosiness in grasshoppers. PMID:27025933

  13. Micro-Evolution in Grasshoppers Mediated by Polymorphic Robertsonian Translocations

    PubMed Central

    Colombo, Pablo C.

    2013-01-01

    This review focuses on grasshoppers that are polymorphic for Robertsonian translocations because in these organisms the clarity of meiotic figures allows the study of both chiasma distribution and the orientation of trivalents and multivalents in metaphase I. Only five species of such grasshoppers were found in the literature, and all of them were from the New World: Oedaleonotus enigma (Scudder) (Orthoptera: Acrididae), Leptysma argentina Bruner, Dichroplus pratensis Bruner, Sinipta dalmani Stål, and Cornops aquaticum Bruner. A general feature of these species (except O. enigma) is that fusion carriers suffer a marked reduction of proximal and interstitial (with respect to the centromere) chiasma frequency; this fact, along with the reduction in the number of linkage groups with the consequent loss of independent segregation, produces a marked decrease of recombination in fusion carriers. This reduction in recombination has led to the conclusion that Robertsonian polymorphic grasshopper species share some properties with inversion polymorphic species of Drosophila, such as the central-marginal pattern (marginal populations are monomorphic, central populations are highly polymorphic). This pattern might be present in D. pratensis, which is certainly the most complex Robertsonian polymorphism system in the present study. However, L. argentina and C. aquaticum do not display this pattern. This issue is open to further research. Since C. aquaticum is soon to be released in South Africa as a biological control, the latitudinal pattern found in South America may repeat there. This experiment's outcome is open and deserves to be followed. PMID:23909914

  14. Biosensors based on modularly designed synthetic peptides for recognition, detection and live/dead differentiation of pathogenic bacteria.

    PubMed

    Liu, Xiaobo; Marrakchi, Mouna; Xu, Dawei; Dong, He; Andreescu, Silvana

    2016-06-15

    Rapid and sensitive detection of bacterial pathogens is critical for assessing public health, food and environmental safety. We report the use of modularly designed and site-specifically oriented synthetic antimicrobial peptides (sAMPs) as novel recognition agents enabling detection and quantification of bacterial pathogens. The oriented assembly of the synthetic peptides on electrode surfaces through an engineered cysteine residue coupled with impedimetric detection facilitated rapid and sensitive detection of bacterial pathogens with a detection limit of 10(2)CFU/mL for four bacterial strains including Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). The approach enabled differentiation between live and dead bacteria. The fabrication of the sAMPs functionalized surface and the importance of the sAMPs orientation for providing optimum recognition and detection ability against pathogens are discussed. The proposed methodology provides a universal platform for the detection of bacterial pathogens based on engineered peptides, as alternative to the most commonly used immunological and gene based assays. The method can also be used to fabricate antimicrobial coatings and surfaces for inactivation and screening of viable bacteria. PMID:26802747

  15. Biosensors based on modularly designed synthetic peptides for recognition, detection and live/dead differentiation of pathogenic bacteria.

    PubMed

    Liu, Xiaobo; Marrakchi, Mouna; Xu, Dawei; Dong, He; Andreescu, Silvana

    2016-06-15

    Rapid and sensitive detection of bacterial pathogens is critical for assessing public health, food and environmental safety. We report the use of modularly designed and site-specifically oriented synthetic antimicrobial peptides (sAMPs) as novel recognition agents enabling detection and quantification of bacterial pathogens. The oriented assembly of the synthetic peptides on electrode surfaces through an engineered cysteine residue coupled with impedimetric detection facilitated rapid and sensitive detection of bacterial pathogens with a detection limit of 10(2)CFU/mL for four bacterial strains including Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). The approach enabled differentiation between live and dead bacteria. The fabrication of the sAMPs functionalized surface and the importance of the sAMPs orientation for providing optimum recognition and detection ability against pathogens are discussed. The proposed methodology provides a universal platform for the detection of bacterial pathogens based on engineered peptides, as alternative to the most commonly used immunological and gene based assays. The method can also be used to fabricate antimicrobial coatings and surfaces for inactivation and screening of viable bacteria.

  16. Spatial autocorrelation in farmland grasshopper assemblages (Orthoptera: Acrididae) in western France.

    PubMed

    Badenhausser, I; Gouat, M; Goarant, A; Cornulier, T; Bretagnolle, V

    2012-10-01

    Agricultural intensification in western Europe has caused a dramatic loss of grassland surfaces in farmlands, which have resulted in strong declines in grassland invertebrates, leading to cascade effects at higher trophic levels among consumers of invertebrates. Grasshoppers are important components of grassland invertebrate assemblages in European agricultural ecosystems, particularly as prey for bird species. Understanding how grasshopper populations are distributed in fragmented landscapes with low grassland availability is critical for both studies in biodiversity conservation and insect management. We assessed the range and strength of spatial autocorrelation for two grasshopper taxa (Gomphocerinae subfamily and Calliptamus italicus L.) across an intensive farmland in western France. Data from surveys carried out over 8 yr in 1,715 grassland fields were analyzed using geostatistics. Weak spatial patterns were observed at small spatial scales, suggesting important local effects of management practices on grasshopper densities. Spatial autocorrelation patterns for both grasshopper taxa were only detected at intermediate scales. For Gomphocerinae, the range of spatial autocorrelation varied from 802 to 2,613 m according to the year, depending both on grasshopper density and on grassland surfaces in the study site, whereas spatial patterns for the Italian locust were more variable and not related to grasshopper density or grassland surfaces. Spatial patterns in the distribution of Gomphocerinae supported our hypothesis that habitat availability was a major driver of grasshopper distribution in the landscape, and suggested it was related to density-dependent processes such as dispersal.

  17. Populations of the northern grasshopper, Melanoplus borealis (Orthoptera: Acrididae), in Alaska are rarely food limited

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasshoppers can cause substantial losses to forage on rangelands and pastures and to field crops, but chemical control of grasshopper pests is rarely justified because of the low per-area value of forages, the extensive areas needed to be treated to protect crops, and because of potential impacts t...

  18. Diet influences rates of carbon and nitrogen mineralization from decomposing grasshopper frass and cadavers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect herbivory can produce a pulse of mineral nitrogen (N) in soil from the decomposition of frass and cadavers. In this study we examined how diet quality affects rates of N and carbon (C) mineralization from grasshopper frass and cadavers. Frass was collected from grasshoppers fed natural or mer...

  19. Grasshopper responses to fire and postfire grazing in the northern Great Plains vary among species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rangeland management practices such as burning and grazing management may affect grasshopper populations by impacting development, survival and reproduction. Experiments are lacking in the northern Great Plains examining the effects of fire and grazing intensity on grasshoppers. As part of a larger ...

  20. Acquisition of nonspecific Bartonella strains by the northern grasshopper mouse (Onychomys leucogaster)

    USGS Publications Warehouse

    Bai, Y.; Kosoy, M.Y.; Cully, J.F.; Bala, T.; Ray, C.; Collinge, S.K.

    2007-01-01

    Rodent-associated Bartonella species are generally host-specific parasites in North America. Here evidence that Bartonella species can 'jump' between host species is presented. Northern grasshopper mice and other rodents were trapped in the western USA. A study of Bartonella infection in grasshopper mice demonstrated a high prevalence that varied from 25% to 90% by location. Bartonella infection was detected in other rodent species with a high prevalence as well. Sequence analyses of gltA identified 29 Bartonella variants in rodents, 10 of which were obtained from grasshopper mice. Among these 10, only six variants were specific to grasshopper mice, whereas four were identical to variants specific to deer mice or 13-lined ground squirrels. Fourteen of 90 sequenced isolates obtained from grasshopper mice were strains found more commonly in other rodent species and were apparently acquired from these animals. The ecological behavior of grasshopper mice may explain the occurrence of Bartonella strains in occasional hosts. The observed rate at which Bartonella jumps from a donor host species to the grasshopper mouse was directly proportional to a metric of donor host density and to the prevalence of Bartonella in the donor host, and inversely proportional to the same parameters for the grasshopper mouse. ?? 2007 Federation of European Microbiological Societies.

  1. IGS Minisatellites Useful for Race Differentiation in Colletotrichum lentis and a Likely Site of Small RNA Synthesis Affecting Pathogenicity.

    PubMed

    Durkin, Jonathan; Bissett, John; Pahlavani, Mohammadhadi; Mooney, Brent; Buchwaldt, Lone

    2015-01-01

    Colletotrichum lentis is a fungal pathogen of lentil in Canada but rarely reported elsewhere. Two races, Ct0 and Ct1, have been identified using differential lines. Our objective was to develop a PCR-probe differentiating these races. Sequences of the translation elongation factor 1α (tef1α), RNA polymerase II subunit B2 (rpb2), ATP citrate lyase subunit A (acla), and internal transcribed spacer (ITS) regions were monomorphic, while the intergenic spacer (IGS) region showed length polymorphisms at two minisatellites of 23 and 39 nucleotides (nt). A PCR-probe (39F/R) amplifying the 39 nt minisatellite was developed which subsequently revealed 1-5 minisatellites with 1-12 repeats in C. lentis. The probe differentiated race Ct1 isolates having 7, 9 or 7+9 repeats from race Ct0 having primarily 2 or 4 repeats, occasionally 5, 6, or 8, but never 7 or 9 repeats. These isolates were collected between 1991 and 1999. In a 2012 survey isolates with 2 and 4 repeats increased from 34% to 67%, while isolated with 7 or 9 repeats decreased from 40 to 4%, likely because Ct1 resistant lentil varieties had been grown. The 39 nt repeat was identified in C. gloeosporioides, C. trifolii, Ascochyta lentis, Sclerotinia sclerotiorum and Botrytis cinerea. Thus, the 39F/R PCR probe is not species specific, but can differentiate isolates based on repeat number. The 23 nt minisatellite in C. lentis exists as three length variants with ten sequence variations differentiating race Ct0 having 14 or 19 repeats from race Ct1 having 17 repeats, except for one isolate. RNA-translation of 23 nt repeats forms hairpins and has the appropriate length to suggest that IGS could be a site of small RNA synthesis, a hypothesis that warrants further investigation. Small RNA from fungal plant pathogens able to silence genes either in the host or pathogen thereby aiding infection have been reported. PMID:26340001

  2. IGS Minisatellites Useful for Race Differentiation in Colletotrichum lentis and a Likely Site of Small RNA Synthesis Affecting Pathogenicity

    PubMed Central

    Durkin, Jonathan; Bissett, John; Pahlavani, Mohammadhadi; Mooney, Brent; Buchwaldt, Lone

    2015-01-01

    Colletotrichum lentis is a fungal pathogen of lentil in Canada but rarely reported elsewhere. Two races, Ct0 and Ct1, have been identified using differential lines. Our objective was to develop a PCR-probe differentiating these races. Sequences of the translation elongation factor 1α (tef1α), RNA polymerase II subunit B2 (rpb2), ATP citrate lyase subunit A (acla), and internal transcribed spacer (ITS) regions were monomorphic, while the intergenic spacer (IGS) region showed length polymorphisms at two minisatellites of 23 and 39 nucleotides (nt). A PCR-probe (39F/R) amplifying the 39 nt minisatellite was developed which subsequently revealed 1–5 minisatellites with 1–12 repeats in C. lentis. The probe differentiated race Ct1 isolates having 7, 9 or 7+9 repeats from race Ct0 having primarily 2 or 4 repeats, occasionally 5, 6, or 8, but never 7 or 9 repeats. These isolates were collected between 1991 and 1999. In a 2012 survey isolates with 2 and 4 repeats increased from 34% to 67%, while isolated with 7 or 9 repeats decreased from 40 to 4%, likely because Ct1 resistant lentil varieties had been grown. The 39 nt repeat was identified in C. gloeosporioides, C. trifolii, Ascochyta lentis, Sclerotinia sclerotiorum and Botrytis cinerea. Thus, the 39F/R PCR probe is not species specific, but can differentiate isolates based on repeat number. The 23 nt minisatellite in C. lentis exists as three length variants with ten sequence variations differentiating race Ct0 having 14 or 19 repeats from race Ct1 having 17 repeats, except for one isolate. RNA-translation of 23 nt repeats forms hairpins and has the appropriate length to suggest that IGS could be a site of small RNA synthesis, a hypothesis that warrants further investigation. Small RNA from fungal plant pathogens able to silence genes either in the host or pathogen thereby aiding infection have been reported. PMID:26340001

  3. Effects of habitat structure and land-use intensity on the genetic structure of the grasshopper species Chorthippus parallelus

    PubMed Central

    Wiesner, Kerstin R.; Habel, Jan Christian; Gossner, Martin M.; Loxdale, Hugh D.; Köhler, Günter; Schneider, Anja R. R.; Tiedemann, Ralph; Weisser, Wolfgang W.

    2014-01-01

    Land-use intensity (LUI) is assumed to impact the genetic structure of organisms. While effects of landscape structure on the genetics of local populations have frequently been analysed, potential effects of variation in LUI on the genetic diversity of local populations have mostly been neglected. In this study, we used six polymorphic microsatellites to analyse the genetic effects of variation in land use in the highly abundant grasshopper Chorthippus parallelus. We sampled a total of 610 individuals at 22 heterogeneous grassland sites in the Hainich-Dün region of Central Germany. For each of these grassland sites we assessed habitat size, LUI (combined index of mowing, grazing and fertilization), and the proportion of grassland adjoining the sampling site and the landscape heterogeneity (the latter two factors within a 500 m buffer zone surrounding each focal site). We found only marginal genetic differentiation among all local populations and no correlation between geographical and genetic distance. Habitat size, LUI and landscape characteristics had only weak effects on most of the parameters of genetic diversity of C. parallelus; only expected heterozygosity and the grasshopper abundances were affected by interacting effects of LUI, habitat size and landscape characteristics. The lack of any strong relationships between LUI, abundance and the genetic structure might be due to large local populations of the species in the landscape, counteracting local differentiation and potential genetic drift effects. PMID:26064535

  4. Microbial community assessment of mealworm larvae (Tenebrio molitor) and grasshoppers (Locusta migratoria migratorioides) sold for human consumption.

    PubMed

    Stoops, J; Crauwels, S; Waud, M; Claes, J; Lievens, B; Van Campenhout, L

    2016-02-01

    In Western countries, the popularity of edible insects as an alternative animal protein source is increasing. Nevertheless, there is a lack of profound insight into the microbial safety and shelf life of living insects sold for human consumption. The purpose of this study was to characterise the microflora of fresh edible mealworm larvae and grasshoppers in a quantitative and qualitative way. Therefore, culture-dependent analyses (the total viable aerobic count, Enterobacteriaceae, lactic acid bacteria, yeasts and moulds, and bacterial endospores) and next-generation sequencing (454amplicon pyrosequencing) were performed. High microbial counts were obtained for both insect species. Different insect batches resulted in quite similar microbial numbers, except for bacterial endospores. However, the bacterial community composition differed between both insect species. The most abundant operational taxonomic unit in mealworm larvae was Propionibacterium. Also members of the genera Haemophilus, Staphylococcus and Clostridium were found. Grasshoppers were mainly dominated by Weissella, Lactococcus and Yersinia/Rahnella. Overall, a variety of potential spoilage bacteria and food pathogens were characterised. The results of this study suggest that a processing step with a microbiocidal effect is required to avoid or minimize risks involved with the consumption of edible insects.

  5. Microbial community assessment of mealworm larvae (Tenebrio molitor) and grasshoppers (Locusta migratoria migratorioides) sold for human consumption.

    PubMed

    Stoops, J; Crauwels, S; Waud, M; Claes, J; Lievens, B; Van Campenhout, L

    2016-02-01

    In Western countries, the popularity of edible insects as an alternative animal protein source is increasing. Nevertheless, there is a lack of profound insight into the microbial safety and shelf life of living insects sold for human consumption. The purpose of this study was to characterise the microflora of fresh edible mealworm larvae and grasshoppers in a quantitative and qualitative way. Therefore, culture-dependent analyses (the total viable aerobic count, Enterobacteriaceae, lactic acid bacteria, yeasts and moulds, and bacterial endospores) and next-generation sequencing (454amplicon pyrosequencing) were performed. High microbial counts were obtained for both insect species. Different insect batches resulted in quite similar microbial numbers, except for bacterial endospores. However, the bacterial community composition differed between both insect species. The most abundant operational taxonomic unit in mealworm larvae was Propionibacterium. Also members of the genera Haemophilus, Staphylococcus and Clostridium were found. Grasshoppers were mainly dominated by Weissella, Lactococcus and Yersinia/Rahnella. Overall, a variety of potential spoilage bacteria and food pathogens were characterised. The results of this study suggest that a processing step with a microbiocidal effect is required to avoid or minimize risks involved with the consumption of edible insects. PMID:26678139

  6. Expired and Pathogen-Inactivated Platelet Concentrates Support Differentiation and Immunomodulation of Mesenchymal Stromal Cells in Culture.

    PubMed

    Jonsdottir-Buch, Sandra Mjoll; Sigurgrimsdottir, Hildur; Lieder, Ramona; Sigurjonsson, Olafur Eysteinn

    2015-01-01

    Platelet lysates have been reported as suitable cell culture supplement for cultures of mesenchymal stromal cells (MSCs). The demand for safe and animal-free cultures of MSCs is linked to the potential application of MSCs in clinics. While the use of platelet lysates offers an alternative to animal serum in MSC cultures, obtaining supplies of fresh platelet concentrates for lysate production is challenging and raises concerns due to the already existing shortage of platelet donors. We have previously demonstrated that expired platelet concentrates may represent a good source of platelets for lysate production without competing with blood banks for platelet donors. The INTERCEPT Blood System™ treatment of platelet concentrates allows for prolonged storage up to 7 days, using highly specific technology based on amotosalen and UV-A light. The INTERCEPT system has therefore been implemented in blood processing facilities worldwide. In this study, we evaluated the suitability of INTERCEPT-treated, expired platelet concentrates, processed into platelet lysates, for the culture of MSCs compared to nontreated expired platelets. Bone marrow-derived MSCs were cultured in media supplemented with either platelet lysates from traditionally prepared expired platelet concentrates or in platelet lysates from expired and pathogen-inactivated platelet concentrates. The effects of pathogen inactivation on the ability of the platelets to support MSCs in culture were determined by evaluating MSC immunomodulation, immunophenotype, proliferation, and trilineage differentiation. Platelet lysates prepared from expired and pathogen-inactivated platelet concentrates supported MSC differentiation and immunosuppression better compared to traditionally prepared platelet lysates from expired platelet units. Pathogen inactivation of platelets with the INTERCEPT system prior to use in MSC culture had no negative effects on MSC immunophenotype or proliferation. In conclusion, the use of expired

  7. Infection of Melanoplus sanguinipes Grasshoppers following Ingestion of Rangeland Plant Species Harboring Vesicular Stomatitis Virus▿

    PubMed Central

    Drolet, Barbara S.; Stuart, Melissa A.; Derner, Justin D.

    2009-01-01

    Knowledge of the many mechanisms of vesicular stomatitis virus (VSV) transmission is critical for understanding of the epidemiology of sporadic disease outbreaks in the western United States. Migratory grasshoppers [Melanoplus sanguinipes (Fabricius)] have been implicated as reservoirs and mechanical vectors of VSV. The grasshopper-cattle-grasshopper transmission cycle is based on the assumptions that (i) virus shed from clinically infected animals would contaminate pasture plants and remain infectious on plant surfaces and (ii) grasshoppers would become infected by eating the virus-contaminated plants. Our objectives were to determine the stability of VSV on common plant species of U.S. Northern Plains rangelands and to assess the potential of these plant species as a source of virus for grasshoppers. Fourteen plant species were exposed to VSV and assayed for infectious virus over time (0 to 24 h). The frequency of viable virus recovery at 24 h postexposure was as high as 73%. The two most common plant species in Northern Plains rangelands (western wheatgrass [Pascopyrum smithii] and needle and thread [Hesperostipa comata]) were fed to groups of grasshoppers. At 3 weeks postfeeding, the grasshopper infection rate was 44 to 50%. Exposure of VSV to a commonly used grasshopper pesticide resulted in complete viral inactivation. This is the first report demonstrating the stability of VSV on rangeland plant surfaces, and it suggests that a significant window of opportunity exists for grasshoppers to ingest VSV from contaminated plants. The use of grasshopper pesticides on pastures would decrease the incidence of a virus-amplifying mechanical vector and might also decontaminate pastures, thereby decreasing the inter- and intraherd spread of VSV. PMID:19286779

  8. Direct detection and differentiation of pathogenic Leptospira species using a multi-gene targeted real time PCR approach.

    PubMed

    Ferreira, Ana Sofia; Costa, Pedro; Rocha, Teresa; Amaro, Ana; Vieira, Maria Luísa; Ahmed, Ahmed; Thompson, Gertrude; Hartskeerl, Rudy A; Inácio, João

    2014-01-01

    Leptospirosis is a growing public and veterinary health concern caused by pathogenic species of Leptospira. Rapid and reliable laboratory tests for the direct detection of leptospiral infections in animals are in high demand not only to improve diagnosis but also for understanding the epidemiology of the disease. In this work we describe a novel and simple TaqMan-based multi-gene targeted real-time PCR approach able to detect and differentiate Leptospira interrogans, L. kirschneri, L. borgpeteresenii and L. noguchii, which constitute the veterinary most relevant pathogenic species of Leptospira. The method uses sets of species-specific probes, and respective flanking primers, designed from ompL1 and secY gene sequences. To monitor the presence of inhibitors, a duplex amplification assay targeting both the mammal β-actin and the leptospiral lipL32 genes was implemented. The analytical sensitivity of all primer and probe sets was estimated to be <10 genome equivalents (GE) in the reaction mixture. Application of the amplification reactions on genomic DNA from a variety of pathogenic and non-pathogenic Leptospira strains and other non-related bacteria revealed a 100% analytical specificity. Additionally, pathogenic leptospires were successfully detected in five out of 29 tissue samples from animals (Mus spp., Rattus spp., Dolichotis patagonum and Sus domesticus). Two samples were infected with L. borgpetersenii, two with L. interrogans and one with L. kirschneri. The possibility to detect and identify these pathogenic agents to the species level in domestic and wildlife animals reinforces the diagnostic information and will enhance our understanding of the epidemiology of leptopirosis. PMID:25398140

  9. Direct Detection and Differentiation of Pathogenic Leptospira Species Using a Multi-Gene Targeted Real Time PCR Approach

    PubMed Central

    Ferreira, Ana Sofia; Costa, Pedro; Rocha, Teresa; Amaro, Ana; Vieira, Maria Luísa; Ahmed, Ahmed; Thompson, Gertrude; Hartskeerl, Rudy A.; Inácio, João

    2014-01-01

    Leptospirosis is a growing public and veterinary health concern caused by pathogenic species of Leptospira. Rapid and reliable laboratory tests for the direct detection of leptospiral infections in animals are in high demand not only to improve diagnosis but also for understanding the epidemiology of the disease. In this work we describe a novel and simple TaqMan-based multi-gene targeted real-time PCR approach able to detect and differentiate Leptospira interrogans, L. kirschneri, L. borgpeteresenii and L. noguchii, which constitute the veterinary most relevant pathogenic species of Leptospira. The method uses sets of species-specific probes, and respective flanking primers, designed from ompL1 and secY gene sequences. To monitor the presence of inhibitors, a duplex amplification assay targeting both the mammal β-actin and the leptospiral lipL32 genes was implemented. The analytical sensitivity of all primer and probe sets was estimated to be <10 genome equivalents (GE) in the reaction mixture. Application of the amplification reactions on genomic DNA from a variety of pathogenic and non-pathogenic Leptospira strains and other non-related bacteria revealed a 100% analytical specificity. Additionally, pathogenic leptospires were successfully detected in five out of 29 tissue samples from animals (Mus spp., Rattus spp., Dolichotis patagonum and Sus domesticus). Two samples were infected with L. borgpetersenii, two with L. interrogans and one with L. kirschneri. The possibility to detect and identify these pathogenic agents to the species level in domestic and wildlife animals reinforces the diagnostic information and will enhance our understanding of the epidemiology of leptopirosis. PMID:25398140

  10. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae.

    PubMed

    Azizi, Parisa; Rafii, Mohd Y; Mahmood, Maziah; Abdullah, Siti N A; Hanafi, Mohamed M; Nejat, Naghmeh; Latif, Muhammad A; Sahebi, Mahbod

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world's most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects that M. oryzae has on infected plants of these varieties. Real-time PCR was used to explore the differential expression of eight blast resistance genes among the ten local varieties. Blast disease has destructive effects on the growth of rice, and the findings of our study provide evidence that the Pikh, Pi9, Pi21, and Osw45 genes are involved in defence responses in the leaves of Malaysian rice at 31 h after inoculation with M. oryzae pathotype P7.2. Both the chlorophyll content and photosynthesis were reduced, but the levels of Pikh gene expression remained constant in susceptible varieties, with a developed pathogen population and mild or severe symptoms. The Pi9, Pi21, and Osw45 genes, however, were simultaneously upregulated in infected rice plants. Therefore, the presence of the Pikh, Pi9, Pi21, and Osw45 genes in the germplasm is useful for improving the resistance of rice varieties. PMID:26001124

  11. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae

    PubMed Central

    Mahmood, Maziah; Abdullah, Siti N. A.; Hanafi, Mohamed M.; Nejat, Naghmeh; Latif, Muhammad A.

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world’s most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects that M. oryzae has on infected plants of these varieties. Real-time PCR was used to explore the differential expression of eight blast resistance genes among the ten local varieties. Blast disease has destructive effects on the growth of rice, and the findings of our study provide evidence that the Pikh, Pi9, Pi21, and Osw45 genes are involved in defence responses in the leaves of Malaysian rice at 31 h after inoculation with M. oryzae pathotype P7.2. Both the chlorophyll content and photosynthesis were reduced, but the levels of Pikh gene expression remained constant in susceptible varieties, with a developed pathogen population and mild or severe symptoms. The Pi9, Pi21, and Osw45 genes, however, were simultaneously upregulated in infected rice plants. Therefore, the presence of the Pikh, Pi9, Pi21, and Osw45 genes in the germplasm is useful for improving the resistance of rice varieties. PMID:26001124

  12. Differential gene expression for Curvularia eragrostidis pathogenic incidence in crabgrass (Digitaria sanguinalis) revealed by cDNA-AFLP analysis.

    PubMed

    Wang, Jianshu; Wang, Xuemin; Yuan, Bohua; Qiang, Sheng

    2013-01-01

    Gene expression profiles of Digitaria sanguinalis infected by Curvularia eragrostidis strain QZ-2000 at two concentrations of conidia and two dew durations were analyzed by cDNA amplified fragment length polymorphisms (cDNA-AFLP). Inoculum strength was more determinant of gene expression than dew duration. A total of 256 primer combinations were used for selective amplification and 1214 transcript-derived fragments (TDFs) were selected for their differential expression. Of these, 518 up-regulated differentially expressed TDFs were identified. Forty-six differential cDNA fragments were chosen to be cloned and 35 of them were successfully cloned and sequenced, of which 25 were homologous to genes of known function according to the GenBank database. Only 6 genes were up-regulated in Curvularia eragrostidis-inoculated D. sanguinalis, with functions involved in signal transduction, energy metabolism, cell growth and development, stress responses, abscisic acid biosynthesis and response. It appears that a few pathways may be important parts of the pathogenic strategy of C. eragrostidis strain QZ-2000 on D. sanguinalis. Our study provides the fundamentals to further study the pathogenic mechanism, screen for optimal C. eragrostidis strains as potential mycoherbicide and apply this product to control D. sanguinalis.

  13. Use of an axenic medium for differentiation between pathogenic and nonpathogenic Naegleria fowleri isolates.

    PubMed

    De Jonckheere, J

    1977-04-01

    Growth in an axenic medium composed by Chang (3rd Int. Congr. Parasitol. Munich Abstr. ICPIII 1:187-188, 1974) allowed separation of pathogenic from nonpathogenic Naegleria fowleri strains, since only the former show luxuriant growth in this medium. On the basis of these results, this medium was used in early screening for virulent Naegleria isolates. During an extensive ecological study, data were obtained on 102 Naegleria strains. Twenty of these strains grew luxuriantly in this liquid medium. Seventeen of them were tested by intranasal instillation in mice, and all proved to be highly pathogenic. Strains showing only moderate growth or no growth at all in this axenic medium were found to be nonpathogenic for mice. Moreover, it was found that using this medium in the early stage of Naegleria sampling favors isolation of pathogenic strains in mixtures of Naegleria. During these experiments, further evidence was obtained that thermal polluted waters are the main origin of N. fowleri in the environment.

  14. Analysis of the Habitat of Henslow's Sparrows and Grasshopper Sparrows Compared to Random Grassland Areas

    SciTech Connect

    Maier, K.; Walton, R.; Kasper, P.

    2006-01-01

    ABSTRAC T Henslow’s Sparrows are endangered prairie birds, and Grasshopper Sparrows are considered rare prairie birds. Both of these birds were abundant in Illinois, but their populations have been declining due to loss of the grasslands. This begins an ongoing study of the birds’ habitat so Fermilab can develop a land management plan for the Henslow’s and Grasshoppers. The Henslow’s were found at ten sites and Grasshoppers at eight sites. Once the birds were located, the vegetation at their sites was studied. Measurements of the maximum plant height, average plant height, and duff height were taken and estimates of the percent of grass, forbs, duff, and bare ground were recorded for each square meter studied. The same measurements were taken at ten random grassland sites on Fermilab property. Several t-tests were performed on the data, and it was found that both Henslow’s Sparrows and Grasshopper Sparrows preferred areas with a larger percentage of grass than random areas. Henslow’s also preferred areas with less bare ground than random areas, while Grasshoppers preferred areas with more bare ground than random areas. In addition, Grasshopper Sparrows preferred a lower percentage of forbs than was found in random areas and a shorter average plant height than the random locations. Two-sample variance tests suggested significantly less variance for both Henslow’s Sparrows and Grasshopper Sparrows for maximum plant height in comparison to the random sites.

  15. Taxonomic and Functional Resilience of Grasshoppers (Orthoptera, Caelifera) to Fire in South Brazilian Grasslands.

    PubMed

    Ferrando, C P R; Podgaiski, L R; Costa, M K M; Mendonça, M D S

    2016-08-01

    Fire is a frequent disturbance in grassland ecosystems enabling variability in habitat characteristics and creating important environmental filters for community assembly. Changes in vegetation have a large influence on herbivore insect assemblages. Here, we explored the responses of grasshoppers to disturbance by fire in grasslands of southern Brazil through a small-scale experiment based in paired control and burned plots. The resilience of grasshoppers was assessed by monitoring changes to their abundance, taxonomic, and functional parameters along time. Burned patches have been already recolonized by grasshoppers 1 month after fire and did not differ in terms of abundance and richness from control areas in any evaluated time within 1 year. Simpson diversity decreased 1 month after fire due to the increased dominance of Dichroplus misionensis (Carbonell) and Orphulella punctata (De Geer). In this period, grasshoppers presented in average a smaller body and a larger relative head size; these are typically nymph characteristics, which are possibly indicating a preference of juveniles for the young high-quality vegetation, or a diminished vulnerability to predation in open areas. Further, at 6 months after fire grasshoppers with smaller relative hind femur and thus lower dispersal ability seemed to be benefitted in burned patches. Finally, 1 year after fire grasshoppers became more similar to each other in relation to their set of traits. This study demonstrates how taxonomic and functional aspects of grasshopper assemblages can be complementary tools to understand their responses to environmental change. PMID:26957086

  16. Divergence of cuticular hydrocarbons in two sympatric grasshopper species and the evolution of fatty acid synthases and elongases across insects

    PubMed Central

    Finck, Jonas; Berdan, Emma L.; Mayer, Frieder; Ronacher, Bernhard; Geiselhardt, Sven

    2016-01-01

    Cuticular hydrocarbons (CHCs) play a major role in the evolution of reproductive isolation between insect species. The CHC profiles of two closely related sympatric grasshopper species, Chorthippus biguttulus and C. mollis, differ mainly in the position of the first methyl group in major methyl-branched CHCs. The position of methyl branches is determined either by a fatty acid synthase (FAS) or by elongases. Both protein families showed an expansion in insects. Interestingly, the FAS family showed several lineage-specific expansions, especially in insect orders with highly diverse methyl-branched CHC profiles. We found five putative FASs and 12 putative elongases in the reference transcriptomes for both species. A dN/dS test showed no evidence for positive selection acting on FASs and elongases in these grasshoppers. However, one candidate FAS showed species-specific transcriptional differences and may contribute to the shift of the methyl-branch position between the species. In addition, transcript levels of four elongases were expressed differentially between the sexes. Our study indicates that complex methyl-branched CHC profiles are linked to an expansion of FASs genes, but that species differences can also mediated at the transcriptional level. PMID:27677406

  17. A system for the distribution of differential host and pathogen sets.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The vegetable seed industry has been concerned with inconsistent naming of pathogen strains and races which has led to confusion in disease resistance claims. In August 2007, an American Phytopathological Society adhoc committee in cooperation with the International Seed Federation (ISF) was establi...

  18. Differential host response, rather than early viral replication efficiency, correlates with pathogenicity caused by influenza viruses.

    PubMed

    Askovich, Peter S; Sanders, Catherine J; Rosenberger, Carrie M; Diercks, Alan H; Dash, Pradyot; Navarro, Garnet; Vogel, Peter; Doherty, Peter C; Thomas, Paul G; Aderem, Alan

    2013-01-01

    Influenza viruses exhibit large, strain-dependent differences in pathogenicity in mammalian hosts. Although the characteristics of severe disease, including uncontrolled viral replication, infection of the lower airway, and highly inflammatory cytokine responses have been extensively documented, the specific virulence mechanisms that distinguish highly pathogenic strains remain elusive. In this study, we focused on the early events in influenza infection, measuring the growth rate of three strains of varying pathogenicity in the mouse airway epithelium and simultaneously examining the global host transcriptional response over the first 24 hours. Although all strains replicated equally rapidly over the first viral life-cycle, their growth rates in both lung and tracheal tissue strongly diverged at later times, resulting in nearly 10-fold differences in viral load by 24 hours following infection. We identified separate networks of genes in both the lung and tracheal tissues whose rapid up-regulation at early time points by specific strains correlated with a reduced viral replication rate of those strains. The set of early-induced genes in the lung that led to viral growth restriction is enriched for both NF-κB binding site motifs and members of the TREM1 and IL-17 signaling pathways, suggesting that rapid, NF-κB -mediated activation of these pathways may contribute to control of viral replication. Because influenza infection extending into the lung generally results in severe disease, early activation of these pathways may be one factor distinguishing high- and low-pathogenicity strains.

  19. Novel utilization of the outer membrane proteins for the identification and differentiation of pathogenic versus nonpathogenic microbial strains using mass spectrometry-based proteomics approach

    NASA Astrophysics Data System (ADS)

    Jabbour, Rabih E.; Wade, Mary; Deshpande, Samir V.; McCubbin, Patrick; Snyder, A. Peter; Bevilacqua, Vicky

    2012-06-01

    Mass spectrometry based proteomic approaches are showing promising capabilities in addressing various biological and biochemical issues. Outer membrane proteins (OMPs) are often associated with virulence in gram-negative pathogens and could prove to be excellent model biomarkers for strain level differentiation among bacteria. Whole cells and OMP extracts were isolated from pathogenic and non-pathogenic strains of Francisella tularensis, Burkholderia thailandensis, and Burkholderia mallei. OMP extracts were compared for their ability to differentiate and delineate the correct database organism to an experimental sample and for the degree of dissimilarity to the nearest-neighbor database strains. This study addresses the comparative experimental proteome analyses of OMPs vs. whole cell lysates on the strain-level discrimination among gram negative pathogenic and non-pathogenic strains.

  20. Song variation and environmental auditory masking in the grasshopper sparrow

    NASA Astrophysics Data System (ADS)

    Lohr, Bernard; Dooling, Robert J.; Gill, Douglas E.

    2001-05-01

    Some grassland bird species, in particular grasshopper sparrows (Ammodramus savannarum), sing songs with especially high mean frequencies (7.0-8.0 kHz). Acoustic interference is one potential explanation for the evolution of high frequency vocalizations, particularly in open habitats. We tested predictions from a model of effective auditory communication distances to understand the potential effects of vocal production and environmental auditory masking on vocal behavior and territoriality. Variation in the spectral structure of songs and the size and shape of territories was measured for grasshopper sparrows in typical grassland habitats. Median territory areas were 1629 m2 at a site in the center of the species range in Nebraska, and 1466 m2 at our study site in Maryland, with average territory diameters measuring 20.2 m. Species densities and sound pressure levels also were determined for stridulating insects and other noise sources in the habitat. Based on current models of effective communication distances, known noise levels, and information on hearing abilities, our results suggest that auditory sensitivity and environmental noise could be factors influencing the mean frequency and spatial dynamics of territorial behavior in grassland birds. [Work supported by NIH and the CRFRC.

  1. [Correlation between monthly average temperature and grasshopper outbreak in the region around Qinghai Lake based on GIS].

    PubMed

    Zhang, Hongliang; Ni, Shaoxiang; Deng, Ziwang; Chen, Yun

    2002-07-01

    It is necessary to study the relationship between grasshopper and ecological factors for forecasting grasshopper outbreak effectively. Temperature is one of main factors influencing grasshopper outbreak in the region around Qinghai Lake. With the support of Arc/Info and ArcView, monthly average temperatures were simulated under the scale of 150 m by data from sixteen meteorological stations adjacent to Qinghai Lake for adapting the comprehensive method and establishing spatial temperature database. Then, the relationship between grasshopper outbreak and monthly average temperature were analyzed by combining the spatial data of grasshopper density and the spatial data of monthly average temperature. The result showed that effects of monthly average temperature on Grasshopper outbreak were closely related to the life cycle of the dominant grasshopper species in the region, namely, monthly average temperatures of May, June, and July influenced grasshopper outbreak in the current year, and monthly average temperatures of August and September influenced grasshopper outbreak in the next year. Thereby, it could provide a base of establishing forecasting models of grasshopper outbreak. PMID:12385214

  2. Detection and differentiation of foodborne pathogenic bacteria in mung bean sprouts using field deployable label-free SERS devices.

    PubMed

    Wu, Xiaomeng; Xu, Chao; Tripp, Ralph A; Huang, Yao-wen; Zhao, Yiping

    2013-05-21

    Vancomycin functionalized silver nanorod arrays substrates were used to obtain the surface enhanced Raman scattering (SERS) signals of six foodborne pathogenic bacteria in mung bean sprouts samples using both a portable and a handheld Raman system. The silver nanorod arrays substrates were optimized to facilitate quantitative, rapid, and sensitive detection of Salmonella enterica serotype Anatum, Salmonella enterica serotype Cubana, Salmonella enterica serotype Stanley, Salmonella enteritidis, Escherichia coli O157:H7, and Staphylococcus epidermidis. Substrate optimization was achieved by varying the nanorod length and vancomycin incubation concentration. By combining these substrates with a two-step filtration process we found that the foodborne pathogenic bacteria used in this study can be identified in mung bean sprouts with a limit of detection as low as 100 CFU ml(-1) in less than 4 h using both portable and handheld Raman systems. The results show that SERS spectra can be used to differentiate between bacterial species and serotypes when chemometric methods are employed. The low detection limit and rapid detection time of this biosensing platform for foodborne pathogenic bacteria could be a valuable field detection method for the fresh produce and food processing industries.

  3. Customizable PCR-microplate array for differential identification of multiple pathogens

    PubMed Central

    Woubit, Abdela; Yehualaeshet, Teshome; Roberts, Sherrelle; Graham, Martha; Kim, Moonil; Samuel, Temesgen

    2014-01-01

    Customizable PCR-microplate arrays were developed for the rapid identification of Francisella tularensis subsp. tularensis, Salmonella Typhi, Shigella dysenteriae, Yersinia pestis, Vibrio cholerae Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Saintpaul, Francisella tularensis subsp. novicida, Vibrio parahaemolyticus, and Yersinia pseudotuberculosis. Previously, we identified highly specific primers targeting each of the pathogens above. Here, we report the development of customizable PCR-microplate arrays for simultaneous identification of the pathogens using the primers. A mixed aliquot of genomic DNA from 38 different strains was used to validate three PCR-microplate array formats. Identical PCR conditions were used to run all the samples on the three formats. Results show specific amplifications on all the three custom plates. In a preliminary test to evaluate the sensitivity of these assays in laboratory-inoculated samples, detection limits as low as 9 cfu/g/ml S. Typhimurium were obtained from beef hot dog, and 78 cfu/ml from milk. Such microplate arrays could serve as valuable tools for initial identification or secondary confirmation of these pathogens. PMID:24215700

  4. Influence of individual body size on reproductive traits in Melanopline grasshoppers (Orthoptera: Acrididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Body size is a fundamental trait of an organism, affecting most aspects of its performance, including reproduction. Numerous biotic and environmental factors can influence individual body size and reproduction in grasshoppers. Using data from four experiments, I examined intraspecific relationships ...

  5. Analysis of the habitat of Henslow's sparrows and Grasshopper sparrows compared to random grassland areas

    SciTech Connect

    Maier, Kristen; Walton, Rod; Kasper, Peter; /Fermilab

    2005-01-01

    Henslow's Sparrows are endangered prairie birds, and Grasshopper Sparrows are considered rare prairie birds. Both of these birds were abundant in Illinois, but their populations have been declining due to loss of the grasslands. This begins an ongoing study of the birds habitat so Fermilab can develop a land management plan for the Henslow's and Grasshoppers. The Henslow's were found at ten sites and Grasshoppers at eight sites. Once the birds were located, the vegetation at their sites was studied. Measurements of the maximum plant height, average plant height, and duff height were taken and estimates of the percent of grass, forbs, duff, and bare ground were recorded for each square meter studied. The same measurements were taken at ten random grassland sites on Fermilab property. Several t-tests were performed on the data, and it was found that both Henslow's Sparrows and Grasshopper Sparrows preferred areas with a larger percentage of grass than random areas. Henslow's also preferred areas with less bare ground than random areas, while Grasshoppers preferred areas with more bare ground than random areas. In addition, Grasshopper Sparrows preferred a lower percentage of forbs than was found in random areas and a shorter average plant height than the random locations. Two-sample variance tests suggested significantly less variance for both Henslow's Sparrows and Grasshopper Sparrows for maximum plant height in comparison to the random sites. For both birds, the test suggested a significant difference in the variance of the percentage of bare ground compared to random sites, but only the Grasshopper Sparrow showed significance in the variation in the percentage of forbs.

  6. Differential effects of lesion mimic mutants in barley on disease development by facultative pathogens.

    PubMed

    McGrann, Graham R D; Steed, Andrew; Burt, Christopher; Nicholson, Paul; Brown, James K M

    2015-06-01

    Lesion mimic mutants display spontaneous necrotic spots and chlorotic leaves as a result of mis-regulated cell death programmes. Typically these mutants have increased resistance to biotrophic pathogens but their response to facultative fungi that cause necrotrophic diseases is less well studied. The effect of altered cell death regulation on the development of disease caused by Ramularia collo-cygni, Fusarium culmorum and Oculimacula yallundae was explored using a collection of barley necrotic (nec) lesion mimic mutants. nec8 mutants displayed lower levels of all three diseases compared to nec9 mutants, which had increased R. collo-cygni but decreased F. culmorum disease symptoms. nec1 mutants reduced disease development caused by both R. collo-cygni and F. culmorum. The severity of the nec1-induced lesion mimic phenotype and F. culmorum symptom development was reduced by mutation of the negative cell death regulator MLO. The significant reduction in R. collo-cygni symptoms caused by nec1 was completely abolished in the presence of the mlo-5 allele and both symptoms and fungal biomass were greater than in the wild-type. These results indicate that physiological pathways involved in regulation of cell death interact with one another in their effects on different fungal pathogens. PMID:25873675

  7. Histidine kinases mediate differentiation, stress response, and pathogenicity in Magnaporthe oryzae

    PubMed Central

    Jacob, Stefan; Foster, Andrew J; Yemelin, Alexander; Thines, Eckhard

    2014-01-01

    The aim of this study is a functional characterization of 10 putative histidine kinases (HIKs)-encoding genes in the phytopathogenic fungus Magnaporthe oryzae. Two HIKs were found to be required for pathogenicity in the fungus. It was found that the mutant strains ΔMohik5 and ΔMohik8 show abnormal conidial morphology and furthermore ΔMohik5 is unable to form appressoria. Both HIKs MoHik5p and MoHik8p appear to be essential for pathogenicity since the mutants fail to infect rice plants. MoSln1p and MoHik1p were previously reported to be components of the HOG pathway in M. oryzae. The ΔMosln1 mutant is more susceptible to salt stress compared to ΔMohik1, whereas ΔMohik1 appears to be stronger affected by osmotic or sugar stress. In contrast to yeast, the HOG signaling cascade in phytopathogenic fungi apparently comprises more elements. Furthermore, vegetative growth of the mutants ΔMohik5 and ΔMohik9 was found to be sensitive to hypoxia-inducing NaNO2-treatment. Additionally, it was monitored that NaNO2-treatment resulted in MoHog1p phosphorylation. As a consequence we assume a first simplified model for hypoxia signaling in M. oryzae including the HOG pathway and the HIKs MoHik5p and MoHik9p. PMID:25103193

  8. Differential effects of lesion mimic mutants in barley on disease development by facultative pathogens

    PubMed Central

    McGrann, Graham R. D.; Steed, , Andrew; Burt, Christopher; Nicholson, Paul; Brown, James K. M.

    2015-01-01

    Lesion mimic mutants display spontaneous necrotic spots and chlorotic leaves as a result of mis-regulated cell death programmes. Typically these mutants have increased resistance to biotrophic pathogens but their response to facultative fungi that cause necrotrophic diseases is less well studied. The effect of altered cell death regulation on the development of disease caused by Ramularia collo-cygni, Fusarium culmorum and Oculimacula yallundae was explored using a collection of barley necrotic (nec) lesion mimic mutants. nec8 mutants displayed lower levels of all three diseases compared to nec9 mutants, which had increased R. collo-cygni but decreased F. culmorum disease symptoms. nec1 mutants reduced disease development caused by both R. collo-cygni and F. culmorum. The severity of the nec1-induced lesion mimic phenotype and F. culmorum symptom development was reduced by mutation of the negative cell death regulator MLO. The significant reduction in R. collo-cygni symptoms caused by nec1 was completely abolished in the presence of the mlo-5 allele and both symptoms and fungal biomass were greater than in the wild-type. These results indicate that physiological pathways involved in regulation of cell death interact with one another in their effects on different fungal pathogens. PMID:25873675

  9. Genetic differentiation and recombination among geographic populations of the fungal pathogen Colletotrichum truncatum from chili peppers in China.

    PubMed

    Diao, Yongzhao; Zhang, Can; Xu, Jianping; Lin, Dong; Liu, Li; Mtung'e, Olivo G; Liu, Xili

    2015-01-01

    Colletotrichum truncatum is an extremely important fungal pathogen. It can cause diseases both in humans and in over 460 plant species. However, little is known about its genetic diversity within and among populations. One of the major plant hosts of C. truncatum is pepper, and China is one of the main pepper-producing countries in the world. Here, we propose the hypotheses that geography has a major influence on the relationships among populations of C. truncatum in China and that infections in different populations need to be managed differently. To test these hypotheses, we obtained and analyzed 266 C. truncatum isolates from 13 regions representing the main pepper-growing areas throughout China. The analysis based on nine microsatellite markers identified high intrapopulation genetic diversity, evidence of sexual recombination, and geographic differentiation. The genetic differentiation was positively correlated with geographic distance, with the southern and northern China populations grouped in two distinct clusters. Interestingly, isolates collected from the pepper-breeding center harbored the most private alleles. The results suggest that the geographic populations of C. truncatum on peppers in China are genetically differentiated and should be managed accordingly. Our study also provides a solid foundation from which to further explore the global genetic epidemiology of C. truncatum in both plants and humans. PMID:25667606

  10. Genetic differentiation and recombination among geographic populations of the fungal pathogen Colletotrichum truncatum from chili peppers in China.

    PubMed

    Diao, Yongzhao; Zhang, Can; Xu, Jianping; Lin, Dong; Liu, Li; Mtung'e, Olivo G; Liu, Xili

    2015-01-01

    Colletotrichum truncatum is an extremely important fungal pathogen. It can cause diseases both in humans and in over 460 plant species. However, little is known about its genetic diversity within and among populations. One of the major plant hosts of C. truncatum is pepper, and China is one of the main pepper-producing countries in the world. Here, we propose the hypotheses that geography has a major influence on the relationships among populations of C. truncatum in China and that infections in different populations need to be managed differently. To test these hypotheses, we obtained and analyzed 266 C. truncatum isolates from 13 regions representing the main pepper-growing areas throughout China. The analysis based on nine microsatellite markers identified high intrapopulation genetic diversity, evidence of sexual recombination, and geographic differentiation. The genetic differentiation was positively correlated with geographic distance, with the southern and northern China populations grouped in two distinct clusters. Interestingly, isolates collected from the pepper-breeding center harbored the most private alleles. The results suggest that the geographic populations of C. truncatum on peppers in China are genetically differentiated and should be managed accordingly. Our study also provides a solid foundation from which to further explore the global genetic epidemiology of C. truncatum in both plants and humans.

  11. Analysis of Spatial Pattern among Grasshopper and Vegetation in Heihe based on GIS

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Wang, KeMing; Zhao, Chengzhang; Zhang, Qi-peng

    Geostatistics was used to analyze the grasshopper and dominant plants population spatial pattern and their relationship in the upper reaches of Heihe River under GIS platform. The results showed that the plants and grasshoppers populations have strong spatial correlation in study area. The Semivariogram curve of Chorthippus brunneus huabeiensis, Filchnerella, Aneurolepidium dasystanchys and Artemisia dalailamae is spherical model, Gomphocerus licenti and Stipa krylovii's Semivariogram curve is exponential and Gaussian model respectively, and their spatial autocorrelation scope is 10.8, 11.3, 11.5, 12.4, 23.5 and 59.7 meters respectively. Stipa krylovii and Artemisia dalailamae spatial distribution was patchy, Aneurolepidium dasystanchys showed flaky distribution; Gomphocerus licenti and Chorthippus brunneus huabeiensis mainly located in southeast areas with high coverage of Stipa krylovii and Aneurolepidium dasystanchys. Filchnerella nearly located in North areas with high coverage of Artemisia dalailamae, but were rarely found in south and east areas. The effects of different plants coverage on grasshopper abundance are significantly different. Filchnerella abundance and Artemisia dalailamae coverage showed significantly positive correlation, Chorthippus brunneus huabeiensis and Gomphocerus licenti positively correlated with Aneurolepidium dasystanchys and Stipa krylovii. Grasshopper spatial patterns and occurrence numbers are both influenced by grasshopper biological characteristics and plant community composition, which reflected complex coupled relation between grasshopper and plant.

  12. Non-pathogenic bacteria elicit a differential cytokine response by intestinal epithelial cell/leucocyte co-cultures

    PubMed Central

    Haller, D; Bode, C; Hammes, W; Pfeifer, A; Schiffrin, E; Blum, S

    2000-01-01

    BACKGROUND AND AIM—Intestinal epithelial cells (IEC) are thought to participate in the mucosal defence against bacteria and in the regulation of mucosal tissue homeostasis. Reactivity of IEC to bacterial signals may depend on interactions with immunocompetent cells. To address the question of whether non-pathogenic bacteria modify the immune response of the intestinal epithelium, we co-cultivated enterocyte-like CaCO-2 cells with human blood leucocytes in separate compartments of transwell cultures.
METHODS—CaCO-2/PBMC co-cultures were stimulated with non-pathogenic bacteria and enteropathogenic Escherichia coli. Expression of tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-8, monocyte chemoattracting protein 1 (MCP-1), and IL-10 was studied by enzyme linked immunosorbent assays (cytokine secretion) and by semiquantitative reverse transcription-polymerase chain reaction.
RESULTS—Challenge of CaCO-2 cells with non-pathogenic E coli and Lactobacillus sakei induced expression of IL-8, MCP-1, IL-1β, and TNF-α mRNA in the presence of underlying leucocytes. Leucocyte sensitised CaCO-2 cells produced TNF-α and IL-1β whereas IL-10 was exclusively secreted by human peripheral blood mononuclear cells. CaCO-2 cells alone remained hyporesponsive to the bacterial challenge. Lactobacillus johnsonii, an intestinal isolate, showed reduced potential to induce proinflammatory cytokines but increased transforming growth factor beta mRNA in leucocyte sensitised CaCO-2 cells. TNF-α was identified as one of the early mediators involved in cellular cross talk. In the presence of leucocytes, discriminative activation of CaCO-2 cells was observed between enteropathogenic E coli and non-pathogenic bacteria.
CONCLUSION—The differential recognition of non-pathogenic bacteria by CaCO-2 cells required the presence of underlying leucocytes. These results strengthen the hypothesis that bacterial signalling at the mucosal surface is dependent on a network of

  13. Dimorphism in Histoplasma capsulatum: a model for the study of cell differentiation in pathogenic fungi.

    PubMed Central

    Maresca, B; Kobayashi, G S

    1989-01-01

    Several fungi can assume either a filamentous or a unicellular morphology in response to changes in environmental conditions. This process, known as dimorphism, is a characteristic of several pathogenic fungi, e.g., Histoplasma capsulatum, Blastomyces dermatitidis, and Paracoccidioides brasiliensis, and appears to be directly related to adaptation from a saprobic to a parasitic existence. H. capsulatum is the most extensively studied of the dimorphic fungi, with a parasitic phase consisting of yeast cells and a saprobic mycelial phase. In culture, the transition of H. capsulatum from one phase to the other can be triggered reversibly by shifting the temperature of incubation between 25 degrees C (mycelia) and 37 degrees C (yeast phase). Mycelia are found in soil and never in infected tissue, in contrast to the yeast phase, which is the only form present in patients. The temperature-induced phase transition and the events in establishment of the disease state are very likely to be intimately related. Furthermore, the temperature-induced phase transition implies that each growth phase is an adaptation to two critically different environments. A fundamental question concerning dimorphism is the nature of the signal(s) that responds to temperature shifts. So far, both the responding cell component(s) and the mechanism(s) remain unclear. This review describes the work done in the last several years at the biochemical and molecular levels on the mechanisms involved in the mycelium to yeast phase transition and speculates on possible models of regulation of morphogenesis in dimorphic pathogenic fungi. Images PMID:2666842

  14. Differential efficiency among DNA extraction methods influences detection of the amphibian pathogen Batrachochytrium dendrobatidis.

    PubMed

    Bletz, M C; Rebollar, E A; Harris, R N

    2015-02-10

    Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is responsible for massive declines and extinctions of amphibians worldwide. The most common method for detecting Bd is quantitative polymerase chain reaction (qPCR). qPCR is a highly sensitive detection technique, but its ability to determine the presence and accurately quantify the amount of Bd is also contingent on the efficiency of the DNA extraction method used prior to PCR. Using qPCR, we compared the extraction efficiency of 3 different extraction methods commonly used for Bd detection across a range of zoospore quantities: PrepMan Ultra Reagent, Qiagen DNeasy Blood and Tissue Kit, and Mobio PowerSoil DNA Isolation Kit. We show that not all extraction methods led to successful detection of Bd for the low zoospore quantities and that there was variation in the estimated zoospore equivalents among the methods, which demonstrates that these methods have different extraction efficiencies. These results highlight the importance of considering the extraction method when comparing across studies. The Qiagen DNeasy kit had the highest efficiency. We also show that replicated estimates of less than 1 zoospore can result from known zoospore concentrations; therefore, such results should be considered when obtained from field data. Additionally, we discuss the implications of our findings for interpreting previous studies and for conducting future Bd surveys. It is imperative to use the most efficient DNA extraction method in tandem with the highly sensitive qPCR technique in order to accurately diagnose the presence of Bd as well as other pathogens.

  15. Oviposition digging in the grasshopper. II. Descending neural control.

    PubMed

    Thompson, K J

    1986-05-01

    Transection of the ventral nerve cord of female grasshoppers activates the rhythmical motor programme for oviposition digging. Electrical stimulation of the cut nerve cord had the following effects on elicited oviposition motor activity: short- and long-lasting inhibition of activity, phase resetting and modulation of burst frequency. Cold saline applied to the nerve cord reversibly elicited the oviposition motor programme. The effects of transection and stimulation at different levels of the nerve cord indicate that the higher neural control of the motor pattern is not confined to the head ganglia, but includes a thoracic component. In intracellular recordings of ventral opener motoneurones, stimulus-related IPSPs were observed in response to stimulation of the cut nerve cord. Stimulation also abolished slow wave synaptic input to the motoneurones during inhibition of the oviposition motor programme. It is suggested that oviposition digging behaviour is initiated and maintained by a mechanism of 'release' from descending neural inhibition.

  16. Chromosomal Speciation Revisited: Modes of Diversification in Australian Morabine Grasshoppers (Vandiemenella, viatica Species Group)

    PubMed Central

    Kawakami, Takeshi; Butlin, Roger K.; Cooper, Steven J. B.

    2011-01-01

    Chromosomal rearrangements can alter the rate and patterns of gene flow within or between species through a reduction in the fitness of chromosomal hybrids or by reducing recombination rates in rearranged areas of the genome. This concept, together with the observation that many species have structural variation in chromosomes, has led to the theory that the rearrangements may play a direct role in promoting speciation. Australian morabine grasshoppers (genus Vandiemenella, viatica species group) are an excellent model for studying the role of chromosomal rearrangement in speciation because they show extensive chromosomal variation, parapatric distribution patterns, and narrow hybrid zones at their boundaries. This species group stimulated development of one of the classic chromosomal speciation models, the stasipatric speciation model proposed by White in 1968. Our population genetic and phylogeographic analyses revealed extensive non-monophyly of chromosomal races along with historical and on-going gene introgression between them. These findings suggest that geographical isolation leading to the fixation of chromosomal variants in different geographic regions, followed by secondary contact, resulted in the present day parapatric distributions of chromosomal races. The significance of chromosomal rearrangements in the diversification of the viatica species group can be explored by comparing patterns of genetic differentiation between rearranged and co-linear parts of the genome. PMID:26467499

  17. Multiple independent colonization of the Canary Islands by the winged grasshopper genus Sphingonotus Fieber, 1852.

    PubMed

    Husemann, Martin; Deppermann, Jana; Hochkirch, Axel

    2014-12-01

    Volcanic archipelagos represent ideal systems to study processes of colonization, differentiation and speciation. The Canary Islands are one of the best studied archipelagos, being composed of seven main islands with a well-known geological history. Most taxa have colonized these islands stepwise from the African or Iberian mainland from east to west, following their geological origin as well as the predominating wind direction and ocean currents. Furthermore, within-island radiations have been reported for several taxa. The grasshopper genus Sphingonotus is species-rich and occurs with nine fully winged species on the Canary Islands, seven of which are endemic to single or few islands. We inferred a phylogeny of these species and their North African and Iberian relatives based upon sequences of three mitochondrial genes and one nuclear gene of 136 specimens. Surprisingly, our results suggest that almost all Sphingonotus species colonized the archipelago independently from the mainland and nearly no inter-island colonization occurred. Despite their strong flight capabilities, only one pair of endemic species are closely related (S. sublaevis from Gran Canary and S. pachecoi from Lanzarote). Moreover, no within-island speciation events were detected. We hypothesize that passive wind dispersal from the African mainland was the main driver of the colonization process and that most Sphingonotus species are not able to cover inter-island distances by active flight. This, together with strong intrageneric niche overlap might explain the lack of within-island speciation in this taxon.

  18. Comparative cytogenetic analysis of two grasshopper species of the tribe Abracrini (Ommatolampinae, Acrididae)

    PubMed Central

    de França Rocha, Marília; de Melo, Natoniel Franklin; de Souza, Maria José

    2011-01-01

    The grasshopper species Orthoscapheus rufipes and Eujivarus fusiformis were analyzed using several cytogenetic techniques. The karyotype of O. rufipes, described here for the first time, had a diploid number of 2n = 23, whereas E. fusiformis had a karyotype with 2n = 21. The two species showed the same mechanism of sex determination (XO type) but differed in chromosome morphology. Pericentromeric blocks of constitutive heterochromatin (CH) were detected in the chromosome complement of both species. CMA3/DA/DAPI staining revealed CMA3-positive blocks in CH regions in four autosomal bivalents of O. rufipes and in two of E. fusiformis. The location of active NORs differed between the two species, occurring in bivalents M6 and S9 of O. rufipes and M6 and M7 of E. fusiformsi. The rDNA sites revealed by FISH coincided with the number and position of the active NORs detected by AgNO3 staining. The variability in chromosomal markers accounted for the karyotype differentiation observed in the tribe Abracrini. PMID:21734819

  19. Salmonella pathogenicity island 1 differentially modulates bacterial entry to dendritic and non-phagocytic cells

    PubMed Central

    Bueno, Susan M; Wozniak, Aniela; Leiva, Eduardo D; Riquelme, Sebastián A; Carreño, Leandro J; Hardt, Wolf-Dietrich; Riedel, Claudia A; Kalergis, Alexis M

    2010-01-01

    Salmonella enterica serovar Typhimurium can enter non-phagocytic cells, such as intestinal epithelial cells, by virtue of a Type Three Secretion System (TTSS) encoded in the Salmonella Pathogenicity Island 1 (SPI-1), which translocates bacterial effector molecules into the host cell. Salmonella can also be taken up by dendritic cells (DCs). Although the role of SPI-1 in non-phagocytic cell invasion is well established, its contribution to invasion of phagocytic cells has not been evaluated. Here, we have tested the invasive capacity of a S. Typhimurium strain lacking a key component of its TTSS-1 (ΔInvC) leading to defective translocation of SPI-1-encoded effectors. Whereas this mutant Salmonella strain was impaired for invasion of non-phagocytic cells, it was taken up by DCs at a significantly higher rate than wild-type Salmonella. Similar to wild-type Salmonella, the ΔInvC mutant strain retained the capacity to avoid antigen presentation to T cells. However, mice infected with the ΔInvC mutant strain showed higher survival rate and reduced organ colonization. Our data suggest that, besides promoting phagocytosis by non-phagocytic cells, SPI-1 modulates the number of bacteria that enters DCs. The SPI-1 could be considered not only as an inducer of epithelial cell invasion but as a controller of DC entry. PMID:20201987

  20. Differential effects of catecholamines on in vitro growth of pathogenic bacteria

    NASA Technical Reports Server (NTRS)

    Belay, Tesfaye; Sonnenfeld, Gerald

    2002-01-01

    Supplementation of minimal medium inoculated with bacterial cultures with norepinephrine, epinephrine, dopamine, or isoproterenol resulted in marked increases in growth compared to controls. Norepinephrine and dopamine had the greatest enhancing effects on growth of cultures of Pseudomonas aeruginosa and Klebsiella pneumoniae, while epinephrine and isoproterenol also enhanced growth to a lesser extent. The growth of Escherichia coli in the presence of norepinephrine was greater than growth in the presence of the three other neurochemicals used in the study. Growth of Staphylococcus aureus was also enhanced in the presence of norepinephrine, but not to the same degree as was the growth of gram negative bacteria. Addition of culture supernatants from E. coli cultures that had been grown in the presence of norepinephrine was able to enhance the growth of K. pneumoniae. Addition of the culture supernatant fluid culture from E. coli cultures that had been grown in the presence of norepinephrine did not enhance growth of P. aeruginosa or S. aureus. Culture supernatant fluids from bacteria other than E. coli grown in the presence of norepinephrine were not able to enhance the growth of any bacteria tested. The results suggest that catecholamines can enhance growth of pathogenic bacteria, which may contribute to development of pathogenesis; however, there is no uniform effect of catecholamines on bacterial growth.

  1. Differential immune response of mallard duck peripheral blood mononuclear cells to two highly pathogenic avian influenza H5N1 viruses with distinct pathogenicity in mallard ducks.

    PubMed

    Cui, Zhu; Hu, Jiao; He, Liang; Li, Qunhui; Gu, Min; Wang, Xiaoquan; Hu, Shunlin; Liu, Huimou; Liu, Wenbo; Liu, Xiaowen; Liu, Xiufan

    2014-02-01

    CK10 and GS10 are two H5N1 highly pathogenic influenza viruses of similar genetic background but differ in their pathogenicity in mallard ducks. CK10 is highly pathogenic whereas GS10 is low pathogenic. In this study, strong inflammatory response in terms of the expression level of several cytokines was observed in mallard duck peripheral blood mononuclear cells (PBMC) infected with CK10 while mild response was triggered in those by GS10 infection. Two remarkable and intense peaks of immune response were induced by CK10 infection within 24 hours (at 8 and 24 hours post infection, respectively) without reducing the virus replication. Our observations indicated that sustained and intense innate immune responses may be central to the high pathogenicity caused by CK10 in ducks.

  2. A modified visual loop-mediated isothermal amplification method for diagnosis and differentiation of main pathogens from Mycobacterium tuberculosis complex.

    PubMed

    Hong, Ming; Zha, Lei; Fu, Wenliang; Zou, Minji; Li, Wuju; Xu, Donggang

    2012-02-01

    This study was aimed to rapidly identify and differentiate two main pathogens of the Mycobacterium tuberculosis complex: Mycobacterium tuberculosis subsp. tuberculosis and Mycobacterium bovis by a modified loop-mediated isothermal amplification (LAMP) assay. The reaction results could be evaluated by naked eye with two optimized closed tube detection methods as follows: adding the modified fluorescence dye in advance into the reaction mix so as to observe the color changes or putting a tinfoil in the tube and adding the SYBR Green I dye on it, then making the dye drop into the bottom of the tube by centrifuge after reaction. The results showed that the two groups of primers used jointly in this assay could successfully identify and differentiate Mycobacterium tuberculosis subsp. tuberculosis and Mycobacterium tuberculosis bovis. Sensitivity test displayed that the modified LAMP assay with the closed tube system could determine the minimal template concentration of 1 copy/μl, which was more sensitive than that of routine PCR. The advantages of this LAMP method for detection of the Mycobacterium tuberculosis complex included high specificity, high sensitivity, simplicity, and superiority in avoidance of aerosol contamination. The modified LAMP assay would provide a potential for clinical diagnosis and therapy of tuberculosis in the developing countries and the resource-limited areas. PMID:22806847

  3. Construction of a GeogDetector-based model system to indicate the potential occurrence of grasshoppers in Inner Mongolia steppe habitats.

    PubMed

    Shen, J; Zhang, N; Gexigeduren; He, B; Liu, C-Y; Li, Y; Zhang, H-Y; Chen, X-Y; Lin, H

    2015-06-01

    Grasshopper plagues have seriously disturbed grassland ecosystems in Inner Mongolia, China. The accurate prediction of grasshopper infestations and control of grasshopper plagues have become urgent needs. We sampled 234, 342, 335, and 369 plots in Xianghuangqi County of Xilingol League in 2010, 2011, 2012, and 2013, respectively, and measured the density of the most dominant grasshopper species, Oedaleus decorus asiaticus, and the latitude, longitude, and associated relatively stable habitat factors at each plot. We used Excel-GeogDetector software to explore the effects of individual habitat factors and the two-factor interactions on grasshopper density. We estimated the membership of each grasshopper density rank and determined the weights of each habitat category. These results were used to construct a model system evaluating grasshopper habitat suitability. The results showed that our evaluation system was reliable and the fuzzy evaluation scores of grasshopper habitat suitability were good indicators of potential occurrence of grasshoppers. The effects of the two-factor interactions on grasshopper density were greater than the effects of any individual factors. O. d. asiaticus was most likely to be found at elevations of 1300-1400 m, flat terrain or slopes of 4-6°, typical chestnut soil with 70-80% sand content in the top 5 cm of soil, and medium-coverage grassland. The species preferred temperate bunchgrass steppe dominated by Stipa krylovii and Cleistogenes squarrosa. These findings may be used to improve models to predict grasshopper occurrence and to develop management guidelines to control grasshopper plagues by changing habitats.

  4. Identification of new pathogenic races of common bunt and dwarf bunt fungi, and evaluation of known races using an expanded set of differential cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pathogenic races of Tilletia caries and T. foetida, which cause common bunt of wheat (Triticum aestivum), and T. contraversa, which causes dwarf bunt of wheat, have been identified previously by their reaction to ten monogenic differential wheat lines, each containing single bunt resistance genes Bt...

  5. Differential Role of Ferritins in Iron Metabolism and Virulence of the Plant-Pathogenic Bacterium Erwinia chrysanthemi 3937▿

    PubMed Central

    Boughammoura, Aïda; Matzanke, Berthold F.; Böttger, Lars; Reverchon, Sylvie; Lesuisse, Emmanuel; Expert, Dominique; Franza, Thierry

    2008-01-01

    During infection, the phytopathogenic enterobacterium Erwinia chrysanthemi has to cope with iron-limiting conditions and the production of reactive oxygen species by plant cells. Previous studies have shown that a tight control of the bacterial intracellular iron content is necessary for full virulence. The E. chrysanthemi genome possesses two loci that could be devoted to iron storage: the bfr gene, encoding a heme-containing bacterioferritin, and the ftnA gene, coding for a paradigmatic ferritin. To assess the role of these proteins in the physiology of this pathogen, we constructed ferritin-deficient mutants by reverse genetics. Unlike the bfr mutant, the ftnA mutant had increased sensitivity to iron deficiency and to redox stress conditions. Interestingly, the bfr ftnA mutant displayed an intermediate phenotype for sensitivity to these stresses. Whole-cell analysis by Mössbauer spectroscopy showed that the main iron storage protein is FtnA and that there is an increase in the ferrous iron/ferric iron ratio in the ftnA and bfr ftnA mutants. We found that ftnA gene expression is positively controlled by iron and the transcriptional repressor Fur via the small antisense RNA RyhB. bfr gene expression is induced at the stationary phase of growth. The σS transcriptional factor is necessary for this control. Pathogenicity tests showed that FtnA and the Bfr contribute differentially to the virulence of E. chrysanthemi depending on the host, indicating the importance of a perfect control of iron homeostasis in this bacterial species during infection. PMID:18165304

  6. An experimental analysis of grasshopper community responses to fire and livestock grazing in a northern mixed-grass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The outcomes of grasshopper responses to both vertebrate grazing and fire vary across grassland ecosystems, and are strongly influenced by local climactic factors. Thus, the possible application of grazing and fire as components of an ecologically-based grasshopper management strategy must necessari...

  7. Feeding behavior of graminivorous grasshoppers in response to host-plant extracts, alkaloids, and tannins.

    PubMed

    Mole, S; Joern, A

    1994-12-01

    Secondary metabolites exhibit the potential to direct food selection by grass-feeding (graminivorous) grasshoppers. We examined the effects of plant extracts and representative secondary metabolites on the feeding behavior of two such grasshoppers,Ageneotettix deorum (Scudder) andPhoetaliotes nebrascensis (Scudder). Three alkaloids and two tannins were bioassayed for their activity as feeding deterrent allelochemicals, as were extracts from the foliage of the graminoids commonly eaten by these grasshoppers:Agropyron smithii Rydb.,Andropogon hallii Hack.,Andropogon scoparius Michx.,Bouteloua gracilis (H. B. K) Lag. ex Griffiths,Carex heliophila Mack. andStipa comata Trin. & Rupr. Alkaloids strongly deterred feeding but tannins only exhibited a weak effect, even when present at four times the concentration of total phenolics typical for these graminoids. Host-plant extracts also exhibited weak effects, such that we found no evidence for either strong deterrence or phagostimulation. Our results for alkaloids and host-plant extracts are consistent with the view that grass-feeding grasshoppers may be restricted to graminoids because of: (1) the presence of deterrents in nonhosts and (2) the absence of deterrents in hosts. However, our data for tannins show that these are unlikely to be effective barriers to herbivory by these grasshoppers.

  8. Operational-scale application of entomopathogenic fungi for control of Sahelian grasshoppers

    PubMed Central

    Kooyman, C.; Bateman, R. P.; Langewald, J.; Lomer, C. J.; Ouambama, Z.; Thomas, M. B.

    1997-01-01

    Locusts and grasshoppers regularly threaten agricultural production across large parts of the developed and developing worlds. Recent concerns over the health and environmental impacts of standard chemical control measures have led to a demand for alternative, more environmentally benign control technologies. Here we present the results of a field study to investigate the potential of inundative biological control for control of grasshoppers in the Sahelian region of Africa. The biocontrol agent was an oil-based biopesticide formulation of a naturally occurring entomopathogenic fungus, Metarhizium flavoviride. This was applied at a rate of 2l ha-1 to a total area of 150 ha using standard equipment normally used for the application of chemical pesticides. Twenty-one days after application, an 80 per cent reduction in grasshopper populations was recorded in treated plots, relative to control populations in equivalent unsprayed areas. We think that this is the first operational-scale application of a biopesticide to demonstrate significant population reductions of key Sahelian grasshopper pests. This represents a substantial development in locust and grasshopper control, and should open the way for a new era of integrated control strategies where reliance on conventional chemicals is reduced.

  9. Sex chromosome diversity in Armenian toad grasshoppers (Orthoptera, Acridoidea, Pamphagidae).

    PubMed

    Bugrov, Alexander G; Jetybayev, Ilyas E; Karagyan, Gayane H; Rubtsov, Nicolay B

    2016-01-01

    Although previous cytogenetic analysis of Pamphagidae grasshoppers pointed to considerable karyotype uniformity among most of the species in the family, our study of species from Armenia has discovered other, previously unknown karyotypes, differing from the standard for Pamphagidae mainly in having unusual sets of sex chromosomes. Asiotmethis turritus (Fischer von Waldheim, 1833), Paranocaracris rubripes (Fischer von Waldheim, 1846), and Nocaracris cyanipes (Fischer von Waldheim, 1846) were found to have the karyotype 2n♂=16+neo-XY and 2n♀=16+neo-XX, the neo-X chromosome being the result of centromeric fusion of an ancient acrocentric X chromosome and a large acrocentric autosome. The karyotype of Paranothrotes opacus (Brunner von Wattenwyl, 1882) was found to be 2n♂=14+X1X2Y and 2n♀=14+X1X1X2X2., the result of an additional chromosome rearrangement involving translocation of the neo-Y and another large autosome. Furthermore, evolution of the sex chromosomes in these species has involved different variants of heterochromatinization and miniaturization of the neo-Y. The karyotype of Eremopeza festiva (Saussure, 1884), in turn, appeared to have the standard sex determination system described earlier for Pamphagidae grasshoppers, 2n♂=18+X0 and 2n♀=18+XX, but all the chromosomes of this species were found to have small second C-positive arms. Using fluorescent in situ hybridization (FISH) with 18S rDNA and telomeric (TTAGG)n DNA repeats to yield new data on the structural organization of chromosomes in the species studied, we found that for most of them, clusters of repeats homologous to 18S rDNA localize on two, three or four pairs of autosomes and on the X. In Eremopeza festiva, however, FISH with labelled 18S rDNA painted C-positive regions of all autosomes and the X chromosome; clusters of telomeric repeats localized primarily on the ends of the chromosome arms. Overall, we conclude that the different stages of neo-Y degradation revealed in the

  10. Embryonic development of the sensory innervation of the antenna of the grasshopper Schistocerca gregaria.

    PubMed

    Boyan, G S; Williams, J L D

    2004-10-01

    The establishment of the sensory nervous system of the antenna of the grasshopper Schistocerca gregaria was examined using immunocytochemical methods and in the light of the appendicular and articulated nature of this structure. The former is demonstrated first by the expression pattern of the segment polarity gene engrailed in the head neuromere innervating the antenna, the deutocerebrum. Engrailed expression is present in identified deutocerebral neuroblasts and, as elsewhere in the body, is continuous with cells of the posterior epithelium of the associated appendage, in this case the antenna. Second, early expression of the glial homeobox gene reversed polarity (repo) in the antenna is by a stereotypic pair of cells at the antenna base, a pattern we show is repeated metamerically for each thoracic appendage of the embryo. Subsequently, three regions of Repo expression (A1, A2, A3) are seen within the antenna, and may represent a preliminary form of articulation. Bromodeoxyuridine incorporation reveals that these regions are sites of intense cell differentiation. Neuron-specific horseradish peroxidase and Lazarillo expression confirm that the pioneers of the ventral and dorsal tracts of the antennal sensory nervous system are amongst these differentiating cells. Sets of pioneers appear simultaneously in several bands and project confluent axons towards the antennal base. We conclude that the sensory nervous system of the antenna is not pioneered from the tip of the antenna alone, but in a stepwise manner by cells from several zones. The early sensory nervous systems of antenna, maxilla and leg therefore follow a similar developmental program consistent with their serially homologous nature.

  11. Modulation of plasma membrane H+-ATPase activity differentially activates wound and pathogen defense responses in tomato plants.

    PubMed Central

    Schaller, A; Oecking, C

    1999-01-01

    Systemin is an important mediator of wound-induced defense gene activation in tomato plants, and it elicits a rapid alkalinization of the growth medium of cultured Lycopersicon peruvianum cells. A possible mechanistic link between proton fluxes across the plasma membrane and the induction of defense genes was investigated by modulating plasma membrane H+-ATPase activity. Inhibitors of H+-ATPase (erythrosin B, diethyl stilbestrol, and vanadate) were found to alkalinize the growth medium of L. peruvianum cell cultures and to induce wound response genes in whole tomato plants. Conversely, an activator of the H+-ATPase (fusicoccin) acidified the growth medium of L. peruvianum cell cultures and suppressed systemin-induced medium alkalinization. Likewise, in fusicoccin-treated tomato plants, the wound- and systemin-triggered accumulation of wound-responsive mRNAs was found to be suppressed. However, fusicoccin treatment of tomato plants led to the accumulation of salicylic acid and the expression of pathogenesis-related genes. Apparently, the wound and pathogen defense signaling pathways are differentially regulated by changes in the proton electrochemical gradient across the plasma membrane. In addition, alkalinization of the L. peruvianum cell culture medium was found to depend on the influx of Ca2+ and the activity of a protein kinase. Reversible protein phosphorylation was also shown to be involved in the induction of wound response genes. The plasma membrane H+-ATPase as a possible target of a Ca2+-activated protein kinase and its role in defense signaling are discussed. PMID:9927643

  12. Human population, grasshopper and plant species richness in European countries

    NASA Astrophysics Data System (ADS)

    Steck, Claude E.; Pautasso, Marco

    2008-11-01

    Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

  13. Evolutionarily conserved coding properties of auditory neurons across grasshopper species

    PubMed Central

    Neuhofer, Daniela; Wohlgemuth, Sandra; Stumpner, Andreas; Ronacher, Bernhard

    2008-01-01

    We investigated encoding properties of identified auditory interneurons in two not closely related grasshopper species (Acrididae). The neurons can be homologized on the basis of their similar morphologies and physiologies. As test stimuli, we used the species-specific stridulation signals of Chorthippus biguttulus, which evidently are not relevant for the other species, Locusta migratoria. We recorded spike trains produced in response to these signals from several neuron types at the first levels of the auditory pathway in both species. Using a spike train metric to quantify differences between neuronal responses, we found a high similarity in the responses of homologous neurons: interspecific differences between the responses of homologous neurons in the two species were not significantly larger than intraspecific differences (between several specimens of a neuron in one species). These results suggest that the elements of the thoracic auditory pathway have been strongly conserved during the evolutionary divergence of these species. According to the ‘efficient coding’ hypothesis, an adaptation of the thoracic auditory pathway to the specific needs of acoustic communication could be expected. We conclude that there must have been stabilizing selective forces at work that conserved coding characteristics and prevented such an adaptation. PMID:18505715

  14. Asymmetrical integration of sensory information during mating decisions in grasshoppers

    PubMed Central

    Krämer, Stefanie; Ronacher, Bernhard

    2014-01-01

    Decision-making processes, like all traits of an organism, are shaped by evolution; they thus carry a signature of the selection pressures associated with choice behaviors. The way sexual communication signals are integrated during courtship likely reflects the costs and benefits associated with mate choice. Here, we study the evaluation of male song by females during acoustic courtship in grasshoppers. Using playback experiments and computational modeling we find that information of different valence (attractive vs. nonattractive) is weighted asymmetrically: while information associated with nonattractive features has large weight, attractive features add little to the decision to mate. Accordingly, nonattractive features effectively veto female responses. Because attractive features have so little weight, the model suggests that female responses are frequently driven by integration noise. Asymmetrical weighting of negative and positive information may reflect the fitness costs associated with mating with a nonattractive over an attractive singer, which are also highly asymmetrical. In addition, nonattractive cues tend to be more salient and therefore more reliable. Hence, information provided by them should be weighted more heavily. Our findings suggest that characterizing the integration of sensory information during a natural behavior has the potential to provide valuable insights into the selective pressures shaping decision-making during evolution. PMID:25368152

  15. Effects of parental radiation exposure on developmental instability in grasshoppers

    PubMed Central

    BEASLEY, D. E.; BONISOLI-ALQUATI, A.; WELCH, S. M.; MØLLER, A. P.; MOUSSEAU, T. A.

    2014-01-01

    Mutagenic and epigenetic effects of environmental stressors and their transgenerational consequences are of interest to evolutionary biologists because they can amplify natural genetic variation. We studied the effect of parental exposure to radioactive contamination on offspring development in lesser marsh grasshopper Chorthippus albomarginatus. We used a geometric morphometric approach to measure fluctuating asymmetry (FA), wing shape and wing size. We measured time to sexual maturity to check whether parental exposure to radiation influenced offspring developmental trajectory and tested effects of radiation on hatching success and parental fecundity. Wings were larger in early maturing individuals born to parents from high radiation sites compared to early maturing individuals from low radiation sites. As time to sexual maturity increased, wing size decreased but more sharply in individuals from high radiation sites. Radiation exposure did not significantly affect FA or shape in wings nor did it significantly affect hatching success and fecundity. Overall, parental radiation exposure can adversely affect offspring development and fitness depending on developmental trajectories although the cause of this effect remains unclear. We suggest more direct measures of fitness and the inclusion of replication in future studies to help further our understanding of the relationship between developmental instability, fitness and environmental stress. PMID:22507690

  16. Synchrotron imaging of the grasshopper tracheal system : morphological and physiological components of tracheal hypermetry.

    SciTech Connect

    Greenlee, K. J.; Henry, J. R.; Kirkton, S. D.; Westneat, M. W.; Fezzaa, K.; Lee, W.; Harrison, J. F.; North Dakota State Univ.; Arizona State Univ.; Union Coll.; Field Museum of Natural History

    2009-11-01

    As grasshoppers increase in size during ontogeny, they have mass specifically greater whole body tracheal and tidal volumes and ventilation than predicted by an isometric relationship with body mass and body volume. However, the morphological and physiological bases to this respiratory hypermetry are unknown. In this study, we use synchrotron imaging to demonstrate that tracheal hypermetry in developing grasshoppers (Schistocerca americana) is due to increases in air sacs and tracheae and occurs in all three body segments, providing evidence against the hypothesis that hypermetry is due to gaining flight ability. We also assessed the scaling of air sac structure and function by assessing volume changes of focal abdominal air sacs. Ventilatory frequencies increased in larger animals during hypoxia (5% O{sub 2}) but did not scale in normoxia. For grasshoppers in normoxia, inflated and deflated air sac volumes and ventilation scaled hypermetrically. During hypoxia (5% O{sub 2}), many grasshoppers compressed air sacs nearly completely regardless of body size, and air sac volumes scaled isometrically. Together, these results demonstrate that whole body tracheal hypermetry and enhanced ventilation in larger/older grasshoppers are primarily due to proportionally larger air sacs and higher ventilation frequencies in larger animals during hypoxia. Prior studies showed reduced whole body tracheal volumes and tidal volume in late-stage grasshoppers, suggesting that tissue growth compresses air sacs. In contrast, we found that inflated volumes, percent volume changes, and ventilation were identical in abdominal air sacs of late-stage fifth instar and early-stage animals, suggesting that decreasing volume of the tracheal system later in the instar occurs in other body regions that have harder exoskeleton.

  17. Differentiation between pathogenic and non-pathogenic Yersinia enterocolitica strains by colony hybridization with a PCR-mediated digoxigenin-dUTP-labelled probe.

    PubMed

    Ibrahim, A; Liesack, W; Stackebrandt, E

    1992-04-01

    The Polymerase Chain Reaction (PCR) method was used to generate a vector-free digoxigenin-dUTP labelled probe that targets the Yersinia enterocolitica gene encoding the heat stable enterotoxin (yst). The probe was used in DNA-DNA colony hybridization to screen 113 strains of Y. enterocolitica and related species for the presence of the enterotoxin gene. In Y. enterocolitica, the probe clearly discriminated between pathogenic and non-pathogenic strains even those belonging to the same serotype. Of the other Yersinia species, only three strains of Y. kristensenii possessed DNA sequences homologous to the yst gene. The probe was further checked for its specificity in artificially inoculated fecal samples and could easily detect the target sequence of the yst gene. The digoxigenin-labelled probe proved to be a reliable epidemiological tool to discriminate between pathogenic and non-pathogenic strains in pure and mixed culture, thus offering the advantage of using a non-radioactive detection system in clinical laboratories with the possibility of reusing the same hybridization solution several times and obtaining results within a relatively short time.

  18. Revision of the grasshopper genus Sedulia Stål, 1878 (Acrididae: Catantopinae) from Malay Peninsula.

    PubMed

    Tan, Ming Kai; Robillard, Tony; Kamaruddin, Khairul Nizam

    2016-01-01

    Southeast Asia is a highly biodiverse region with many species of grasshoppers described since the 19th century. Historical species descriptions are however often not comprehensive and do not meet the modern criteria of taxonomy. Previously used characters for identification need to be re-examined. Here, we aim to revise the taxonomy of the grasshopper genus Sedulia Stål, 1878. Using morphology and simple morphometry, we compared and investigated interspecific and intraspecific variations among the two species of Sedulia. We also redescribed both species and constructed a key to species and closely related genera.

  19. Revision of the grasshopper genus Sedulia Stål, 1878 (Acrididae: Catantopinae) from Malay Peninsula.

    PubMed

    Tan, Ming Kai; Robillard, Tony; Kamaruddin, Khairul Nizam

    2016-01-01

    Southeast Asia is a highly biodiverse region with many species of grasshoppers described since the 19th century. Historical species descriptions are however often not comprehensive and do not meet the modern criteria of taxonomy. Previously used characters for identification need to be re-examined. Here, we aim to revise the taxonomy of the grasshopper genus Sedulia Stål, 1878. Using morphology and simple morphometry, we compared and investigated interspecific and intraspecific variations among the two species of Sedulia. We also redescribed both species and constructed a key to species and closely related genera. PMID:27394817

  20. Stable Isotope Systematics in Grasshopper Assemblages Along an Elevation Gradient, Colorado

    NASA Astrophysics Data System (ADS)

    Kohn, M. J.; Evans, S.; Dean, J.; Nufio, C.

    2012-12-01

    Insects comprise over three quarters of all animal species, yet studies of body water isotopic composition are limited to only the cockroach, the hoverfly, and chironomid flies. These studies suggest that oxygen and hydrogen isotopic compositions in body water are primarily controlled by dietary water sources, with modification from respiratory and metabolic processes. In particular, outward diffusion of isotopically depleted water vapor through insect spiracles at low humidity enriches residual body water in 18O and 2H (D). Stable isotope compositions (δ18O and δD) also respond to gradients in elevation and humidity, but these influences remain poorly understood. In this study, we measured grasshopper body water and local vegetation isotopic compositions along an elevation gradient in Colorado to evaluate three hypotheses: 1) Insect body water isotopic composition is directly related to food source water composition 2) Water vapor transport alters body water isotopic compositions relative to original diet sources, and 3) Elevation gradients influence isotopic compositions in insect body water. Thirty-five species of grasshopper were collected from 14 locations in Colorado grasslands, ranging in elevation from 450 to 800 meters (n=131). Body water was distilled from previously frozen grasshopper specimens using a vacuum extraction line, furnaces (90 °C), and liquid nitrogen traps. Water samples were then analyzed for δ18O and δD on an LGR Liquid Water Isotope Analyzer, housed in the Department of Geosciences, Boise State University. Grasshopper body water isotopic compositions show wide variation, with values ranging between -76.64‰ to +42.82‰ in δD and -3.06‰ to +26.78‰ in δ18O. Precipitation δ18O values over the entire Earth excluding the poles vary by approximately 30‰, comparable to the total range measured in our single study area. Most grasshopper values deviate from the global meteoric water line relating δ18O and δD in precipitation

  1. De Novo Assembly and Characterization of the Transcriptome of Grasshopper Shirakiacris shirakii

    PubMed Central

    Qiu, Zhongying; Liu, Fei; Lu, Huimeng; Yuan, Hao; Zhang, Qin; Huang, Yuan

    2016-01-01

    Background: The grasshopper Shirakiacris shirakii is an important agricultural pest and feeds mainly on gramineous plants, thereby causing economic damage to a wide range of crops. However, genomic information on this species is extremely limited thus far, and transcriptome data relevant to insecticide resistance and pest control are also not available. Methods: The transcriptome of S. shirakii was sequenced using the Illumina HiSeq platform, and we de novo assembled the transcriptome. Results: Its sequencing produced a total of 105,408,878 clean reads, and the de novo assembly revealed 74,657 unigenes with an average length of 680 bp and N50 of 1057 bp. A total of 28,173 unigenes were annotated for the NCBI non-redundant protein sequences (Nr), NCBI non-redundant nucleotide sequences (Nt), a manually-annotated and reviewed protein sequence database (Swiss-Prot), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Based on the Nr annotation results, we manually identified 79 unigenes encoding cytochrome P450 monooxygenases (P450s), 36 unigenes encoding carboxylesterases (CarEs) and 36 unigenes encoding glutathione S-transferases (GSTs) in S. shirakii. Core RNAi components relevant to miroRNA, siRNA and piRNA pathways, including Pasha, Loquacious, Argonaute-1, Argonaute-2, Argonaute-3, Zucchini, Aubergine, enhanced RNAi-1 and Piwi, were expressed in S. shirakii. We also identified five unigenes that were homologous to the Sid-1 gene. In addition, the analysis of differential gene expressions revealed that a total of 19,764 unigenes were up-regulated and 4185 unigenes were down-regulated in larvae. In total, we predicted 7504 simple sequence repeats (SSRs) from 74,657 unigenes. Conclusions: The comprehensive de novo transcriptomic data of S. shirakii will offer a series of valuable molecular resources for better studying insecticide resistance, RNAi and molecular marker discovery in the transcriptome. PMID:27455245

  2. Preferential Occupancy of R2 Retroelements on the B Chromosomes of the Grasshopper Eyprepocnemis plorans

    PubMed Central

    Montiel, Eugenia E.; Cabrero, Josefa; Ruiz-Estévez, Mercedes; Burke, William D.; Eickbush, Thomas H.; Camacho, Juan Pedro M.; López-León, María Dolores

    2014-01-01

    R2 non-LTR retrotransposons exclusively insert into the 28S rRNA genes of their host, and are expressed by co-transcription with the rDNA unit. The grasshopper Eyprepocnemis plorans contains transcribed rDNA clusters on most of its A chromosomes, as well as non-transcribed rDNA clusters on the parasitic B chromosomes found in many populations. Here the structure of the E. plorans R2 element, its abundance relative to the number of rDNA units and its retrotransposition activity were determined. Animals screened from five populations contained on average over 12,000 rDNA units on their A chromosomes, but surprisingly only about 100 R2 elements. Monitoring the patterns of R2 insertions in individuals from these populations revealed only low levels of retrotransposition. The low rates of R2 insertion observed in E. plorans differ from the high levels of R2 insertion previously observed in insect species that have many fewer rDNA units. It is proposed that high levels of R2 are strongly selected against in E. plorans, because the rDNA transcription machinery in this species is unable to differentiate between R2-inserted and uninserted units. The B chromosomes of E. plorans contain an additional 7,000 to 15,000 rDNA units, but in contrast to the A chromosomes, from 150 to over 1,500 R2 elements. The higher concentration of R2 in the inactive B chromosomes rDNA clusters suggests these chromosomes can act as a sink for R2 insertions thus further reducing the level of insertions on the A chromosomes. These studies suggest an interesting evolutionary relationship between the parasitic B chromosomes and R2 elements. PMID:24632855

  3. Preferential occupancy of R2 retroelements on the B chromosomes of the grasshopper Eyprepocnemis plorans.

    PubMed

    Montiel, Eugenia E; Cabrero, Josefa; Ruiz-Estévez, Mercedes; Burke, William D; Eickbush, Thomas H; Camacho, Juan Pedro M; López-León, María Dolores

    2014-01-01

    R2 non-LTR retrotransposons exclusively insert into the 28S rRNA genes of their host, and are expressed by co-transcription with the rDNA unit. The grasshopper Eyprepocnemis plorans contains transcribed rDNA clusters on most of its A chromosomes, as well as non-transcribed rDNA clusters on the parasitic B chromosomes found in many populations. Here the structure of the E. plorans R2 element, its abundance relative to the number of rDNA units and its retrotransposition activity were determined. Animals screened from five populations contained on average over 12,000 rDNA units on their A chromosomes, but surprisingly only about 100 R2 elements. Monitoring the patterns of R2 insertions in individuals from these populations revealed only low levels of retrotransposition. The low rates of R2 insertion observed in E. plorans differ from the high levels of R2 insertion previously observed in insect species that have many fewer rDNA units. It is proposed that high levels of R2 are strongly selected against in E. plorans, because the rDNA transcription machinery in this species is unable to differentiate between R2-inserted and uninserted units. The B chromosomes of E. plorans contain an additional 7,000 to 15,000 rDNA units, but in contrast to the A chromosomes, from 150 to over 1,500 R2 elements. The higher concentration of R2 in the inactive B chromosomes rDNA clusters suggests these chromosomes can act as a sink for R2 insertions thus further reducing the level of insertions on the A chromosomes. These studies suggest an interesting evolutionary relationship between the parasitic B chromosomes and R2 elements.

  4. Post-ingestive feedbacks and associative learning regulate the intake of unsuitable sterols in a generalist grasshopper.

    PubMed

    Behmer, S T; Elias, D O; Bernays, E A

    1999-03-01

    Behavioural studies of the grasshopper Schistocerca americana were undertaken to identify the mechanisms that regulate the intake of dietary sterols. In the first experiment, grasshoppers were allowed to feed on spinach, a plant containing only unsuitable sterols; immediately after this first meal, a suitable or unsuitable sterol was injected into the haemolymph. Grasshoppers injected with unsuitable sterols had second meals on spinach that were significantly shorter than those of grasshoppers injected with suitable sterols, indicating that unsuitable dietary sterols are detected post-ingestively. In the second experiment, grasshoppers were fed food containing only unsuitable sterols and were then presented with glass-fibre discs containing different concentrations of a suitable sterol or sucrose only (the control). The results suggest that grasshoppers do not use a direct feedback operating on mouthpart chemoreceptors to regulate their intake of suitable sterols. In the third experiment, grasshoppers were presented with artificial diets containing different sterols and flavours, and feeding was observed over a sequence of meals. The results from both the first and last experiments suggest a role for associative learning in regulating the intake of unsuitable sterols.

  5. Development of indirect ELISAs for differential serodiagnosis of classical and highly pathogenic porcine reproductive and respiratory syndrome virus.

    PubMed

    Xiao, Y H; Wang, T T; Zhao, Q; Wang, C B; Lv, J H; Nie, L; Gao, J M; Ma, X C; Hsu, W H; Zhou, E M

    2014-08-01

    The objective of this study was to develop two indirect enzyme-linked immunosorbent assays (iELISAs) for detection of serum antibodies against classical vaccine strain of porcine reproductive and respiratory syndrome virus (PRRSV) and highly pathogenic PRRSV (HP-PRRSV). To detect the common antibodies against classical and HP-PRRSV, the coating antigen used in the iELISA (designated iELISA-180) was the antigen of Nsp2-180, the 180aa at amino terminal of Nsp2. To detect the different antibodies against classical and HP-PRRSV, the coating antigen in the second iELISA (designated iELISA-D29) was Nsp2-D29, the deleted 29aa in Nsp2 of HP-PRRSV. The antigen concentration and serum dilutions were optimized using a draughtboard titration. The cut-off values of 0.361 at OD(450nm) for the iELISA-180 and 0.27 at OD(450nm) for the iELISA-D29 were determined by testing a panel of 120 classical PRRSV positive and 198 PRRSV negative pig serum samples, which generated the specificity of 97.1% and 96.7%, the sensitivity of 96.9% and 96.3% for iELISA-180 and iELISA-D29, respectively. The agreements between the Western blot and iELISA-180 and iELISA-D29 were 98%, 96.7%, respectively. The developed iELISAs can be used to differentiate serologically HP-PRRSV from the vaccinated or classical PRRSV in clinical serum samples.

  6. Effect of Ethanol on Differential Protein Production and Expression of Potential Virulence Functions in the Opportunistic Pathogen Acinetobacter baumannii

    PubMed Central

    Nwugo, Chika C.; Arivett, Brock A.; Zimbler, Daniel L.; Gaddy, Jennifer A.; Richards, Ashley M.; Actis, Luis A.

    2012-01-01

    Acinetobacter baumannii persists in the medical environment and causes severe human nosocomial infections. Previous studies showed that low-level ethanol exposure increases the virulence of A. baumannii ATCC 17978. To better understand the mechanisms involved in this response, 2-D gel electrophoresis combined with mass spectrometry was used to investigate differential protein production in bacteria cultured in the presence or absence of ethanol. This approach showed that the presence of ethanol significantly induces and represses the production of 22 and 12 proteins, respectively. Although over 25% of the ethanol-induced proteins were stress-response related, the overall bacterial viability was uncompromised when cultured under these conditions. Production of proteins involved in lipid and carbohydrate anabolism was increased in the presence of ethanol, a response that correlates with increased carbohydrate biofilm content, enhanced biofilm formation on abiotic surfaces and decrease bacterial motility on semi-solid surfaces. The presence of ethanol also induced the acidification of bacterial cultures and the production of indole-3-acetic acid (IAA), a ubiquitous plant hormone that signals bacterial stress-tolerance and promotes plant-bacteria interactions. These responses could be responsible for the significantly enhanced virulence of A. baumannii ATCC 17978 cells cultured in the presence of ethanol when tested with the Galleria mellonella experimental infection model. Taken together, these observations provide new insights into the effect of ethanol in bacterial virulence. This alcohol predisposes the human host to infections by A. baumannii and could favor the survival and adaptation of this pathogen to medical settings and adverse host environments. PMID:23284824

  7. Loss of Abaxial Leaf Epicuticular Wax in Medicago truncatula irg1/palm1 Mutants Results in Reduced Spore Differentiation of Anthracnose and Nonhost Rust Pathogens[W

    PubMed Central

    Uppalapati, Srinivasa Rao; Ishiga, Yasuhiro; Doraiswamy, Vanthana; Bedair, Mohamed; Mittal, Shipra; Chen, Jianghua; Nakashima, Jin; Tang, Yuhong; Tadege, Million; Ratet, Pascal; Chen, Rujin; Schultheiss, Holger; Mysore, Kirankumar S.

    2012-01-01

    To identify genes that confer nonhost resistance to biotrophic fungal pathogens, we did a forward-genetics screen using Medicago truncatula Tnt1 retrotransposon insertion lines. From this screen, we identified an inhibitor of rust germ tube differentation1 (irg1) mutant that failed to promote preinfection structure differentiation of two rust pathogens, Phakopsora pachyrhizi and Puccinia emaculata, and one anthracnose pathogen, Colletotrichum trifolii, on the abaxial leaf surface. Cytological and chemical analyses revealed that the inhibition of rust preinfection structures in irg1 mutants is due to complete loss of the abaxial epicuticular wax crystals and reduced surface hydrophobicity. The composition of waxes on abaxial leaf surface of irg1 mutants had >90% reduction of C30 primary alcohols and a preferential increase of C29 and C31 alkanes compared with the wild type. IRG1 encodes a Cys(2)His(2) zinc finger transcription factor, PALM1, which also controls dissected leaf morphology in M. truncatula. Transcriptome analysis of irg1/palm1 mutants revealed downregulation of eceriferum4, an enzyme implicated in primary alcohol biosynthesis, and MYB96, a major transcription factor that regulates wax biosynthesis. Our results demonstrate that PALM1 plays a role in regulating epicuticular wax metabolism and transport and that epicuticular wax influences spore differentiation of host and nonhost fungal pathogens. PMID:22294617

  8. Grasshoppers Regulate N:P Stoichiometric Homeostasis by Changing Phosphorus Contents in Their Frass

    PubMed Central

    Zhang, Zijia; Elser, James J.; Cease, Arianne J.; Zhang, Ximei; Yu, Qiang; Han, Xingguo; Zhang, Guangming

    2014-01-01

    Nitrogen (N) and phosphorus (P) are important limiting nutrients for plant production and consumer performance in a variety of ecosystems. As a result, the N:P stoichiometry of herbivores has received increased attention in ecology. However, the mechanisms by which herbivores maintain N:P stoichiometric homeostasis are poorly understood. Here, using a field manipulation experiment we show that the grasshopper Oedaleus asiaticus maintains strong N:P stoichiometric homeostasis regardless of whether grasshoppers were reared at low or high density. Grasshoppers maintained homeostasis by increasing P excretion when eating plants with higher P contents. However, while grasshoppers also maintained constant body N contents, we found no changes in N excretion in response to changing plant N content over the range measured. These results suggest that O. asiaticus maintains P homeostasis primarily by changing P absorption and excretion rates, but that other mechanisms may be more important for regulating N homeostasis. Our findings improve our understanding of consumer-driven P recycling and may help in understanding the factors affecting plant-herbivore interactions and ecosystem processes in grasslands. PMID:25089521

  9. Excretion of cadmium and zinc during moulting in the grasshopper Omocestus viridulus (Orthoptera)

    SciTech Connect

    Lindqvist, L.; Block, M. )

    1994-10-01

    Nymphs of Omocestus viridulus (Orthoptera) were reared on grass leaves containing known amounts of [sup 109]Cd or [sup 65]Zn. After the animals molted to adults, contents of these metals were measured in the grasshoppers, in the cast of exuviae and in the feces produced during rearing. Dry weights of adult bodies and exuviae were lower for [sup 109]Cd-treated grasshoppers than for those given [sup 65]Zn. Exuviae accounted for only a minor part of the excreted [sup 109]Cd and [sup 65]Zn. The [sup 109]Cd was assimilated from food to a much smaller extent than was [sup 65]Zn. After 15 d of rearing, [approximately] 50% of the ingested [sup 65]Zn, but only 10% of the ingested [sup 109]Cd, remained in the grasshoppers. Because the amount of [sup 109]Cd in the grasshopper nymphs decreased with time, whereas that of the exuviae were constant, content in exuviae constituted a larger portion of the total content of [sup 109]Cd with increasing time between feeding of [sup 109]Cd and molting. For [sup 65]Zn there was no such trend.

  10. Stage-based mortality of grassland grasshoppers (Acrididae) from wandering spider (Lycosidae) predation

    NASA Astrophysics Data System (ADS)

    Oedekoven, Mark A.; Joern, Anthony

    1998-12-01

    Mortality rates in insects, including grasshoppers (Acrididae), are often stage- or size-specific. We estimated stage-specific mortality rates for three common grasshopper species from a Nebraska (USA) sandhills grassland ( Ageneotettix deorum, Melanoplus sanguinipes and Phoetaliotes nebrascensis), and partitioned the impact due to wandering spider predation from remaining sources. Survivorship was estimated for multiple developmental stages (3rd instar through adult) under experimental conditions that either prevented or permitted predation from free-living, wandering spiders (primarily Schizocosa species). Total stage-specific mortality, including spider predation, examined over the period of single stages was greatest for the youngest stages (91% for 3rd instar, 73% for 4th instar, 63.5% for 5th instar and 30.4% for adults). For the developmental stages considered and averaged for all species, the contribution to total mortality from spider predation over the 10-d period (approximately the length of a developmental stage) ranged from 17% for 3rd instar nymphs to 23% for 4th and 5th instars, and an undetectable level for adults. While spiders may depress grasshopper numbers, contributions from spider predation to grasshopper population dynamics are uncertain.

  11. Embryonic development rates of northern grasshoppers (Orthoptera: Acrididae): implications for climate change and habitat management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperature-dependent rates of embryonic development are a primary determinant of the life cycle of many species of grasshoppers which, in cold climates, spend two winters in the egg stage. Knowledge of embryonic developmental rates is important for an assessment of the effects of climate change and...

  12. Sea gulls, butterflies, and grasshoppers: A brief history of the butterfly effect in nonlinear dynamics

    NASA Astrophysics Data System (ADS)

    Hilborn, Robert C.

    2004-04-01

    The butterfly effect has become a popular metaphor for sensitive dependence on initial conditions—the hallmark of chaotic behavior. I describe how, where, and when this term was conceived in the 1970s. Surprisingly, the butterfly metaphor was predated by more than 70 years by the grasshopper effect.

  13. Infection of Melanoplus Sanguinipes Grasshoppers Following Ingestion of Rangeland Plant Species Harboring Vesicular Stomatitis Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of the many mechanisms of vesicular stomatitis virus (VSV) transmission is critical to understanding the epidemiology of sporadic disease outbreaks in the western U.S. Migratory grasshoppers (Melanoplus sanguinipes, Fabricius) have been implicated as reservoirs and mechanical vectors of VS...

  14. A remarkable new pygmy grasshopper (Orthoptera, Tetrigidae) in Miocene amber from the Dominican Republic

    PubMed Central

    Heads, Sam W.; Thomas, M. Jared; Wang, Yinan

    2014-01-01

    Abstract A new genus and species of pygmy grasshopper (Orthoptera: Tetrigidae) is described from Early Miocene (Burdigalian) Dominican amber. Electrotettix attenboroughi Heads & Thomas, gen. et sp. n. is assigned to the subfamily Cladonotinae based on the deeply forked frontal costa, but is remarkable for the presence of tegmina and hind wings, hitherto unknown in this subfamily. PMID:25147472

  15. Status assessment and conservation plan for the Grasshopper Sparrow (Ammodramus savannarum)

    USGS Publications Warehouse

    Ruth, Janet M.

    2015-01-01

    The Grasshopper Sparrow (Ammodramus savannarum) breeds in grassland habitats throughout much of the U.S., southern and southeastern Canada, and northern Mexico. Additional subspecies are resident in Central America, northern South America, and the Caribbean. It winters primarily in the coastal states of the southeastern U.S., southern portions of the southwestern states, and in Mexico, Central America, and the Caribbean. The species prefers relatively open grassland with intermediate grass height and density and patchy bare ground; because it is widely distributed across different grassland types in North America, it selects different vegetation structure and species composition depending on what is available. In the winter, they use a broader range of grassland habitats including open grasslands, as well as weedy fields and grasslands with woody vegetation. Analyses show significant range-wide population declines from the late 1960s through the present, primarily caused by habitat loss, degradation, and fragmentation. Grasshopper Sparrow is still a relatively common and broadly distributed species, but because of significant population declines and stakeholder concerns, the species is considered of conservation concern nationally and at the state level for numerous states. Many factors, often related to different grassland management practices (e.g., grazing, burning, mowing, management of shrub encroachment, etc.) throughout the species’ range, have impacts on Grasshopper Sparrow distribution, abundance, and reproduction and may represent limiting factors or threats given steep declines in this species’ population. Because of the concerns for this species, Grasshopper Sparrow has been identified as a focal species by the U.S. Fish and Wildlife Service (USFWS) and this Status Assessment and Conservation Plan for Grasshopper Sparrow has been developed. Through literature searches and input from stakeholders across its range, this plan presents information about

  16. Modulation of CD4+ T Cell-Dependent Specific Cytotoxic CD8+ T Cells Differentiation and Proliferation by the Timing of Increase in the Pathogen Load

    PubMed Central

    Tzelepis, Fanny; Persechini, Pedro M.; Rodrigues, Mauricio M.

    2007-01-01

    Background Following infection with viruses, bacteria or protozoan parasites, naïve antigen-specific CD8+ T cells undergo a process of differentiation and proliferation to generate effector cells. Recent evidences suggest that the timing of generation of specific effector CD8+ T cells varies widely according to different pathogens. We hypothesized that the timing of increase in the pathogen load could be a critical parameter governing this process. Methodology/Principal Findings Using increasing doses of the protozoan parasite Trypanosoma cruzi to infect C57BL/6 mice, we observed a significant acceleration in the timing of parasitemia without an increase in mouse susceptibility. In contrast, in CD8 deficient mice, we observed an inverse relationship between the parasite inoculum and the timing of death. These results suggest that in normal mice CD8+ T cells became protective earlier, following the accelerated development of parasitemia. The evaluation of specific cytotoxic responses in vivo to three distinct epitopes revealed that increasing the parasite inoculum hastened the expansion of specific CD8+ cytotoxic T cells following infection. The differentiation and expansion of T. cruzi-specific CD8+ cytotoxic T cells is in fact dependent on parasite multiplication, as radiation-attenuated parasites were unable to activate these cells. We also observed that, in contrast to most pathogens, the activation process of T. cruzi-specific CD8+ cytotoxic T cells was dependent on MHC class II restricted CD4+ T cells. Conclusions/Significance Our results are compatible with our initial hypothesis that the timing of increase in the pathogen load can be a critical parameter governing the kinetics of CD4+ T cell-dependent expansion of pathogen-specific CD8+ cytotoxic T cells. PMID:17460760

  17. The Entomophaga grylli (Fresenius) Batko species complex (Zygomycetes: Entomophthorales) infecting grasshoppers in Ilheus (Bahia) Brazil: notes and new records

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungi from the Entomophthoraceae (Zygomycotina; Zygomycetes: Entomophthorales) belonging to the Entomophaga grylli species complex have been found in the state of Bahia, Brazil, to affect populations of grasshoppers (Orthoptera: Acrididae) of the species Rhammatocerus brasiliensis Bruner, Rhammatoce...

  18. Environmental factors governing population dynamics of rangeland grasshoppers: The first application of GIS and remote sensing to acridology in Russia

    NASA Astrophysics Data System (ADS)

    Latchininsky, Alexandre Vsevolodovich

    Grasshoppers (Orthoptera: Acrididae) are pests of rangeland and crops in temperate Eurasia (Siberia) where landscapes are dominated by short-grass vegetation and have many common features with the prairies of the Great Plains of North America. The zone of economic importance of grasshoppers in Siberia is localized in its southern part between 50° and 55°N and 68° and 132°E. In particular, grasshopper infestations are concentrated in close proximity to Lake Baikal, the world's deepest lake, holding one-fifth of the Earth's total fresh water supply. From a biodiversity perspective, Lake Baikal is unparalleled because >80% of its 1,085 plant and 1,550 animal species are endemic. Broad-scale pesticide applications in the zone close to the Baikal ecosystem can seriously aggravate the hazards of environmental pollution, with potentially catastrophic consequences on a vast scale. Specific composition and density of grasshopper communities were studied over a variety of habitats. Of about 50 local grasshopper species, two gomphocerines, Aeropus sibiricus and Chorthippus albomarginatus, dominated grasshopper communities in dry and mesic habitats, respectively. These species accounted for the most of the crop damage during recent outbreaks in the 1990s requiring large-scale insecticidal control. Annual fluctuations of grasshopper infestations appeared to track changes in air temperature and summer precipitation, but only a synthetic "Aridity index" was statistically significant. Spatial distribution of historic grasshopper infestations was studied using GIS (ERDAS IMAGINERTM) and remote sensing (Landsat TM satellite imagery) and was found to be significantly clumped. The highest grasshopper densities were associated with dry grasslands in transitional zones between foothills and valleys characterized by a particular elevation (600--650 m), soil type (sod-forest, or pararendzina), amount of April--October precipitation (250 mm) and degree of grazing (moderate

  19. Damage potential of grasshoppers (Orthoptera: Acrididae) on early growth stages of small-grains and canola under subarctic conditions.

    PubMed

    Begna, Sultan H; Fielding, Dennis J

    2003-08-01

    We characterized the type and extent of grasshopper injury to above- and below-ground plant parts for four crops [barley (Hordeum vulgare L.), oats (Avena sativa L.), wheat (Triticum aestivum L.), and canola (Brassica campestris L.)] commonly grown, or with potential to grow, in central Alaska. Cages were placed on 48 pots containing plants in second to third leaf stages and stocked with 0, 2, 4, and 6 first-instar Melanoplus sanguinipes F. pot(-1). Plants were harvested 22 d after planting. Stem growth of barley and oats was not affected except at the highest grasshopper treatment. In canola, stem biomass was reduced at the medium and high grasshopper treatments, when most of the leaves had been consumed. The highest grasshopper treatment reduced leaf area in barley and oats by approximately 55%, and caused a significant reduction in dry weight of leaves, stems, and roots (41-72%). Wheat and canola plants were smaller than barley and oats across all treatments and, at the highest grasshopper density, above-ground portions of wheat and canola were completely destroyed. Length and surface area of roots of barley and oats were reduced by 20-28% again at the highest grasshopper density, whereas the reduction for wheat and canola ranged from 50 to 90%. There was little or no difference among all grasshopper densities for C-N ratio in leaf and stem tissues of all crops. The results suggest that wheat and canola are more susceptible than barley and oats and that densities > or = 2 pot(-1) (approximately > or = 50 m(-2)) of even very small grasshoppers could cause significant damage in small-grain and oilseed crop production.

  20. Predator-Prey Interactions are Context Dependent in a Grassland Plant-Grasshopper-Wolf Spider Food Chain.

    PubMed

    Laws, Angela N; Joern, Anthony

    2015-06-01

    Species interactions are often context dependent, where outcomes vary in response to one or more environmental factors. It remains unclear how abiotic conditions like temperature combine with biotic factors such as consumer density or food quality to affect resource availability or influence species interactions. Using the large grasshopper Melanoplus bivittatus (Say) and a common wolf spider [Rabidosa rabida (Walkenaer)], we conducted manipulative field experiments in tallgrass prairie to examine how spider-grasshopper interactions respond to manipulations of temperature, grasshopper density, and food quality. Grasshopper survival was density dependent, as were the effects of spider presence and food quality in context-dependent ways. In high grasshopper density treatments, predation resulted in increased grasshopper survival, likely as a result of reduced intraspecific competition in the presence of spiders. Spiders had no effect on grasshopper survival when grasshoppers were stocked at low densities. Effects of the experimental treatments were often interdependent so that effects were only observed when examined together with other treatments. The occurrence of trophic cascades was context dependent, where the effects of food quality and spider presence varied with temperature under high-density treatments. Temperature weakly affected the impact of spider presence on M. bivittatus survivorship when all treatments were considered simultaneously, but different context-dependent responses to spider presence and food quality were observed among the three temperature treatments under high-density conditions. Our results indicate that context-dependent species interactions are common and highlight the importance of understanding how key biotic and abiotic factors combine to influence species interactions. PMID:26313957

  1. Predator-Prey Interactions are Context Dependent in a Grassland Plant-Grasshopper-Wolf Spider Food Chain.

    PubMed

    Laws, Angela N; Joern, Anthony

    2015-06-01

    Species interactions are often context dependent, where outcomes vary in response to one or more environmental factors. It remains unclear how abiotic conditions like temperature combine with biotic factors such as consumer density or food quality to affect resource availability or influence species interactions. Using the large grasshopper Melanoplus bivittatus (Say) and a common wolf spider [Rabidosa rabida (Walkenaer)], we conducted manipulative field experiments in tallgrass prairie to examine how spider-grasshopper interactions respond to manipulations of temperature, grasshopper density, and food quality. Grasshopper survival was density dependent, as were the effects of spider presence and food quality in context-dependent ways. In high grasshopper density treatments, predation resulted in increased grasshopper survival, likely as a result of reduced intraspecific competition in the presence of spiders. Spiders had no effect on grasshopper survival when grasshoppers were stocked at low densities. Effects of the experimental treatments were often interdependent so that effects were only observed when examined together with other treatments. The occurrence of trophic cascades was context dependent, where the effects of food quality and spider presence varied with temperature under high-density treatments. Temperature weakly affected the impact of spider presence on M. bivittatus survivorship when all treatments were considered simultaneously, but different context-dependent responses to spider presence and food quality were observed among the three temperature treatments under high-density conditions. Our results indicate that context-dependent species interactions are common and highlight the importance of understanding how key biotic and abiotic factors combine to influence species interactions.

  2. Grasshopper (Orthoptera: Acrididae) Community Composition in the Rangeland of the Northern Slopes of the Qilian Mountains in Northwestern China

    PubMed Central

    Sun, T.; Liu, Z. Y.; Qin, L. P.; Long, R. J.

    2015-01-01

    In order to describe grasshopper (Orthoptera: Acrididae) species composition, diversity, abundance, and density of four rangelands types, we compared the grasshopper community composition and dynamics in the rangeland of the northern slopes of the Qilian Mountains. In total, 55 grasshopper species were collected from 2007 to 2009, representing three families and six subfamilies. The subfamily Oedipodinae was dominant, followed by Gomphocerinae and Catantopinae. Species abundance varied among rangeland types (RTs). The greatest abundance of grasshoppers was found in mountain rangeland, while the lowest abundance of grasshoppers was caught in alpine shrublands. Three species (Chorthippus cf. brunneus (Thunberg) (Acrididae), Chorthippus Dubius (Zubovski), and Gomphocerus licenti (Chang) were broadly distributed in the four RTs and constituted 7.5% of all grasshoppers collected. Ch. dubius was very abundant in desert rangeland and alpine shrubland. Bryodema dolichoptera Yin et Feng Eremippus qilianshanensis Lian and Zheng, and Filchnerella qilianshanensis Xi and Zheng (Pamphagidae) were endemic to the region of the Qilian Mountains. Species similarity between RTs ranged from 17.8 to 51.6 based on the Renkonen index. Similarly, the Sörensen index indicated a wide separation in species composition among RTs. The abundance of the eight most common species showed obvious differences among RTs and years. On average, mountain rangeland had the highest density values in 2007 and 2008, and alpine shrubland supported the smallest density. The densities in desert and mountain rangeland in 2007 were significantly higher than in 2008, while alpine rangeland and shrublands did not present obvious differences among years. PMID:25688084

  3. Effect of Soil Texture and Soil Sterilization on Susceptibility of Ovipositing Grasshoppers to Beauveria bassiana

    PubMed

    Inglis; Johnson; Kawchuk; Goettel

    1998-01-01

    The effect of conidial concentration, soil texture, and soil sterilization on the efficacy of Beauveria bassiana against ovipositing grasshoppers (Melanoplus sanguinipes) was investigated in a controlled environment. In the first experiment, mortality of female grasshoppers ovipositing into a sterile loamy-sand soil containing conidia of B. bassiana was measured. The prevalence of mortality increased as the concentration of conidia in soil increased, and a median lethal concentration of 10(4) colony-forming units (CFU) per gram of soil (dry weight) was observed. Conidia (10(2.9) to 10(3) CFU per abdomen) were recovered from the abdomens of grasshoppers ovipositing into sand containing 10(5.5) and 10(6) conidia per gram. Similar numbers of eggs were laid among treatments during the first oviposition period (1 to 7 days), but an effect of conidial concentration on eggs laid was observed during the second oviposition period (8 to 14 days). This was attributed to reduction in female numbers and not to reduction in fecundity independent of mortality. In a second experiment, grasshoppers oviposited into soils of three different textures (loamy-sand, sandy-loam, or clay-loam) that were amended with 10(5) B. bassiana conidia per gram and possessed either a viable or heat-killed microflora. There was no effect of soil texture on mortality of ovipositing grasshoppers, on the number of eggs laid, on positioning of egg pods in the soil profile, or on numbers of B. bassiana CFU recovered from female abdomens. However, a higher prevalence of mortality was observed for females ovipositing into the sterilized than nonsterilized sandy-loam and clay-loam soils. Substantial populations of fungi and bacteria were recovered from nonsterilized soils. The predominant fungi isolated from these soils were members of the genera Chrysosporium, Fusarium, Gliocladium, Penicillium, Rhizopus, and Trichoderma, whereas Bacillus, Paenibacillus, and Pseudomonas species were the most commonly

  4. Genealogical portraits of speciation in montane grasshoppers (genus Melanoplus) from the sky islands of the Rocky Mountains.

    PubMed

    Knowles, L L

    2001-02-01

    Grasshoppers in the genus Melanoplus have undergone a radiation in the 'sky islands' of western North America, with many species originating during the Pleistocene. Despite their recent origins, phylogenetic analyses indicate that all the species exhibit monophyletic or paraphyletic gene trees. The objectives of this study were to determine whether the monophyletic genealogies are the result of a bottleneck at speciation and to investigate the extent to which the different phylogenetic states of eight species (i.e. monophyletic versus paraphyletic gene trees) can be ascribed to the effects of speciation. A coalescent simulation was used to test for a bottleneck at speciation in each species. The effective population sizes and demographic histories of species were compared across taxa to evaluate the possibility that the paraphyly versus monophyly of the species reflects differential rates of lineage loss rather than speciation mode. While coalescent analyses indicate that the monophyly of Melanoplus species might not be indicative of bottlenecks at speciation, the results suggest that the paraphyletic gene trees may reflect the demography of speciation, involving localized divergences in the ancestral species. With respect to different models of Pleistocene divergence, the data do not support a model of founder-effect speciation but are compatible with divergence in allopatric refugia. PMID:11217904

  5. Genealogical portraits of speciation in montane grasshoppers (genus Melanoplus) from the sky islands of the Rocky Mountains.

    PubMed Central

    Knowles, L. L.

    2001-01-01

    Grasshoppers in the genus Melanoplus have undergone a radiation in the 'sky islands' of western North America, with many species originating during the Pleistocene. Despite their recent origins, phylogenetic analyses indicate that all the species exhibit monophyletic or paraphyletic gene trees. The objectives of this study were to determine whether the monophyletic genealogies are the result of a bottleneck at speciation and to investigate the extent to which the different phylogenetic states of eight species (i.e. monophyletic versus paraphyletic gene trees) can be ascribed to the effects of speciation. A coalescent simulation was used to test for a bottleneck at speciation in each species. The effective population sizes and demographic histories of species were compared across taxa to evaluate the possibility that the paraphyly versus monophyly of the species reflects differential rates of lineage loss rather than speciation mode. While coalescent analyses indicate that the monophyly of Melanoplus species might not be indicative of bottlenecks at speciation, the results suggest that the paraphyletic gene trees may reflect the demography of speciation, involving localized divergences in the ancestral species. With respect to different models of Pleistocene divergence, the data do not support a model of founder-effect speciation but are compatible with divergence in allopatric refugia. PMID:11217904

  6. Comparison of elliptical and spherical mirrors for the grasshopper monochromators at SSRL

    SciTech Connect

    Waldhauer, A. P.

    1989-07-01

    A comparison of the performance of a spherical and elliptical mirror in the grasshopper monochromator is presented. The problem was studied by ray tracing and then tested using visible (/lambda/=633 nm) laser light. Calculations using ideal optics yield an improvement in flux by a factor of up to 2.7, while tests with visible light show an increase by a factor of 5 because the old spherical mirror is compared to a new, perfect elliptical one. The FWHM of the measured focus is 90 /mu/m with a spherical mirror, and 25 /mu/m with an elliptical one. Elliptical mirrors have been acquired and are now being installed in the two grasshoppers at SSRL.

  7. Comparison of elliptical and spherical mirrors for the grasshopper monochromators at SSRL

    NASA Astrophysics Data System (ADS)

    Waldhauer, A. P.

    1989-07-01

    A comparison of the performance of a spherical and elliptical mirror in the grasshopper monochromator is presented. The problem was studied by ray tracing and then tested using visible (λ=633 nm) laser light. Calculations using ideal optics yield an improvement in flux by a factor of up to 2.7, while tests with visible light show an increase by a factor of 5 because the old spherical mirror is compared to a new, perfect elliptical one. The FWHM of the measured focus is 90 μm with a spherical mirror, and 25 μm with an elliptical one. Elliptical mirrors have been acquired and are now being installed in the two grasshoppers at SSRL.

  8. Distribution, habitat and behavior of grasshopper sparrows, Ammodramus savannarum (Passeriformes: Emberizidae) in northeastern Nicaragua.

    PubMed

    Arguedas-Negrini, N

    2001-06-01

    During March and April of 1996, I made field observations of the sedentary subspecies of grasshopper sparrow (Ammodramus savannarum cracens), in 600 points of the pine savannas of northeastern Nicaragua. Isolated individuals were found in the humid depressions, but breeding populations were located exclusively in areas that had suffered a recent fire. Territorial behavior varied in intensity apparently as a function of territory size: the most aggressive males were those trying to defend smaller territories in populations close to Miskito villages, where most of the fires occur. In contrast to what is happening in other parts of Central America, the Nicaraguan grasshopper sparrow may be indirectly protected from extinction by the Miskito's traditional fire practices.

  9. Differentiation between pathogenic serotype 1 isolates of Marek's disease virus and the Rispens CVI988 vaccine in Australia using real-time PCR and high resolution melt curve analysis.

    PubMed

    Renz, K G; Cheetham, B F; Walkden-Brown, S W

    2013-01-01

    Two real-time PCR assays were developed which enable quantitation and differentiation between pathogenic Australian isolates of Marek's disease virus (MDV) serotype 1 and the serotype 1 vaccine strain Rispens CVI988. The assays are based on a DNA sequence variation in the meq gene between pathogenic and vaccinal MDV1 which has been confirmed by sequencing of 20 Australian field strains of MDV. Complete specificity has been demonstrated in samples containing pathogenic MDV (n=20), Rispens (3 commercial vaccine strains), or both. The limit of detection of both the Rispens-specific and the pathogenic MDV1-specific assays was 10 viral copies/reaction. The tests successfully differentiated and quantified MDV in mixtures of pathogenic and vaccinal Rispens virus. A high resolution melt curve analysis targeting the same SNP used for the real-time PCR assays was also developed which successfully detected sequence variation between Md5, six Australian MDV1 isolates and the three Rispens vaccines. However it was ineffective at differentiating mixtures of pathogenic and vaccinal MDV1. The real-time PCR assays have both diagnostic and epidemiological applications as they enable differentiation and quantitation of Rispens CVI988 and pathogenic MDV1 in co-infected chickens in Australia.

  10. High plant species diversity indirectly mitigates CO 2- and N-induced effects on grasshopper growth

    NASA Astrophysics Data System (ADS)

    Strengbom, Joachim; Reich, Peter B.; Ritchie, Mark E.

    2008-09-01

    We examined how elevated atmospheric [CO 2] and higher rate of nitrogen (N) input may influence grasshopper growth by changing food plant quality and how such effects may be modified by species diversity of the plant community. We reared grasshopper nymphs ( Melanoplus femurrubrum) on Poa pratensis from field-grown monocultures or polycultures (16 species) that were subjected to either ambient or elevated levels of CO 2 and N. Grasshopper growth rate was higher on P. pratensis leaves grown in monocultures than in polycultures, higher on P. pratensis grown under elevated than under ambient [CO 2], and higher on P. pratensis grown under elevated than under ambient [N]. The higher growth rate observed on P. pratensis exposed to elevated [CO 2] was, however, less pronounced for polyculture- than monoculture-grown P. pratensis. Growth rate of the grasshoppers was positively correlated with leaf [N], [C], and concentration of soluble carbohydrates + lipids. Concentration of non-structural carbohydrates + lipids was higher in leaves grown under elevated than under ambient [CO 2], and the difference between P. pratensis grown under ambient and elevated [CO 2] was greater for monoculture- than polyculture-grown P. pratensis. In addition, leaf N concentration was higher in P. pratensis grown in monocultures than in polycultures, suggesting that plant species richness, indirectly, may influence insect performance by changed nutritional value of the plants. Because we found interactive effects between all factors included ([CO 2], [N], and plant species diversity), our results suggest that these parameters may influence plant-insect interactions in a complex way that is not predictable from the sum of single factor manipulations.

  11. Reproduction-Related Sound Production of Grasshoppers Regulated by Internal State and Actual Sensory Environment

    PubMed Central

    Heinrich, Ralf; Kunst, Michael; Wirmer, Andrea

    2012-01-01

    The interplay of neural and hormonal mechanisms activated by entero- and extero-receptors biases the selection of actions by decision making neuronal circuits. The reproductive behavior of acoustically communicating grasshoppers, which is regulated by short-term neural and longer-term hormonal mechanisms, has frequently been used to study the cellular and physiological processes that select particular actions from the species-specific repertoire of behaviors. Various grasshoppers communicate with species- and situation-specific songs in order to attract and court mating partners, to signal reproductive readiness, or to fend off competitors. Selection and coordination of type, intensity, and timing of sound signals is mediated by the central complex, a highly structured brain neuropil known to integrate multimodal pre-processed sensory information by a large number of chemical messengers. In addition, reproductive activity including sound production critically depends on maturation, previous mating experience, and oviposition cycles. In this regard, juvenile hormone released from the corpora allata has been identified as a decisive hormonal signal necessary to establish reproductive motivation in grasshopper females. Both regulatory systems, the central complex mediating short-term regulation and the corpora allata mediating longer-term regulation of reproduction-related sound production mutually influence each other’s activity in order to generate a coherent state of excitation that promotes or suppresses reproductive behavior in respective appropriate or inappropriate situations. This review summarizes our current knowledge about extrinsic and intrinsic factors that influence grasshopper reproductive motivation, their representation in the nervous system and their integrative processing that mediates the initiation or suppression of reproductive behaviors. PMID:22737107

  12. Grasshopper ontogeny in relation to time constraints: adaptive divergence and stasis.

    PubMed

    Berner, Daniel; Blanckenhorn, Wolf U

    2006-01-01

    1. Life history theory generally predicts a trade-off between shortjuvenile development and large adult size, assuming invariant growth rates within species. This pivotal assumption has been explicitly tested in few organisms. 2. We studied ontogeny in 13 populations of Omocestus viridulus grasshoppers under common garden conditions. High-altitude populations, facing short growing seasons and thus seasonal time constraints, were found to grow at a similar rate to low altitude conspecifics. 3. Instead, high-altitude grasshoppers evolved faster development, and the correlated change in body size led to an altitudinal size cline mediating a trade-off with female fecundity. 4. An additional juvenile stage occurred in low- but not high-altitude females. This difference is probably due to the evolution of lowered critical size thresholds in high-altitude grasshoppers to accelerate development. 5. We found a strikingly lower growth rate in males than females that we interpret as the outcome of concurrent selection for protandry and small male size. 6. Within populations, large individuals developed faster than small individuals, suggesting within-population genetic variation in growth rates. 7. We provide evidence that different time constraints (seasonal, protandry selection) can lead to different evolutionary responses in intrinsic growth, and that correlations among ontogenetic traits within populations cannot generally be used to predict life history adaptation among populations. Moreover, our study illustrates that comparisons of ontogenetic patterns can shed light on the developmental basis underlying phenotypic evolution.

  13. The effectiveness of common thermo-regulatory behaviours in a cool temperate grasshopper.

    PubMed

    Harris, Rebecca M B; McQuillan, Peter; Hughes, Lesley

    2015-08-01

    Behavioural thermoregulation has the potential to alleviate the short-term impacts of climate change on some small ectotherms, without the need for changes to species distributions or genetic adaptation. We illustrate this by measuring the effect of behaviour in a cool temperate species of grasshopper (Phaulacridium vittatum) over a range of spatial and temporal scales in laboratory and natural field experiments. Microhabitat selection at the site scale was tested in free-ranging grasshoppers and related to changing thermal quality over a daily period. Artificial warming experiments were then used to measure the temperature at which common thermoregulatory behaviours are initiated and the subsequent reductions in body temperature. Behavioural means such as timing of activity, choice of substrates with optimum surface temperatures, shade seeking and postural adjustments (e.g. stilting, vertical orientation) were found to be highly effective at maintaining preferred body temperature. The maximum voluntarily tolerated temperature (MVT) was determined to be 44°C±0.4°C, indicating the upper bounds of thermal flexibility in this species. Behavioural thermoregulation effectively enables small ectotherms to regulate exposure to changing environmental temperatures and utilize the spatially and temporally heterogeneous environments they occupy. Species such as the wingless grasshopper, although adapted to cool temperate conditions, are likely to be well equipped to respond successfully to coarse scale climate change.

  14. The effectiveness of common thermo-regulatory behaviours in a cool temperate grasshopper.

    PubMed

    Harris, Rebecca M B; McQuillan, Peter; Hughes, Lesley

    2015-08-01

    Behavioural thermoregulation has the potential to alleviate the short-term impacts of climate change on some small ectotherms, without the need for changes to species distributions or genetic adaptation. We illustrate this by measuring the effect of behaviour in a cool temperate species of grasshopper (Phaulacridium vittatum) over a range of spatial and temporal scales in laboratory and natural field experiments. Microhabitat selection at the site scale was tested in free-ranging grasshoppers and related to changing thermal quality over a daily period. Artificial warming experiments were then used to measure the temperature at which common thermoregulatory behaviours are initiated and the subsequent reductions in body temperature. Behavioural means such as timing of activity, choice of substrates with optimum surface temperatures, shade seeking and postural adjustments (e.g. stilting, vertical orientation) were found to be highly effective at maintaining preferred body temperature. The maximum voluntarily tolerated temperature (MVT) was determined to be 44°C±0.4°C, indicating the upper bounds of thermal flexibility in this species. Behavioural thermoregulation effectively enables small ectotherms to regulate exposure to changing environmental temperatures and utilize the spatially and temporally heterogeneous environments they occupy. Species such as the wingless grasshopper, although adapted to cool temperate conditions, are likely to be well equipped to respond successfully to coarse scale climate change. PMID:26267501

  15. Reprint of: The effectiveness of common thermo-regulatory behaviours in a cool temperate grasshopper.

    PubMed

    Harris, Rebecca M B; McQuillan, Peter; Hughes, Lesley

    2015-12-01

    Behavioural thermoregulation has the potential to alleviate the short-term impacts of climate change on some small ectotherms, without the need for changes to species distributions or genetic adaptation. We illustrate this by measuring the effect of behaviour in a cool temperate species of grasshopper (Phaulacridium vittatum) over a range of spatial and temporal scales in laboratory and natural field experiments. Microhabitat selection at the site scale was tested in free-ranging grasshoppers and related to changing thermal quality over a daily period. Artificial warming experiments were then used to measure the temperature at which common thermoregulatory behaviours are initiated and the subsequent reductions in body temperature. Behavioural means such as timing of activity, choice of substrates with optimum surface temperatures, shade seeking and postural adjustments (e.g. stilting, vertical orientation) were found to be highly effective at maintaining preferred body temperature. The maximum voluntarily tolerated temperature (MVT) was determined to be 44 °C ± 0.4 °C, indicating the upper bounds of thermal flexibility in this species. Behavioural thermoregulation effectively enables small ectotherms to regulate exposure to changing environmental temperatures and utilize the spatially and temporally heterogeneous environments they occupy. Species such as the wingless grasshopper, although adapted to cool temperate conditions, are likely to be well equipped to respond successfully to coarse scale climate change. PMID:26615722

  16. Reduced predation risk for melanistic pygmy grasshoppers in post-fire environments.

    PubMed

    Karpestam, Einat; Merilaita, Sami; Forsman, Anders

    2012-09-01

    The existence of melanistic (black) color forms in many species represents interesting model systems that have played important roles for our understanding of selective processes, evolution of adaptations, and the maintenance of variation. A recent study reported on rapid evolutionary shifts in frequencies of the melanistic forms in replicated populations of Tetrix subulata pygmy grasshoppers; the incidence of the melanistic form was higher in recently burned areas with backgrounds blackened by fire than in nonburned areas, and it declined over time in postfire environments. Here, we tested the hypothesis that the frequency shifts of the black color variant were driven, at least in part, by changes in the selective regime imposed by visual predators. To study detectability of the melanistic form, we presented human "predators" with images of black grasshoppers and samples of the natural habitat on computer screens. We demonstrate that the protective value of black coloration differs between burnt and nonburnt environments and gradually increases in habitats that have been more blackened by fire. These findings support the notion that a black color pattern provides improved protection from visually oriented predators against blackened backgrounds and implicate camouflage and predation as important drivers of fire melanism in pygmy grasshoppers. PMID:23139879

  17. Grasshopper sparrow reproductive success and habitat use on reclaimed surface mines varies by age of reclamation

    USGS Publications Warehouse

    Wood, Petra; Ammer, Frank K.

    2015-01-01

    We studied 3 mountaintop mining–valley fill (MTMVF) complexes in southern West Virginia, USA to examine grasshopper sparrow (Ammodramus savannarum pratensis) demographic response to different age classes of mine land reclamation. For 71 nests monitored during the 2001–2002 breeding seasons, overall nest success (36%) was within the range of nest success rates previously reported for this species, but it was highest on more recently reclaimed sites (56%). Nest density and clutch size did not differ (P > 0.30) among reclamation age classes, whereas number of fledglings was greater (P = 0.01) on more recently reclaimed sites. We measured vegetation variables at 70 nest subplots and at 96 systematic subplots to compare nest vegetation with vegetation available on the plots. We found that nests occurred in areas with more bare ground near the nest, greater vegetation height–density surrounding the nest site, lower grass height, and fewer woody stems, similar to previous studies. As postreclamation age increased, vegetation height–density and maximum grass height increased, and sericea (Lespedeza cuneata) became more dominant. Nest success declined with increasing vegetation height–density at the nest. The grasslands available on these reclaimed mine complexes are of sufficient quality to support breeding populations of grasshopper sparrows, but nest success decreased on the older reclaimed areas. Without active management, grasslands on reclaimed MTMVF mines become less suitable for nesting grasshopper sparrows about 10 years after reclamation.

  18. Pairing Competition between Identical and Homologous Chromosomes in Rye and Grasshoppers

    PubMed Central

    Santos, J. L.; Orellana, J.; Giraldez, R.

    1983-01-01

    Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material. PMID:17246148

  19. Reduced predation risk for melanistic pygmy grasshoppers in post-fire environments.

    PubMed

    Karpestam, Einat; Merilaita, Sami; Forsman, Anders

    2012-09-01

    The existence of melanistic (black) color forms in many species represents interesting model systems that have played important roles for our understanding of selective processes, evolution of adaptations, and the maintenance of variation. A recent study reported on rapid evolutionary shifts in frequencies of the melanistic forms in replicated populations of Tetrix subulata pygmy grasshoppers; the incidence of the melanistic form was higher in recently burned areas with backgrounds blackened by fire than in nonburned areas, and it declined over time in postfire environments. Here, we tested the hypothesis that the frequency shifts of the black color variant were driven, at least in part, by changes in the selective regime imposed by visual predators. To study detectability of the melanistic form, we presented human "predators" with images of black grasshoppers and samples of the natural habitat on computer screens. We demonstrate that the protective value of black coloration differs between burnt and nonburnt environments and gradually increases in habitats that have been more blackened by fire. These findings support the notion that a black color pattern provides improved protection from visually oriented predators against blackened backgrounds and implicate camouflage and predation as important drivers of fire melanism in pygmy grasshoppers.

  20. Resource-mediated impact of spider predation risk on performance in the grasshopper Ageneotettix deorum (Orthoptera: Acrididae).

    PubMed

    Danner, Bradford J; Joern, Anthony

    2003-11-01

    In response to increased exposure to predators when searching for food, many prey increase the frequency of antipredator behaviors, potentially reducing foraging rate and food intake. Such direct, nonlethal interactions between predators and prey resulting in reduced food intake can indirectly influence lifecycle development through effects on growth, developmental rate, and survival. We investigated the general hypothesis that individual performance of a herbivorous insect can be negatively affected when exposed to nonlethal predation risk, and that the response can be mediated by food quality. This hypothesis was tested using the common rangeland grasshopper Ageneotettix deorum with and without exposure to common wolf spider predators (Lycosidae, Schizocosa spp.) on both untreated natural and fertilized vegetation. All spiders were rendered temporarily incapable of direct feeding by restricting function of the chelicerae with beeswax. Detectable responses by grasshoppers to spiders indicate indirect consequences for lifecycle development. Grasshopper performance was measured as hind femur growth, duration of nymphal lifecycle stages, and survivorship in a caged field experiment conducted over 2 years. Grasshoppers developed faster and grew 3-5% larger when allowed to forage on fertilized vegetation in the absence of risk from a spider predator. Failure-time analysis illustrated enhanced survival probability in response to elevated food quality and the negative effects of grasshopper susceptibility to nonlethal predation risk. Performance on food of relatively low, ambient quality with no predation risk equaled that of grasshoppers caged with high quality vegetation in the presence of a modified spider. Increased resource quality can clearly moderate the negative life history responses caused by the behavioral modification of grasshoppers when exposed to spider predation risk, a compensatory response.

  1. Differential Communications between Fungi and Host Plants Revealed by Secretome Analysis of Phylogenetically Related Endophytic and Pathogenic Fungi

    PubMed Central

    Xu, Xihui; He, Qin; Zhang, Chulong

    2016-01-01

    During infection, both phytopathogenic and endophytic fungi form intimate contact with living plant cells, and need to resist or disable host defences and modify host metabolism to adapt to their host. Fungi can achieve these changes by secreting proteins and enzymes. A comprehensive comparison of the secretomes of both endophytic and pathogenic fungi can improve our understanding of the interactions between plants and fungi. Although Magnaporthe oryzae, Gaeumannomyces graminis, and M. poae are economically important fungal pathogens, and the related species Harpophora oryzae is an endophyte, they evolved from a common pathogenic ancestor. We used a pipeline analysis to predict the H. oryzae, M. oryzae, G. graminis, and M. poae secretomes and identified 1142, 1370, 1001, and 974 proteins, respectively. Orthologue gene analyses demonstrated that the M. oryzae secretome evolved more rapidly than those of the other three related species, resulting in many species-specific secreted protein-encoding genes, such as avirulence genes. Functional analyses highlighted the abundance of proteins involved in the breakdown of host plant cell walls and oxidation-reduction processes. We identified three novel motifs in the H. and M. oryzae secretomes, which may play key roles in the interaction between rice and H. oryzae. Furthermore, we found that expression of the H. oryzae secretome involved in plant cell wall degradation was downregulated, but the M. oryzae secretome was upregulated with many more upregulated genes involved in oxidation-reduction processes. The divergent in planta expression patterns of the H. and M. oryzae secretomes reveal differences that are associated with mutualistic and pathogenic interactions, respectively. PMID:27658302

  2. Friend or foe: differential responses of rice to invasion by mutualistic or pathogenic fungi revealed by RNAseq and metabolite profiling.

    PubMed

    Xu, Xi-Hui; Wang, Chen; Li, Shu-Xian; Su, Zhen-Zhu; Zhou, Hui-Na; Mao, Li-Juan; Feng, Xiao-Xiao; Liu, Ping-Ping; Chen, Xia; Hugh Snyder, John; Kubicek, Christian P; Zhang, Chu-Long; Lin, Fu-Cheng

    2015-09-08

    The rice endophyte Harpophora oryzae shares a common pathogenic ancestor with the rice blast fungus Magnaporthe oryzae. Direct comparison of the interactions between a single plant species and two closely-related (1) pathogenic and (2) mutualistic fungi species can improve our understanding of the evolution of the interactions between plants and fungi that lead to either mutualistic or pathogenic interactions. Differences in the metabolome and transcriptome of rice in response to challenge by H. or M. oryzae were investigated with GC-MS, RNA-seq, and qRT-PCR. Levels of metabolites of the shikimate and lignin biosynthesis pathways increased continuously in the M. oryzae-challenged rice roots (Mo-roots); these pathways were initially induced, but then suppressed, in the H. oryzae-challenged rice roots (Ho-roots). Compared to control samples, concentrations of sucrose and maltose were reduced in the Ho-roots and Mo-roots. The expression of most genes encoding enzymes involved in glycolysis and the TCA cycle were suppressed in the Ho-roots, but enhanced in the Mo-roots. The suppressed glycolysis in Ho-roots would result in the accumulation of glucose and fructose which was not detected in the Mo-roots. A novel co-evolution pattern of fungi-host interaction is proposed which highlights the importance of plant host in the evolution of fungal symbioses.

  3. Expression and secretion of Salmonella pathogenicity island-2 virulence genes in response to acidification exhibit differential requirements of a functional type III secretion apparatus and SsaL.

    PubMed

    Coombes, Brian K; Brown, Nat F; Valdez, Yanet; Brumell, John H; Finlay, B Brett

    2004-11-26

    Salmonella pathogenicity island (SPI)-2 is pivotal to the intracellular survival of Salmonella and for virulence in mammals. SPI-2 encodes virulence factors (called effectors) that are translocated into the host cell, a type III secretion apparatus and a two-component regulatory system that regulates intracellular expression of SPI-2. Salmonella SPI-2 secretion activity appears to be induced in response to acidification of the vacuole in which it replicates. Here we show that the expression of the SPI-2 proteins, SseB and SseD (filament and pore forming components of the secretion apparatus, respectively) in response to acidification requires an intact secretion system and SsaL, a Salmonella homologue of SepL, a regulator required for type III-dependent secretion of translocators but not effectors in attaching and effacing gastrointestinal pathogens. We show that the expression of SPI-2-encoded effectors is acid-regulated but can be uncoupled from the expression of filament and translocon components, thus showing a differential requirement of SsaL for expression. The secretion and translocation of SPI-2-encoded effectors requires SsaL, but SsaL is dispensable for the secretion of SPI-2 effectors encoded in other pathogenicity loci, suggesting a secretion regulation function for SsaL. Further, we demonstrate that the differential expression of adjacent genes within the sseA operon (sseD and sseE) occurs at the transcriptional level. These data indicate that a Salmonella SPI-2 activation state is achieved by an acidregulated response that requires SsaL. These data also suggest the existence of a previously unrecognized regulatory element within SPI-2 for the "effector operon" region downstream of sseD that might demarcate the expression of translocators and effectors.

  4. Development of a toxic bait for control of eastern lubber grasshopper (Orthoptera: Acrididae).

    PubMed

    Barbara, Kathryn A; Capinera, John L

    2003-06-01

    This study assessed baits for eastern lubber grasshopper, Romalea guttata (Houttuyn). When offered a choice among several grain-based baits (rolled oats, wheat bran, oat bran, yeast, corn meal, cornflakes) and vegetable oils (canola, corn, peanut, soybean), eastern lubber grasshopper adults preferred bait consisting of wheat bran carrier with corn oil as an added phagostimulant. Other carriers were accepted but consumed less frequently. Discrimination by eastern lubber grasshoppers among oils was poor. Similarly, addition of flavorings (peppermint, anise, lemon, banana) resulted in few significant effects. The carbaryl, wheat bran, and oil bait developed in this study was effective at causing eastern lubber grasshopper mortality in field-cage studies. Significant mortality occurred even though grasshoppers had to locate dishes of bait in a large cage, and could feed on daylilies, or grass growing through the bottom of the cage, rather than on the bran flakes. Consumption of as little as a single carbaryl-treated bran flake could induce mortality, although individuals varied greatly in their susceptibility. The bait matrix developed in this study was readily consumed when in the presence of some plant species. We expect that wheat bran and corn oil bait would be most effective as protection for less preferred plants (tomato, pepper, eggplant, leek, parsley, fennel, daylily, lily of the Nile, and canna lily) because baits were readily consumed in the presence of these plants. Plants that are readily consumed in the presence of bait (preferred plants) included butter crunch lettuce, carrot, yellow squash, cauliflower, collards, green onion, chive, cucumber, cabbage, cantalope, endive, red leaf lettuce, society garlic, caladium, and amaryllis. Baits are likely to be less effective in the presence of such plants. On average, vegetables in Solanaceae (i.e., tomato, pepper, and eggplant) and Apiaceae (i.e., fennel and parsley) elicited high levels of bait-feeding activity

  5. Sympatric genetic differentiation of a generalist pathogenic fungus, Botrytis cinerea, on two different host plants, grapevine and bramble.

    PubMed

    Fournier, E; Giraud, T

    2008-01-01

    Prime candidates for sympatric ecological divergence include parasites that differentiate via host shifts, because different host species exert strong disruptive selection and because both hosts and parasites are continually co-evolving. Sympatric divergence may be fostered even more strongly in phytopathogenic fungi, in particular those where sex must occur on the host, which allows adaptation alone to restrict gene flow between populations developing on different hosts. We sampled populations of Botrytis cinerea, a generalist ascomycete fungus, on sympatric grapes and brambles in six regions in France. Microsatellite data were analyzed using standard population genetics, a population graph analysis and a Bayesian approach. In addition to confirming that B. cinerea reproduces sexually, our results showed that the fungal populations on the two hosts were significantly differentiated, indicating restricted gene flow, even in sympatry. In contrast, only weak geographical differentiation could be detected. These results support the possibility of sympatric divergence associated with host use in generalist parasites. PMID:18028352

  6. Salmonella effectors within a single pathogenicity island are differentially expressed and translocated by separate type III secretion systems.

    PubMed

    Knodler, Leigh A; Celli, Jean; Hardt, Wolf-Dietrich; Vallance, Bruce A; Yip, Calvin; Finlay, B Brett

    2002-03-01

    Pathogenicity islands (PAIs) are large DNA segments in the genomes of bacterial pathogens that encode virulence factors. Five PAIs have been identified in the Gram-negative bacterium Salmonella enterica. Two of these PAIs, Salmonella pathogenicity island (SPI)-1 and SPI-2, encode type III secretion systems (TTSS), which are essential virulence determinants. These 'molecular syringes' inject effectors directly into the host cell, whereupon they manipulate host cell functions. These effectors are either encoded with their respective TTSS or scattered elsewhere on the Salmonella chromosome. Importantly, SPI-1 and SPI-2 are expressed under distinct environmental conditions: SPI-1 is induced upon initial contact with the host cell, whereas SPI-2 is induced intracellularly. Here, we demonstrate that a single PAI, in this case SPI-5, can encode effectors that are induced by distinct regulatory cues and targeted to different TTSS. SPI-5 encodes the SPI-1 TTSS translocated effector, SigD/SopB. In contrast, we report that the adjacently encoded effector PipB is part of the SPI-2 regulon. PipB is translocated by the SPI-2 TTSS to the Salmonella-containing vacuole and Salmonella-induced filaments. We also show that regions of SPI-5 are not conserved in all Salmonella spp. Although sigD/sopB is present in all Salmonella spp., pipB is not found in Salmonella bongori, which also lacks a functional SPI-2 TTSS. Thus, we demonstrate a functional and regulatory cross-talk between three chromosomal PAIs, SPI-1, SPI-2 and SPI-5, which has significant implications for the evolution and role of PAIs in bacterial pathogenesis.

  7. Quantitative analysis of diet structure by real-time PCR, reveals different feeding patterns by two dominant grasshopper species.

    PubMed

    Huang, Xunbing; Wu, Huihui; McNeill, Mark Richard; Qin, Xinghu; Ma, Jingchuan; Tu, Xiongbing; Cao, Guangchun; Wang, Guangjun; Nong, Xiangqun; Zhang, Zehua

    2016-01-01

    Studies on grasshopper diets have historically employed a range of methodologies, each with certain advantages and disadvantages. For example, some methodologies are qualitative instead of quantitative. Others require long experimental periods or examine population-level effects, only. In this study, we used real-time PCR to examine diets of individual grasshoppers. The method has the advantage of being both fast and quantitative. Using two grasshopper species, Oedaleus asiaticus and Dasyhippus barbipes, we designed ITS primer sequences for their three main host plants, Stipa krylovii, Leymus chinensis and Cleistogenes squarrosa and used real-time PCR method to test diet structure both qualitatively and quantitatively. The lowest detection efficiency of the three grass species was ~80% with a strong correlation between actual and PCR-measured food intake. We found that Oedaleus asiaticus maintained an unchanged diet structure across grasslands with different grass communities. By comparison, Dasyhippus barbipes changed its diet structure. These results revealed why O. asiaticus distribution is mainly confined to Stipa-dominated grassland, and D. barbipes is more widely distributed across Inner Mongolia. Overall, real-time PCR was shown to be a useful tool for investigating grasshopper diets, which in turn offers some insight into grasshopper distributions and improved pest management. PMID:27562455

  8. Quantitative analysis of diet structure by real-time PCR, reveals different feeding patterns by two dominant grasshopper species

    PubMed Central

    Huang, Xunbing; Wu, Huihui; McNeill, Mark Richard; Qin, Xinghu; Ma, Jingchuan; Tu, Xiongbing; Cao, Guangchun; Wang, Guangjun; Nong, Xiangqun; Zhang, Zehua

    2016-01-01

    Studies on grasshopper diets have historically employed a range of methodologies, each with certain advantages and disadvantages. For example, some methodologies are qualitative instead of quantitative. Others require long experimental periods or examine population-level effects, only. In this study, we used real-time PCR to examine diets of individual grasshoppers. The method has the advantage of being both fast and quantitative. Using two grasshopper species, Oedaleus asiaticus and Dasyhippus barbipes, we designed ITS primer sequences for their three main host plants, Stipa krylovii, Leymus chinensis and Cleistogenes squarrosa and used real-time PCR method to test diet structure both qualitatively and quantitatively. The lowest detection efficiency of the three grass species was ~80% with a strong correlation between actual and PCR-measured food intake. We found that Oedaleus asiaticus maintained an unchanged diet structure across grasslands with different grass communities. By comparison, Dasyhippus barbipes changed its diet structure. These results revealed why O. asiaticus distribution is mainly confined to Stipa-dominated grassland, and D. barbipes is more widely distributed across Inner Mongolia. Overall, real-time PCR was shown to be a useful tool for investigating grasshopper diets, which in turn offers some insight into grasshopper distributions and improved pest management. PMID:27562455

  9. Differential Phosphorylation of Akt and signaling in CD4+ T Cells in Pathogenic and Apathogenic SIV Infection.

    PubMed

    Stephenson, S T; Bostik, V; Bostik, P

    2016-01-01

    Increased CD4+ T cell apoptosis and activation induced cell death (AICD) as a result of HIV infection in humans and SIV infection in Rhesus macaques (RM) is indicative of disease. Some non-human primate species naturally infected by SIV, such as African sooty mangabeys (SM), do not succumb to SIV despite high viral loads. Previously, we showed that mRNA levels of GSK-3β a kinase involved in T cell signaling, are significantly decreased in SIV+ RM compared to SIV+ SM. The current study confirms that expression of GSK-3β is decreased at the protein level in SIV+ RM. In addition, CD4+ T cells from SIV+ RM, but not other animals show an increase in both total Akt, a kinase directly interacting with GSK-3β and p-AktThr308 in response to stimulation via CD3/CD28, which is associated with an increase in apoptosis. Furthermore, the differences between the uninfected and pathogenically or non-pathogenically infected animals are not only species specific, but also T cell subset specific and that these trends correlate with AICD. This is one of few studies indicating the activity of Akt can be specific to only one phosphorylation site and may be linked to the differences in AICD and resistance to the lentivirus induced disease. PMID:27467331

  10. Culture-differentiated CD8(+) T cells acquire innate memory-like traits and respond to a pathogen-associated molecule.

    PubMed

    Biswas, Ratna; Mukherjee, Subhadeep; Sinha, Debolina; Ghosh, Amlan Kanti; Biswas, Tapas

    2014-04-01

    Selection of conventional CD4(+) or CD8(+) T cells is usually driven by the interaction of double-positive CD4(+)CD8(+) thymocytes with epithelial cells. Here, we demonstrate preferential selection of CD8(+) thymocytes from in vitro differentiation of CD4(+)CD8(+) double-positive thymocytes exhibiting the characteristics of nonconventional innate memory CD8(+) cells. In contrast to conventional CD8(+) thymocytes, these culture-differentiated CD8(+) cells are eomesodermin positive and robustly express CXCR3, CD44, CD122 and TLR2. Interestingly, the pathogen-associated molecule porin promotes preferential differentiation of the CD8(+) single-positive subset in association with promyelocytic leukemia zinc-finger upregulation and interleukin (IL)-4 production. On priming with anti-CD3 antibody, porin augmented TLR2 and IFN-γ indicating a role of the TLR ligand in acquisition of innate memory response of CD8(+) thymocytes. In addition, porin has a cooperative role with IL-15 on the expansion of memory-phenotype CD8(+) T cells along with its effector function. Thus, the study opens an avenue to unfold the cues for development of these cells and the strategies adopted for bolstering immunity during primary infection.

  11. Differential specificity of selective culture media for enumeration of pathogenic vibrios: advantages and limitations of multi-plating methods.

    PubMed

    Nigro, Olivia D; Steward, Grieg F

    2015-04-01

    Plating environmental samples on vibrio-selective chromogenic media is a commonly used technique that allows one to quickly estimate concentrations of putative vibrio pathogens or to isolate them for further study. Although this approach is convenient, its usefulness depends directly on how well the procedure selects against false positives. We tested whether a chromogenic medium, CHROMagar Vibrio (CaV), used alone (single-plating) or in combination (double-plating) with a traditional medium thiosulfate-citrate-bile-salts (TCBS), could improve the discrimination among three pathogenic vibrio species (Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus) and thereby decrease the number of false-positive colonies that must be screened by molecular methods. Assays were conducted on water samples from two estuarine environments (one subtropical, one tropical) in a variety of seasonal conditions. The results of the double-plating method were confirmed by PCR and 16S rRNA sequencing. Our data indicate that there is no significant difference in the false-positive rate between CaV and TCBS when using a single-plating technique, but determining color changes on the two media sequentially (double-plating) reduced the rate of false positive identification in most cases. The improvement achieved was about two-fold on average, but varied greatly (from 0- to 5-fold) and depended on the sampling time and location. The double-plating method was most effective for V. vulnificus in warm months, when overall V. vulnificus abundance is high (false positive rates as low as 2%, n=178). Similar results were obtained for V. cholerae (minimum false positive rate of 16%, n=146). In contrast, the false positive rate for V. parahaemolyticus was always high (minimum of 59%, n=109). Sequence analysis of false-positive isolates indicated that the majority of confounding isolates are from the Vibrionaceae family, however, members of distantly related bacterial groups were also able to

  12. Grazing damage to plants and gastropod and grasshopper densities in a CO 2-enrichment experiment on calcareous grassland

    NASA Astrophysics Data System (ADS)

    Ledergerber, Stephan; Thommen, G. Heinrich; Baur, Bruno

    Plant-herbivore interactions may change as atmospheric CO 2 concentrations continue to rise. We examined the effects of elevated atmospheric CO 2 and CO 2-exposure chambers on the grazing damage to plants, and on the abundances of potential herbivores (terrestrial gastropods and grasshoppers) in a calcareous grassland in the Jura mountains of Switzerland (village of Nenzlingen). Individuals of most plant species examined showed slight grazing damage. However, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in the extent of grazing damage. Similarly, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in either gastropod or grasshopper density. Experimental plots with and without chambers did not differ in the number of gastropods. However, the densities of gastropods and grasshoppers and extent of grazing damage to plants were generally lower in the experimental area than in the grassland outside the experimental field.

  13. Duplicate maize 13-lipoxygenase genes are differentially regulated by circadian rhythm, cold stress, wounding, pathogen infection, and hormonal treatments.

    PubMed

    Nemchenko, Andriy; Kunze, Susan; Feussner, Ivo; Kolomiets, Michael

    2006-01-01

    Most plant oxylipins, a large class of diverse oxygenated polyunsaturated fatty acids and their derivatives, are produced through the lipoxygenase (LOX) pathway. Recent progress in dicots has highlighted the biological roles of oxylipins in plant defence responses to pathogens and pests. By contrast, the physiological function of LOXs and their metabolites in monocots is poorly understood. Two maize LOXs, ZmLOX10 and ZmLOX11 that share >90% amino acid sequence identity but are localized on different chromosomes, were cloned and characterized. Phylogenetic analysis revealed that ZmLOX10 and ZmLOX11 cluster together with well-characterized plastidic type 2 linoleate 13-LOXs from diverse plant species. Regio-specificity analysis of recombinant ZmLOX10 protein overexpressed in Escherichia coli proved it to be a linoleate 13-LOX with a pH optimum at approximately pH 8.0. Both predicted proteins contain putative transit peptides for chloroplast import. ZmLOX10 was preferentially expressed in leaves and was induced in response to wounding, cold stress, defence-related hormones jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA), and inoculation with an avirulent strain of Cochliobolus carbonum. These data suggested a role for this gene in maize adaptation to abiotic stresses and defence responses against pathogens and pests. ZmLOX11 was preferentially expressed in silks and was induced in leaves only by ABA, indicating its possible involvement in responses to osmotic stress. In leaves, mRNA accumulation of ZmLOX10 is strictly regulated by a circadian rhythm, with maximal expression coinciding temporally with the highest photosynthetic activity. This study reveals the evolutionary divergence of physiological roles for relatively recently duplicated genes. Possible physiological functions of these 13-LOXs are suggested.

  14. Ancestral polymorphisms in genetic markers obscure detection of evolutionarily distinct populations in the endangered Florida grasshopper sparrow (Ammodramus savannarum floridanus).

    PubMed

    Bulgin, Natalie L; Gibbs, H Lisle; Vickery, Peter; Baker, Allan J

    2003-04-01

    Genetic analyses of bird subspecies designated as conservation units can address whether they represent units with independent evolutionary histories and provide insights into the evolutionary processes that determine the degree to which they are genetically distinct. Here we use mitochondrial DNA control region sequence and six microsatellite DNA loci to examine phylogeographical structure and genetic differentiation among five North American grasshopper sparrow (Ammodramus savannarum) populations representing three subspecies, including a population of the endangered Florida subspecies (A. s. floridanus). This federally listed taxon is of particular interest because it differs phenotypically from other subspecies in plumage and behaviour and has also undergone a drastic decline in population size over the past century. Despite this designation, we observed no phylogeographical structure among populations in either marker: mtDNA haplotypes and microsatellite genotypes from floridanus samples did not form clades that were phylogenetically distinct from variants found in other subspecies. However, there was low but significant differentiation between Florida and all other populations combined in both mtDNA (FST = 0.069) and in one measure of microsatellite differentiation (theta = 0.016), while the non-Florida populations were not different from each other. Based on analyses of mtDNA variation using a coalescent-based model, the effective sizes of these populations are large (approximately 80,000 females) and they have only recently diverged from each other (< 26,000 ybp). These populations are probably far from genetic equilibrium and therefore the lack of phylogenetic distinctiveness of the floridanus subspecies and minimal genetic differentiation is due most probably to retained ancestral polymorphism. Finally, levels of variation in Florida were similar to other populations supporting the idea that the drastic reduction in population size which has occurred

  15. Vitellogenin-RNAi and ovariectomy each increase lifespan, increase protein storage, and decrease feeding, but are not additive in grasshoppers.

    PubMed

    Tetlak, Alicia G; Burnett, Jacob B; Hahn, Daniel A; Hatle, John D

    2015-12-01

    Reduced reproduction has been shown to increase lifespan in many animals, yet the mechanisms behind this trade-off are unclear. We addressed this question by combining two distinct, direct means of life-extension via reduced reproduction, to test whether they were additive. In the lubber grasshopper, Romalea microptera, ovariectomized (OVX) individuals had a ~20% increase in lifespan and a doubling of storage relative to controls (Sham operated). Similarly, young female grasshoppers treated with RNAi against vitellogenin (the precursor to egg yolk protein) had increased fat body mass and halted ovarian growth. In this study, we compared VgRNAi to two control groups that do not reduce reproduction, namely buffer injection (Buffer) and injection with RNAi against a hexameric storage protein (Hex90RNAi). Each injection treatment was tested with and without ovariectomy. Hence, we tested feeding, storage, and lifespans in six groups: OVX and Buffer, OVX and Hex90RNAi, OVX and VgRNAi, Sham and Buffer, Sham and Hex90RNAi, and Sham and VgRNAi. Ovariectomized grasshoppers and VgRNAi grasshoppers each had similar reductions in feeding (~40%), increases in protein storage in the hemolymph (150-300%), and extensions in lifespan (13-21%). Ovariectomized grasshoppers had higher vitellogenin protein levels than did VgRNAi grasshoppers. Last but not least, when ovariectomy and VgRNAi were applied together, there was no greater effect on feeding, protein storage, or longevity. Hence, feeding regulation, and protein storage in insects, may be conserved components of life-extension via reduced reproduction. PMID:26298568

  16. Differential Expression Analysis by RNA-Seq Reveals Perturbations in the Platelet mRNA Transcriptome Triggered by Pathogen Reduction Systems.

    PubMed

    Osman, Abdimajid; Hitzler, Walter E; Ameur, Adam; Provost, Patrick

    2015-01-01

    Platelet concentrates (PCs) are prepared at blood banks for transfusion to patients in certain clinical conditions associated with a low platelet count. To prevent transfusion-transmitted infections via PCs, different pathogen reduction (PR) systems have been developed that inactivate the nucleic acids of contaminating pathogens by chemical cross-linking, a mechanism that may also affect platelets' nucleic acids. We previously reported that treatment of stored platelets with the PR system Intercept significantly reduced the level of half of the microRNAs that were monitored, induced platelet activation and compromised the platelet response to physiological agonists. Using genome-wide differential expression (DE) RNA sequencing (RNA-Seq), we now report that Intercept markedly perturbs the mRNA transcriptome of human platelets and alters the expression level of >800 mRNAs (P<0.05) compared to other PR systems and control platelets. Of these, 400 genes were deregulated with DE corresponding to fold changes (FC) ≥ 2. At the p-value < 0.001, as many as 147 genes were deregulated by ≥ 2-fold in Intercept-treated platelets, compared to none in the other groups. Finally, integrated analysis combining expression data for microRNA (miRNA) and mRNA, and involving prediction of miRNA-mRNA interactions, disclosed several positive and inverse correlations between miRNAs and mRNAs in stored platelets. In conclusion, this study demonstrates that Intercept markedly deregulates the platelet mRNA transcriptome, concomitant with reduced levels of mRNA-regulatory miRNAs. These findings should enlighten authorities worldwide when considering the implementation of PR systems, that target nucleic acids and are not specific to pathogens, for the management of blood products.

  17. Differential Expression Analysis by RNA-Seq Reveals Perturbations in the Platelet mRNA Transcriptome Triggered by Pathogen Reduction Systems

    PubMed Central

    Osman, Abdimajid; Hitzler, Walter E.; Ameur, Adam; Provost, Patrick

    2015-01-01

    Platelet concentrates (PCs) are prepared at blood banks for transfusion to patients in certain clinical conditions associated with a low platelet count. To prevent transfusion-transmitted infections via PCs, different pathogen reduction (PR) systems have been developed that inactivate the nucleic acids of contaminating pathogens by chemical cross-linking, a mechanism that may also affect platelets’ nucleic acids. We previously reported that treatment of stored platelets with the PR system Intercept significantly reduced the level of half of the microRNAs that were monitored, induced platelet activation and compromised the platelet response to physiological agonists. Using genome-wide differential expression (DE) RNA sequencing (RNA-Seq), we now report that Intercept markedly perturbs the mRNA transcriptome of human platelets and alters the expression level of >800 mRNAs (P<0.05) compared to other PR systems and control platelets. Of these, 400 genes were deregulated with DE corresponding to fold changes (FC) ≥2. At the p-value < 0.001, as many as 147 genes were deregulated by ≥ 2-fold in Intercept-treated platelets, compared to none in the other groups. Finally, integrated analysis combining expression data for microRNA (miRNA) and mRNA, and involving prediction of miRNA-mRNA interactions, disclosed several positive and inverse correlations between miRNAs and mRNAs in stored platelets. In conclusion, this study demonstrates that Intercept markedly deregulates the platelet mRNA transcriptome, concomitant with reduced levels of mRNA-regulatory miRNAs. These findings should enlighten authorities worldwide when considering the implementation of PR systems, that target nucleic acids and are not specific to pathogens, for the management of blood products. PMID:26172280

  18. Change in the Chemical Profile of Mangifera indica Leaves after their Metabolism in the Tropidacris collaris Grasshopper.

    PubMed

    da Silva, Rodolfo R; Moraes, Marcilio M; Camara, Claudio A G; Ramos, Clécio S

    2015-11-01

    This present work addresses research on the discovery of new compounds from natural sources. It is based on a study of Mangifera indica leaf metabolism by the Tropidacris collaris grasshopper. We found that the grasshopper hydrolyzed the flavonoid isoquercitrin to quercetin when the O-glycosidic bond was broken and sugar released as a probable energy source for the insect. There was not, however, hydrolysis of the major compound in the leaves, mangiferin, which contains the C-glycosidic bond. All compounds were isolated and their chemical structure determined by UV, IR, MS, 1H and 13C NMR. PMID:26749802

  19. Effect of controlled low levels of SO/sub 2/ on grasshopper densities on a northern mixed-grass prairie

    SciTech Connect

    McNary, T.J.; Milchunas, D.G.; Leetham, J.W.; Lauenroth, W.K.; Dodd, J.L.

    1981-02-01

    A northern mixed-grass prairie was exposed to monthly median SO/sub 2/ concentrations of 73, 134, and 228 ..mu..g/m/sup 3/. Total grasshopper density and the density of Melanoplus sanguinipes (F.) were significantly (P < 0.01) reduced by SO/sub 2/ treatment on late-growing-season dates within each year of SO/sub 2/ exposure. Grasshopper density tended to decrease with increasing SO/sub 2/ concentration. Sulfur dioxide did not alter the relative proportions of M. sanguinipes in the total population. 14 references, 1 figure.

  20. Evaluation of a reproductive index to estimate grasshopper sparrow and eastern meadowlark reproductive success

    USGS Publications Warehouse

    Althoff, D.P.; Gipson, P.S.; Pontius, J.S.; Japuntich, R.D.

    2009-01-01

    We compared an index of reproductive success based on breeding behavior to actual nest fates of grasshopper sparrows (Ammodramus savannarum) and eastern meadowlarks (Sturnella magna) on 12 plots (4-ha). Concordance of results between the two methods was 58% for grasshopper sparrows and 42% for eastern meadowlarks on a plot-by-plot basis. The indirect method yielded higher estimates of reproductive activity than nest monitoring for the balance of the plots,. There was little evidence that brown-headed cowbird (Molothrus ater) parasitism influenced the estimates of reproductive success using the indirect method. We concluded that nests and about-to-fledge nestlings were missed during searches on some plots. It may be appropriate to use an indirect method to more efficiently survey territories and/or plots for species with hard-to-find nests or when monitoring large areas. Use of a reproductive index may be appropriate and more time-efficient than nest searching and monitoring for comparing management effects such as burning, grazing, haying, military training, and other localized disturbances that are likely to affect reproductive success of grasshopper sparrows and eastern meadowlarks. However, nest monitoring may be necessary for more precise estimates of productivity necessary for long-term monitoring. Nest monitoring results are also likely to allow for direct comparisons to results from other studies because the index method requires intimate knowledge of the species being evaluated - a factor that could lead to reduced precision because the experience level of technicians relying only on behavioral cues from study-to-study is likely to vary considerably.

  1. Differential gene expression between the biotrophic-like and saprotrophic mycelia of the witches' broom pathogen Moniliophthora perniciosa.

    PubMed

    Rincones, Johana; Scarpari, Leandra M; Carazzolle, Marcelo F; Mondego, Jorge M C; Formighieri, Eduardo F; Barau, Joan G; Costa, Gustavo G L; Carraro, Dirce M; Brentani, Helena P; Vilas-Boas, Laurival A; de Oliveira, Bruno V; Sabha, Maricene; Dias, Robson; Cascardo, Júlio M; Azevedo, Ricardo A; Meinhardt, Lyndel W; Pereira, Gonçalo A G

    2008-07-01

    Moniliophthora perniciosa is a hemibiotrophic fungus that causes witches' broom disease (WBD) in cacao. Marked dimorphism characterizes this fungus, showing a monokaryotic or biotrophic phase that causes disease symptoms and a later dikaryotic or saprotrophic phase. A combined strategy of DNA microarray, expressed sequence tag, and real-time reverse-transcriptase polymerase chain reaction analyses was employed to analyze differences between these two fungal stages in vitro. In all, 1,131 putative genes were hybridized with cDNA from different phases, resulting in 189 differentially expressed genes, and 4,595 reads were clusterized, producing 1,534 unigenes. The analysis of these genes, which represent approximately 21% of the total genes, indicates that the biotrophic-like phase undergoes carbon and nitrogen catabolite repression that correlates to the expression of phytopathogenicity genes. Moreover, downregulation of mitochondrial oxidative phosphorylation and the presence of a putative ngr1 of Saccharomyces cerevisiae could help explain its lower growth rate. In contrast, the saprotrophic mycelium expresses genes related to the metabolism of hexoses, ammonia, and oxidative phosphorylation, which could explain its faster growth. Antifungal toxins were upregulated and could prevent the colonization by competing fungi. This work significantly contributes to our understanding of the molecular mechanisms of WBD and, to our knowledge, is the first to analyze differential gene expression of the different phases of a hemibiotrophic fungus.

  2. The vOTU domain of highly-pathogenic porcine reproductive and respiratory syndrome virus displays a differential substrate preference

    PubMed Central

    Deaton, Michelle K.; Spear, Allyn; Faaberg, Kay S.; Pegan, Scott D.

    2014-01-01

    Arterivirus genus member Porcine reproductive and respiratory syndrome virus (PRRSV) causes an economically devastating disease, recently exacerbated by the emergence of highly pathogenic strains (HP-PRRSV). Within the nonstructural protein 2 of PRRSV is a deubiquitinating enzyme domain belonging to the viral ovarian tumor (vOTU) protease superfamily. vOTUs, which can greatly vary in their preference for their host ubiquitin (Ub) and Ub-like substrates such as interferon stimulated gene 15 (ISG15), have been implicated as a potential virulence factor. Since various strains of PRRSV have large variations in virulence, the specificity of vOTUs from two PRRSV strains of varying virulence were determined. While both vOTUs showed de-ubiquitinating activity and markedly low deISGylating activity, HP-PRRSV demonstrated a strong preference for lysine 63-linked poly-Ubiquitin, tied to innate immune response regulation. This represents the first report of biochemical activity unique to HP-PRRSV that has implications for a potential increase in immunosuppression and virulence. PMID:24725951

  3. Short Communication A small B chromosome in the grasshopper Ommexecha virens (Ommexechidae).

    PubMed

    Souza, T E; Silva-Neto, L C; Santos, J F; Loreto, V; Rieger, T T

    2015-12-21

    B chromosomes, also called supernumerary or accessory chromosomes, have been characterized as extra elements found in the karyotypes of different eukaryotic species. B chromosomes are nonvital and only occur in some individuals within a species. Moreover, the chromosomes contain silenced genes, and they exhibit heterochromatinization and the accumulation of repetitive DNA and transposons. In the present study, we describe an extra chromosome in the grasshopper Ommexecha virens for the first time, using conventional staining and fluorescent in situ hybridization techniques, and we discuss the possible origin of the B chromosome.

  4. New and little-known pygmy grasshoppers (Orthoptera: Tetrigidae) from Thailand.

    PubMed

    Storozhenko, Sergey Yu; Dawwrueng, Pattarawich

    2015-01-01

    An annotated list of 39 species in 25 genera and seven subfamilies of the pygmy grasshoppers (Orthoptera: Tetrididae) from Thailand is given; from these 18 species are recorded from this country for the first time. Five new species are described: Cotysoides gaponi sp. nov. (subfamily Metrodorinae), Eucriotettix anisyutkini sp. nov., Gavialidium bufocrocodil sp. nov., Scelimena bellula sp. nov. (subfamily Scelimeninae) and Phaesticus uvarovi sp. nov. (subfamily Discotettiginae). One species is transferred from Scelimena to Amphibotettix and a new combination is proposed: Scelimena hafizhaii Mahmmod, Idris et Salman, 2007 = Amphibotettix hafizhaii (Mahmmod, Idris et Salman, 2007), comb. nov. The previously unknown male of Falconius tschernovi Storozhenko, 2014 is described. PMID:26701451

  5. Lazarillo, a neuronal lipocalin in grasshoppers with a role in axon guidance.

    PubMed

    Sánchez, D; Ganfornina, M D; Bastiani, M J

    2000-10-18

    In this report we present a review on the grasshopper lipocalin Lazarillo with special emphasis on how its molecular properties could account for its known function: the guidance of pioneer neurons during nervous system development. The expression and function of Lazarillo in a subset of developing neurons, its heavy glycosylation and its glycosylphosphatidylinositol linkage to the plasma membrane, make Lazarillo a unique member of the lipocalin family. We have built a model of the tertiary structure of Lazarillo in which we have studied the exposed surfaces in search for clues about ligand and protein interactions with Lazarillo. Our hypotheses about how this lipocalin can exert its function are discussed.

  6. Two specific amino acid variations in colonization factor CS6 subtypes of enterotoxigenic Escherichia coli results in differential binding and pathogenicity.

    PubMed

    Debnath, Anusuya; Wajima, Takeaki; Sabui, Subrata; Hamabata, Takashi; Ramamurthy, Thandavarayan; Chatterjee, Nabendu Sekhar

    2015-04-01

    CS6 is the predominant colonization factor of enterotoxigenic Escherichia coli (ETEC). We report the existence of multiple CS6 subtypes caused by natural point mutations in cssA and cssB, the structural genes for CS6. The subtype AIBI was mostly associated with ETEC isolated from diarrhoeal cases, whereas AIIBII was mostly found in asymptomatic controls. Here we explore the rationale behind this association. ETEC isolates expressing AIIBII showed weaker adherence to intestinal epithelial cells compared with ETEC expressing AIBI. AIIBII expression on the ETEC cell surface was threefold less than AIBI. We found that alanine at position 37 in CssAII, in conjunction with asparagine at position 97 in CssBII, was responsible for the decreased levels of AIIBII on the bacterial surface. In addition, purified AIIBII showed fourfold less mucin binding compared with AIBI. The asparagine at position 97 in CssBII was also accountable for the decreased mucin binding by AIIBII. Reduced fluid accumulation and colonization occurred during infection with ETEC expressing AIIBII in animal models. Together these results indicate that the differential adherence between AIBI and AIIBII was a cumulative effect of decreased surface-level expression and mucin binding of AIIBII due to two specific amino acid variations. As a consequence, ETEC expressing these two subtypes displayed differential pathogenicity. We speculate that this might explain the subjective association of AIBI with ETEC from diarrhoeal cases and AIIBII with asymptomatic controls. PMID:25635273

  7. Distinct and Redundant Roles of Protein Tyrosine Phosphatases Ptp1 and Ptp2 in Governing the Differentiation and Pathogenicity of Cryptococcus neoformans

    PubMed Central

    Lee, Kyung-Tae; Byun, Hyo-Jeong; Jung, Kwang-Woo; Hong, Joohyeon; Cheong, Eunji

    2014-01-01

    Protein tyrosine phosphatases (PTPs) serve as key negative-feedback regulators of mitogen-activated protein kinase (MAPK) signaling cascades. However, their roles and regulatory mechanisms in human fungal pathogens remain elusive. In this study, we characterized the functions of two PTPs, Ptp1 and Ptp2, in Cryptococcus neoformans, which causes fatal meningoencephalitis. PTP1 and PTP2 were found to be stress-inducible genes, which were controlled by the MAPK Hog1 and the transcription factor Atf1. Ptp2 suppressed the hyperphosphorylation of Hog1 and was involved in mediating vegetative growth, sexual differentiation, stress responses, antifungal drug resistance, and virulence factor regulation through the negative-feedback loop of the HOG pathway. In contrast, Ptp1 was not essential for Hog1 regulation, despite its Hog1-dependent induction. However, in the absence of Ptp2, Ptp1 served as a complementary PTP to control some stress responses. In differentiation, Ptp1 acted as a negative regulator, but in a Hog1- and Cpk1-independent manner. Additionally, Ptp1 and Ptp2 localized to the cytosol but were enriched in the nucleus during the stress response, affecting the transient nuclear localization of Hog1. Finally, Ptp1 and Ptp2 played minor and major roles, respectively, in the virulence of C. neoformans. Taken together, our data suggested that PTPs could be exploited as novel antifungal targets. PMID:24728196

  8. Differential Regulation of the Surface-Exposed and Secreted SslE Lipoprotein in Extraintestinal Pathogenic Escherichia coli.

    PubMed

    Tan, Lendl; Moriel, Danilo G; Totsika, Makrina; Beatson, Scott A; Schembri, Mark A

    2016-01-01

    Extra-intestinal pathogenic Escherichia coli (ExPEC) are responsible for diverse infections including meningitis, sepsis and urinary tract infections. The alarming rise in anti-microbial resistance amongst ExPEC complicates treatment and has highlighted the need for alternative preventive measures. SslE is a lipoprotein secreted by a dedicated type II secretion system in E. coli that was first identified as a potential vaccine candidate using reverse genetics. Although the function and protective efficacy of SslE has been studied, the molecular mechanisms that regulate SslE expression remain to be fully elucidated. Here, we show that while the expression of SslE can be detected in E. coli culture supernatants, different strains express and secrete different amounts of SslE when grown under the same conditions. While the histone-like transcriptional regulator H-NS strongly represses sslE at ambient temperatures, the variation in SslE expression at human physiological temperature suggested a more complex mode of regulation. Using a genetic screen to identify novel regulators of sslE in the high SslE-expressing strain UTI89, we defined a new role for the nucleoid-associated regulator Fis and the ribosome-binding GTPase TypA as positive regulators of sslE transcription. We also showed that Fis-mediated enhancement of sslE transcription is dependent on a putative Fis-binding sequence located upstream of the -35 sequence in the core promoter element, and provide evidence to suggest that Fis may work in complex with H-NS to control SslE expression. Overall, this study has defined a new mechanism for sslE regulation and increases our understanding of this broadly conserved E. coli vaccine antigen. PMID:27598999

  9. Differential Regulation of the Surface-Exposed and Secreted SslE Lipoprotein in Extraintestinal Pathogenic Escherichia coli

    PubMed Central

    Tan, Lendl; Moriel, Danilo G.; Totsika, Makrina; Beatson, Scott A.

    2016-01-01

    Extra-intestinal pathogenic Escherichia coli (ExPEC) are responsible for diverse infections including meningitis, sepsis and urinary tract infections. The alarming rise in anti-microbial resistance amongst ExPEC complicates treatment and has highlighted the need for alternative preventive measures. SslE is a lipoprotein secreted by a dedicated type II secretion system in E. coli that was first identified as a potential vaccine candidate using reverse genetics. Although the function and protective efficacy of SslE has been studied, the molecular mechanisms that regulate SslE expression remain to be fully elucidated. Here, we show that while the expression of SslE can be detected in E. coli culture supernatants, different strains express and secrete different amounts of SslE when grown under the same conditions. While the histone-like transcriptional regulator H-NS strongly represses sslE at ambient temperatures, the variation in SslE expression at human physiological temperature suggested a more complex mode of regulation. Using a genetic screen to identify novel regulators of sslE in the high SslE-expressing strain UTI89, we defined a new role for the nucleoid-associated regulator Fis and the ribosome-binding GTPase TypA as positive regulators of sslE transcription. We also showed that Fis-mediated enhancement of sslE transcription is dependent on a putative Fis-binding sequence located upstream of the -35 sequence in the core promoter element, and provide evidence to suggest that Fis may work in complex with H-NS to control SslE expression. Overall, this study has defined a new mechanism for sslE regulation and increases our understanding of this broadly conserved E. coli vaccine antigen. PMID:27598999

  10. Using the Alexander Collection to measure the effects of climate change on the grasshoppers of the southern Rocky Mountains of Colorado

    NASA Astrophysics Data System (ADS)

    Nufio, C. R.; Bowers, D. M.; Guralnick, R. P.

    2007-12-01

    The current study utilizes the recently curated and databased Alexander Grasshopper Collection coupled with a new resurvey program to measure the effects of climate change on grasshoppers found along an elevational gradient in the southern Rocky Mountains of Colorado. The Alexander Collection is composed of approximately 19,000 pinned grasshoppers and a series of field data notebooks from a three year 1958-1960 survey project. During these survey years, Alexander processed over 65,000 grasshoppers from repeatedly sampled sites along an elevational gradient from Boulder (1530 m elev.) to Mt Evans (3900m elev.) in the Colorado Front Range. Data from 2006 shows that at mid-elevation sites grasshoppers are becoming adults 15-28 days earlier than they did nearly a half century ago. We found no changes in the time to reach adulthood at the high elevation sites. Preliminary data from 2007 (a year with milder spring temperatures) suggests that unlike the dramatic patterns documented in 2006, that the time to reach adulthood for grasshoppers at low and high elevation sites was not much different than it was 50 years ago. In 2007, several grasshopper species at mid-elevation did become adults earlier than they had a half century ago.

  11. Differential gene expression in laboratory strains of human head and body lice when challenged with Bartonella quintana, a pathogenic bacterium.

    PubMed

    Previte, D; Olds, B P; Yoon, K; Sun, W; Muir, W; Paige, K N; Lee, S H; Clark, J; Koehler, J E; Pittendrigh, B R

    2014-04-01

    Human head and body lice are obligatory hematophagous ectoparasites that belong to a single species, Pediculus humanus. Only body lice, however, are vectors of the infectious Gram-negative bacterium Bartonella quintana. Because of their near identical genomes, yet differential vector competence, head and body lice provide a unique model system to study the gain or loss of vector competence. Using our in vitro louse-rearing system, we infected head and body lice with blood containing B. quintana in order to detect both differences in the proliferation of B. quintana and transcriptional differences of immune-related genes in the lice. B. quintana proliferated rapidly in body lice at 6 days post-infection, but plateaued in head lice at 4 days post-infection. RNAseq and quantitative real-time PCR validation analyses determined gene expression differences. Eight immunoresponse genes were observed to be significantly different with many associated with the Toll pathway: Fibrinogen-like protein, Spaetzle, Defensin 1, Serpin, Scavenger receptor A and Apolipoporhrin 2. Our findings support the hypothesis that body lice, unlike head lice, fight infection from B. quintana only at the later stages of its proliferation. PMID:24404961

  12. Differentiation of Crohn’s Disease-Associated Isolates from Other Pathogenic Escherichia coli by Fimbrial Adhesion under Shear Force

    PubMed Central

    Szunerits, Sabine; Zagorodko, Oleksandr; Cogez, Virginie; Dumych, Tetiana; Chalopin, Thibaut; Alvarez Dorta, Dimitri; Sivignon, Adeline; Barnich, Nicolas; Harduin-Lepers, Anne; Larroulet, Iban; Yanguas Serrano, Aritz; Siriwardena, Aloysius; Pesquera, Amaia; Zurutuza, Amaia; Gouin, Sébastien G.; Boukherroub, Rabah; Bouckaert, Julie

    2016-01-01

    Shear force exerted on uropathogenic Escherichia coli adhering to surfaces makes type-1 fimbriae stretch out like springs to catch on to mannosidic receptors. This mechanism is initiated by a disruption of the quaternary interactions between the lectin and the pilin of the two-domain FimH adhesin and transduces allosterically to the mannose-binding pocket of FimH to increase its affinity. Mannose-specific adhesion of 14 E. coli pathovars was measured under flow, using surface plasmon resonance detection on functionalized graphene-coated gold interfaces. Increasing the shear had important differential consequences on bacterial adhesion. Adherent-invasive E. coli, isolated from the feces and biopsies of Crohn’s disease patients, consistently changed their adhesion behavior less under shear and displayed lower SPR signals, compared to E. coli opportunistically infecting the urinary tract, intestines or loci of knee and hip prostheses. We exemplified this further with the extreme behaviors of the reference strains UTI89 and LF82. Whereas their FimA major pilins have identical sequences, FimH of LF82 E. coli is marked by the Thr158Pro mutation. Positioned in the inter-domain region known to carry hot spots of mutations in E. coli pathotypes, residue 158 is indicated to play a structural role in the allosteric regulation of type-1 fimbriae-mediated bacterial adhesion. PMID:27043645

  13. Differential sensitivity of osteoblasts and bacterial pathogens to 405-nm light highlighting potential for decontamination applications in orthopedic surgery

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Praveen; Maclean, Michelle; MacGregor, Scott J.; Anderson, John G.; Grant, M. Helen

    2014-10-01

    Healthcare associated infections pose a major threat to patients admitted to hospitals and infection rates following orthopedic arthroplasty surgery are as high as 4%. A 405-nm high-intensity narrow spectrum light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in arthroplasty surgery. Cultured rat osteoblasts were exposed to varying light intensities and it was found that exposures of up to a dose of 36 J/cm2 had no significant effect on cell viability [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay], function (alkaline phosphatase activity), and proliferation rate (BrdU cell proliferation assay). High irradiance exposures (54 J/cm2) significantly affected the cell viability indicating that the effects of 405-nm light on osteoblasts are dose dependent. Additionally, exposure of a variety of clinically related bacteria to a dose of 36 J/cm2 resulted in up to 100% kill. These results demonstrating the differential sensitivity of osteoblasts and bacteria to 405-nm light are an essential step toward developing the technique for decontamination in orthopedic surgery.

  14. Two groups of rhinoviruses revealed by a panel of antiviral compounds present sequence divergence and differential pathogenicity.

    PubMed Central

    Andries, K; Dewindt, B; Snoeks, J; Wouters, L; Moereels, H; Lewi, P J; Janssen, P A

    1990-01-01

    A variety of chemically different compounds inhibit the replication of several serotypes of rhinoviruses (common-cold viruses). We noticed that one of these antiviral compounds, WIN 51711, had an antiviral spectrum clearly distinctive from a consensus spectrum or other capsid-binding compounds, although all of them were shown to share the same binding site. A systematic evaluation of all known rhinovirus capsid-binding compounds against all serotyped rhinoviruses was therefore initiated. Multivariate analysis of the results revealed the existence of two groups of rhinoviruses, which we will call antiviral groups A and B. The differential sensitivity of members of these groups to antiviral compounds suggests the existence of a dimorphic binding site. The antiviral groups turned out to be a reflection of a divergence of rhinovirus serotypes on a much broader level. Similarities in antiviral spectra were highly correlated with sequence similarities, not only of amino acids lining the antiviral compound-binding-site, but also of amino acids of the whole VP1 protein. Furthermore, analysis of epidemiological data indicated that group B rhinoviruses produced more than twice as many clinical infections per serotype than group A rhinoviruses did. Rhinoviruses belonging to the minor receptor group were without exception all computed to lie in the same region of antiviral group B. PMID:2154596

  15. Differential gene expression in laboratory strains of human head and body lice when challenged with Bartonella quintana, a pathogenic bacterium

    PubMed Central

    Previte, D.; Olds, B. P.; Yoon, K.; Sun, W.; Muir, W.; Paige, K. N.; Lee, S. H.; Clark, J.; Koehler, J. E.; Pittendrigh, B. R.

    2014-01-01

    Human head and body lice are obligatory hematophagous ectoparasites that belong to a single species, Pediculus humanus. Only body lice, however, are vectors of the infectious Gram-negative bacterium Bartonella quintana. Because of their near identical genomes, yet differential vector competence, head and body lice provide a unique model system to study the gain or loss of vector competence. Using our in vitro louse-rearing system, we infected head and body lice with blood containing B. quintana in order to detect both differences in the proliferation of B. quintana and transcriptional differences of immune-related genes in the lice. B. quintana proliferated rapidly in body lice at 6 days postinfection, but plateaued in head lice at 4 days postinfection. RNAseq and quantitative real-time PCR validation analyses determined gene expression differences. Eight immunoresponse genes were observed to be significantly different with many associated with the Toll pathway: Fibrinogen-like protein, Spaetzle, Defensin 1, Serpin, Scavenger receptor A and Apolipoporhrin 2. Our findings support the hypothesis that body lice, unlike head lice, fight infection from B. quintana only at the later stages of its proliferation. PMID:24404961

  16. MicroRNAs of the mesothorax in Qinlingacris elaeodes, an alpine grasshopper showing a wing polymorphism with unilateral wing form.

    PubMed

    Li, R; Jiang, G F; Ren, Q P; Wang, Y T; Zhou, X M; Zhou, C F; Qin, D Z

    2016-04-01

    MicroRNAs (miRNAs) are now recognized as key post-transcriptional regulators in regulation of phenotypic diversity. Qinlingacris elaeodes is a species of the alpine grasshopper, which is endemic to China. Adult individuals have three wing forms: wingless, unilateral-winged and short-winged. This is an ideal species to investigate the phenotypic plasticity, development and evolution of insect wings because of its case of unilateral wing form in both the sexes. We sequenced a small RNA library prepared from mesothoraxes of the adult grasshoppers using the Illumina deep sequencing technology. Approximately 12,792,458 raw reads were generated, of which the 854,580 high-quality reads were used only for miRNA identification. In this study, we identified 49 conserved miRNAs belonging to 41 families and 69 species-specific miRNAs. Moreover, seven miRNA*s were detected both for conserved miRNAs and species-specific miRNAs, which were supported by hairpin forming precursors based on polymerase chain reaction. This is the first description of miRNAs in alpine grasshoppers. The results provide a useful resource for further studies on molecular regulation and evolution of miRNAs in grasshoppers. These findings not only enrich the miRNAs for insects but also lay the groundwork for the study of post-transcriptional regulation of wing forms. PMID:26693589

  17. Rapid evolution of fire melanism in replicated populations of pygmy grasshoppers.

    PubMed

    Forsman, Anders; Karlsson, Magnus; Wennersten, Lena; Johansson, Jenny; Karpestam, Einat

    2011-09-01

    Evolutionary theory predicts an interactive process whereby spatiotemporal environmental heterogeneity will maintain genetic variation, while genetic and phenotypic diversity will buffer populations against stress and allow for fast adaptive evolution in rapidly changing environments. Here, we study color polymorphism patterns in pygmy grasshoppers (Tetrix subulata) and show that the frequency of the melanistic (black) color variant was higher in areas that had been ravaged by fires the previous year than in nonburned habitats, that, in burned areas, the frequency of melanistic grasshoppers dropped from ca. 50% one year after a fire to 30% after four years, and that the variation in frequencies of melanistic individuals among and within populations was genetically based on and represented evolutionary modifications. Dark coloration may confer a selective benefit mediated by enhanced camouflage in recently fire-ravaged areas characterized by blackened visual backgrounds before vegetation has recovered. These findings provide rare evidence for unusually large, extremely rapid adaptive contemporary evolution in replicated natural populations in response to divergent and fluctuating selection associated with spatiotemporal environmental changes. PMID:21884054

  18. Local climate determines intra- and interspecific variation in sexual size dimorphism in mountain grasshopper communities.

    PubMed

    Laiolo, P; Illera, J C; Obeso, J R

    2013-10-01

    The climate is often evoked to explain broad-scale clines of body size, yet its involvement in the processes that generate size inequality in the two sexes (sexual size dimorphism) remains elusive. Here, we analyse climatic clines of sexual size dimorphism along a wide elevation gradient (i) among grasshopper species in a phylogenetically controlled scenario and (ii) within species differing in distribution and cold tolerance, to highlight patterns generated at different time scales, mainly evolutionary (among species or higher taxa) and ontogenetic or microevolutionary (within species). At the interspecific level, grasshoppers were slightly smaller and less dimorphic at high elevations. These clines were associated with gradients of precipitation and sun exposure, which are likely indicators of other factors that directly exert selective pressures, such as resource availability and conditions for effective thermoregulation. Within species, we found a positive effect of temperature and a negative effect of elevation on body size, especially on condition-dependent measures of body size (total body length rather than hind femur length) and in species inhabiting the highest elevations. In spite of a certain degree of species-specific variation, females tended to adjust their body size more often than males, suggesting that body size in females can evolve faster among species and can be more plastic or dependent on nutritional conditions within species living in adverse climates. Natural selection on female body size may therefore prevail over sexual selection on male body size in alpine environments, and abiotic factors may trigger consistent phenotypic patterns across taxonomic scales.

  19. Postfledging survival of Grasshopper Sparrows in grasslands managed with fire and grazing

    USGS Publications Warehouse

    Hovick, Torre J.; Miller, James R.; Koford, Rolf R.; Engle, David M.; Debinski, Diane M.

    2011-01-01

    More accurate estimates of survival after nestlings fledge are needed for population models to be parameterized and population dynamics to be understood during this vulnerable life stage. The period after fledging is the time when chicks learn to fly, forage, and hide from predators. We monitored postfledging survival, causespecific mortality, and movements of Grasshopper Sparrows (Ammodramus savannarum) in grassland managed with fire and grazing. In 2009, we attached radio transmitters to 50 nestlings from 50 different broods and modeled their survival in response to climatic, biological, and ecological variables. There was no effect of treatment on survival. The factor most influencing postfledging survival was age; no other variable was significant. The majority of chicks (74%) died within 3 days of radio-transmitter attachment. We attributed most mortality to mesopredators (48%) and exposure (28%). Fledglings' movements increased rapidly for the first 4 days after they left the nest and were relatively stable for the remaining 10 days we tracked them. On average, fledglings took flight for the first time 4 days after fledging and flew ≥10 m 9 days after fledging. Our data show that the Grasshopper Sparrow's survival rates may be less than most models relying on nest-success estimates predict, and we emphasize the importance of incorporating estimates of survival during the postfledging period in demographic models.

  20. The Ku70 DNA-repair protein is involved in centromere function in a grasshopper species.

    PubMed

    Cabrero, Josefa; Bakkali, Mohammed; Navarro-Domínguez, Beatriz; Ruíz-Ruano, Francisco J; Martín-Blázquez, Rubén; López-León, María Dolores; Camacho, Juan Pedro M

    2013-06-25

    The Ku70 protein is involved in numerous cell functions, the nonhomologous end joining (NHEJ) DNA repair pathway being the best known. Here, we report a novel function for this protein in the grasshopper Eyprepocnemis plorans. We observed the presence of large Ku70 foci on the centromeres of meiotic and mitotic chromosomes during the cell cycle stages showing the highest centromeric activity (i.e., metaphase and anaphase). The fact that colchicine treatment prevented centromeric location of Ku70, suggests a microtubule-dependent centromeric function for Ku70. Likewise, the absence of Ku70 at metaphase-anaphase centromeres from three males whose Ku70 gene had been knocked down using interference RNA, and the dramatic increase in the frequency of polyploid spermatids observed in these males, suggest that the centromeric presence of Ku70 is required for normal cytokinesis in this species. The centromeric function of Ku70 was not observed in 14 other grasshopper and locust species, or in the mouse, thus suggesting that it is an autapomorphy in E. plorans. PMID:23797468

  1. DNA barcoding reveals polymorphism in the pygmy grasshopper Tetrix bolivari (Orthoptera, Tetrigidae).

    PubMed

    Zhao, Ling; Lin, Li-Liang; Zheng, Zhe-Min

    2016-01-01

    Many pygmy grasshopper species exhibit colour-marking polymorphism. However, this polymorphism in some species, such as Tetrix bolivari, is almost unknown. The aim of this work is to identify using DNA barcoding the colour-marking polymorphic morphs of this pygmy grasshopper species collected from both grass and sand microhabitats. Analysis by NJ clustering and pairwise distances indicated that all specimens collected showing colour-marking polymorphism are species of Tetrix bolivari. Haplotype network construction showed ten different haplotypes from a total of 57 Tetrix bolivari individuals with H1(82.5%) being the most common type and it also displayed low divergence within Tetrix bolivari population. The haplotype analyses were consistent with the NJ clustering. Our field census showed the frequency of Tetrix bolivari morphs differed significantly, with the rank order of morphs (from high to low) typeA1, type B1, type A2, type A3, type A4, type A5, type A6, type A7, type B2, type B3, and type B4. The most common type A morphs were without contrasting markings, while the rarer type B morphs have contrasting white markings. We suggest that type B morphs have greater camouflage effects against natural backgrounds such as grass or sand than type A morphs. Both our field census and haplotype analysis revealed that type A has higher frequency and more haplotypes than type B. PMID:27199587

  2. Pioneer neurons of the antennal nervous system project to protocerebral pioneers in the grasshopper Schistocerca gregaria.

    PubMed

    Boyan, George; Ehrhardt, Erica

    2015-11-01

    The twin nerve tracts of the antenna of the grasshopper Schistocerca gregaria are established early in embryogenesis by sibling pairs of pioneers which delaminate from the epithelium into the lumen at the antennal tip. These cells can be uniquely identified via their co-expression of the neuronal labels horseradish peroxidase and the lipocalin Lazarillo. The apical pioneers direct axons toward the antennal base where they encounter guidepost-like cells called base pioneers which transiently express the same molecular labels as the apical pioneers. To what extent the pioneer growth cones then progress into the brain neuropil proper, and what their targets there might be, has remained unclear. In this study, we show that the apical antennal pioneers project centrally beyond the antennal base first into the deutocerebral, and then into the protocerebral brain neuropils. In the protocerebrum, we identify their target circuitry as being identified Lazarillo-positive cells which themselves pioneer the primary axon scaffold of the brain. The apical and base antennal pioneers therefore form part of a molecularly contiguous pathway from the periphery to an identified central circuit of the embryonic grasshopper brain. PMID:26553379

  3. DNA barcoding reveals polymorphism in the pygmy grasshopper Tetrix bolivari (Orthoptera, Tetrigidae)

    PubMed Central

    Zhao, Ling; Lin, Li-Liang; Zheng, Zhe-Min

    2016-01-01

    Abstract Many pygmy grasshopper species exhibit colour-marking polymorphism. However, this polymorphism in some species, such as Tetrix bolivari, is almost unknown. The aim of this work is to identify using DNA barcoding the colour-marking polymorphic morphs of this pygmy grasshopper species collected from both grass and sand microhabitats. Analysis by NJ clustering and pairwise distances indicated that all specimens collected showing colour-marking polymorphism are species of Tetrix bolivari. Haplotype network construction showed ten different haplotypes from a total of 57 Tetrix bolivari individuals with H1(82.5%) being the most common type and it also displayed low divergence within Tetrix bolivari population. The haplotype analyses were consistent with the NJ clustering. Our field census showed the frequency of Tetrix bolivari morphs differed significantly, with the rank order of morphs (from high to low) typeA1, type B1, type A2, type A3, type A4, type A5, type A6, type A7, type B2, type B3, and type B4. The most common type A morphs were without contrasting markings, while the rarer type B morphs have contrasting white markings. We suggest that type B morphs have greater camouflage effects against natural backgrounds such as grass or sand than type A morphs. Both our field census and haplotype analysis revealed that type A has higher frequency and more haplotypes than type B. PMID:27199587

  4. High similarity in physicochemical properties of chitin and chitosan from nymphs and adults of a grasshopper.

    PubMed

    Erdogan, Sevil; Kaya, Murat

    2016-08-01

    This is the first study to explain the differences in the physicochemical properties of chitin and chitosan obtained from the nymphs and adults of Dociostaurus maroccanus using the same method. Fourier transform infrared spectroscopy, thermogravimetric analysis and x-ray diffraction analysis results demonstrated that the chitins from both the adults and nymphs were in the α-form. The chitin contents of the adults (14%) and nymphs (12%) were of the same order of magnitude. The crystalline index values of chitins from the adult and nymph grasshoppers were 71% and 74%, respectively. Thermal stabilities of the chitins and chitosans from adult and nymph grasshoppers were close to each other. Both the adult (7.2kDa) and nymph (5.6kDa) chitosans had low molar masses. Environmental scanning electron microscopy revealed that the surface morphologies of both chitins consisted of nanofibers and nanopores together, and they were very similar to each other. Consequently, it was determined that the physicochemical properties of the chitins and chitosans from adults and nymphs of D. maroccanus were not very different, so it can be hypothesized that the development of the chitin structure in the nymph has almost been completed and the nymph chitin has the same characteristics as the adult. PMID:27112982

  5. Limited condition dependence of male acoustic signals in the grasshopper Chorthippus biguttulus

    PubMed Central

    Franzke, Alexandra; Reinhold, Klaus

    2012-01-01

    In many animal species, male acoustic signals serve to attract a mate and therefore often play a major role for male mating success. Male body condition is likely to be correlated with male acoustic signal traits, which signal male quality and provide choosy females indirect benefits. Environmental factors such as food quantity or quality can influence male body condition and therefore possibly lead to condition-dependent changes in the attractiveness of acoustic signals. Here, we test whether stressing food plants influences acoustic signal traits of males via condition-dependent expression of these traits. We examined four male song characteristics, which are vital for mate choice in females of the grasshopper Chorthippus biguttulus. Only one of the examined acoustic traits, loudness, was significantly altered by changing body condition because of drought- and moisture-related stress of food plants. No condition dependence could be observed for syllable to pause ratio, gap duration within syllables, and onset accentuation. We suggest that food plant stress and therefore food plant quality led to shifts in loudness of male grasshopper songs via body condition changes. The other three examined acoustic traits of males do not reflect male body condition induced by food plant quality. PMID:22957192

  6. Pioneer neurons of the antennal nervous system project to protocerebral pioneers in the grasshopper Schistocerca gregaria.

    PubMed

    Boyan, George; Ehrhardt, Erica

    2015-11-01

    The twin nerve tracts of the antenna of the grasshopper Schistocerca gregaria are established early in embryogenesis by sibling pairs of pioneers which delaminate from the epithelium into the lumen at the antennal tip. These cells can be uniquely identified via their co-expression of the neuronal labels horseradish peroxidase and the lipocalin Lazarillo. The apical pioneers direct axons toward the antennal base where they encounter guidepost-like cells called base pioneers which transiently express the same molecular labels as the apical pioneers. To what extent the pioneer growth cones then progress into the brain neuropil proper, and what their targets there might be, has remained unclear. In this study, we show that the apical antennal pioneers project centrally beyond the antennal base first into the deutocerebral, and then into the protocerebral brain neuropils. In the protocerebrum, we identify their target circuitry as being identified Lazarillo-positive cells which themselves pioneer the primary axon scaffold of the brain. The apical and base antennal pioneers therefore form part of a molecularly contiguous pathway from the periphery to an identified central circuit of the embryonic grasshopper brain.

  7. Computational principles underlying recognition of acoustic signals in grasshoppers and crickets.

    PubMed

    Ronacher, Bernhard; Hennig, R Matthias; Clemens, Jan

    2015-01-01

    Grasshoppers and crickets independently evolved hearing organs and acoustic communication. They differ considerably in the organization of their auditory pathways, and the complexity of their songs, which are essential for mate attraction. Recent approaches aimed at describing the behavioral preference functions of females in both taxa by a simple modeling framework. The basic structure of the model consists of three processing steps: (1) feature extraction with a bank of 'LN models'-each containing a linear filter followed by a nonlinearity, (2) temporal integration, and (3) linear combination. The specific properties of the filters and nonlinearities were determined using a genetic learning algorithm trained on a large set of different song features and the corresponding behavioral response scores. The model showed an excellent prediction of the behavioral responses to the tested songs. Most remarkably, in both taxa the genetic algorithm found Gabor-like functions as the optimal filter shapes. By slight modifications of Gabor filters several types of preference functions could be modeled, which are observed in different cricket species. Furthermore, this model was able to explain several so far enigmatic results in grasshoppers. The computational approach offered a remarkably simple framework that can account for phenotypically rather different preference functions across several taxa.

  8. Oviposition digging in the grasshopper. I. Functional anatomy and the motor programme.

    PubMed

    Thompson, K J

    1986-05-01

    The ovipositor appendages of acridid insects (grasshoppers and locusts) consist of two pairs of shovel-shaped valves that are used to dig a deep chamber in the ground for egg burial, to manipulate the eggs, and to assist in capping the egg-pod with froth. During oviposition the valves undergo cyclical opening, closing, retraction and protraction movements. These movements are produced by the contractions of ten pairs of muscles. The eighth and ninth segmental nerves of the terminal abdominal ganglion supply the ovipositor muscles. Rhythmical ovipositor movements are produced by the severed abdomen of sexually mature female grasshoppers. By comparing this activity to the activity underlying the natural behaviour, it was determined that the isolated abdomen produced the digging portion of the oviposition motor programme. Electrical recordings from the ovipositor nerves in the isolated nervous system showed spontaneous rhythmical bursting activity. This activity corresponds to the neural correlate of digging behaviour and indicates the presence of a central pattern generator for oviposition digging in the terminal abdominal ganglion of females.

  9. Developmental expression and molecular characterization of two gap junction channel proteins expressed during embryogenesis in the grasshopper Schistocerca americana.

    PubMed

    Ganfornina, M D; Sánchez, D; Herrera, M; Bastiani, M J

    1999-01-01

    Gap junctions are membrane channels that directly connect the cytoplasm of neighboring cells, allowing the exchange of ions and small molecules. Two analogous families of proteins, the connexins and innexins, are the channel-forming molecules in vertebrates and invertebrates, respectively. In order to study the role of gap junctions in the embryonic development of the nervous system, we searched for innexins in the grasshopper Schistocerca americana. Here we present the molecular cloning and sequence analysis of two novel innexins, G-Inx(1) and G-Inx(2), expressed during grasshopper embryonic development. The analysis of G-Inx(1) and G-Inx(2) proteins suggests they bear four transmembrane domains, which show strong conservation in members of the innexin family. The study of the phylogenetic relationships between members of the innexin family and the new grasshopper proteins suggests that G-Inx(1) is orthologous to the Drosophila 1(1)-ogre. However, G-Inx(2) seems to be a member of a new group of insect innexins. We used in situ hybridization with the G-Inx(1) and G-Inx(2) cDNA clones, and two polyclonal sera raised against different regions of G-Inx(1) to study the mRNA and protein expression patterns and the subcellular localization of the grasshopper innexins. G-Inx(1) is primarily expressed in the embryonic nervous system, in neural precursors and glial cells. In addition, a restricted stripe of epithelial cells in the developing limb, involved in the guidance of sensory growth cones, expresses G-Inx(1). G-Inx(2) expression is more widespread in the grasshopper embryo, but a restricted expression is found in a subset of neural precursors. The generally different but partially overlapping expression patterns of G-Inx(1) and G-Inx(2) supports the combinatorial character of gap junction formation in invertebrates, an essential property to generate specificity in this form of cell-cell communication.

  10. The improved PCR of the fstA (ferric siderophore receptor) gene differentiates the fish pathogen Aeromonas salmonicida from other Aeromonas species.

    PubMed

    Beaz-Hidalgo, Roxana; Latif-Eugenín, Fadua; Figueras, María José

    2013-10-25

    The members of the genus Aeromonas are autochthonous of aquatic ecosystems and several species have been associated to septicaemia, ulcerative and haemorrhagic diseases in fish, causing significant mortality in both wild and farmed, freshwater and marine fish species. The species Aeromonas salmonicida is generally recognized as the most important fish pathogen responsible for epidemic outbreaks of furunculosis in salmonids, also being able to produce infections in other cultured fish such as turbot, halibut, sea bream or goldfish. New species, i.e. Aeromonas aquariorum, Aeromonas tecta and Aeromonas piscicola, have recently been discovered and isolated from diseased fish. The species A. piscicola and Aeromonas bestiarum are practically impossible to differentiate phenotypically and genetically (when using the 16S rRNA gene) from each other and from A. salmonicida. In the present study, two previously described PCR protocols, based on the fstA and gyrB genes, for the specific detection of A. salmonicida were re-evaluated with the type strains of all Aeromonas species and with a set of A. piscicola and A. bestiarum strains. Contrary to what had been published previously it was demonstrated that the gyrB-PCR is not specific for A. salmonicida because of cross-reactions with other Aeromonas species. However, in agreement with previous results, A. salmonicida was detected on the basis of the fstA-PCR, for which an improved protocol was proposed. PMID:23890674

  11. Supercooling capacity and cold hardiness of band-winged grasshopper eggs (Orthoptera: Acrididae).

    PubMed

    Pang, Bao-Ping; Li, Na; Zhou, Xiao-Rong

    2014-01-01

    The band-winged grasshopper, Oedaleus asiaticus Bei-Bienko, is one of the most dominant and economically important grasshopper species in the steppe grasslands and farming-pastoral ecotone in northern China. It is a univoltine species and overwinters as eggs in soil. The cold hardiness of its eggs was examined in the laboratory. Water content in soil significantly affected the supercooling points (SCPs), water content and fat content of prediapause eggs. With the increase of water content in soil, the SCP, and water content of prediapause eggs rose whereas the fat content declined. There was a significant relationship between the SCP and water content or fat content of prediapause eggs. The SCPs of prediapause and diapause eggs varied from -7.6 to -28.4°C and the SCPs of eggs 30 d after oviposition could be divided into two groups. The means of high SCP group (-11.0 to -11.9°C) were much higher than those of low SCP group (-21.8 to -21.9°C), and the majority belonged to the latter (90.48-93.33%). The SCPs of prediapause eggs and early-diapause eggs 30 d after oviposition were significantly higher than those of deep-diapause eggs 60 d after oviposition. The survival rates of diapause eggs were significantly different among different temperature treatments. The survival rate was higher than 88% at greater than -20°C and declined significantly to 57% at -25°C, and suddenly dropped to zero at -30°C. The lower lethal temperature (Ltemp50) for 12 h exposure was -25.3°C and the lower lethal time (Ltime50) at -20°C was 32.8 d. As the mean SCPs of diapause eggs were similar to their Ltemp50, the SCP of eggs can be considered as a good indicator of cold hardiness for O. asiaticus and that this grasshopper is a freeze-intolerant insect.

  12. Elevational differences in developmental plasticity determine phenological responses of grasshoppers to recent climate warming.

    PubMed

    Buckley, Lauren B; Nufio, César R; Kirk, Evan M; Kingsolver, Joel G

    2015-06-22

    Annual species may increase reproduction by increasing adult body size through extended development, but risk being unable to complete development in seasonally limited environments. Synthetic reviews indicate that most, but not all, species have responded to recent climate warming by advancing the seasonal timing of adult emergence or reproduction. Here, we show that 50 years of climate change have delayed development in high-elevation, season-limited grasshopper populations, but advanced development in populations at lower elevations. Developmental delays are most pronounced for early-season species, which might benefit most from delaying development when released from seasonal time constraints. Rearing experiments confirm that population, elevation and temperature interact to determine development time. Population differences in developmental plasticity may account for variability in phenological shifts among adults. An integrated consideration of the full life cycle that considers local adaptation and plasticity may be essential for understanding and predicting responses to climate change.

  13. The B chromosomes of the grasshopper Eyprepocnemis plorans and the intragenomic conflict.

    PubMed

    Camacho, J P M; Cabrero, J; López-León, M D; Bakkali, M; Perfectti, F

    2003-01-01

    The grasshopper Eyprepocnemis plorans harbours an extremely widespread polymorphism for supernumerary (B) chromosomes, which is found in almost all circum-Mediterranean and Caucasian populations hitherto analysed. B chromosomes in this species have been shown to evolve through several stages of parasitic and near-neutral nature, presumably because of an arms race between the standard (A) and B chromosomes. This intragenomic conflict can either be solved with the extinction of the neutralised B chromosome or, more interestingly, with the replacement of the neutralised B by a mutant version being parasitic again and thus prolonging B chromosome life. This species thus provides a complete view of the long-term life-cycle of parasitic B chromosomes.

  14. Cross-fostering alters advertisement vocalizations of grasshopper mice (Onychomys): Evidence for the developmental stress hypothesis.

    PubMed

    Pasch, Bret; Abbasi, Mustafa Z; Wilson, Macey; Zhao, Daniel; Searle, Jeremy B; Webster, Michael S; Rice, Aaron N

    2016-04-01

    Nutritional stress can have lasting impacts on the development of traits involved in vocal production. Cross-fostering experiments are often used to examine the propensity for vocal learning in a variety of taxa, but few studies assess the influence of malnourishment that can occur as a byproduct of this technique. In this study, we reciprocally cross-fostered sister taxa of voluble grasshopper mice (genus Onychomys) to explore their propensity for vocal learning. Vocalizations of Onychomys leucogaster did not differ between control and cross-fostered animals, but cross-fostered Onychomys arenicola produced vocalizations that were higher in frequency in a direction away from tutors. These same animals exhibited a transient reduction in body mass early in development, indicative of malnutrition. Our findings simultaneously refute vocal learning and support the developmental stress hypothesis to highlight the importance of early ontogeny on the production of vocalizations later in life. PMID:26873411

  15. Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.

    PubMed

    Umbers, K D L; Herberstein, M E; Madin, J S

    2013-01-01

    Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature.

  16. The closed spiracle phase of discontinuous gas exchange predicts diving duration in the grasshopper Paracinema tricolor.

    PubMed

    Gudowska, Agnieszka; Boardman, Leigh; Terblanche, John S

    2016-08-15

    The discontinuous gas exchange (DGE) pattern of respiration shown by many arthropods includes periods of spiracle closure (C-phase) and is largely thought to serve as a physiological adaptation to restrict water loss in terrestrial environments. One major challenge to this hypothesis is to explain the presence of DGE in insects in moist environments. Here, we show a novel ecological correlate of the C-phase, namely, diving behaviour in mesic Paracinema tricolor grasshoppers. Notably, maximal dive duration is positively correlated with C-phase length, even after accounting for mass scaling and absolute metabolic rate. Here, we propose that an additional advantage of DGE may be conferred by allowing the tracheal system to act as a sealed underwater oxygen reservoir. Spiracle closure may facilitate underwater submersion, which, in turn, may contribute to predator avoidance, the survival of accidental immersion or periodic flooding and the exploitation of underwater resources. PMID:27296045

  17. Developmental expression of the lipocalin Lazarillo and its role in axonal pathfinding in the grasshopper embryo.

    PubMed

    Sánchez, D; Ganfornina, M D; Bastiani, M J

    1995-01-01

    This article describes the expression pattern and functional analysis of Lazarillo, a novel cell surface glycoprotein expressed in the embryonic grasshopper nervous system, and a member of the lipocalin family. Lazarillo is expressed by a subset of neuroblasts, ganglion mother cells and neurons of the central nervous system, by all sensory neurons of the peripheral nervous system, and by a subset of neurons of the enteric nervous system. It is also present in a few non neuronal cells associated mainly with the excretory system. A monoclonal antibody raised against Lazarillo perturbs the extent and direction of growth of identified commissural pioneer neurons. We propose that Lazarillo is the receptor for a midline morphogen involved in the outgrowth and guidance of these neurons.

  18. Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.

    PubMed

    Umbers, K D L; Herberstein, M E; Madin, J S

    2013-01-01

    Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature. PMID:23108152

  19. Gender identification of Grasshopper Sparrows comparing behavioral, morphological, and molecular techniques

    USGS Publications Warehouse

    Ammer, F.K.; Wood, P.B.; McPherson, R.J.

    2008-01-01

    Correct gender identification in monomorphic species is often difficult especially if males and females do not display obvious behavioral and breeding differences. We compared gender specific morphology and behavior with recently developed DNA techniques for gender identification in the monomorphic Grasshopper Sparrow (Ammodramus savannarum). Gender was ascertained with DNA in 213 individuals using the 2550F/2718R primer set and 3% agarose gel electrophoresis. Field observations using behavior and breeding characteristics to identify gender matched DNA analyses with 100% accuracy for adult males and females. Gender was identified with DNA for all captured juveniles that did not display gender specific traits or behaviors in the field. The molecular techniques used offered a high level of accuracy and may be useful in studies of dispersal mechanisms and winter assemblage composition in monomorphic species.

  20. Exposure to Exogenous Enkephalins Disrupts Reproductive Development in the Eastern Lubber Grasshopper, Romalea microptera (Insecta: Orthoptera)

    PubMed Central

    Kumar, Sandeep; Ganji, Purnachandra Nagaraju; Song, Hojun; von Kalm, Laurence; Borst, David W.

    2012-01-01

    Enkephalins play a major role in reproductive physiology in crustaceans; however their role in reproductive development in insects is largely unknown. We investigated the effect of exposure to exogenous leucine-enkephalin (Leu-Enk), methionine-enkephalin (Met-Enk), and the opioid antagonist naloxone on gonad development in the Eastern lubber grasshopper, Romalea microptera. Injection of either Leu-Enk or naloxone alone significantly increased the testicular index and testicular follicular diameter in males, and the ovarian index, oocyte length, and oocyte diameter in females. In contrast, injection of Met-Enk inhibited all measures of reproductive development in both sexes. Surprisingly, co-injection of naloxone with either enkephalin enhanced the effect associated with administration of the enkephalin alone. This study clearly demonstrates the ability of enkephalins to disrupt insect sexual development and also suggests the existence of conserved enkephaline-dependent regulatory mechanisms in insects and crustaceans. PMID:23226477

  1. Relevance of multiple spatial scales in habitat models: A case study with amphibians and grasshoppers

    NASA Astrophysics Data System (ADS)

    Altmoos, Michael; Henle, Klaus

    2010-11-01

    Habitat models for animal species are important tools in conservation planning. We assessed the need to consider several scales in a case study for three amphibian and two grasshopper species in the post-mining landscapes near Leipzig (Germany). The two species groups were selected because habitat analyses for grasshoppers are usually conducted on one scale only whereas amphibians are thought to depend on more than one spatial scale. First, we analysed how the preference to single habitat variables changed across nested scales. Most environmental variables were only significant for a habitat model on one or two scales, with the smallest scale being particularly important. On larger scales, other variables became significant, which cannot be recognized on lower scales. Similar preferences across scales occurred in only 13 out of 79 cases and in 3 out of 79 cases the preference and avoidance for the same variable were even reversed among scales. Second, we developed habitat models by using a logistic regression on every scale and for all combinations of scales and analysed how the quality of habitat models changed with the scales considered. To achieve a sufficient accuracy of the habitat models with a minimum number of variables, at least two scales were required for all species except for Bufo viridis, for which a single scale, the microscale, was sufficient. Only for the European tree frog ( Hyla arborea), at least three scales were required. The results indicate that the quality of habitat models increases with the number of surveyed variables and with the number of scales, but costs increase too. Searching for simplifications in multi-scaled habitat models, we suggest that 2 or 3 scales should be a suitable trade-off, when attempting to define a suitable microscale.

  2. Sexual signalling in bladder grasshoppers: tactical design for maximizing calling range.

    PubMed

    Van Staaden, M; Römer, H

    1997-10-01

    Pair formation in the bladder grasshopper (Bullacris membracioides) is by duetting and male phonotaxis. Low-frequency stridulatory signals are emitted by an abdominal resonator in the male and are answered by females using a species-specific time delay. Acoustic transmission in the natural environment was studied using playback of sexual signals over distances of 450m under two atmospheric conditions (day and night). Upward-refracting sound conditions and a sound shadow zone beyond approximately 50m prevailed during the day. Acoustic enhancement was demonstrated at night when downward-refracting temperature inversions created a tunnel effect with sound caught between the ground and zones of different temperatures. Transmission conditions are almost ideal at night when the species actually calls; calling distances of 150m for the male signal in the afternoon increased to 1.5-1.9km at night, arguably the largest calling distance yet reported for insects. In contrast, female calls transmit over a maximum of 50m, signifying a marked discrepancy in the active space of sex-specific signals. Transmission distance may, however, be profoundly affected by levels of masking noise. Adaptations to increase the signal range may variously be found in the signal itself, in behaviour patterns or in the sensory system. Here we demonstrate aspects of the first two types of adaptation in the sexual signalling system of a grasshopper in which maximizing the calling range appears to be the major selection pressure, with lesser effects imposed by inter- and intraspecific pressures and by the transmission channel.

  3. Ribosomal DNA is active in different B chromosome variants of the grasshopper Eyprepocnemis plorans.

    PubMed

    Ruíz-Estévez, Mercedes; López-León, M Dolores; Cabrero, Josefa; Camacho, Juan Pedro M

    2013-09-01

    B chromosomes are considered to be genetically inert elements. However, some of them are able to show nucleolus organizer region (NOR) activity, as detected by both cytological and molecular means. The grasshopper Eyprepocnemis plorans shows a B chromosome polymorphism characterized by the existence of many B variants. One of them, B24, shows NOR activity in about half of B-carrying males in the Torrox population. Molecular data have suggested the recent origin for B chromosomes in this species, and on this basis it would be expected that NOR activity was widespread among the different B variants. Here we test this hypothesis in four different B chromosome variants (B1, B2, B5, and B24) from 11 natural populations of the grasshopper E. plorans covering the south and east of the Iberian Peninsula plus the Balearic Islands. We used two different approaches: (1) the cytological observation of nucleoli attached to the distal region of the B chromosome (where the rDNA is located), and (2) the molecular detection of the rDNA transcripts carrying an adenine insertion characteristic of B chromosome ITS2 sequences. The results showed NOR expression not only for B24 but also for the B1 and B2 variants. However, the level of B-NOR expression in these latter variants, measured by the proportion of cells showing nucleoli attached to the B chromosomes, was much lower than that previously reported for B24. This suggests the possibility that structural or genetic background conditions are enhancing the expressivity of the rDNA in the B24 variant.

  4. U1 snDNA clusters in grasshoppers: chromosomal dynamics and genomic organization

    PubMed Central

    Anjos, A; Ruiz-Ruano, F J; Camacho, J P M; Loreto, V; Cabrero, J; de Souza, M J; Cabral-de-Mello, D C

    2015-01-01

    The spliceosome, constituted by a protein set associated with small nuclear RNA (snRNA), is responsible for mRNA maturation through intron removal. Among snRNA genes, U1 is generally a conserved repetitive sequence. To unveil the chromosomal/genomic dynamics of this multigene family in grasshoppers, we mapped U1 genes by fluorescence in situ hybridization in 70 species belonging to the families Proscopiidae, Pyrgomorphidae, Ommexechidae, Romaleidae and Acrididae. Evident clusters were observed in all species, indicating that, at least, some U1 repeats are tandemly arrayed. High conservation was observed in the first four families, with most species carrying a single U1 cluster, frequently located in the third or fourth longest autosome. By contrast, extensive variation was observed among Acrididae, from a single chromosome pair carrying U1 to all chromosome pairs carrying it, with occasional occurrence of two or more clusters in the same chromosome. DNA sequence analysis in Eyprepocnemis plorans (species carrying U1 clusters on seven different chromosome pairs) and Locusta migratoria (carrying U1 in a single chromosome pair) supported the coexistence of functional and pseudogenic lineages. One of these pseudogenic lineages was truncated in the same nucleotide position in both species, suggesting that it was present in a common ancestor to both species. At least in E. plorans, this U1 snDNA pseudogenic lineage was associated with 5S rDNA and short interspersed elements (SINE)-like mobile elements. Given that we conclude in grasshoppers that the U1 snDNA had evolved under the birth-and-death model and that its intragenomic spread might be related with mobile elements. PMID:25248465

  5. A test of Allen's rule in ectotherms: the case of two south American Melanopline Grasshoppers (Orthoptera: Acrididae) with partially overlapping geographic ranges.

    PubMed

    Bidau, Claudio J; Martí, Dardo A

    2008-01-01

    We studied the geographic variation of three morphometric characters in relation to body size in two South American grasshoppers (Acrididae), Dichroplus vittatus Bruner and D. pratensis Bruner to test Allen's rule in these ectotherms. Since both species follow the converse to Bergmann's rule owing to latitudinal and/or altitudinal variation in time available for growth and reproduction, geographic variation in body size proportions of protruding parts may obey to differential allometric growth in different geographic areas. Alternatively, it could reflect true Allenian variation related to thermoregulation. Body proportions were studied by correlation/regression analyses with geographic and climatic variables. In D. pratensis, body proportions increased with latitude and decreased with altitude. These results probably obey to the effects of water balance and seasonality on final body size, and on the allometric growth of the three studied characters not being related to thermoregulation. In D. vittatus, a generally non-significant trend towards the decrease of the mean proportions of all three characters with increasing latitude was observed. Nevertheless, also in this species, it is probable that the environmental gradient responds to seasonality factors (although not to water balance) that affect the length of growing season and, in consequence, body size and its allometric relationships. We conclude that the regularities in the geographic distribution of body proportions of D. pratensis and D. vittatus do not follow Allen's rule in the sense of thermoregulation, and result from variables that determine growing season length and the allometric growth of different body parts.

  6. Mutation of Lon protease differentially affects the expression of Pseudomonas syringae type III secretion system genes in rich and minimal media and reduces pathogenicity.

    PubMed

    Lan, Lefu; Deng, Xin; Xiao, Yanmei; Zhou, Jian-Min; Tang, Xiaoyan

    2007-06-01

    The bacterial Lon protease participates in a variety of biological processes. In Pseudomonas syringae, mutation of lon is known to activate hrpL and a few hrpL-regulated genes in rich medium. The elevated expression of hrpL and hrpL-regulated genes results from increased stability of HrpR, the transcriptional activator of hrpL, in the lon mutant. Here, we conducted a microarray analysis to identify genes that are differentially expressed in a lon- mutant of P. syringae pv. tomato DC3000 grown in the rich medium King's B (KB). Most genes induced in the lon- mutant belong to the HrpL regulon or are related to transcription, protein synthesis, and energy metabolism. A major group of genes reduced in the lon- mutant are related to cell wall biogenesis. The HrpL-regulated genes exhibit different induction patterns in the lon- mutant, suggesting that additional regulators other than HrpL are likely to be involved in regulation of these genes. Compared with the wild-type bacteria, lon- mutants of P. syringae pv. tomato DC3000 and P. syringae pv. phaseolicola NPS3121 strains exhibit elevated hrpL expression in KB medium, but reduced hrpL expression in minimal medium (MM). The reduced hrpL RNA is correlated with reduced hrpR and hrpS RNAs, suggesting that the Lon-mediated regulation of hrpL involves different mechanisms in KB and MM. The lon- mutation also reduced bacterial pathogenicity.

  7. Mycobacterium avium subspecies induce differential expression of pro-inflammatory mediators in a murine macrophage model: evidence for enhanced pathogenicity of Mycobacterium avium subspecies paratuberculosis.

    PubMed

    Basler, Tina; Geffers, Robert; Weiss, Siegfried; Valentin-Weigand, Peter; Goethe, Ralph

    2008-01-01

    Mycobacterium avium subspecies (ssp.) paratuberculosis (MAP) is the etiological agent of paratuberculosis, a chronic, non-treatable granulomatous enteritis of ruminants. MAP is the only mycobacterium affecting the intestinal tract, which is of interest since it is presently the most favoured pathogen linked to Crohn's disease (CD) in humans due to its frequent detection in CD tissues. MAP is genetically closely related to other M. avium ssp. such as M. avium ssp. avium (MAA) and M. avium ssp. hominissuis (MAH) which can cause mycobacteriosis in animals and immunocompromised humans. We have recently shown that murine macrophage cell lines represent suitable systems to analyse M. avium ssp. patho-mechanisms and could show that MAP, but not MAA, specifically inhibited the antigen-specific stimulatory capacity for CD4(+) T-cells. In the present study, we compared gene expression profiles of murine RAW264.7 macrophages in response to infections with MAP or MAA using murine high-density oligonucleotide Affymetrix microarrays. A comparison of MAP and MAA infection revealed 17 differentially expressed genes. They were expressed at a much lower level in MAP-infected macrophages than in MAA-infected macrophages. Among these were the genes for IL-1beta, IL-1alpha, CXCL2, PTGS2 (COX2), lipocalin (LCN2) and TNF, which are important pro-inflammatory factors. The microarray data were confirmed for selected genes by quantitative real-time reverse transcription PCR and, by protein array analyses and ELISA. Similar to MAA, infection with MAH also showed robust induction of IL-1beta, CXCL2, COX2, LCN2 and TNF. Taken together, our results from M. avium ssp.-infected murine macrophages provide evidence that MAP in contrast to MAA and MAH specifically suppresses the pro-inflammatory defence mechanisms of infected macrophages.

  8. A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania

    PubMed Central

    Lyda, Todd A.; Joshi, Manju B.; Andersen, John F.; Kelada, Andrew Y.; Owings, Joshua P.; Bates, Paul A.; Dwyer, Dennis M.

    2015-01-01

    Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts. PMID:25763714

  9. A unique, highly conserved secretory invertase is differentially expressed by promastigote developmental forms of all species of the human pathogen, Leishmania.

    PubMed

    Lyda, Todd A; Joshi, Manju B; Andersen, John F; Kelada, Andrew Y; Owings, Joshua P; Bates, Paul A; Dwyer, Dennis M

    2015-06-01

    Leishmania are protozoan pathogens of humans that exist as extracellular promastigotes in the gut of their sand fly vectors and as obligate intracellular amastigotes within phagolysosomes of infected macrophages. Between infectious blood meal feeds, sand flies take plant juice meals that contain sucrose and store these sugars in their crop. Such sugars are regurgitated into the sand fly anterior midgut where they impact the developing promastigote parasite population. In this report we showed that promastigotes of all Leishmania species secreted an invertase/sucrase enzyme during their growth in vitro. In contrast, neither L. donovani nor L. mexicana amastigotes possessed any detectable invertase activity. Importantly, no released/secreted invertase activity was detected in culture supernatants from either Trypanosoma brucei or Trypanosoma cruzi. Using HPLC, the L. donovani secretory invertase was isolated and subjected to amino acid sequencing. Subsequently, we used a molecular approach to identify the LdINV and LmexINV genes encoding the ~72 kDa invertases produced by these organisms. Interestingly, we identified high fidelity LdINV-like homologs in the genomes of all Leishmania sp. but none were present in either T. brucei or T. cruzi. Northern blot and RT-PCR analyses showed that these genes were developmentally/differentially expressed in promastigotes but not amastigotes of these parasites. Homologous transfection studies demonstrated that these genes in fact encoded the functional secretory invertases produced by these parasites. Cumulatively, our results suggest that these secretory enzymes play critical roles in the survival/growth/development and transmission of all Leishmania parasites within their sand fly vector hosts. PMID:25763714

  10. Effects of weather and plague-induced die-offs of prairie dogs on the fleas of northern grasshopper mice.

    PubMed

    Salkeld, Daniel J; Stapp, Paul

    2009-05-01

    Plague, the disease caused by the bacterium Yersinia pestis, can have devastating impacts on black-tailed prairie dogs (Cynomys ludovicianus Ord). Other mammal hosts living on prairie dog colonies may be important in the transmission and maintenance of plague. We examined the flea populations of northern grasshopper mice (Onychomys leucogaster Wied) before, during, and after plague epizootics in northern Colorado and studied the influence of host and environmental factors on flea abundance patterns. Grasshopper mice were frequently infested with high numbers of fleas, most commonly Pleochaetis exilis Jordan and Thrassis fotus Jordan. Flea loads changed in response to both environmental temperature and rainfall. After plague-induced prairie dog die-offs, flea loads and likelihood of infestation were unchanged for P. exilis, but T. fotus loads declined. PMID:19496431

  11. Distribution of breeding Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) in the southwestern United States: Past, present, and future

    USGS Publications Warehouse

    Ruth, Janet M.

    2008-01-01

    The Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) breeds in desert grasslands of southeastern Arizona and southwestern New Mexico in the US, and in adjacent parts of northern Sonora and Chihuahua, Mexico. Roads that were surveyed in 1982 and 1987 in Arizona and New Mexico were relocated and roadside survey protocols were repeated in 2004 and 2005 to identify changes in distribution or abundance of the subspecies during the subsequent 17 yr. The Sonoita and San Rafael valleys in Arizona and the Animas Valley in New Mexico remain as primary population centers, supporting the highest mean numbers of singing males per stop, as well as the largest populations of Arizona Grasshopper Sparrows in the US. Mean number of singing males per stop was highest in the San Rafael Valley. Mean number of singing males per survey stop showed an increasing pattern from 1982–1987 and a subsequent decline to the present (2004–2005). Present bird densities are intermediate in value between 1982 and 1987 values. Small populations remain in the Altar, San Pedro, Sulphur Springs, and San Bernardino valleys in Arizona. The valleys evaluated in this and historical surveys represent the areas in which almost all Arizona Grasshopper Sparrows breed in the US; if any additional areas exist, they support peripheral, small, or remnant populations. Although historic, current, and future land use, and current and future threats differ among valleys, the primary factors posing threats to the future of Arizona Grasshopper Sparrow populations appear to be loss and/or degradation of habitat due to exurban development, overgrazing, and the effects of long-term drought.

  12. Factors associated with arrival densities of grasshopper sparrow (Ammodramus Savannarum) and baird's sparrow (A. Bairdii) in the upper great plains

    USGS Publications Warehouse

    Ahlering, M.A.; Johnson, D.H.; Faaborg, J.

    2009-01-01

    Although critical to habitat and population management, the proximate cues that birds use to establish territories are largely unknown. Understanding these cues is important for birds, such as many grassland birds, that exhibit high annual variability in population density and make new habitat-selection decisions annually. Identifying the actual cues used is difficult in the field, but the factors associated with the arrival densities of birds can help uncover variables that are involved in or correlated with cues used for selection. During the summers of 2002-2004, we investigated how weather and local vegetation factors were related to arrival densities of Grasshopper Sparrows (Ammodramus savannarum) and Baird's Sparrows (A. bairdii) at three locations across North Dakota and Saskatchewan. Spring densities of Grasshopper Sparrows were positively correlated with concurrent May precipitation, whereas densities of Baird's Sparrows were negatively correlated with the previous winter's snowfall. We used a model-selection approach to evaluate the vegetation characteristics associated with arrival densities of birds. Grasshopper Sparrow densities showed a strong negative relationship to woody cover, and Baird's Sparrow densities showed a negative relationship to vegetation height and vegetation density near the ground. Our results provide a first detailed look at habitat and weather associations immediately after arrival in spring and an important first step in uncovering factors that may be involved in habitat selection in two grassland species. Received 13 August 2008, accepted 20 April 2009. ?? The American Ornithologists' Union, 2009.

  13. Are color or high rearing density related to migratory polyphenism in the band-winged grasshopper, Oedaleus asiaticus?

    PubMed

    Cease, Arianne J; Hao, Shuguang; Kang, Le; Elser, James J; Harrison, Jon F

    2010-08-01

    Locusts represent an impressive example of migratory polyphenism, with high densities triggering a switch from a solitarious, shorter dispersal range, and sometimes greenish phenotype to a gregarious and sometimes darker form exhibiting behavioral, morphological and physiological traits associated with long-distance migratory swarms. While such polyphenism has been well documented in Locusta migratoria and Schistocerca gregaria, the extent to which other grasshoppers exhibit this type of migratory polyphenism is unclear. Anecdotally, the Chinese grasshopper, Oedaleus asiaticus, forms migratory swarms comprised mostly of a darker, brown-colored morph, but also exhibits a non-migratory green-colored morph that predominates at low densities. In a population in Inner Mongolia not currently exhibiting migratory swarms, we found that while green and brown O. asiaticus are found concurrently across our sampled range, only brown grasshoppers were found in high densities. Differences between field-collected brown and green forms matched some but not key predictions associated with the hypothesis that the brown form is morphologically and physiologically specialized for gregarious migration. Controlling for body mass, brown forms had more massive thoraxes, abdomens and legs, and higher metabolic rates, but not more flight muscle or lipid stores. Further, the brown and green grasshoppers did not differ in gregarious behavior, and neither would fly in multiple lab and field trials. Lab or field-rearing at high densities for one-to-multiple juvenile instars caused grasshoppers to exhibit some morphological traits predicted to benefit migration (larger wings and a shift in relative mass from abdomen to thorax), but did not change color or induce flight behavior. One hypothesis to explain these data is that a migratory form of O. asiaticus is partially triggered by high field densities, but that existing ecological conditions blocked full expression of such traits (and outbreak

  14. PdeH, a High-Affinity cAMP Phosphodiesterase, Is a Key Regulator of Asexual and Pathogenic Differentiation in Magnaporthe oryzae

    PubMed Central

    Ramanujam, Ravikrishna; Naqvi, Naweed I.

    2010-01-01

    Cyclic AMP-dependent pathways mediate the communication between external stimuli and the intracellular signaling machinery, thereby influencing important aspects of cellular growth, morphogenesis and differentiation. Crucial to proper function and robustness of these signaling cascades is the strict regulation and maintenance of intracellular levels of cAMP through a fine balance between biosynthesis (by adenylate cyclases) and hydrolysis (by cAMP phosphodiesterases). We functionally characterized gene-deletion mutants of a high-affinity (PdeH) and a low-affinity (PdeL) cAMP phosphodiesterase in order to gain insights into the spatial and temporal regulation of cAMP signaling in the rice-blast fungus Magnaporthe oryzae. In contrast to the expendable PdeL function, the PdeH activity was found to be a key regulator of asexual and pathogenic development in M. oryzae. Loss of PdeH led to increased accumulation of intracellular cAMP during vegetative and infectious growth. Furthermore, the pdeHΔ showed enhanced conidiation (2–3 fold), precocious appressorial development, loss of surface dependency during pathogenesis, and highly reduced in planta growth and host colonization. A pdeHΔ pdeLΔ mutant showed reduced conidiation, exhibited dramatically increased (∼10 fold) cAMP levels relative to the wild type, and was completely defective in virulence. Exogenous addition of 8-Br-cAMP to the wild type simulated the pdeHΔ defects in conidiation as well as in planta growth and development. While a fully functional GFP-PdeH was cytosolic but associated dynamically with the plasma membrane and vesicular compartments, the GFP-PdeL localized predominantly to the nucleus. Based on data from cAMP measurements and Real-Time RTPCR, we uncover a PdeH-dependent biphasic regulation of cAMP levels during early and late stages of appressorial development in M. oryzae. We propose that PdeH-mediated sustenance and dynamic regulation of cAMP signaling during M. oryzae development is

  15. Bloodborne pathogens

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000453.htm Bloodborne pathogens To use the sharing features on this page, please enable JavaScript. A pathogen is something that causes disease. Germs that can ...

  16. Differential activation of ammonium transporters during the accumulation of ammonia by Colletotrichum gloeosporioides and its effect on appressoria formation and pathogenicity.

    PubMed

    Shnaiderman, Chen; Miyara, Itay; Kobiler, Ilana; Sherman, Amir; Prusky, Dov

    2013-03-01

    Ammonium secreted by the post-harvest pathogen Colletotrichum gloeosporioides during host colonization accumulates in the host environment due to enhanced fungal nitrogen metabolism. Two types of ammonium transporter-encoding genes, AMET and MEP, are expressed during pathogenicity. Gene disruption of AMET, a gene modulating ammonia secretion, showed twofold reduced ammonia secretion and 45% less colonization on avocado fruit, suggesting a contribution to pathogenicity. MEPB, a gene modulating ammonium transport, is expressed by C. gloeosporioides during pathogenicity and starvation conditions in culture. Gene disruption of MEPB, the most highly expressed gene of the MEP family, resulted in twofold overexpression of MEPA and MEPC but reduced colonization, suggesting MEPB expression's contribution to pathogenicity. Analysis of internal and external ammonia accumulation by ΔmepB strains in mycelia and germinated spores showed rapid uptake and accumulation, and reduced secretion of ammonia in the mutant versus wild-type (WT) strains. Ammonia uptake by the WT germinating spores but not by the ΔmepB strain with compromised ammonium transport activated cAMP and transcription of PKA subunits PKAR and PKA2. ΔmepB mutants showed 75% less appressorium formation and colonization than the WT, which was partially restored by 10 mM exogenous ammonia. Thus, whereas both AMET and MEPB genes modulate ammonia secretion, only MEPB contributes to ammonia accumulation by mycelia and germinating spores that activate the cAMP pathways, inducing the morphogenetic processes contributing to C. gloeosporioides pathogenicity. PMID:23387470

  17. Patterns of male sterility in a grasshopper hybrid zone imply accumulation of hybrid incompatibilities without selection.

    PubMed

    Shuker, David M; Underwood, Karen; King, Tania M; Butlin, Roger K

    2005-12-01

    It is now widely accepted that post-zygotic reproductive isolation is the result of negative epistatic interactions between derived alleles fixed independently at different loci in diverging populations (the Dobzhansky-Muller model). What is less clear is the nature of the loci involved and whether the derived alleles increase in frequency through genetic drift, or as a result of natural or sexual selection. If incompatible alleles are fixed by selection, transient polymorphisms will be rare and clines for these alleles will be steep where divergent populations meet. If they evolve by drift, populations are expected to harbour substantial genetic variation in compatibility and alleles will introgress across hybrid zones once they recombine onto a genetic background with which they are compatible. Here we show that variation in male sterility in a naturally occurring Chorthippus parallelus grasshopper hybrid zone conforms to the neutral expectations. Asymmetrical clines for male sterility have long tails of introgression and populations distant from the zone centre show significant genetic variation for compatibility. Our data contrast with recent observations on 'speciation genes' that have diverged as a result of strong natural selection.

  18. Novel odorant-binding proteins and their expression patterns in grasshopper, Oedaleus asiaticus.

    PubMed

    Zhang, Shuo; Pang, Baoping; Zhang, Long

    2015-05-01

    Insects use olfaction to detect exogenous odors and adapt to environments. In their olfaction systems, odorant-binding proteins (OBPs) are believed to be a key component. The unique OBP system of each species reflects the evolution of chemosensation of insects with habits. Here, we for the first time identified 15 OBPs, OasiOBP1-15, of a grasshopper, Oedaleus asiaticus, that lives in the grasslands of Northern China and is closely related to the locust, Locusta migratoria. OasiOBP9 and OasiOBP10 are specifically expressed in the antennae. Other OBPs are expressed in the antennae as well as other chemosensory organs, such as the mouthparts and wings. Significantly more OasiOBP7 was detected in male than female antennae, but there are 9 OBPs that were more expressed in female than male antennae by quantitative real-time PCR. Phylogenetic analysis indicated that most of the O. asiaticus OBPs are similar to those of L. migratoria, but some are substantially different. This indicates that the OBPs originally evolved in a common ancestor, but their unique chemosensory systems are adapted to different ecosystems. PMID:25778868

  19. Neural representation of calling songs and their behavioral relevance in the grasshopper auditory system.

    PubMed

    Meckenhäuser, Gundula; Krämer, Stefanie; Farkhooi, Farzad; Ronacher, Bernhard; Nawrot, Martin P

    2014-01-01

    Acoustic communication plays a key role for mate attraction in grasshoppers. Males use songs to advertise themselves to females. Females evaluate the song pattern, a repetitive structure of sound syllables separated by short pauses, to recognize a conspecific male and as proxy to its fitness. In their natural habitat females often receive songs with degraded temporal structure. Perturbations may, for example, result from the overlap with other songs. We studied the response behavior of females to songs that show different signal degradations. A perturbation of an otherwise attractive song at later positions in the syllable diminished the behavioral response, whereas the same perturbation at the onset of a syllable did not affect song attractiveness. We applied naïve Bayes classifiers to the spike trains of identified neurons in the auditory pathway to explore how sensory evidence about the acoustic stimulus and its attractiveness is represented in the neuronal responses. We find that populations of three or more neurons were sufficient to reliably decode the acoustic stimulus and to predict its behavioral relevance from the single-trial integrated firing rate. A simple model of decision making simulates the female response behavior. It computes for each syllable the likelihood for the presence of an attractive song pattern as evidenced by the population firing rate. Integration across syllables allows the likelihood to reach a decision threshold and to elicit the behavioral response. The close match between model performance and animal behavior shows that a spike rate code is sufficient to enable song pattern recognition. PMID:25565983

  20. The 5S rDNA in two Abracris grasshoppers (Ommatolampidinae: Acrididae): molecular and chromosomal organization.

    PubMed

    Bueno, Danilo; Palacios-Gimenez, Octavio Manuel; Martí, Dardo Andrea; Mariguela, Tatiane Casagrande; Cabral-de-Mello, Diogo Cavalcanti

    2016-08-01

    The 5S ribosomal DNA (rDNA) sequences are subject of dynamic evolution at chromosomal and molecular levels, evolving through concerted and/or birth-and-death fashion. Among grasshoppers, the chromosomal location for this sequence was established for some species, but little molecular information was obtained to infer evolutionary patterns. Here, we integrated data from chromosomal and nucleotide sequence analysis for 5S rDNA in two Abracris species aiming to identify evolutionary dynamics. For both species, two arrays were identified, a larger sequence (named type-I) that consisted of the entire 5S rDNA gene plus NTS (non-transcribed spacer) and a smaller (named type-II) with truncated 5S rDNA gene plus short NTS that was considered a pseudogene. For type-I sequences, the gene corresponding region contained the internal control region and poly-T motif and the NTS presented partial transposable elements. Between the species, nucleotide differences for type-I were noticed, while type-II was identical, suggesting pseudogenization in a common ancestor. At chromosomal point to view, the type-II was placed in one bivalent, while type-I occurred in multiple copies in distinct chromosomes. In Abracris, the evolution of 5S rDNA was apparently influenced by the chromosomal distribution of clusters (single or multiple location), resulting in a mixed mechanism integrating concerted and birth-and-death evolution depending on the unit. PMID:27106499

  1. Complete mitochondrial genome of the Chinese endemic grasshopper Fruhstorferiola kulinga (Orthoptera: Acrididae: Podismini).

    PubMed

    Yang, Rui; Guan, De-Long; Xu, Sheng-Quan

    2016-09-01

    The whole-genome Illumina sequence of the Chinese endemic grasshopper Fruhstorferiola kulinga mitogenome was constructed and reported in this study. In all, the circular genome was obtained with 15,655 bp in length and contains 75.4% A + T. It typically consists of 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs) and 1 D-loop region. All PCGs are initiated with ATN codons. Most of the PCGs use TAA as their stop codons, while the others use TAG as stop codons (COX1 and ND1). The size of the large and small ribosomal RNA genes are 1314 bp and 851 bp. The A + T-rich region (777 bp) showed strong resemblance to the other known Orthoptera insects. Our data would contribute to confirm the close relationship and other evolutionary researches of the F. kulinga.

  2. The 5S rDNA in two Abracris grasshoppers (Ommatolampidinae: Acrididae): molecular and chromosomal organization.

    PubMed

    Bueno, Danilo; Palacios-Gimenez, Octavio Manuel; Martí, Dardo Andrea; Mariguela, Tatiane Casagrande; Cabral-de-Mello, Diogo Cavalcanti

    2016-08-01

    The 5S ribosomal DNA (rDNA) sequences are subject of dynamic evolution at chromosomal and molecular levels, evolving through concerted and/or birth-and-death fashion. Among grasshoppers, the chromosomal location for this sequence was established for some species, but little molecular information was obtained to infer evolutionary patterns. Here, we integrated data from chromosomal and nucleotide sequence analysis for 5S rDNA in two Abracris species aiming to identify evolutionary dynamics. For both species, two arrays were identified, a larger sequence (named type-I) that consisted of the entire 5S rDNA gene plus NTS (non-transcribed spacer) and a smaller (named type-II) with truncated 5S rDNA gene plus short NTS that was considered a pseudogene. For type-I sequences, the gene corresponding region contained the internal control region and poly-T motif and the NTS presented partial transposable elements. Between the species, nucleotide differences for type-I were noticed, while type-II was identical, suggesting pseudogenization in a common ancestor. At chromosomal point to view, the type-II was placed in one bivalent, while type-I occurred in multiple copies in distinct chromosomes. In Abracris, the evolution of 5S rDNA was apparently influenced by the chromosomal distribution of clusters (single or multiple location), resulting in a mixed mechanism integrating concerted and birth-and-death evolution depending on the unit.

  3. Metaphase I orientation of Robertsonian trivalents in the water-hyacinth grasshopper, Cornops aquaticum (Acrididae, Orthoptera)

    PubMed Central

    2009-01-01

    Trivalents resulting from polymorphic Robertsonian rearrangements must have a regular orientation in metaphase I if the polymorphisms are to be maintained. It has been argued that redistribution of proximal and interstitial chiasmata to more distal positions is necessary for a convergent orientation, the only one that produces viable gametes. Cornops aquaticum is a South-American grasshopper that lives and feeds on water-hyacinths, and has three polymorphic Robertsonian rearrangements in its southernmost distribution area in Central Argentina and Uruguay. The orientation of trivalents in metaphase I, the formation of abnormal spermatids and the frequency and position of chiasmata in the trivalents, was analysed in a polymorphic population of C. aquaticus. In this study we observed a correlation between the number of trivalents with the frequency of abnormal spermatids; additionally, the number of chiasmata, especially proximal and interstitial ones, was strongly correlated with the frequency of the linear orientation. Therefore we confirmed our previous assumption, based on other evidence, that the chiasmata redistribution in fusion carriers is essential to the maintenance of the polymorphisms. PMID:21637651

  4. Direct visualization of hemolymph flow in the heart of a grasshopper (Schistocerca americana)

    PubMed Central

    Lee, Wah-Keat; Socha, John J

    2009-01-01

    Background Hemolymph flow patterns in opaque insects have never been directly visualized due to the lack of an appropriate imaging technique. The required spatial and temporal resolutions, together with the lack of contrast between the hemolymph and the surrounding soft tissue, are major challenges. Previously, indirect techniques have been used to infer insect heart motion and hemolymph flow, but such methods fail to reveal fine-scale kinematics of heartbeat and details of intra-heart flow patterns. Results With the use of microbubbles as high contrast tracer particles, we directly visualized hemolymph flow in a grasshopper (Schistocerca americana) using synchrotron x-ray phase-contrast imaging. In-vivo intra-heart flow patterns and the relationship between respiratory (tracheae and air sacs) and circulatory (heart) systems were directly observed for the first time. Conclusion Synchrotron x-ray phase contrast imaging is the only generally applicable technique that has the necessary spatial, temporal resolutions and sensitivity to directly visualize heart dynamics and flow patterns inside opaque animals. This technique has the potential to illuminate many long-standing questions regarding small animal circulation, encompassing topics such as retrograde heart flow in some insects and the development of flow in embryonic vertebrates. PMID:19272159

  5. Axogenesis in the antennal nervous system of the grasshopper Schistocerca gregaria revisited: the base pioneers.

    PubMed

    Ehrhardt, Erica; Liu, Yu; Boyan, George

    2015-01-01

    The antennal nervous system of the grasshopper Schistocerca gregaria comprises two parallel pathways projecting to the brain, each pioneered early in embryogenesis by a pair of sibling cells located at the antennal tip. En route, the growth cones of pioneers from one pathway have been shown to contact a guidepost-like cell called the base pioneer. Its role in axon guidance remains unclear as do the cellular guidance cues regulating axogenesis in the other pathway supposedly without a base pioneer. Further, while the tip pioneers are known to delaminate from the antennal epithelium into the lumen, the origin of this base pioneer is unknown. Here, we use immunolabeling and immunoblocking methods to clarify these issues. Co-labeling against the neuron-specific marker horseradish peroxidase and the pioneer-specific cell surface glycoprotein Lazarillo identifies not only the tip pioneers but also a base pioneer associated with each of the developing antennal pathways. Both base pioneers co-express the mesodermal label Mes3, consistent with a lumenal origin, whereas the tip pioneers proved Mes3-negative confirming their affiliation with the ectodermal epithelium. Lazarillo antigen expression in the antennal pioneers followed a different temporal dynamic: continuous in the tip pioneers, but in the base pioneers, only at the time their filopodia and those of the tip pioneers first recognize one another. Immunoblocking of Lazarillo expression in cultured embryos disrupts this recognition resulting in misguided axogenesis in both antennal pathways.

  6. A population genomic scan in Chorthippus grasshoppers unveils previously unknown phenotypic divergence.

    PubMed

    Berdan, Emma L; Mazzoni, Camila J; Waurick, Isabelle; Roehr, Johannes T; Mayer, Frieder

    2015-08-01

    Understanding the genetics of speciation and the processes that drive it is a central goal of evolutionary biology. Grasshoppers of the Chorthippus species group differ strongly in calling song (and corresponding female preferences) but are exceedingly similar in other characteristics such as morphology. Here, we performed a population genomic scan on three Chorthippus species (Chorthippus biguttulus, C. mollis and C. brunneus) to gain insight into the genes and processes involved in divergence and speciation in this group. Using an RNA-seq approach, we examined functional variation between the species by calling SNPs for each of the three species pairs and using FST -based approaches to identify outliers. We found approximately 1% of SNPs in each comparison to be outliers. Between 37% and 40% of these outliers were nonsynonymous SNPs (as opposed to a global level of 17%) indicating that we recovered loci under selection. Among the outliers were several genes that may be involved in song production and hearing as well as genes involved in other traits such as food preferences and metabolism. Differences in food preferences between species were confirmed with a behavioural experiment. This indicates that multiple phenotypic differences implicating multiple evolutionary processes (sexual selection and natural selection) are present between the species. PMID:26081018

  7. Muscle group dependent responses to stimuli in a grasshopper model for tonic immobility

    PubMed Central

    Miriyala, Ashwin; Dutta-Gupta, Aparna; Joseph, Joby

    2013-01-01

    Summary Tonic Immobility (TI) is a prolonged immobile condition exhibited by a variety of animals when exposed to certain stimuli, and is thought to be associated with a specific state of arousal. In our study, we characterize this state by using the reliably inducible TI state of the grasshopper (Hieroglyphus banian) and by monitoring abdominal pulsations and body movements in response to visual and auditory stimuli. These pulsations are present during the TI and ‘awake’, standing states, but not in the CO2 anesthetized state. In response to the stimuli, animals exhibited a suppression in pulsation and a startle response. The suppression of pulsation lasted longer than the duration of stimulus application. During TI, the suppression of pulsation does not habituate over time, whereas the startle response does. In response to the translating visual stimulus, the pulsations are suppressed at a certain phase independent of the time of stimulus application. Thus, we describe TI in Hieroglyphus banian as a state more similar to an ‘awake’ state than to an anesthetized state. During TI, the circuitry to the muscle outputs controlling the abdomen pulsation and the startle response are, at least in some part, different. The central pattern generators that maintain the abdomen pulsation receive inputs from visual and auditory pathways. PMID:24244858

  8. Next generation sequencing and FISH reveal uneven and nonrandom microsatellite distribution in two grasshopper genomes.

    PubMed

    Ruiz-Ruano, Francisco J; Cuadrado, Ángeles; Montiel, Eugenia E; Camacho, Juan Pedro M; López-León, María Dolores

    2015-06-01

    Simple sequence repeats (SSRs), also known as microsatellites, are one of the prominent DNA sequences shaping the repeated fraction of eukaryotic genomes. In spite of their profuse use as molecular markers for a variety of genetic and evolutionary studies, their genomic location, distribution, and function are not yet well understood. Here we report the first thorough joint analysis of microsatellite motifs at both genomic and chromosomal levels in animal species, by a combination of 454 sequencing and fluorescent in situ hybridization (FISH) techniques performed on two grasshopper species. The in silico analysis of the 454 reads suggested that microsatellite expansion is not driving size increase of these genomes, as SSR abundance was higher in the species showing the smallest genome. However, the two species showed the same uneven and nonrandom location of SSRs, with clear predominance of dinucleotide motifs and association with several types of repetitive elements, mostly histone gene spacers, ribosomal DNA intergenic spacers (IGS), and transposable elements (TEs). The FISH analysis showed a dispersed chromosome distribution of microsatellite motifs in euchromatic regions, in coincidence with chromosome location patterns previously observed for many mobile elements in these species. However, some SSR motifs were clustered, especially those located in the histone gene cluster.

  9. Variation in complex mating signals in an "island" hybrid zone between Stenobothrus grasshopper species.

    PubMed

    Sradnick, Jan; Klöpfel, Anja; Elsner, Norbert; Vedenina, Varvara

    2016-07-01

    Two grasshopper species Stenobothrus rubicundus and S. clavatus were previously shown to meet in a narrow hybrid zone on Mount Tomaros in northern Greece. The species are remarkable for their complex courtship songs accompanied by conspicuous movements of antennae and wings. We analyzed variations in forewing morphology, antenna shape, and courtship song across the hybrid zone using a geographic information system, and we documented three contact zones on Mount Tomaros. All male traits and female wings show abrupt transitions across the contact zones, suggesting that these traits are driven by selection rather than by drift. Male clines in antennae are displaced toward S. clavatus, whereas all clines in wings are displaced toward S. rubicundus. We explain cline discordance as depending on sexual selection via female choice. The high covariance between wings and antennae found in the centers of all contact zones results from high levels of linkage disequilibria among the underlying loci, which in turn more likely results from assortative mating than from selection against hybrids. The covariance is found to be higher in clavatus-like than rubicundus-like populations, which implies asymmetric assortative mating in parental-like sites of the hybrid zone and a movement of the hybrid zone in favor of S. clavatus. PMID:27547333

  10. Temporal integration at consecutive processing stages in the auditory pathway of the grasshopper

    PubMed Central

    Ronacher, Bernhard

    2015-01-01

    Temporal integration in the auditory system of locusts was quantified by presenting single clicks and click pairs while performing intracellular recordings. Auditory neurons were studied at three processing stages, which form a feed-forward network in the metathoracic ganglion. Receptor neurons and most first-order interneurons (“local neurons”) encode the signal envelope, while second-order interneurons (“ascending neurons”) tend to extract more complex, behaviorally relevant sound features. In different neuron types of the auditory pathway we found three response types: no significant temporal integration (some ascending neurons), leaky energy integration (receptor neurons and some local neurons), and facilitatory processes (some local and ascending neurons). The receptor neurons integrated input over very short time windows (<2 ms). Temporal integration on longer time scales was found at subsequent processing stages, indicative of within-neuron computations and network activity. These different strategies, realized at separate processing stages and in parallel neuronal pathways within one processing stage, could enable the grasshopper's auditory system to evaluate longer time windows and thus to implement temporal filters, while at the same time maintaining a high temporal resolution. PMID:25609104

  11. Effects of forest-dune ecotone management on the endangered heath grasshopper, Chorthippus vagans (Orthoptera: Acrididae).

    PubMed

    Hochkirch, A; Gärtner, A-C; Brandt, T

    2008-10-01

    Dry, oligotrophic ecosystems are highly threatened in Europe due to massive changes in land use and eutrophication. The conservation of these xeric habitats has received much attention, whereas the ecotones between xeric habitats and other habitat types are often disregarded. One species which mainly inhabits the transition zone between pine forests and adjacent xeric habitats is the heath grasshopper, Chorthippus vagans. This species is endangered in large parts of Europe. One of the largest populations in northern Germany is found on a degraded inland dune near Hanover. This population is threatened by dense growth of deciduous trees and litter accumulation. We analyzed changes in the distribution of this population after the implementation of conservation measures (thinning out the forest and removal of leaf litter). Moreover, we examined dispersal distances of the species in order to assess its colonization potential. We also studied the microhabitat preferences of C. vagans to assess key factors influencing its local distribution. Our data show a substantial growth in population size, which might be a consequence of the conservation measures. New patches on the dune were colonized, promoting dispersal between the subpopulations. We propose that restoration of forest-dune ecotones should be considered more often in landscape planning and conservation management.

  12. Prevalence and Molecular Identification of Nematode and Dipteran Parasites in an Australian Alpine Grasshopper (Kosciuscola tristis)

    PubMed Central

    Umbers, Kate D. L.; Byatt, Lachlan J.; Hill, Nichola J.; Bartolini, Remo J.; Hose, Grant C.; Herberstein, Marie E.; Power, Michelle L

    2015-01-01

    In alpine Australia, Orthoptera are abundant, dominant herbivores, important prey species, and hosts for parasites and parasitoids. Despite the central role of orthopterans in alpine ecosystems, the impact of parasites on orthopteran populations is under-explored. In this study we describe the relationship between parasite prevalence and host sex, body size and year of collection. We accessed an existing, preserved collection of 640 Kosciuscola tristis collected from across its range between 2007 and 2011. Upon dissection we collected juvenile parasites and used molecular tools to identify them to three families (Nematoda; Mermithidae, and Arthropoda: Diptera: Tachinidae and Sarcophagidae). The prevalence of nematodes ranged from 3.5% to 25.0% and dipterans from 2.4% to 20.0%. Contrary to predictions, we found no associations between parasite prevalence and grasshopper sex or size. Although there was an association between prevalence of both nematodes and dipterans with year of collection, this is likely driven by a small sample size in the first year. Our results provide a foundation for future studies into parasite prevalence within the alpine environment and the abiotic factors that might influence these associations. PMID:25919745

  13. Transcriptome and Metabolite Profiling of the Infection Cycle of Zymoseptoria tritici on Wheat Reveals a Biphasic Interaction with Plant Immunity Involving Differential Pathogen Chromosomal Contributions and a Variation on the Hemibiotrophic Lifestyle Definition1[OPEN

    PubMed Central

    Rudd, Jason J.; Kanyuka, Kostya; Hassani-Pak, Keywan; Derbyshire, Mark; Andongabo, Ambrose; Devonshire, Jean; Lysenko, Artem; Saqi, Mansoor; Desai, Nalini M.; Powers, Stephen J.; Hooper, Juliet; Ambroso, Linda; Bharti, Arvind; Farmer, Andrew; Hammond-Kosack, Kim E.; Dietrich, Robert A.; Courbot, Mikael

    2015-01-01

    The hemibiotrophic fungus Zymoseptoria tritici causes Septoria tritici blotch disease of wheat (Triticum aestivum). Pathogen reproduction on wheat occurs without cell penetration, suggesting that dynamic and intimate intercellular communication occurs between fungus and plant throughout the disease cycle. We used deep RNA sequencing and metabolomics to investigate the physiology of plant and pathogen throughout an asexual reproductive cycle of Z. tritici on wheat leaves. Over 3,000 pathogen genes, more than 7,000 wheat genes, and more than 300 metabolites were differentially regulated. Intriguingly, individual fungal chromosomes contributed unequally to the overall gene expression changes. Early transcriptional down-regulation of putative host defense genes was detected in inoculated leaves. There was little evidence for fungal nutrient acquisition from the plant throughout symptomless colonization by Z. tritici, which may instead be utilizing lipid and fatty acid stores for growth. However, the fungus then subsequently manipulated specific plant carbohydrates, including fructan metabolites, during the switch to necrotrophic growth and reproduction. This switch coincided with increased expression of jasmonic acid biosynthesis genes and large-scale activation of other plant defense responses. Fungal genes encoding putative secondary metabolite clusters and secreted effector proteins were identified with distinct infection phase-specific expression patterns, although functional analysis suggested that many have overlapping/redundant functions in virulence. The pathogenic lifestyle of Z. tritici on wheat revealed through this study, involving initial defense suppression by a slow-growing extracellular and nutritionally limited pathogen followed by defense (hyper) activation during reproduction, reveals a subtle modification of the conceptual definition of hemibiotrophic plant infection. PMID:25596183

  14. Identification of differentially expressed genes associated with changes in the morphology and pathogenicity of Pichia fermentans on apple and peach fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pichia fermentans (strain DISAABA 726) is an effective biocontrol agent against Monilinia fructicola or Botrytis cinerea when inoculated in artificially wounded apple fruit but is an aggressive pathogen when inoculated on wounded peach fruit, causing severe fruit decay. P. fermentans grows as a bud...

  15. Two strains of Pseudomonas fluorscens bacteria differentially affect survivorship of waxworm (Galleria mellonella) larvae exposed to an arthropod fungal pathogen, Beauveria bassiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two strains of Pseudomonas fluorescens were found contaminating a biopesticide used in a previous study against Varroa destructor infestations in honey bee hives. In the aforementioned study the biopesticide, a formulation of the arthropod pathogen Beauveria bassiana, failed to have any impact on t...

  16. Grasshopper Lazarillo, a GPI-anchored Lipocalin, increases Drosophila longevity and stress resistance, and functionally replaces its secreted homolog NLaz.

    PubMed

    Ruiz, Mario; Wicker-Thomas, Claude; Sanchez, Diego; Ganfornina, Maria D

    2012-10-01

    Lazarillo (Laz) is a glycosyl-phosphatidylinositol (GPI)-linked glycoprotein first characterized in the developing nervous system of the grasshopper Schistocerca americana. It belongs to the Lipocalins, a functionally diverse family of mostly secreted proteins. In this work we test whether the protective capacity known for Laz homologs in flies and vertebrates (NLaz, GLaz and ApoD) is evolutionarily conserved in grasshopper Laz, and can be exerted from the plasma membrane in a cell-autonomous manner. First we demonstrate that extracellular forms of Laz have autocrine and paracrine protecting effects for oxidative stress-challenged Drosophila S2 cells. Then we assay the effects of overexpressing GPI-linked Laz in adult Drosophila and whether it rescues both known and novel phenotypes of NLaz null mutants. Local effects of GPI-linked Laz inside and outside the nervous system promote survival upon different stress forms, and extend lifespan and healthspan of the flies in a cell-type dependent manner. Outside the nervous system, expression in fat body cells but not in hemocytes results in protection. Within the nervous system, glial cell expression is more effective than neuronal expression. Laz actions are sexually dimorphic in some expression domains. Fat storage promotion and not modifications in hydrocarbon profiles or quantities explain the starvation-desiccation resistance caused by Laz overexpression. This effect is exerted when Laz is expressed ubiquitously or in dopaminergic cells, but not in hemocytes. Grasshopper Laz functionally restores the loss of NLaz, rescuing stress-sensitivity as well as premature accumulation of aging-related damage, monitored by advanced glycation end products (AGEs). However Laz does not rescue NLaz courtship behavioral defects. Finally, the presence of two new Lipocalins with predicted GPI-anchors in mosquitoes shows that the functional advantages of GPI-linkage have been commonly exploited by Lipocalins in the arthropodan lineage.

  17. Growth and reproduction of the alpine grasshopper Miramella alpina feeding on CO2-enriched dwarf shrubs at treeline.

    PubMed

    Asshoff, Roman; Hättenschwiler, Stephan

    2005-01-01

    The consequences for plant-insect interactions of atmospheric changes in alpine ecosystems are not well understood. Here, we tested the effects of elevated CO(2) on leaf quality in two dwarf shrub species (Vaccinium myrtillus and V. uliginosum) and the response of the alpine grasshopper (Miramella alpina) feeding on these plants in a field experiment at the alpine treeline (2,180 m a.s.l.) in Davos, Switzerland. Relative growth rates (RGR) of M. alpina nymphs were lower when they were feeding on V. myrtillus compared to V. uliginosum, and were affected by elevated CO(2) depending on plant species and nymph developmental stage. Changes in RGR correlated with CO(2)-induced changes in leaf water, nitrogen, and starch concentrations. Elevated CO(2) resulted in reduced female adult weight irrespective of plant species, and prolonged development time on V. uliginosum only, but there were no significant differences in nymphal mortality. Newly molted adults of M. alpina produced lighter eggs and less secretion (serving as egg protection) under elevated CO(2). When grasshoppers had a choice among four different plant species grown either under ambient or elevated CO(2), V. myrtillus and V. uliginosum consumption increased under elevated CO(2) in females while it decreased in males compared to ambient CO(2)-grown leaves. Our findings suggest that rising atmospheric CO(2) distinctly affects leaf chemistry in two important dwarf shrub species at the alpine treeline, leading to changes in feeding behavior, growth, and reproduction of the most important insect herbivore in this system. Changes in plant-grasshopper interactions might have significant long-term impacts on herbivore pressure, community dynamics and ecosystem stability in the alpine treeline ecotone. PMID:15480804

  18. Lazarillo expression reveals a subset of neurons contributing to the primary axon scaffold of the embryonic brain of the grasshopper Schistocerca gregaria.

    PubMed

    Graf, S; Ludwig, P; Boyan, G

    2000-04-10

    The authors studied the contribution of seven clusters of Lazarillo-expressing cells to the primary axon scaffold of the brain in the grasshopper Schistocerca gregaria from 26% to 43% of embryogenesis. Each cluster, which was numbered according to when Lazarillo expression first appeared, was uniquely identifiable on the basis of its stereotypic position in the brain and the number of Lazarillo-expressing cells it contained. At no time during embryogenesis was Lazarillo expression found in brain neuroblasts: It was found only in progeny. For ease of analysis, axogenesis was followed in a cell cluster that contained only a single Lazarillo-expressing cell (the lateral cell) in the dorsal median domain of the brain midline. Bromodeoxyuridine incorporation revealed the presence of only a single midline precursor cell in this region during embryogenesis. Intracellular injection of Lucifer yellow into the lateral cell at various ages showed that there was no dye coupling to the midline precursor or to the nearby term-1-expressing primary commissure pioneers. The lateral cell is not related lineally to these cells and most likely differentiates directly from the neuroectoderm of the brain midline. Lazarillo expression appears at the onset of axogenesis as the lateral cell projects an axon laterally toward the next Lazarillo-expressing cell cluster. The cells of this target cluster direct axons into separate brain regions, thereby establishing an orthogonally organized scaffold that the lateral cell axon follows as it navigates away from the brain midline. The primary axon scaffold of the brain results from a stepwise interlinking of discrete brain regions, as exemplified by axons from neighboring Lazarillo-expressing cell clusters.

  19. Body Size Adaptations to Altitudinal Climatic Variation in Neotropical Grasshoppers of the Genus Sphenarium (Orthoptera: Pyrgomorphidae).

    PubMed

    Sanabria-Urbán, Salomón; Song, Hojun; Oyama, Ken; González-Rodríguez, Antonio; Serrano-Meneses, Martin A; Cueva Del Castillo, Raúl

    2015-01-01

    Altitudinal clines in body size can result from the effects of natural and sexual selection on growth rates and developing times in seasonal environments. Short growing and reproductive seasons constrain the body size that adults can attain and their reproductive success. Little is known about the effects of altitudinal climatic variation on the diversification of Neotropical insects. In central Mexico, in addition to altitude, highly heterogeneous topography generates diverse climates that can occur even at the same latitude. Altitudinal variation and heterogeneous topography open an opportunity to test the relative impact of climatic variation on body size adaptations. In this study, we investigated the relationship between altitudinal climatic variation and body size, and the divergence rates of sexual size dimorphism (SSD) in Neotropical grasshoppers of the genus Sphenarium using a phylogenetic comparative approach. In order to distinguish the relative impact of natural and sexual selection on the diversification of the group, we also tracked the altitudinal distribution of the species and trends of both body size and SSD on the phylogeny of Sphenarium. The correlative evidence suggests no relationship between altitude and body size. However, larger species were associated with places having a warmer winter season in which the temporal window for development and reproduction can be longer. Nonetheless, the largest species were also associated with highly seasonal environments. Moreover, large body size and high levels of SSD have evolved independently several times throughout the history of the group and male body size has experienced a greater evolutionary divergence than females. These lines of evidence suggest that natural selection, associated with seasonality and sexual selection, on maturation time and body size could have enhanced the diversification of this insect group. PMID:26684616

  20. Body Size Adaptations to Altitudinal Climatic Variation in Neotropical Grasshoppers of the Genus Sphenarium (Orthoptera: Pyrgomorphidae)

    PubMed Central

    2015-01-01

    Altitudinal clines in body size can result from the effects of natural and sexual selection on growth rates and developing times in seasonal environments. Short growing and reproductive seasons constrain the body size that adults can attain and their reproductive success. Little is known about the effects of altitudinal climatic variation on the diversification of Neotropical insects. In central Mexico, in addition to altitude, highly heterogeneous topography generates diverse climates that can occur even at the same latitude. Altitudinal variation and heterogeneous topography open an opportunity to test the relative impact of climatic variation on body size adaptations. In this study, we investigated the relationship between altitudinal climatic variation and body size, and the divergence rates of sexual size dimorphism (SSD) in Neotropical grasshoppers of the genus Sphenarium using a phylogenetic comparative approach. In order to distinguish the relative impact of natural and sexual selection on the diversification of the group, we also tracked the altitudinal distribution of the species and trends of both body size and SSD on the phylogeny of Sphenarium. The correlative evidence suggests no relationship between altitude and body size. However, larger species were associated with places having a warmer winter season in which the temporal window for development and reproduction can be longer. Nonetheless, the largest species were also associated with highly seasonal environments. Moreover, large body size and high levels of SSD have evolved independently several times throughout the history of the group and male body size has experienced a greater evolutionary divergence than females. These lines of evidence suggest that natural selection, associated with seasonality and sexual selection, on maturation time and body size could have enhanced the diversification of this insect group. PMID:26684616

  1. Body Size Adaptations to Altitudinal Climatic Variation in Neotropical Grasshoppers of the Genus Sphenarium (Orthoptera: Pyrgomorphidae).

    PubMed

    Sanabria-Urbán, Salomón; Song, Hojun; Oyama, Ken; González-Rodríguez, Antonio; Serrano-Meneses, Martin A; Cueva Del Castillo, Raúl

    2015-01-01

    Altitudinal clines in body size can result from the effects of natural and sexual selection on growth rates and developing times in seasonal environments. Short growing and reproductive seasons constrain the body size that adults can attain and their reproductive success. Little is known about the effects of altitudinal climatic variation on the diversification of Neotropical insects. In central Mexico, in addition to altitude, highly heterogeneous topography generates diverse climates that can occur even at the same latitude. Altitudinal variation and heterogeneous topography open an opportunity to test the relative impact of climatic variation on body size adaptations. In this study, we investigated the relationship between altitudinal climatic variation and body size, and the divergence rates of sexual size dimorphism (SSD) in Neotropical grasshoppers of the genus Sphenarium using a phylogenetic comparative approach. In order to distinguish the relative impact of natural and sexual selection on the diversification of the group, we also tracked the altitudinal distribution of the species and trends of both body size and SSD on the phylogeny of Sphenarium. The correlative evidence suggests no relationship between altitude and body size. However, larger species were associated with places having a warmer winter season in which the temporal window for development and reproduction can be longer. Nonetheless, the largest species were also associated with highly seasonal environments. Moreover, large body size and high levels of SSD have evolved independently several times throughout the history of the group and male body size has experienced a greater evolutionary divergence than females. These lines of evidence suggest that natural selection, associated with seasonality and sexual selection, on maturation time and body size could have enhanced the diversification of this insect group.

  2. Geographically localised bursts of ribosomal DNA mobility in the grasshopper Podisma pedestris.

    PubMed

    Veltsos, P; Keller, I; Nichols, R A

    2009-07-01

    We report extraordinary variation in the number and the chromosomal location of ribosomal DNA (rDNA) arrays within populations of the alpine grasshopper Podisma pedestris; even greater differences were found between populations. The sites were detected by in situ hybridisation of labelled rDNA to chromosomal preparations. The total number of rDNA sites in an individual varied from three to thirteen. In the most extreme case, individuals from populations only 10 km apart had no rDNA loci in common. A survey of the geographical distribution of this variation identified clusters of populations with relatively similar chromosomal distribution of rDNA loci. These clusters correspond to those identified earlier by analysis of rDNA sequences. To explain this geographical clustering, we reconstructed the post-glacial colonisation of the region by assuming that the species' distribution has ascended to its current altitudinal range as the climate warmed. The reconstruction suggests that each cluster is descended from a colonisation route up a different alpine valley. That history would imply rapid establishment of rDNA differences, conceivably during the last 10,000 years since the last glaciation. The proposal for rapid change is consistent with the extensive within-population variation, which indicates that the processes responsible for the change in rDNA's chromosomal location continue to occur at a higher rate. We discuss whether our reconstruction of colonisation routes implies movement of the hybrid zone, which would indicate that a neo-XY sex chromosome system has spread through extant populations.

  3. Nutrient balancing in grasshoppers: behavioural and physiological correlates of dietary breadth.

    PubMed

    Raubenheimer, D; Simpson, S J

    2003-05-01

    We examined correlates of nutrient balancing with dietary range by comparing diet selection and ingestive, post-ingestive and performance-related responses to macronutrient imbalance in two species of grasshopper. One of the two species, Locusta migratoria (the African migratory locust), is a specialist grass-feeder, while the other, Schistocerca gregaria (the desert locust), is a generalist herbivore that includes both grasses and forbs in its diet. In ad libitum conditions, both species composed a balanced intake of the two macronutrients protein and carbohydrate from nutritionally complementary synthetic foods, but the composition of the selected diet differed, with the generalist selecting more protein, but not carbohydrate, than the grass-specialist. The grass-specialist, by contrast, retained ingested nitrogen more efficiently on the ad libitum diets. When confined to nutritionally imbalanced foods, both species regulated ingestion in such a way as to mitigate excesses as well as deficits of the two nutrients. The responses were, however, distinct in the two species, with the generalist feeder ingesting greater excesses of protein than the specialist. The species also differed in their post-ingestive responses to ingested excesses of nutrient, with the generalist but not the specialist using protein-derived carbon as an energy source when fed carbohydrate-deficient foods. The generalist also retained a higher level of body protein when confined to protein-deficient diets. The data suggested one functional reason why the generalist species selected a diet with higher protein content in the ad libitum treatment because, when confined to the nutritionally imbalanced foods, development rate peaked on higher protein foods for the generalist compared with the specialist. Many aspects of these data agree with the prediction that generalist-feeding animals should show greater behavioural and physiological flexibility in their responses to nutrient imbalance than do

  4. The Biology and some Population Parameters of the Grasshopper, Ronderosia bergi, Under Laboratory Conditions

    PubMed Central

    Mariottini, Yanina; de Wysiecki, Maria Laura; Lange, Carlos

    2010-01-01

    Some biological and population parameters of Ronderosia bergi (Stål) (Orthoptera: Acrididae: Melanoplinae) were estimated by monitoring five cohorts of the first generation (F1) of individuals born in captivity from grasshoppers collected in the South of Misiones province, northeastern Argentina, and held under controlled conditions (30° C, 14:10 L:D, 40% RH). The mean embryonic development time was 40.6 ± 1.7 days. Five nymphal instars were recorded. Total duration of nymphal development was 30.8 ± 0.54 days. The mean lifespan of cohorts was 22.6 ± 0.7 weeks. The number of egg-pods per female was 7.6 ± 1.44, and the amount of eggs per egg-pod was 16.45 ± 0.85. Mean fecundity was 125 ± 5.83 eggs per female with an oviposition rate of 1.55 ± 0.57 eggs/female/day. Survivorship curves showed that mortality was concentrated in the final weeks of adulthood, and the life expectancy curve decreased accordingly. The population parameters estimated gave the following values: the net rate of reproduction (R0) was 46.75 ± 11.2, generation time (T) was 18.87 ± 1.67 weeks, duplication time (D) was 3.31 ± 0.34, the intrinsic rate of population growth (rm) was 0.21 ± 0.021 and the finite rate of population increase (λ) was 1.24 ± 0.026. The reproductive values (Vx) indicated that the largest contribution of females to the subsequent generation was between weeks 15 and 25. PMID:20673116

  5. DNA damage in grasshoppers' larvae--comet assay in environmental approach.

    PubMed

    Augustyniak, Maria; Orzechowska, Helena; Kędziorski, Andrzej; Sawczyn, Tomasz; Doleżych, Bogdan

    2014-02-01

    The comet assay that provides a quantitative measure of the DNA-strand breaks may be used for assessing the 'genotoxic potential' of the environment. Young adults of Chorthippus brunneus (Orthoptera), collected at three sites in Southern Poland, differing in the level of pollution, particularly with heavy metals: Pilica (reference), Olkusz (moderately polluted) and Szopienice (heavily polluted) - were allowed to mate under laboratory conditions that were free from any pollution. Egg-pods were collected and, after diapause, brain cells from one-day old larvae were used for the comet assay. We compared the level of DNA damage in the larvae originating from these sites and also measured time-dependent DNA repair after single 10min. application of H2O2 (20μM final concentration). The DNA damage was relatively low in larval cells irrespectively of the site pollution their parents came from. However, measured comet parameters - tail DNA content (TDNA), tail length (TL), and olive tail moment (OTM) - were significantly higher in larvae originating from the Szopienice site than in those from the reference site. Incubation of cells with H2O2 resulted in significantly higher values of the comet parameters in the insects from all the study sites with the highest ones observed in the offspring of grasshoppers from Szopienice. Moreover, DNA repair, following the treatment, did not occur in the latter group. These data contribute to almost unexplored subject of genotoxic effects of environmental pollutants in insects. They are discussed in the light of the concept of adaptive strategies in energy allocation depending on the level of biotope pollution.

  6. Differential response of tomato genotypes to Xanthomonas-specific pathogen-associated molecular patterns and correlation with bacterial spot (Xanthomonas perforans) resistance

    PubMed Central

    Bhattarai, Krishna; Louws, Frank J; Williamson, John D; Panthee, Dilip R

    2016-01-01

    Plants depend on innate immune responses to retard the initial spread of pathogens entering through stomata, hydathodes or injuries. These responses are triggered by conserved patterns in pathogen-encoded molecules known as pathogen-associated molecular patterns (PAMPs). Production of reactive oxygen species (ROS) is one of the first responses, and the resulting ‘oxidative burst’ is considered to be a first line of defense. In this study, we conducted association analyses between ROS production and bacterial spot (BS; Xanthomonas spp.) resistance in 63 genotypes of tomato (Solanum lycopersicum L.). A luminol-based assay was performed on leaf tissues that had been treated with a flagellin 22 (flg22), flagellin 28 and a Xanthomonas-specific flg22 (flg22-Xac) peptide, to measure PAMP-induced ROS production in each genotype. These genotypes were also assessed for BS disease response by inoculation with Xanthomonas perforans, race T4. Although there was no consistent relationship between peptides used and host response to the BS, there was a significant negative correlation (r=−0.25, P<0.05) between foliar disease severity and ROS production, when flg22-Xac was used. This response could potentially be used to identify the Xanthomonas-specific PRR allele in tomato, and eventually PAMP-triggered immunity loci could be mapped in a segregating population. This has potential significance in tomato improvement. PMID:27555919

  7. Differential response of tomato genotypes to Xanthomonas-specific pathogen-associated molecular patterns and correlation with bacterial spot (Xanthomonas perforans) resistance.

    PubMed

    Bhattarai, Krishna; Louws, Frank J; Williamson, John D; Panthee, Dilip R

    2016-01-01

    Plants depend on innate immune responses to retard the initial spread of pathogens entering through stomata, hydathodes or injuries. These responses are triggered by conserved patterns in pathogen-encoded molecules known as pathogen-associated molecular patterns (PAMPs). Production of reactive oxygen species (ROS) is one of the first responses, and the resulting 'oxidative burst' is considered to be a first line of defense. In this study, we conducted association analyses between ROS production and bacterial spot (BS; Xanthomonas spp.) resistance in 63 genotypes of tomato (Solanum lycopersicum L.). A luminol-based assay was performed on leaf tissues that had been treated with a flagellin 22 (flg22), flagellin 28 and a Xanthomonas-specific flg22 (flg22-Xac) peptide, to measure PAMP-induced ROS production in each genotype. These genotypes were also assessed for BS disease response by inoculation with Xanthomonas perforans, race T4. Although there was no consistent relationship between peptides used and host response to the BS, there was a significant negative correlation (r=-0.25, P<0.05) between foliar disease severity and ROS production, when flg22-Xac was used. This response could potentially be used to identify the Xanthomonas-specific PRR allele in tomato, and eventually PAMP-triggered immunity loci could be mapped in a segregating population. This has potential significance in tomato improvement. PMID:27555919

  8. Aspects of lipid oxidation of meat from free-range broilers consuming a diet containing grasshoppers on alpine steppe of the Tibetan Plateau.

    PubMed

    Sun, T; Long, R J; Liu, Z Y; Ding, W R; Zhang, Y

    2012-01-01

    The objective of this study was to evaluate the characteristics of lipid oxidation in the meat of free-range broilers feeding on grasshoppers in alpine rangeland on the Tibetan Plateau. Eighty 28-d-old Qinjiaoma male broilers were introduced into a rangeland where there was a dense population of grasshoppers (PB). Control birds were reared under intensive conditions and given a maize-soybean diet. At 91 d of age, 24 birds from each treatment were slaughtered. Fresh breast and thigh meats were packaged and refrigerated for determination. The results indicate that rearing conditions, which included a diet rich in grasshoppers for PB broilers, significantly (P < 0.05) affected α-tocopherol content, total iron, heme iron, and nonheme iron content in the muscle of both the breast and leg. Rearing system and diet also had an important effect on antioxidant activity and lipid oxidation during refrigerated storage. This influence changed with storage time between different tissues. The activities of glutathione peroxidase and superoxide dismutase in the muscle of chicken breasts or legs from PB broilers were significantly (P < 0.05) higher than those from the controls, but no significant (P > 0.05) differences were found for the activities of catalase between the PB broilers and the controls. In conclusion, the meat in free-range broilers feeding on grasshoppers has more antioxidative potential and longer storage life.

  9. The Grasshopper and the Taxonomer. Use of Song and Structure in Orthoptera Saltatoria for Teaching the Principles of Taxonomy. Part 1. Field and Laboratory Exercises

    ERIC Educational Resources Information Center

    Broughton, W. B.

    1972-01-01

    Describes the coordinated study of European grasshoppers as living specimens in the field and as permanent laboratory preparations for introducing taxonomic principles. Provides details for the preparation of specimens and sample instructions provided to students. Part I of a three-part series. (AL)

  10. Neurochemical Architecture of the Central Complex Related to Its Function in the Control of Grasshopper Acoustic Communication

    PubMed Central

    Kunst, Michael; Pförtner, Ramona; Aschenbrenner, Katja; Heinrich, Ralf

    2011-01-01

    The central complex selects and coordinates the species- and situation-specific song production in acoustically communicating grasshoppers. Control of sound production is mediated by several neurotransmitters and modulators, their receptors and intracellular signaling pathways. It has previously been shown that muscarinic cholinergic excitation in the central complex promotes sound production whereas both GABA and nitric oxide/cyclic GMP signaling suppress its performance. The present immunocytochemical and pharmacological study investigates the question whether GABA and nitric oxide mediate inhibition of sound production independently. Muscarinic ACh receptors are expressed by columnar output neurons of the central complex that innervate the lower division of the central body and terminate in the lateral accessory lobes. GABAergic tangential neurons that innervate the lower division of the central body arborize in close proximity of columnar neurons and thus may directly inhibit these central complex output neurons. A subset of these GABAergic tangential neurons accumulates cyclic GMP following the release of nitric oxide from neurites in the upper division of the central body. While sound production stimulated by muscarine injection into the central complex is suppressed by co-application of sodium nitroprusside, picrotoxin-stimulated singing was not affected by co-application of this nitric oxide donor, indicating that nitric oxide mediated inhibition requires functional GABA signaling. Hence, grasshopper sound production is controlled by processing of information in the lower division of the central body which is subject to modulation by nitric oxide released from neurons in the upper division. PMID:21980504

  11. Turn the temperature to turquoise: cues for colour change in the male chameleon grasshopper (Kosciuscola tristis) (Orthoptera: Acrididae).

    PubMed

    Umbers, Kate D L

    2011-09-01

    Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis. PMID:21708162

  12. Turn the temperature to turquoise: cues for colour change in the male chameleon grasshopper (Kosciuscola tristis) (Orthoptera: Acrididae).

    PubMed

    Umbers, Kate D L

    2011-09-01

    Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis.

  13. Detection of differential host susceptibility to the marine oomycete pathogen Eurychasma dicksonii by real-time PCR: not all algae are equal.

    PubMed

    Gachon, Claire M M; Strittmatter, Martina; Müller, Dieter G; Kleinteich, Julia; Küpper, Frithjof C

    2009-01-01

    In the marine environment, a growing body of evidence points to parasites as key players in the control of population dynamics and overall ecosystem structure. However, their prevalence and impact on marine macroalgal communities remain virtually unknown. Indeed, infectious diseases of seaweeds are largely underdocumented, partly because of the expertise required to diagnose them with a microscope. Over the last few years, however, real-time quantitative PCR (qPCR) has emerged as a rapid and reliable alternative to visual symptom scoring for monitoring pathogens. Thus, we present here a qPCR assay suitable for the detection and quantification of the intracellular oomycete pathogen Eurychasma dicksonii in its ectocarpalean and laminarialean brown algal hosts. qPCR and microscopic observations made of laboratory-controlled cultures revealed that clonal brown algal strains exhibit different levels of resistance against Eurychasma, ranging from high susceptibility to complete absence of symptoms. This observation strongly argues for the existence of a genetic determinism for disease resistance in brown algae, which would have broad implications for the dynamics and genetic structure of natural populations. We also used qPCR for the rapid detection of Eurychasma in filamentous brown algae collected in Northern Europe and South America and found that the assay is specific, robust, and widely applicable to field samples. Hence, this study opens the perspective of combining large-scale disease monitoring in the field with laboratory-controlled experiments on the genome model seaweed Ectocarpus siliculosus to improve our understanding of brown algal diseases.

  14. Differentiation of pulmonary bacterial pathogens in cystic fibrosis by volatile metabolites emitted by their in vitro cultures: Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia and the Burkholderia cepacia complex.

    PubMed

    Dryahina, Kseniya; Sovová, Kristýna; Nemec, Alexandr; Španěl, Patrik

    2016-01-01

    As a contribution to the continuing search for breath biomarkers of lung and airways infection in patients with cystic fibrosis, CF, we have analysed the volatile metabolites released in vitro by Pseudomonas aeruginosa and other bacteria involved in respiratory infections in these patients, i.e. those belonging to the Burkholderia cepacia complex, Staphylococcus aureus or Stenotrophomonas maltophilia. These opportunistic pathogens are generally harmless to healthy people but they may cause serious infections in patients with severe underlying disease or impaired immunity such as CF patients. Volatile organic compounds emitted from the cultures of strains belonging to the above-mentioned four taxa were analysed by selected ion flow tube mass spectrometry. In order to minimize the effect of differences in media composition all strains were cultured in three different liquid media. Multivariate statistical analysis reveals that the four taxa can be well discriminated by the differences in the headspace VOC concentration profiles. The compounds that should be targeted in breath as potential biomarkers of airway infection were identified for each of these taxa of CF pathogens. PMID:27506232

  15. Differential effect of immune cells on non-pathogenic Gram-negative bacteria-induced nuclear factor-κB activation and pro-inflammatory gene expression in intestinal epithelial cells

    PubMed Central

    Haller, D; Holt, L; Parlesak, A; Zanga, J; Bäuerlein, A; Sartor, R B; Jobin, C

    2004-01-01

    We have previously shown that non-pathogenic Gram negative bacteria induce RelA phosphorylation, nuclear factor (NF)-κB transcriptional activity and pro-inflammatory gene expression in intestinal epithelial cells (IEC) in vivo and in vitro. In this study, we investigated the molecular mechanism of immune-epithelial cell cross-talk on Gram-negative enteric bacteria-induced NF-κB signalling and pro-inflammatory gene expression in IEC using HT-29/MTX as well as CaCO-2 transwell cultures Interestingly, while differentiated HT-29/MTX cells are unresponsive to non-pathogenic Gram negative bacterial stimulation, interleukin-8 (IL-8) mRNA accumulation is strongly induced in Escherichia coli- but not Bacteroides vulgatus-stimulated IEC cocultured with peripheral blood (PBMC) and lamina propria mononuclear cells (LPMC). The presence of PBMC triggered both E. coli- and B. vulgatus-induced mRNA expression of the Toll-like receptor-4 accessory protein MD-2 as well as endogenous IκBα phosphorylation, demonstrating similar capabilities of these bacteria to induce proximal NF-κB signalling. However, B. vulgatus failed to trigger IκBα degradation and NF-κB transcriptional activity in the presence of PBMC. Interestingly, B. vulgatus- and E. coli-derived lipopolysaccharide-induced similar IL-8 mRNA expression in epithelial cells after basolateral stimulation of HT-29/PBMC cocultures. Although luminal enteric bacteria have adjuvant and antigenic properties in chronic intestinal inflammation, PBMC from patients with active ulcerative colitis and Crohn's disease differentially trigger epithelial cell activation in response to E. coli and E. coli-derived LPS. In conclusion, this study provides evidence for a differential regulation of non-pathogenic Gram-negative bacteria-induced NF-κB signalling and IL-8 gene expression in IEC cocultured with immune cells and suggests the presence of mechanisms that assure hyporesponsiveness of the intestinal epithelium to certain commensally

  16. Coevolution of color pattern and thermoregulatory behavior in polymorphic pygmy grasshoppers Tetrix undulata.

    PubMed

    Forsman, Anders; Ringblom, Karin; Civantos, Emilio; Ahnesjö, Jonas

    2002-02-01

    Ectothermic organisms, such as insects and reptiles, rely on external heat sources to control body temperature and possess physiological and behavioral traits that are temperature dependent. It has therefore been hypothesised that differences in body temperature resulting from phenotypic properties, such as color pattern, may translate into selection against thermally inferior phenotypes. We tested for costs and benefits of pale versus dark coloration by comparing the behaviors (i.e., basking duration and bouts) of pygmy grasshopper (Tetrix undulata) individuals exposed to experimental situations imposing a trade-off between temperature regulation and feeding. We used pairs consisting of two full-siblings of the same sex that represented different (genetically coded) color morphs but had shared identical conditions from the time of fertilization. Our results revealed significant differences in behavioral thermoregulation between dark and pale individuals in females, but not in males. Pale females spent more time feeding than dark females, regardless of whether feeding was associated with a risk of either hypothermia or overheating. In contrast, only minor differences in behavior (if any) were evident between individuals that belonged to the same color morph but had been painted black or gray to increase and decrease their heating rates. This suggests that the behavioral differences between individuals belonging to different color morphs are genetically determined, rather than simply reflecting a response to different heating rates. To test for effects of acclimation on behaviors, we used pairs of individuals that had been reared from hatchlings to adults under controlled conditions in either low or high temperature. The thermal regime experienced during rearing had little effect on behaviors during the experiments reported above, but significantly influenced the body temperatures selected in a laboratory thermal gradient. In females (but not in males) preferred

  17. The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum.

    PubMed

    Salas-Marina, Miguel A; Isordia-Jasso, María I; Islas-Osuna, María A; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F; Rodríguez-Kessler, Margarita; Rosales-Saavedra, María T; Herrera-Estrella, Alfredo; Casas-Flores, Sergio

    2015-01-01

    Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought. PMID:25755658

  18. The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum

    PubMed Central

    Salas-Marina, Miguel A.; Isordia-Jasso, María I.; Islas-Osuna, María A.; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F.; Rodríguez-Kessler, Margarita; Rosales-Saavedra, María T.; Herrera-Estrella, Alfredo; Casas-Flores, Sergio

    2015-01-01

    Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought. PMID:25755658

  19. The Epl1 and Sm1 proteins from Trichoderma atroviride and Trichoderma virens differentially modulate systemic disease resistance against different life style pathogens in Solanum lycopersicum.

    PubMed

    Salas-Marina, Miguel A; Isordia-Jasso, María I; Islas-Osuna, María A; Delgado-Sánchez, Pablo; Jiménez-Bremont, Juan F; Rodríguez-Kessler, Margarita; Rosales-Saavedra, María T; Herrera-Estrella, Alfredo; Casas-Flores, Sergio

    2015-01-01

    Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum) plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000). Deletion (KO) of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, overexpression (OE) of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR)- and induced systemic resistance (ISR)-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought.

  20. Pathogen intelligence.

    PubMed

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  1. Pathogen intelligence

    PubMed Central

    Steinert, Michael

    2014-01-01

    Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

  2. The grapevine flagellin receptor VvFLS2 differentially recognizes flagellin-derived epitopes from the endophytic growth-promoting bacterium Burkholderia phytofirmans and plant pathogenic bacteria.

    PubMed

    Trdá, Lucie; Fernandez, Olivier; Boutrot, Freddy; Héloir, Marie-Claire; Kelloniemi, Jani; Daire, Xavier; Adrian, Marielle; Clément, Christophe; Zipfel, Cyril; Dorey, Stéphan; Poinssot, Benoit

    2014-03-01

    • The role of flagellin perception in the context of plant beneficial bacteria still remains unclear. Here, we characterized the flagellin sensing system flg22-FLAGELLIN SENSING 2 (FLS2) in grapevine, and analyzed the flagellin perception in the interaction with the endophytic plant growth-promoting rhizobacterium (PGPR) Burkholderia phytofirmans. • The functionality of the grapevine FLS2 receptor, VvFLS2, was demonstrated by complementation assays in the Arabidopsis thaliana fls2 mutant, which restored flg22-induced H₂O₂ production and growth inhibition. Using synthetic flg22 peptides from different bacterial origins, we compared recognition specificities between VvFLS2 and AtFLS2. • In grapevine, flg22-triggered immune responses are conserved and led to partial resistance against Botrytis cinerea. Unlike flg22 peptides derived from Pseudomonas aeruginosa or Xanthomonas campestris, flg22 peptide derived from B. phytofirmans triggered only a small oxidative burst, weak and transient defense gene induction and no growth inhibition in grapevine. Although, in Arabidopsis, all the flg22 epitopes exhibited similar biological activities, the expression of VvFLS2 into the fls2 background conferred differential flg22 responses characteristic for grapevine. • These results demonstrate that VvFLS2 differentially recognizes flg22 from different bacteria, and suggest that flagellin from the beneficial PGPR B. phytofirmans has evolved to evade this grapevine immune recognition system. PMID:24491115

  3. Lazarillo, a new GPI-linked surface lipocalin, is restricted to a subset of neurons in the grasshopper embryo.

    PubMed

    Ganfornina, M D; Sánchez, D; Bastiani, M J

    1995-01-01

    Lazarillo, a protein recognized by the monoclonal antibody 10E6, is expressed by a subset of neurons in the developing nervous system of the grasshopper. It is a glycoprotein of 45x10(3) M(r) with internal disulfide bonds and linked to the extracellular side of the plasma membrane by a glycosylphosphatidylinositol moiety. Peptide sequences obtained from affinity purified adult protein were used to identify an embryonic cDNA clone, and in situ hybridizations confirmed that the distribution of the Lazarillo mRNA paralleled that of the monoclonal antibody labeling on embryos. Sequence analysis defines Lazarillo as a member of the lipocalin family, extracellular carriers of small hydrophobic ligands, and most related to the porphyrin- and retinol-binding lipocalins. Lazarillo is the first example of a lipocalin anchored to the plasma membrane, highly glycosylated, and restricted to a subset of developing neurons.

  4. The attractiveness fragment—AFLP analysis of local adaptation and sexual selection in a caeliferan grasshopper, Chorthippus biguttulus

    NASA Astrophysics Data System (ADS)

    Klappert, Kirsten; Butlin, Roger K.; Reinhold, Klaus

    2007-08-01

    Genetic variability among males is a necessary precondition for the evolution of female choice based on indirect genetic benefits. In addition to mutations and host parasite cycles, migration of locally adapted individuals offers an explanation for the maintenance of genetic variability. In a previous study, conducting a reciprocal transplant experiment on a grasshopper, Chorthippus biguttulus, we found that environmental conditions significantly influenced not only body condition but also an important trait of male calling song, the amplitude of song. Although not significant, all other analysed physical and courtship song traits and attractiveness were superior in native than in transferred males. Thus, we concluded that local adaptation has a slight but consistent influence on a range of traits in our study populations, including male acoustic attractiveness. In our present study, we scanned male grasshoppers from the same two populations for amplification fragment length polymorphism (AFLP) loci connected with acoustic attractiveness to conspecific females. We found greater differences in allele frequencies between the two populations, for some loci, than are expected from a balance between drift and gene flow. These loci are potentially connected with locally adapted traits. We examined whether these alleles show the proposed genotype environment interaction by having different associations with attractiveness in the two populations. One locus was significantly related to sexual attractiveness; however, this was independent of the males’ population affiliation. Future research on the evolution of female choice will benefit from knowledge of the underlying genetic architecture of male traits under intraspecific sexual selection, and the ‘population genomics’ approach can be a powerful tool for revealing this structure.

  5. Molecular evidence for an old world origin of Galapagos and Caribbean band-winged grasshoppers (Acrididae: Oedipodinae: Sphingonotus).

    PubMed

    Husemann, Martin; Habel, Jan Christian; Namkung, Suk; Hochkirch, Axel; Otte, Daniel; Danley, Patrick D

    2015-01-01

    Patterns of colonization and diversification on islands provide valuable insights into evolutionary processes. Due to their unique geographic position and well known history, the Galapagos Islands are an important model system for evolutionary studies. Here we investigate the evolutionary history of a winged grasshopper genus to infer its origin and pattern of colonization in the Galapagos archipelago. The grasshopper genus Sphingonotus has radiated extensively in the Palaearctic and many species are endemic to islands. In the New World, the genus is largely replaced by the genus Trimerotropis. Oddly, in the Caribbean and on the Galapagos archipelago, two species of Sphingonotus are found, which has led to the suggestion that these might be the result of anthropogenic translocations from Europe. Here, we test this hypothesis using mitochondrial and nuclear DNA sequences from a broad sample of Sphingonotini and Trimerotropini species from the Old World and New World. The genetic data show two distinct genetic clusters representing the New World Trimerotropini and the Old World Sphingonotini. However, the Sphingonotus species from Galapagos and the Caribbean split basally within the Old World Sphingonotini lineage. The Galapagos and Caribbean species appear to be related to Old World taxa, but are not the result of recent anthropogenic translocations as revealed by divergence time estimates. Distinct genetic lineages occur on the four investigated Galapagos Islands, with deep splits among them compared to their relatives from the Palaearctic. A scenario of a past wider distribution of Sphingonotus in the New World with subsequent extinction on the mainland and replacement by Trimerotropis might explain the disjunct distribution.

  6. Influence of Different Envelope Maskers on Signal Recognition and Neuronal Representation in the Auditory System of a Grasshopper

    PubMed Central

    Neuhofer, Daniela; Ronacher, Bernhard

    2012-01-01

    Background Animals that communicate by sound face the problem that the signals arriving at the receiver often are degraded and masked by noise. Frequency filters in the receiver's auditory system may improve the signal-to-noise ratio (SNR) by excluding parts of the spectrum which are not occupied by the species-specific signals. This solution, however, is hardly amenable to species that produce broad band signals or have ears with broad frequency tuning. In mammals auditory filters exist that work in the temporal domain of amplitude modulations (AM). Do insects also use this type of filtering? Principal Findings Combining behavioural and neurophysiological experiments we investigated whether AM filters may improve the recognition of masked communication signals in grasshoppers. The AM pattern of the sound, its envelope, is crucial for signal recognition in these animals. We degraded the species-specific song by adding random fluctuations to its envelope. Six noise bands were used that differed in their overlap with the spectral content of the song envelope. If AM filters contribute to reduced masking, signal recognition should depend on the degree of overlap between the song envelope spectrum and the noise spectra. Contrary to this prediction, the resistance against signal degradation was the same for five of six masker bands. Most remarkably, the band with the strongest frequency overlap to the natural song envelope (0–100 Hz) impaired acceptance of degraded signals the least. To assess the noise filter capacities of single auditory neurons, the changes of spike trains as a function of the masking level were assessed. Increasing levels of signal degradation in different frequency bands led to similar changes in the spike trains in most neurones. Conclusions There is no indication that auditory neurones of grasshoppers are specialized to improve the SNR with respect to the pattern of amplitude modulations. PMID:22479619

  7. Molecular Evidence for an Old World Origin of Galapagos and Caribbean Band-Winged Grasshoppers (Acrididae: Oedipodinae: Sphingonotus)

    PubMed Central

    Husemann, Martin; Habel, Jan Christian; Namkung, Suk; Hochkirch, Axel; Otte, Daniel; Danley, Patrick D.

    2015-01-01

    Patterns of colonization and diversification on islands provide valuable insights into evolutionary processes. Due to their unique geographic position and well known history, the Galapagos Islands are an important model system for evolutionary studies. Here we investigate the evolutionary history of a winged grasshopper genus to infer its origin and pattern of colonization in the Galapagos archipelago. The grasshopper genus Sphingonotus has radiated extensively in the Palaearctic and many species are endemic to islands. In the New World, the genus is largely replaced by the genus Trimerotropis. Oddly, in the Caribbean and on the Galapagos archipelago, two species of Sphingonotus are found, which has led to the suggestion that these might be the result of anthropogenic translocations from Europe. Here, we test this hypothesis using mitochondrial and nuclear DNA sequences from a broad sample of Sphingonotini and Trimerotropini species from the Old World and New World. The genetic data show two distinct genetic clusters representing the New World Trimerotropini and the Old World Sphingonotini. However, the Sphingonotus species from Galapagos and the Caribbean split basally within the Old World Sphingonotini lineage. The Galapagos and Caribbean species appear to be related to Old World taxa, but are not the result of recent anthropogenic translocations as revealed by divergence time estimates. Distinct genetic lineages occur on the four investigated Galapagos Islands, with deep splits among them compared to their relatives from the Palaearctic. A scenario of a past wider distribution of Sphingonotus in the New World with subsequent extinction on the mainland and replacement by Trimerotropis might explain the disjunct distribution. PMID:25692768

  8. Assessing the effects of light on differentiation and virulence of the plant pathogen Botrytis cinerea: characterization of the White Collar Complex.

    PubMed

    Canessa, Paulo; Schumacher, Julia; Hevia, Montserrat A; Tudzynski, Paul; Larrondo, Luis F

    2013-01-01

    Organisms are exposed to a tough environment, where acute daily challenges, like light, can strongly affect several aspects of an individual's physiology, including pathogenesis. While several fungal models have been widely employed to understand the physiological and molecular events associated with light perception, various other agricultural-relevant fungi still remain, in terms of their responsiveness to light, in the dark. The fungus Botrytis cinerea is an aggressive pathogen able to cause disease on a wide range of plant species. Natural B. cinerea isolates exhibit a high degree of diversity in their predominant mode of reproduction. Thus, the majority of naturally occurring strains are known to reproduce asexually via conidia and sclerotia, and sexually via apothecia. Studies from the 1970's reported on specific developmental responses to treatments with near-UV, blue, red and far-red light. To unravel the signaling machinery triggering development--and possibly also connected with virulence--we initiated the functional characterization of the transcription factor/photoreceptor BcWCL1 and its partner BcWCL2, that form the White Collar Complex (WCC) in B. cinerea. Using mutants either abolished in or exhibiting enhanced WCC signaling (overexpression of both bcwcl1 and bcwcl2), we demonstrate that the WCC is an integral part of the mentioned machinery by mediating transcriptional responses to white light and the inhibition of conidiation in response to this stimulus. Furthermore, the WCC is required for coping with excessive light, oxidative stress and also to achieve full virulence. Although several transcriptional responses are abolished in the absence of bcwcl1, the expression of some genes is still light induced and a distinct conidiation pattern in response to daily light oscillations is enhanced, revealing a complex underlying photobiology. Though overlaps with well-studied fungal systems exist, the light-associated machinery of B. cinerea appears more

  9. The mitogen-activated protein kinase kinase kinase BcOs4 is required for vegetative differentiation and pathogenicity in Botrytis cinerea.

    PubMed

    Yang, Qianqian; Yan, Leiyan; Gu, Qin; Ma, Zhonghua

    2012-10-01

    The high-osmolarity glycerol signal pathway plays an important role in the response of fungi to various environmental stresses. In this study, we characterized a mitogen-activated protein kinase kinase kinase gene BcOS4 in Botrytis cinerea, which is homologous to Saccharomyces cerevisiae SSK2/SSK22. The BcOS4 deletion mutant was significantly impaired in vegetative growth and conidial formation. The mutant exhibited increased sensitivity to the osmotic, oxidative stresses and to the fungicides iprodione and fludioxonil. Western blot analysis showed that BcSak1, a putative downstream component of BcOs4, was not phosphorylated in the mutant. In addition, the BcOS4 mutant was unable to infect leaves of rapeseed and cucumber, and grape fruits, although it can cause disease on apple fruits. All the defects were restored by genetic complementation of the BcOS4 deletion mutant with the wild-type BcOS4 gene. The data of this study indicate that BcOS4 is involved in vegetative differentiation, virulence, adaption to hyperosmotic and oxidative stresses, and to fungicides in B. cinerea.

  10. Genome-wide analysis and differential expression of chitinases in banana against root lesion nematode (Pratylenchus coffeae) and eumusa leaf spot (Mycosphaerella eumusae) pathogens.

    PubMed

    Backiyarani, S; Uma, S; Nithya, S; Chandrasekar, A; Saraswathi, M S; Thangavelu, R; Mayilvaganan, M; Sundararaju, P; Singh, N K

    2015-04-01

    Knowledge on structure and conserved domain of Musa chitinase isoforms and their responses to various biotic stresses will give a lead to select the suitable chitinase isoform for developing biotic stress-resistant genotypes. Hence, in this study, chitinase sequences available in the Musa genome hub were analyzed for their gene structure, conserved domain, as well as intron and exon regions. To identify the Musa chitinase isoforms involved in Pratylenchus coffeae (root lesion nematode) and Mycosphaerella eumusae (eumusa leaf spot) resistant mechanisms, differential gene expression analysis was carried out in P. coffeae- and M. eumusae-challenged resistant and susceptible banana genotypes. This study revealed that more number of chitinase isoforms (CIs) were responses upon eumusa leaf spot stress than nematode stress. The nematode challenge studies revealed that class II chitinase (GSMUA_Achr9G16770_001) was significantly overexpressed with 6.75-fold (with high fragments per kilobase of exon per million fragments mapped (FPKM)) in resistant genotype (Karthobiumtham-ABB) than susceptible (Nendran-AAB) genotype, whereas when M. eumusae was challenge inoculated, two class III CIs (GSMUA_Achr9G25580_001 and GSMUA_Achr8G27880_001) were overexpressed in resistant genotype (Manoranjitham-AAA) than the susceptible genotype (Grand Naine-AAA). However, none of the CIs were found to be commonly overexpressed under both stress conditions. This study reiterated that the chitinase genes are responding differently to different biotic stresses in their respective resistant genotypes.

  11. Comment on Schielzeth et al. (2014): "Genome size variation affects song attractiveness in grasshoppers: Evidence for sexual selection against large genomes".

    PubMed

    Camacho, Juan Pedro M

    2016-06-01

    Schielzeth et al. (2014) concluded that attractive grasshopper singers have significantly smaller genomes thus suggesting a possible role for sexual selection on genome size. Whereas this conclusion could still be conceivably valid, it is not supported by the data presented due to some technical flaws. In addition, the interpretation of the results, speculating on the possible presence of B chromosomes, is not justified. PMID:27327141

  12. Gas-liquid chromatographic and gas-liquid-mass spectometric determination of fenvalerate and permethrin residues in grasshoppers and duck tissue samples

    USGS Publications Warehouse

    Reichel, W.L.; Kolbe, E.J.; Stafford, C.J.

    1981-01-01

    A procedure is described for determining fenvalerate and permethrin residues in grasshoppers and duck tissues. Samples are Soxhlet-extracted with hexane and cleaned up by gel permeation chromatography with an in-line alumina column. Samples are analyzed by gas-liquid chromatography with electron capture detection, and confirmed by gas-liquid chromatography-mass spectrometry. The average recovery from fortified tissues was 97%.

  13. Rapid detection and differentiation of Gram-negative and Gram-positive pathogenic bacteria in urine using TaqMan probe.

    PubMed

    Shigemura, K; Shirakawa, T; Okada, H; Tanaka, K; Kamidono, S; Arakawa, S; Gotoh, A

    2005-03-01

    Urinary tract infection has been shown to be quite complicated and often difficult to diagnose and treat. For appropriate diagnosis, it is very important to find the correct Gram stain classification as soon as possible, especially in severe cases where there is a possibility of severe sepsis developing. In order to solve this problem, we developed a new method to detect a Gram stain of bacteria obtained from 1 ml of urine from urinary tract infection patients using a consensus real-time PCR protocol with a TaqMan probe that allows detection of spiked bacterial 16S DNA from urine. We extracted DNA of 55 urine samples obtained from patients with complicated urinary tract infection and at the same time performed urine culture testing. After DNA extraction, they were subjected to real-time PCR using a TaqMan discrimination system. Sixteen kinds of bacteria were cultured from the urine culture testing. Of these bacteria, eight were classified as Gram-positive bacteria and the other eight were classified as Gram-negative bacteria. Of the 55 samples, the TaqMan technique result showed 27 samples that were classified as Gram-negative bacteria; 11 samples that were Gram-positive, 10 that included both Gram-negative and -positive bacteria, and 7 that showed no amplification. The classifications of all samples corresponded exactly to those determined by urine culture testing. The present genotyping method of real-time PCR using a TaqMan discrimination system could be applied to the rapid detection of Gram-positive or -negative bacteria in urine of urinary tract infection patients. This assay can differentiate those species tested, but whether the presence of other (untested) bacteria could lead to misinterpretation is unknown. For further investigation, it is important to test other (untested) bacteria in the near future.

  14. Rapid detection and differentiation of Gram-negative and Gram-positive pathogenic bacteria in urine using TaqMan probe.

    PubMed

    Shigemura, K; Shirakawa, T; Okada, H; Tanaka, K; Kamidono, S; Arakawa, S; Gotoh, A

    2005-03-01

    Urinary tract infection has been shown to be quite complicated and often difficult to diagnose and treat. For appropriate diagnosis, it is very important to find the correct Gram stain classification as soon as possible, especially in severe cases where there is a possibility of severe sepsis developing. In order to solve this problem, we developed a new method to detect a Gram stain of bacteria obtained from 1 ml of urine from urinary tract infection patients using a consensus real-time PCR protocol with a TaqMan probe that allows detection of spiked bacterial 16S DNA from urine. We extracted DNA of 55 urine samples obtained from patients with complicated urinary tract infection and at the same time performed urine culture testing. After DNA extraction, they were subjected to real-time PCR using a TaqMan discrimination system. Sixteen kinds of bacteria were cultured from the urine culture testing. Of these bacteria, eight were classified as Gram-positive bacteria and the other eight were classified as Gram-negative bacteria. Of the 55 samples, the TaqMan technique result showed 27 samples that were classified as Gram-negative bacteria; 11 samples that were Gram-positive, 10 that included both Gram-negative and -positive bacteria, and 7 that showed no amplification. The classifications of all samples corresponded exactly to those determined by urine culture testing. The present genotyping method of real-time PCR using a TaqMan discrimination system could be applied to the rapid detection of Gram-positive or -negative bacteria in urine of urinary tract infection patients. This assay can differentiate those species tested, but whether the presence of other (untested) bacteria could lead to misinterpretation is unknown. For further investigation, it is important to test other (untested) bacteria in the near future. PMID:15750767

  15. Activation‐Induced Killer Cell Immunoglobulin‐like Receptor 3DL2 Binding to HLA–B27 Licenses Pathogenic T Cell Differentiation in Spondyloarthritis

    PubMed Central

    Ridley, Anna; Hatano, Hiroko; Wong‐Baeza, Isabel; Shaw, Jacqueline; Matthews, Katherine K.; Al‐Mossawi, Hussein; Ladell, Kristin; Price, David A.; Bowness, Paul

    2016-01-01

    Objective In the spondyloarthritides (SpA), increased numbers of CD4+ T cells express killer cell immunoglobulin‐like receptor 3DL2 (KIR‐3DL2). The aim of this study was to determine the factors that induce KIR‐3DL2 expression, and to characterize the relationship between HLA–B27 and the phenotype and function of KIR‐3DL2–expressing CD4+ T cells in SpA. Methods In total, 34 B27+ patients with SpA, 28 age‐ and sex‐matched healthy controls (20 B27− and 8 B27+), and 9 patients with rheumatoid arthritis were studied. KIR-3DL2 expression and other phenotypic characteristics of peripheral blood and synovial fluid CD4+ T cells were studied by flow cytometry, quantitative polymerase chain reaction, and Western blotting. T cell receptor clonality was determined by template‐switch anchored reverse transcription–polymerase chain reaction and sequencing analysis. Cytokines were measured by enzyme‐linked immunosorbent assay. Results Cellular activation induced KIR‐3DL2 expression on both naive and effector CD4+ T cells. KIR‐3DL2 binding to B27+ cells promoted expression of KIR‐3DL2, the Th17‐specific transcription factor retinoic acid receptor–related orphan nuclear receptor γt, and the antiapoptotic factor B cell lymphoma 2. KIR‐3DL2+CD4+ T cells in patients with ankylosing spondylitis were oligoclonal and enriched for markers of T cell activation and for the gut homing receptor CCR9. In the presence of B27+ antigen‐presenting cells, KIR‐3DL2+CD4+ T cells produced less interleukin‐2 (IL‐2) but more IL‐17. This effect was blocked by HC10, an antibody that inhibits the binding of KIR‐3DL2 to B27 heavy chains. Conclusion KIR‐3DL2 binding to HLA–B27 licenses Th17 cell differentiation in SpA. These findings raise the therapeutic potential of targeting HLA–B27–KIR‐3DL2 interactions for the treatment of B27+ patients with SpA. PMID:26841353

  16. Differential effect of environmental conditions on the growth and regulation of the fumonisin biosynthetic gene FUM1 in the maize pathogens and fumonisin producers Fusarium verticillioides and Fusarium proliferatum.

    PubMed

    Marín, Patricia; Magan, Naresh; Vázquez, Covadonga; González-Jaén, María Teresa

    2010-08-01

    The effects of ecophysiological factors, temperature and solute potential, on both the growth and the regulation of the fumonisin biosynthetic FUM1 gene were studied and compared in one isolate each of the two closely related fumonisin-producing and maize pathogens Fusarium verticillioides and Fusarium proliferatum. The effect of solute potential and temperature was examined on in vitro mycelia growth and on the expression of the FUM1 gene, quantified by species-specific real-time reverse transcriptase-PCR assays. Although both isolates showed similar two-dimensional profiles of growth, for F. verticillioides, optimal growth conditions were maintained at higher temperatures and lower solute potential values. FUM1 gene expression was markedly induced at 20 degrees C in both isolates, under suboptimal conditions for growth; however, their expression patterns differed in relation to solute potential. Whereas FUM1 expression was induced in response to increasing water stress in the isolate of F. verticillioides, the F. proliferatum one showed a stable expression pattern regardless of water potential conditions. These results suggest a differential regulation of fumonisin biosynthesis in these isolates of the two species that might be related to their different host range, and play an ecological role. Additionally, environmental conditions leading to water stress (drought) might result in increased risk of fumonisin contamination of maize caused by F. verticillioides.

  17. Map kinases in fungal pathogens.

    PubMed

    Xu, J R

    2000-12-01

    MAP kinases in eukaryotic cells are well known for transducing a variety of extracellular signals to regulate cell growth and differentiation. Recently, MAP kinases homologous to the yeast Fus3/Kss1 MAP kinases have been identified in several fungal pathogens and found to be important for appressorium formation, invasive hyphal growth, and fungal pathogenesis. This MAP kinase pathway also controls diverse growth or differentiation processes, including conidiation, conidial germination, and female fertility. MAP kinases homologous to yeast Slt2 and Hog1 have also been characterized in Candida albicans and Magnaporthe grisea. Mutants disrupted of the Slt2 homologues have weak cell walls, altered hyphal growth, and reduced virulence. The Hog1 homologues are dispensable for growth but are essential for regulating responses to hyperosmotic stress in C. albicans and M. grisea. Overall, recent studies have indicated that MAP kinase pathways may play important roles in regulating growth, differentiation, survival, and pathogenesis in fungal pathogens. PMID:11273677

  18. Insertion of an esterase gene into a specific locust pathogen (Metarhizium acridum) enables it to infect caterpillars.

    PubMed

    Wang, Sibao; Fang, Weiguo; Wang, Chengshu; St Leger, Raymond J

    2011-06-01

    An enduring theme in pathogenic microbiology is poor understanding of the mechanisms of host specificity. Metarhizium is a cosmopolitan genus of invertebrate pathogens that contains generalist species with broad host ranges such as M. robertsii (formerly known as M. anisopliae var. anisopliae) as well as specialists such as the acridid-specific grasshopper pathogen M. acridum. During growth on caterpillar (Manduca sexta) cuticle, M. robertsii up-regulates a gene (Mest1) that is absent in M. acridum and most other fungi. Disrupting M. robertsii Mest1 reduced virulence and overexpression increased virulence to caterpillars (Galleria mellonella and M. sexta), while virulence to grasshoppers (Melanoplus femurrubrum) was unaffected. When Mest1 was transferred to M. acridum under control of its native M. robertsii promoter, the transformants killed and colonized caterpillars in a similar fashion to M. robertsii. MEST1 localized exclusively to lipid droplets in M. robertsii conidia and infection structures was up-regulated during nutrient deprivation and had esterase activity against lipids with short chain fatty acids. The mobilization of stored lipids was delayed in the Mest1 disruptant mutant. Overall, our results suggest that expression of Mest1 allows rapid hydrolysis of stored lipids, and promotes germination and infection structure formation by M. robertsii during nutrient deprivation and invasion, while Mest1 expression in M. acridum broadens its host range by bypassing the regulatory signals found on natural hosts that trigger the mobilization of endogenous nutrient reserves. This study suggests that speciation in an insect pathogen could potentially be driven by host shifts resulting from changes in a single gene.

  19. Insertion of an Esterase Gene into a Specific Locust Pathogen (Metarhizium acridum) Enables It to Infect Caterpillars

    PubMed Central

    Wang, Sibao; Fang, Weiguo; Wang, Chengshu; St. Leger, Raymond J.

    2011-01-01

    An enduring theme in pathogenic microbiology is poor understanding of the mechanisms of host specificity. Metarhizium is a cosmopolitan genus of invertebrate pathogens that contains generalist species with broad host ranges such as M. robertsii (formerly known as M. anisopliae var. anisopliae) as well as specialists such as the acridid-specific grasshopper pathogen M. acridum. During growth on caterpillar (Manduca sexta) cuticle, M. robertsii up-regulates a gene (Mest1) that is absent in M. acridum and most other fungi. Disrupting M. robertsii Mest1 reduced virulence and overexpression increased virulence to caterpillars (Galleria mellonella and M. sexta), while virulence to grasshoppers (Melanoplus femurrubrum) was unaffected. When Mest1 was transferred to M. acridum under control of its native M. robertsii promoter, the transformants killed and colonized caterpillars in a similar fashion to M. robertsii. MEST1 localized exclusively to lipid droplets in M. robertsii conidia and infection structures was up-regulated during nutrient deprivation and had esterase activity against lipids with short chain fatty acids. The mobilization of stored lipids was delayed in the Mest1 disruptant mutant. Overall, our results suggest that expression of Mest1 allows rapid hydrolysis of stored lipids, and promotes germination and infection structure formation by M. robertsii during nutrient deprivation and invasion, while Mest1 expression in M. acridum broadens its host range by bypassing the regulatory signals found on natural hosts that trigger the mobilization of endogenous nutrient reserves. This study suggests that speciation in an insect pathogen could potentially be driven by host shifts resulting from changes in a single gene. PMID:21731492

  20. Consequences of extensive habitat fragmentation in landscape-level patterns of genetic diversity and structure in the Mediterranean esparto grasshopper.

    PubMed

    Ortego, Joaquín; Aguirre, María P; Noguerales, Víctor; Cordero, Pedro J

    2015-07-01

    Anthropogenic habitat fragmentation has altered the distribution and population sizes in many organisms worldwide. For this reason, understanding the demographic and genetic consequences of this process is necessary to predict the fate of populations and establish management practices aimed to ensure their viability. In this study, we analyse whether the spatial configuration of remnant semi-natural habitat patches within a chronically fragmented landscape has shaped the patterns of genetic diversity and structure in the habitat-specialist esparto grasshopper (Ramburiella hispanica). In particular, we predict that agricultural lands constitute barriers to gene flow and hypothesize that fragmentation has restricted interpopulation dispersal and reduced local levels of genetic diversity. Our results confirmed the expectation that isolation and habitat fragmentation have reduced the genetic diversity of local populations. Landscape genetic analyses based on circuit theory showed that agricultural land offers ∽1000 times more resistance to gene flow than semi-natural habitats, indicating that patterns of dispersal are constrained by the spatial configuration of remnant patches of suitable habitat. Overall, this study shows that semi-natural habitat patches act as corridors for interpopulation gene flow and should be preserved due to the disproportionately large ecological function that they provide considering their insignificant area within these human-modified landscapes.

  1. Organization of some repetitive DNAs and B chromosomes in the grasshopper Eumastusia koebelei koebelei (Rehn, 1909) (Orthoptera, Acrididae, Leptysminae).

    PubMed

    Anjos, Allison; Loreto, Vilma; Cabral-de-Mello, Diogo C

    2016-01-01

    B chromosomes occur in approximately 15% of eukaryotes and are usually heterochromatic and rich in repetitive DNAs. Here we describe characteristics of a B chromosome in the grasshopper Eumastusia koebelei koebelei (Rehn, 1909) through classical cytogenetic methods and mapping of some repetitive DNAs, including multigene families, telomeric repeats and a DNA fraction enriched with repetitive DNAs obtained from DOP-PCR. Eumastusia koebelei koebelei presented 2n=23, X0 and, in one individual, two copies of the same variant of a B chromosome were noticed, which are associated during meiosis. The C-positive blocks were located in the pericentromeric regions of the standard complement and along the entire length of the B chromosomes. Some G+C-rich heterochromatic blocks were noticed, including conspicuous blocks in the B chromosomes. The mapping of 18S rDNA and U2 snDNA revealed only autosomal clusters, and the telomeric probe hybridized in terminal regions. Finally, the DOP-PCR probe obtained from an individual without a B chromosome revealed signals in the heterochromatic regions, including the entire length of the B chromosome. The possible intraspecific origin of the B chromosomes, due to the shared pool of repetitive DNAs between the A and B chromosomes and the possible consequences of their association are discussed. PMID:27551344

  2. Disparate molecular evolution of two types of repetitive DNAs in the genome of the grasshopper Eyprepocnemis plorans.

    PubMed

    Teruel, M; Ruíz-Ruano, F J; Marchal, J A; Sánchez, A; Cabrero, J; Camacho, J Pm; Perfectti, F

    2014-05-01

    Wide arrays of repetitive DNA sequences form an important part of eukaryotic genomes. These repeats appear to evolve as coherent families, where repeats within a family are more similar to each other than to other orthologous representatives in related species. The continuous homogenization of repeats, through selective and non-selective processes, is termed concerted evolution. Ascertaining the level of variation between repeats is crucial to determining which evolutionary model best explains the homogenization observed for these sequences. Here, for the grasshopper Eyprepocnemis plorans, we present the analysis of intragenomic diversity for two repetitive DNA sequences (a satellite DNA (satDNA) and the 45S rDNA) resulting from the independent microdissection of several chromosomes. Our results show different homogenization patterns for these two kinds of paralogous DNA sequences, with a high between-chromosome structure for rDNA but no structure at all for the satDNA. This difference is puzzling, considering the adjacent localization of the two repetitive DNAs on paracentromeric regions in most chromosomes. The disparate homogenization patterns detected for these two repetitive DNA sequences suggest that several processes participate in the concerted evolution in E. plorans, and that these mechanisms might not work as genome-wide processes but rather as sequence-specific ones.

  3. Sequence analyses of two neuropeptides of the AKH/RPCH-family from the lubber grasshopper, Romalea microptera.

    PubMed

    Gäde, G; Hilbich, C; Beyreuther, K; Rinehart, K L

    1988-01-01

    Two neuropeptides with adipokinetic activity in Locusta migratoria and hypertrehalosaemic activity in Periplaneta americana were purified by high-performance liquid chromatography from the corpus cardiacum of the lubber grasshopper, Romalea microptera. The sequences of both peptides, designated Ro I and Ro II, were determined by gas-phase sequencing employing Edman degradation after the N-terminal pyroglutamate residue was enzymatically deblocked, as well as by fast atom bombardment mass spectrometry. Ro I was found to be a decapeptide with the primary structure: pGlu-Val-Asn-Phe-Thr-Pro-Asn-Trp-Gly-Thr-NH2, whereas Ro II is an octapeptide with the structure: pGlu-Val-Asn-Phe-Ser-Thr-Gly-Trp-NH2. Ro II is identical with AKH-G isolated from the cricket Gryllus bimaculatus. Synthetic materials having the assigned structures were found to be chromatographically, mass spectrometrically, and biologically indistinguishable from the natural peptides, confirming the sequences and establishing the Romalea peptides as members of the AKH/RPCH-family of peptides. PMID:3226948

  4. Consequences of extensive habitat fragmentation in landscape-level patterns of genetic diversity and structure in the Mediterranean esparto grasshopper

    PubMed Central

    Ortego, Joaquín; Aguirre, María P; Noguerales, Víctor; Cordero, Pedro J

    2015-01-01

    Anthropogenic habitat fragmentation has altered the distribution and population sizes in many organisms worldwide. For this reason, understanding the demographic and genetic consequences of this process is necessary to predict the fate of populations and establish management practices aimed to ensure their viability. In this study, we analyse whether the spatial configuration of remnant semi-natural habitat patches within a chronically fragmented landscape has shaped the patterns of genetic diversity and structure in the habitat-specialist esparto grasshopper (Ramburiella hispanica). In particular, we predict that agricultural lands constitute barriers to gene flow and hypothesize that fragmentation has restricted interpopulation dispersal and reduced local levels of genetic diversity. Our results confirmed the expectation that isolation and habitat fragmentation have reduced the genetic diversity of local populations. Landscape genetic analyses based on circuit theory showed that agricultural land offers ∽1000 times more resistance to gene flow than semi-natural habitats, indicating that patterns of dispersal are constrained by the spatial configuration of remnant patches of suitable habitat. Overall, this study shows that semi-natural habitat patches act as corridors for interpopulation gene flow and should be preserved due to the disproportionately large ecological function that they provide considering their insignificant area within these human-modified landscapes. PMID:26136826

  5. The effect of discontinuous gas exchange on respiratory water loss in grasshoppers (Orthoptera: Acrididae) varies across an aridity gradient.

    PubMed

    Huang, Shu-Ping; Talal, Stav; Ayali, Amir; Gefen, Eran

    2015-08-01

    The significance of discontinuous gas-exchange cycles (DGC) in reducing respiratory water loss (RWL) in insects is contentious. Results from single-species studies are equivocal in their support of the classic 'hygric hypothesis' for the evolution of DGC, whereas comparative analyses generally support a link between DGC and water balance. In this study, we investigated DGC prevalence and characteristics and RWL in three grasshopper species (Acrididae, subfamily Pamphaginae) across an aridity gradient in Israel. In order to determine whether DGC contributes to a reduction in RWL, we compared the DGC characteristics and RWL associated with CO2 release (transpiration ratio, i.e. the molar ratio of RWL to CO2 emission rates) among these species. Transpiration ratios of DGC and continuous breathers were also compared intraspecifically. Our data show that DGC characteristics, DGC prevalence and the transpiration ratios correlate well with habitat aridity. The xeric-adapted Tmethis pulchripennis exhibited a significantly shorter burst period and lower transpiration ratio compared with the other two mesic species, Ocneropsis bethlemita and Ocneropsis lividipes. However, DGC resulted in significant water savings compared with continuous exchange in T. pulchripennis only. These unique DGC characteristics for T. pulchripennis were correlated with its significantly higher mass-specific tracheal volume. Our data suggest that the origin of DGC may not be adaptive, but rather that evolved modulation of cycle characteristics confers a fitness advantage under stressful conditions. This modulation may result from morphological and/or physiological modifications. PMID:26290590

  6. Spatial heterogeneity in landscape structure influences dispersal and genetic structure: empirical evidence from a grasshopper in an agricultural landscape.

    PubMed

    Gauffre, Bertrand; Mallez, Sophie; Chapuis, Marie-Pierre; Leblois, Raphael; Litrico, Isabelle; Delaunay, Sabrina; Badenhausser, Isabelle

    2015-04-01

    Dispersal may be strongly influenced by landscape and habitat characteristics that could either enhance or restrict movements of organisms. Therefore, spatial heterogeneity in landscape structure could influence gene flow and the spatial structure of populations. In the past decades, agricultural intensification has led to the reduction in grassland surfaces, their fragmentation and intensification. As these changes are not homogeneously distributed in landscapes, they have resulted in spatial heterogeneity with generally less intensified hedged farmland areas remaining alongside streams and rivers. In this study, we assessed spatial pattern of abundance and population genetic structure of a flightless grasshopper species, Pezotettix giornae, based on the surveys of 363 grasslands in a 430-km² agricultural landscape of western France. Data were analysed using geostatistics and landscape genetics based on microsatellites markers and computer simulations. Results suggested that small-scale intense dispersal allows this species to survive in intensive agricultural landscapes. A complex spatial genetic structure related to landscape and habitat characteristics was also detected. Two P. giornae genetic clusters bisected by a linear hedged farmland were inferred from clustering analyses. This linear hedged farmland was characterized by high hedgerow and grassland density as well as higher grassland temporal stability that were suspected to slow down dispersal. Computer simulations demonstrated that a linear-shaped landscape feature limiting dispersal could be detected as a barrier to gene flow and generate the observed genetic pattern. This study illustrates the relevance of using computer simulations to test hypotheses in landscape genetics studies.

  7. Discrimination of grasshopper (Orthoptera: Acrididae) diet and niche overlap using next-generation sequencing of gut contents

    PubMed Central

    McClenaghan, Beverly; Gibson, Joel F; Shokralla, Shadi; Hajibabaei, Mehrdad

    2015-01-01

    Species of grasshopper have been divided into three diet classifications based on mandible morphology: forbivorous (specialist on forbs), graminivorous (specialist on grasses), and mixed feeding (broad-scale generalists). For example, Melanoplus bivittatus and Dissosteira carolina are presumed to be broad-scale generalists, Chortophaga viridifasciata is a specialist on grasses, and Melanoplus femurrubrum is a specialist on forbs. These classifications, however, have not been verified in the wild. Multiple specimens of these four species were collected, and diet analysis was performed using DNA metabarcoding of the gut contents. The rbcLa gene region was amplified and sequenced using Illumina MiSeq sequencing. Levins’ measure and the Shannon–Wiener measure of niche breadth were calculated using family-level identifications and Morisita’s measure of niche overlap was calculated using operational taxonomic units (OTUs). Gut contents confirm both D. carolina and M. bivittatus as generalists and C. viridifasciata as a specialist on grasses. For M. femurrubrum, a high niche breadth was observed and species of grasses were identified in the gut as well as forbs. Niche overlap values did not follow predicted patterns, however, the low values suggest low competition between these species. PMID:26356479

  8. Ontogeny of identified cells from the median domain in the embryonic brain of the grasshopper Schistocerca gregaria.

    PubMed

    Boyan, George; Posser, Susanne; Ludwig, Peter; Güntner, Michaela; Williams, Lez

    2004-04-01

    In this paper, we propose an ontogeny for previously identified cells from the median domain in the midline of the embryonic brain of the grasshopper Schistocerca gregaria. The so-called lateral cells (LCs) are characteristically located laterally within the median domain at its border with the protocerebral hemispheres. The LC occurs singly and can be identified in the early embryo on the basis of their expression of the cell surface lipocalin Lazarillo. Using immunocytochemical, dye injection, electron microscopical and histological methods, we show that these LC are neurons and derive as postmitotic cells directly from the epithelium of the median domain. Further, they and the other identified cells of the median domain such as the protocerebral commissure pioneers (PCP), co-express the Mes-3 antigen, consistent with a derivation from the mesectodermal germ layer of the embryo. Subsequent to axogenesis, electron microscopy reveals that these Mes-3-expressing LC fasciculate with the co-expressing PCPs within the developing protocerebral commissure. We present a model for the origin of all these cells based on histological data and bromodeoxyuridine incorporation. The model suggests a delamination of cells from the mesectoderm followed by a migration to their ultimate sites within the median domain.

  9. Organization of some repetitive DNAs and B chromosomes in the grasshopper Eumastusia koebelei koebelei (Rehn, 1909) (Orthoptera, Acrididae, Leptysminae)

    PubMed Central

    Anjos, Allison; Loreto, Vilma; Cabral-de-Mello, Diogo C.

    2016-01-01

    Abstract B chromosomes occur in approximately 15% of eukaryotes and are usually heterochromatic and rich in repetitive DNAs. Here we describe characteristics of a B chromosome in the grasshopper Eumastusia koebelei koebelei (Rehn, 1909) through classical cytogenetic methods and mapping of some repetitive DNAs, including multigene families, telomeric repeats and a DNA fraction enriched with repetitive DNAs obtained from DOP-PCR. Eumastusia koebelei koebelei presented 2n=23, X0 and, in one individual, two copies of the same variant of a B chromosome were noticed, which are associated during meiosis. The C-positive blocks were located in the pericentromeric regions of the standard complement and along the entire length of the B chromosomes. Some G+C-rich heterochromatic blocks were noticed, including conspicuous blocks in the B chromosomes. The mapping of 18S rDNA and U2 snDNA revealed only autosomal clusters, and the telomeric probe hybridized in terminal regions. Finally, the DOP-PCR probe obtained from an individual without a B chromosome revealed signals in the heterochromatic regions, including the entire length of the B chromosome. The possible intraspecific origin of the B chromosomes, due to the shared pool of repetitive DNAs between the A and B chromosomes and the possible consequences of their association are discussed. PMID:27551344

  10. Goose Toll-like receptor 7 (TLR7), myeloid differentiation factor 88 (MyD88) and antiviral molecules involved in anti-H5N1 highly pathogenic avian influenza virus response.

    PubMed

    Wei, Liangmeng; Jiao, Peirong; Yuan, Runyu; Song, Yafen; Cui, Pengfei; Guo, Xuchen; Zheng, Bofang; Jia, Weixin; Qi, Wenbao; Ren, Tao; Liao, Ming

    2013-05-15

    In mammals, Toll-like receptor 7 (TLR7) is an important membrane-bound receptor triggered by antiviral compounds and single-stranded RNA. It is implicated in the immune response to viruses such as influenza virus. It was not known whether geese, a natural host for avian influenza viruses, possess a homologue of mammalian TLR7 for recognizing avian influenza virus. In this study, we cloned the full-length of goose TLR7 and partial sequences of its adaptor protein, myeloid differentiation factor 88 (MyD88), some antiviral molecules such as RNA-dependent protein kinase (PKR) and 2',5'-oligoadenylate synthetase (OAS). Goose TLR7 has a protein secondary structure identical to that of mammals, consisting of several leucine-rich domains, a transmembrane domain, and Toll/interleukin-1 receptor domain. To further understand whether the MyD88-dependent pathway of TLR7 is involved in the antiviral innate immune response against highly pathogenic avian influenza virus (HPAIV) infection in geese, we inoculated geese with an H5N1 HPAIV isolated from ducks in 2004. The virus, A/Duck/Guangdong/212/2004, replicated in various tissues resulting in 40% mortality. Quantitative real-time PCR analysis showed upregulation of mRNA transcripts for TLR7, MyD88, PKR and OAS in the lungs of geese at 1, 2 and 3 days post-inoculation. Therefore, the MyD88-dependent pathway of TLR7 was involved in the early stage of antiviral innate immune response in geese during H5N1 HPAIV infection.

  11. Pathogene Mikroorganismen

    NASA Astrophysics Data System (ADS)

    Wagner, Martin

    Infektionen, die vom Tier auf den Menschen übertragen werden, werden als Zoonosen bezeichnet. Pathogene Mikroorganismen können entweder durch Mensch-Mensch, Mensch-Tier-Kontakt oder durch Kontakt mit kontaminierten Vektoren übertragen werden [39]. Vektoren können einerseits belebt (z. B. blutsaugende Insekten), andererseits unbelebt sein. Kontaminierte Lebensmittel und Wasser gehören zu den wichtigsten unbelebten Vektoren. Neben Lebensmitteln können aber auch kontaminierte Gegenstände oder der Kontakt mit Kontaminationsquellen in der Umwelt Auslöser von Krankheitsfällen sein. Weltweit sind mehr als 1400 krankheitsverursachende biologische Agentien bekannt, von denen über 60 % ein zoonotisches Potenzial aufweisen. Als Ergebnis von Expertengesprächen wurde kürzlich berichtet, dass etwa 3 bis 4, meist virale, neu auftretende Infektionskrankheiten ("emerging diseases“) pro Jahr erwartet werden können [15]. Es handelt sich bei diesen Vorgängen aber nicht nur um das Auftauchen vollkommen neuer oder unbeschriebener Spezies, sondern auch um evolutionsbedingte Anpassungen von mikrobiellen Populationen an neue Bedingungen in ihrem Ökosystem [7]. Molekulare Analysen an Umweltchlamydien erbrachten Hinweise, dass die Evolution erste genetische Pathogenitätsmerkmale in dieser Spezies schon vor 700 Mio. Jahren entstehen ließ [14]. Viele Faktoren befeuern den Prozess der Anpassung, unter anderem auch alle Strategien, mit denen der Mensch seit Jahrtausenden versucht, Lebensmittel sicher und haltbar zu machen. Als die treibenden Kräfte des Auftretens neuer Krankheitserreger werden in der Gegenwart vor allem das sich ändernde Weltklima, die globalen Warenströme und die sich verändernden Konsumgewohnheiten genannt. Es steht auch außer Zweifel, dass viele dieser Erreger Tiere als ihr natürliches Reservoir haben werden, d. h. Zoonosen im klassischen Sinne sind [15].

  12. Proteomics of Plant Pathogenic Fungi

    PubMed Central

    González-Fernández, Raquel; Prats, Elena; Jorrín-Novo, Jesús V.

    2010-01-01

    Plant pathogenic fungi cause important yield losses in crops. In order to develop efficient and environmental friendly crop protection strategies, molecular studies of the fungal biological cycle, virulence factors, and interaction with its host are necessary. For that reason, several approaches have been performed using both classical genetic, cell biology, and biochemistry and the modern, holistic, and high-throughput, omic techniques. This work briefly overviews the tools available for studying Plant Pathogenic Fungi and is amply focused on MS-based Proteomics analysis, based on original papers published up to December 2009. At a methodological level, different steps in a proteomic workflow experiment are discussed. Separate sections are devoted to fungal descriptive (intracellular, subcellular, extracellular) and differential expression proteomics and interactomics. From the work published we can conclude that Proteomics, in combination with other techniques, constitutes a powerful tool for providing important information about pathogenicity and virulence factors, thus opening up new possibilities for crop disease diagnosis and crop protection. PMID:20589070

  13. Phytotoxic and antibacterial metabolites from Fusarium proliferatum ZS07 isolated from the gut of long-horned grasshoppers.

    PubMed

    Li, Shuai; Shao, Ming-Wei; Lu, Yi-Hui; Kong, Li-Chun; Jiang, Dong-Hua; Zhang, Ying-Lao

    2014-09-10

    In the proceeding of screening new bioactive natural products, the ethyl acetate extract of the fermentation broth of Fusarium proliferatum ZS07, a fungus residing in the gut of long-horned grasshoppers (Tettigonia chinensis), was found possessing selective phytotoxic activity against the radicle growth of Amaranthus retroflexus L. Bioactivity-guided fractionation lead to the isolation of six fungal metabolites 1-6, including a new polyketide derivate O-methylated SMA93 (2) and five known compounds SMA93 (1), rhodolamprometrin (3), radicinin (4), dehydroallogibberic acid (5), and 3-methyl-6,8-dihydroxyisocoumarin (6). Their structures were identified on the basis of spectroscopic analysis and by comparison of the corresponding data to those reported in the literature previously. Phytotoxic effects of the four isolated compounds 1-4 on the radicle growth of A. retroflexus L. seeds were investigated under laboratory conditions, and compounds 2 and 4 showed good phytotoxic activity in the concentration of 100 μg/mL, with the inhibition rates of 83.0 and 65.2%, respectively. Furthermore, the antibacterial activity of compounds 1-5 were evaluated against selected bacteria. Compounds 1-3 were found to possess potent antibacterial activity against Bacillus subtilis (ATCC 6633), with the minimum inhibitory concentration (MIC) values of 3.13-12.50 μg/mL, while Escherichia coli (ATCC 8739) and Salmonella typhimurium [CMCC(B) 50115] were not susceptible. These results suggest that the new polyketide derivate 2 and known compounds 1, 3, and 4 have potential to be used as biocontrol agents in agriculture.

  14. Two Species with an Unusual Combination of Traits Dominate Responses of British Grasshoppers and Crickets to Environmental Change.

    PubMed

    Beckmann, Björn C; Purse, Bethan V; Roy, David B; Roy, Helen E; Sutton, Peter G; Thomas, Chris D

    2015-01-01

    There are large variations in the responses of species to the environmental changes of recent decades, heightening interest in whether their traits may explain inter-specific differences in range expansions and contractions. Using a long-term distributional dataset, we calculated range changes of grasshoppers and crickets in Britain between the 1980s and the 2000s and assessed whether their traits (resource use, life history, dispersal ability, geographic location) explain relative performance of different species. Our analysis showed large changes in the distributions of some species, and we found a positive relationship between three traits and range change: ranges tended to increase for habitat generalists, species that oviposit in the vegetation above ground, and for those with a southerly distribution. These findings accord well with the nature of environmental changes over this period (climatic warming; reductions in the diversity and increases in the height of vegetation). However, the trait effects applied mainly to just two species, Conocephalus discolor and Metrioptera roeselii, which had shown the greatest range increases. Once they were omitted from the analysis, trait effects were no longer statistically significant. Previous studies on these two species emphasised wing-length dimorphism as the key to their success, resulting in a high phenotypic plasticity of dispersal and evolutionary-ecological feedback at their expanding range margins. This, combined with our results, suggests that an unusual combination of traits have enabled these two species to undertake extremely rapid responses to recent environmental changes. The fact that our results are dominated by two species only became apparent through cautious testing of the results' robustness, not through standard statistical checks. We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms, but

  15. Two Species with an Unusual Combination of Traits Dominate Responses of British Grasshoppers and Crickets to Environmental Change.

    PubMed

    Beckmann, Björn C; Purse, Bethan V; Roy, David B; Roy, Helen E; Sutton, Peter G; Thomas, Chris D

    2015-01-01

    There are large variations in the responses of species to the environmental changes of recent decades, heightening interest in whether their traits may explain inter-specific differences in range expansions and contractions. Using a long-term distributional dataset, we calculated range changes of grasshoppers and crickets in Britain between the 1980s and the 2000s and assessed whether their traits (resource use, life history, dispersal ability, geographic location) explain relative performance of different species. Our analysis showed large changes in the distributions of some species, and we found a positive relationship between three traits and range change: ranges tended to increase for habitat generalists, species that oviposit in the vegetation above ground, and for those with a southerly distribution. These findings accord well with the nature of environmental changes over this period (climatic warming; reductions in the diversity and increases in the height of vegetation). However, the trait effects applied mainly to just two species, Conocephalus discolor and Metrioptera roeselii, which had shown the greatest range increases. Once they were omitted from the analysis, trait effects were no longer statistically significant. Previous studies on these two species emphasised wing-length dimorphism as the key to their success, resulting in a high phenotypic plasticity of dispersal and evolutionary-ecological feedback at their expanding range margins. This, combined with our results, suggests that an unusual combination of traits have enabled these two species to undertake extremely rapid responses to recent environmental changes. The fact that our results are dominated by two species only became apparent through cautious testing of the results' robustness, not through standard statistical checks. We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms, but

  16. Two Species with an Unusual Combination of Traits Dominate Responses of British Grasshoppers and Crickets to Environmental Change

    PubMed Central

    Beckmann, Björn C.; Purse, Bethan V.; Roy, David B.; Roy, Helen E.; Sutton, Peter G.; Thomas, Chris D.

    2015-01-01

    There are large variations in the responses of species to the environmental changes of recent decades, heightening interest in whether their traits may explain inter-specific differences in range expansions and contractions. Using a long-term distributional dataset, we calculated range changes of grasshoppers and crickets in Britain between the 1980s and the 2000s and assessed whether their traits (resource use, life history, dispersal ability, geographic location) explain relative performance of different species. Our analysis showed large changes in the distributions of some species, and we found a positive relationship between three traits and range change: ranges tended to increase for habitat generalists, species that oviposit in the vegetation above ground, and for those with a southerly distribution. These findings accord well with the nature of environmental changes over this period (climatic warming; reductions in the diversity and increases in the height of vegetation). However, the trait effects applied mainly to just two species, Conocephalus discolor and Metrioptera roeselii, which had shown the greatest range increases. Once they were omitted from the analysis, trait effects were no longer statistically significant. Previous studies on these two species emphasised wing-length dimorphism as the key to their success, resulting in a high phenotypic plasticity of dispersal and evolutionary-ecological feedback at their expanding range margins. This, combined with our results, suggests that an unusual combination of traits have enabled these two species to undertake extremely rapid responses to recent environmental changes. The fact that our results are dominated by two species only became apparent through cautious testing of the results’ robustness, not through standard statistical checks. We conclude that trait-based analyses may contribute to the assessment of species responses to environmental change and provide insights into underlying mechanisms

  17. High similarity of U2 snDNA sequence between A and B chromosomes in the grasshopper Abracris flavolineata.

    PubMed

    Menezes-de-Carvalho, Nahanna Zimmermann; Palacios-Gimenez, Octavio Manuel; Milani, Diogo; Cabral-de-Mello, Diogo Cavalcanti

    2015-10-01

    B chromosomes are frequently enriched for a wide variety of repetitive DNAs. Among grasshoppers in the species Abracris flavolineata (Ommatolampidinae) the B chromosomes are submetacentric, C-negative and harbor repetitive DNAs such as, U2 snDNA, C 0 t-1 DNA, two Mariner-like elements and some microsatellites. Here, we provide evidence showing the intragenome similarity between the B chromosome and the A complement in A. flavolineata, combining analysis of microdissection and chromosome painting and B chromosome-specific amplification through polymerase chain reaction (PCR) of U2 snDNA. Chromosome painting revealed signals spread through the C-negative regions, including the A and B chromosomes. Moreover, significant clustered signals forming bands were observed in some A chromosomes, and for the B chromosome, significant signals were located on both arms, which could be caused by accumulation of repetitive DNA sequences. The C-positive regions did not reveal any signals. Sequence comparison of U2 snDNA between that obtained from a genome without the B chromosome and that from µB-DNA revealed high similarity with the occurrence of four shared haplotypes, one of them (i.e., Hap1) being highly prevalent and putatively ancestral. The highest divergence from Hap1 was observed for Hap3, which was caused by only six mutational steps. These data support an intraspecific origin of the B chromosome in A. flavolineata that is highly similar with the A complement, and the low U2 snDNA sequence diversity observed in the B chromosome could be related to its recent origin, besides intrachromosomal concerted evolution for U2 snDNA repeats in the B chromosome.

  18. Double trouble for grasshopper molecular systematics: intra-individual heterogeneity of both mitochondrial 12S-valine-16S and nuclear internal transcribed spacer ribosomal DNA sequences in Hesperotettix viridis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hesperotettix viridis grasshoppers (Orthoptera: Acrididae:Melanoplinae) exhibit intra-individual variation in both mitochondrial 12S-valine-16S and nuclear internal transcribed spacer (ITS) ribosomal DNA sequences. These findings violate core assumptions underlying DNA sequence data obtained via pol...

  19. Cytogenetic mapping of 5S and 18S rRNAs and H3 histone genes in 4 ancient Proscopiidae grasshopper species: contribution to understanding the evolutionary dynamics of multigene families.

    PubMed

    Cabral-de-Mello, D C; Martins, C; Souza, M J; Moura, R C

    2011-01-01

    This paper reports on the chromosomal location of 18S rRNA, 5S rRNA and H3 histone multigene families in 4 species of a relatively ancient and diversified group of grasshoppers belonging to the family Proscopiidae. The 5S rRNA and H3 histone genes were highly conserved in the number of sites and chromosomal position in the 4th chromosome pair in all species analyzed, whereas the 18S rRNA genes showed slightly more variation because they were present on one or 2 chromosome pairs, depending on the species. The 5S and 18S rRNA gene families occurred in different chromosomes; in contrast, H3 histone and 5S rRNA genes co-localized in the same chromosomal position, with an apparently interspersed organization. Considering that the Proscopiidae family is a relatively ancient group compared with the Acrididae family, the association of the H3 histone and 5S rRNA multigene families can represent a basal condition for grasshoppers, although more research is needed on other representatives of this insect group to confirm this statement. The presence of such an association of 5S rDNA and H3 histone in mussels and arthropods (beetles, grasshoppers and crustaceans) suggests that this linked configuration could represent an ancestral pattern for invertebrates. These results provide new insights into the understanding of the genome organization and the evolution of multigene families in grasshoppers and in insects as a whole.

  20. Geographic variation in wing size and shape of the grasshopper Trilophidia annulata (Orthoptera: Oedipodidae): morphological trait variations follow an ecogeographical rule.

    PubMed

    Bai, Yi; Dong, Jia-Jia; Guan, De-Long; Xie, Juan-Ying; Xu, Sheng-Quan

    2016-01-01

    A quantitative analysis of wing variation in grasshoppers can help us to understand how environmental heterogeneity affects the phenotypic patterns of insects. In this study, geometric morphometric methods were used to measure the differences in wing shape and size of Trilophidia annulata among 39 geographical populations in China, and a regression analysis was applied to identify the major environmental factors contributing to the observed morphological variations. The results showed that the size of the forewing and hindwing were significantly different among populations; the shape of the forewing among populations can be divided into geographical groups, however hindwing shape are geographical overlapped, and populations cannot be divided into geographical groups. Environmental PCA and thin-plate spline analysis suggested that smaller individuals with shorter and blunter-tip forewings were mainly distributed in the lower latitudes and mountainous areas, where they have higher temperatures and more precipitation. Correspondingly, the larger-bodied grasshoppers, those that have longer forewings with a longer radial sector, are distributed in contrary circumstances. We conclude that the size variations in body, forewing and hindwing of T. annulata apparently follow the Bergmann clines. The importance of climatic variables in influencing morphological variation among populations, forewing shape of T. annulata varies along an environmental gradient. PMID:27597437

  1. The effect of a diet containing grasshoppers and access to free-range on carcase and meat physicochemical and sensory characteristics in broilers.

    PubMed

    Sun, T; Long, R J; Liu, Z Y

    2013-01-01

    1. Research was conducted to evaluate the impact of a diet containing grasshoppers on the carcase, physicochemical and sensory characteristics in a free-range, grassland-based broiler production system. 2. A total of 80, 28-d-old male broilers were reared on grassland containing a large population of grasshoppers (treatment PB). Control birds were reared intensively on a maize-soybean diet (treatment CB). At 91 d of age, 24 birds from each treatment were slaughtered to evaluate carcase, meat and sensory characteristics. 3. Treatment PB produced birds with significantly lower live weights, breast, wing, thigh and drum weights, and higher dressing percentage and breast percentage of carcase, compared with CB. Treatment PB produced breast meat with significantly higher redness values, shear force and protein content, and lower pH values, cooking loss, moisture and fat content compared with CB. Sensory panel results for breast and thigh meats showed no treatment effect on colour and juiciness, but significantly higher scores for chewiness, flavour, aroma and overall appreciation, and lower scores for tenderness from treatment PB compared with CB. 4. Rearing chickens on rangeland may provide an alternative way to produce poultry meat which is considered superior by modern consumers.

  2. Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading

    PubMed Central

    Bueno, Danilo; Palacios-Gimenez, Octavio Manuel; Cabral-de-Mello, Diogo Cavalcanti

    2013-01-01

    Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in most cases. The accumulation of repetitive DNAs is one remarkable characteristic of B chromosomes, and the occurrence of distinct types of multigene families, satellite DNAs and some transposable elements have been reported. Here, we describe the organization of repetitive DNAs in the A complement and B chromosome system in the grasshopper species Abracris flavolineata using classical cytogenetic techniques and FISH analysis using probes for five multigene families, telomeric repeats and repetitive C0t-1 DNA fractions. The 18S rRNA and H3 histone multigene families are highly variable and well distributed in A. flavolineata chromosomes, which contrasts with the conservation of U snRNA genes and less variable distribution of 5S rDNA sequences. The H3 histone gene was an extensively distributed with clusters occurring in all chromosomes. Repetitive DNAs were concentrated in C-positive regions, including the pericentromeric region and small chromosomal arms, with some occurrence in C-negative regions, but abundance was low in the B chromosome. Finally, the first demonstration of the U2 snRNA gene in B chromosomes in A. flavolineata may shed light on its possible origin. These results provide new information regarding chromosomal variability for repetitive DNAs in grasshoppers and the specific molecular composition of B chromosomes. PMID:23826099

  3. Geographic variation in wing size and shape of the grasshopper Trilophidia annulata (Orthoptera: Oedipodidae): morphological trait variations follow an ecogeographical rule

    PubMed Central

    Bai, Yi; Dong, Jia-Jia; Guan, De-Long; Xie, Juan-Ying; Xu, Sheng-Quan

    2016-01-01

    A quantitative analysis of wing variation in grasshoppers can help us to understand how environmental heterogeneity affects the phenotypic patterns of insects. In this study, geometric morphometric methods were used to measure the differences in wing shape and size of Trilophidia annulata among 39 geographical populations in China, and a regression analysis was applied to identify the major environmental factors contributing to the observed morphological variations. The results showed that the size of the forewing and hindwing were significantly different among populations; the shape of the forewing among populations can be divided into geographical groups, however hindwing shape are geographical overlapped, and populations cannot be divided into geographical groups. Environmental PCA and thin-plate spline analysis suggested that smaller individuals with shorter and blunter-tip forewings were mainly distributed in the lower latitudes and mountainous areas, where they have higher temperatures and more precipitation. Correspondingly, the larger-bodied grasshoppers, those that have longer forewings with a longer radial sector, are distributed in contrary circumstances. We conclude that the size variations in body, forewing and hindwing of T. annulata apparently follow the Bergmann clines. The importance of climatic variables in influencing morphological variation among populations, forewing shape of T. annulata varies along an environmental gradient. PMID:27597437

  4. Biochemical basis of synergism between pathogenic fungus Metarhizium anisopliae and insecticide chlorantraniliprole in Locusta migratoria (Meyen).

    PubMed

    Jia, Miao; Cao, Guangchun; Li, Yibo; Tu, Xiongbing; Wang, Guangjun; Nong, Xiangqun; Whitman, Douglas W; Zhang, Zehua

    2016-01-01

    We challenged Locusta migratoria (Meyen) grasshoppers with simultaneous doses of both the insecticide chlorantraniliprole and the fungal pathogen, Metarhizium anisopliae. Our results showed synergistic and antagonistic effects on host mortality and enzyme activities. To elucidate the biochemical mechanisms that underlie detoxification and pathogen-immune responses in insects, we monitored the activities of 10 enzymes. After administration of insecticide and fungus, activities of glutathione-S-transferase (GST), general esterases (ESTs) and phenol oxidase (PO) decreased in the insect during the initial time period, whereas those of aryl acylamidase (AA) and chitinase (CHI) increased during the initial period and that of acetylcholinesterase (AChE) increased during a later time period. Activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) decreased at a later time period post treatment. Interestingly, treatment with chlorantraniliprole and M. anisopliae relieved the convulsions that normally accompany M. anisopliae infection. We speculate that locust mortality increased as a result of synergism via a mechanism related to Ca(2+) disruption in the host. Our study illuminates the biochemical mechanisms involved in insect immunity to xenobiotics and pathogens as well as the mechanisms by which these factors disrupt host homeostasis and induce death. We expect this knowledge to lead to more effective pest control. PMID:27328936

  5. Biochemical basis of synergism between pathogenic fungus Metarhizium anisopliae and insecticide chlorantraniliprole in Locusta migratoria (Meyen)

    PubMed Central

    Jia, Miao; Cao, Guangchun; Li, Yibo; Tu, Xiongbing; Wang, Guangjun; Nong, Xiangqun; Whitman, Douglas W.; Zhang, Zehua

    2016-01-01

    We challenged Locusta migratoria (Meyen) grasshoppers with simultaneous doses of both the insecticide chlorantraniliprole and the fungal pathogen, Metarhizium anisopliae. Our results showed synergistic and antagonistic effects on host mortality and enzyme activities. To elucidate the biochemical mechanisms that underlie detoxification and pathogen-immune responses in insects, we monitored the activities of 10 enzymes. After administration of insecticide and fungus, activities of glutathione-S-transferase (GST), general esterases (ESTs) and phenol oxidase (PO) decreased in the insect during the initial time period, whereas those of aryl acylamidase (AA) and chitinase (CHI) increased during the initial period and that of acetylcholinesterase (AChE) increased during a later time period. Activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) decreased at a later time period post treatment. Interestingly, treatment with chlorantraniliprole and M. anisopliae relieved the convulsions that normally accompany M. anisopliae infection. We speculate that locust mortality increased as a result of synergism via a mechanism related to Ca2+ disruption in the host. Our study illuminates the biochemical mechanisms involved in insect immunity to xenobiotics and pathogens as well as the mechanisms by which these factors disrupt host homeostasis and induce death. We expect this knowledge to lead to more effective pest control. PMID:27328936

  6. Microsporidia: emerging pathogenic protists.

    PubMed

    Weiss, L M

    2001-02-23

    Microsporidia are eukaryotic spore forming obligate intracellular protozoan parasites first recognized over 100 years ago. These organisms infect all of the major animal groups and are now recognized as opportunistic pathogens of humans. Microsporidian spores are common in the environment and microsporidia pathogenic to humans have been found in water supplies. The genera Nosema, Vittaforma, Brachiola, Pleistophora, Encephalitozoon, Enterocytozoon, Septata (reclassified to Encephalitozoon) and Trachipleistophora have been found in human infections. These organisms have the smallest known eukaryotic genomes. Microsporidian ribosomal RNA sequences have proven useful as diagnostic tools as well as for phylogenetic analysis. Recent phylogenetic analysis suggests that Microsporidia are related to the fungi. These organisms are defined by the presence of a unique invasion organelle consisting of a single polar tube that coils around the interior of the spore. All microsporidia exhibit the same response to stimuli, that is, the polar tube discharges from the anterior pole of the spore in an explosive reaction. If the polar tube is discharged next to a cell, it can pierce the cell and transfer its sporoplasm into the cell. A technique was developed for the purification of polar tube proteins (PTPs) using differential extraction followed by reverse phase HPLC. This method was used to purify the PTPs from Glugea americanus, Encephalitozoon cuniculi, Enc. hellem and Enc. intestinalis. These PTPs demonstrate conserved characteristics such as solubility, hydrophobicity, mass, proline content and immunologic epitopes. The major PTP gene from Enc. cuniculi and Enc. hellem has been cloned and expressed in vitro. The gene sequences support the importance of ER and in the formation of the polar tube as suggested by morphologic studies. Analysis of the cloned proteins also indicates that secondary structural characteristics are conserved. These characteristics are probably important

  7. Lagenidium giganteum Pathogenicity in Mammals

    PubMed Central

    Vilela, Raquel; Taylor, John W.; Walker, Edward D.

    2015-01-01

    Infections of mammals by species in the phylum Oomycota taxonomically and molecularly similar to known Lagenidium giganteum strains have increased. During 2013–2014, we conducted a phylogenetic study of 21 mammalian Lagenidium isolates; we found that 11 cannot be differentiated from L. giganteum strains that the US Environmental Protection Agency approved for biological control of mosquitoes; these strains were later unregistered and are no longer available. L. giganteum strains pathogenic to mammals formed a strongly supported clade with the biological control isolates, and both types experimentally infected mosquito larvae. However, the strains from mammals grew well at 25°C and 37°C, whereas the biological control strains developed normally at 25°C but poorly at higher temperatures. The emergence of heat-tolerant strains of L. giganteum pathogenic to lower animals and humans is of environmental and public health concern. PMID:25625190

  8. Evolutionary dynamics of 5S rDNA location in acridid grasshoppers and its relationship with H3 histone gene and 45S rDNA location.

    PubMed

    Cabral-de-Mello, Diogo C; Cabrero, Josefa; López-León, María Dolores; Camacho, Juan Pedro M

    2011-07-01

    We analyze the chromosomal location of 5S rDNA clusters in 29 species of grasshoppers belonging to the family Acrididae. There was extensive variation among species for the number and location of 5S rDNA sites. Out of 148 sites detected, 75% were proximally located, 21.6% were interstitial, and only 3.4% were distal. The number of 5S rDNA sites per species varied from a single chromosome pair (in six species) to all chromosome pairs (in five species), with a range of intermediate situations. Thirteen chromosomes from eight species carried two 5S rDNA clusters. At intraspecific level, differences among populations were detected in Eyprepocnemis plorans, and some heteromorphisms have also been observed in some species. Double FISH for 5S rDNA and H3 histone gene DNA, performed on 17 of these 29 species, revealed that both markers are sometimes placed in a same chromosome but at different location, whereas they appeared to co-localize in five species (Calliptamus barbarus, Heteracris adpersa, Aiolopus strepens, Oedipoda charpentieri and O. coerulescens). Double fiber-FISH in A. strepens and O. coerulescens showed that the two DNAs are closely interspersed with variable relative amounts of both classes of DNA. Finally, no correlation was observed between the number of 5S and 45S rDNA clusters in 23 species where this information was available. These results are discussed in the light of possible mechanisms of spread that led to the extensive variation in the number of clusters observed for both rDNA types in acridid grasshoppers.

  9. Object-Based Classification as an Alternative Approach to the Traditional Pixel-Based Classification to Identify Potential Habitat of the Grasshopper Sparrow

    NASA Astrophysics Data System (ADS)

    Jobin, Benoît; Labrecque, Sandra; Grenier, Marcelle; Falardeau, Gilles

    2008-01-01

    The traditional method of identifying wildlife habitat distribution over large regions consists of pixel-based classification of satellite images into a suite of habitat classes used to select suitable habitat patches. Object-based classification is a new method that can achieve the same objective based on the segmentation of spectral bands of the image creating homogeneous polygons with regard to spatial or spectral characteristics. The segmentation algorithm does not solely rely on the single pixel value, but also on shape, texture, and pixel spatial continuity. The object-based classification is a knowledge base process where an interpretation key is developed using ground control points and objects are assigned to specific classes according to threshold values of determined spectral and/or spatial attributes. We developed a model using the eCognition software to identify suitable habitats for the Grasshopper Sparrow, a rare and declining species found in southwestern Québec. The model was developed in a region with known breeding sites and applied on other images covering adjacent regions where potential breeding habitats may be present. We were successful in locating potential habitats in areas where dairy farming prevailed but failed in an adjacent region covered by a distinct Landsat scene and dominated by annual crops. We discuss the added value of this method, such as the possibility to use the contextual information associated to objects and the ability to eliminate unsuitable areas in the segmentation and land cover classification processes, as well as technical and logistical constraints. A series of recommendations on the use of this method and on conservation issues of Grasshopper Sparrow habitat is also provided.

  10. Object-based classification as an alternative approach to the traditional pixel-based classification to identify potential habitat of the grasshopper sparrow.

    PubMed

    Jobin, Benoît; Labrecque, Sandra; Grenier, Marcelle; Falardeau, Gilles

    2008-01-01

    The traditional method of identifying wildlife habitat distribution over large regions consists of pixel-based classification of satellite images into a suite of habitat classes used to select suitable habitat patches. Object-based classification is a new method that can achieve the same objective based on the segmentation of spectral bands of the image creating homogeneous polygons with regard to spatial or spectral characteristics. The segmentation algorithm does not solely rely on the single pixel value, but also on shape, texture, and pixel spatial continuity. The object-based classification is a knowledge base process where an interpretation key is developed using ground control points and objects are assigned to specific classes according to threshold values of determined spectral and/or spatial attributes. We developed a model using the eCognition software to identify suitable habitats for the Grasshopper Sparrow, a rare and declining species found in southwestern Québec. The model was developed in a region with known breeding sites and applied on other images covering adjacent regions where potential breeding habitats may be present. We were successful in locating potential habitats in areas where dairy farming prevailed but failed in an adjacent region covered by a distinct Landsat scene and dominated by annual crops. We discuss the added value of this method, such as the possibility to use the contextual information associated to objects and the ability to eliminate unsuitable areas in the segmentation and land cover classification processes, as well as technical and logistical constraints. A series of recommendations on the use of this method and on conservation issues of Grasshopper Sparrow habitat is also provided.

  11. The level of DNA damage in adult grasshoppers Chorthippus biguttulus (Orthoptera, Acrididae) following dimethoate exposure is dependent on the insects' habitat.

    PubMed

    Karpeta-Kaczmarek, Julia; Kubok, Magdalena; Dziewięcka, Marta; Sawczyn, Tomasz; Augustyniak, Maria

    2016-08-01

    The comet assay was used to study the DNA damage that was induced by dimethoate in the hemocyte cells of adult Chorthippus biguttulus grasshoppers (Insecta: Orthoptera) that originated from two sites with varying levels of pollution. The primary focus of the study was to examine whether continuous exposure to environmental stress can modify the effect of pesticides on genome stability. After three days of acclimation to laboratory conditions, the level of DNA damage in the hemocytes of Bow-winged grasshoppers was within a similar range in the insects from both areas. However, the level of DNA damage following dimethoate treatment was significantly higher in the insects from the reference area (Pogoria) than in the individuals from the heavily polluted location (Szopienice). Four hours after pesticide treatment, the Tail DNA (TDNA) in the hemocytes of the male and female specimens from Pogoria was as high as 75% and 50% respectively, whereas the values in males and females from Szopienice only reached 30% and 20%, respectively. A rapid decrease in DNA damage was observed in both populations 24 h after the pesticide application. The habitat of an insect (site), the administration of the dimethoate (treatment), and the period following the application of the pesticide (time), all significantly influenced the levels of DNA damage. No interactions related to TDNA were observed between the variables 'sex' and 'treatment'. Similarly, the variable 'sex', when analyzed alongside 'treatment' and 'site' (the area from which the insects were collected), or 'treatment' and 'time' had no influence on TL. Exposure to dimethoate undoubtedly contributed to the formation of DNA damage in the hemocytes of adult C. biguttulus. However, the level of damage was clearly dependent on the place where the insects were captured. PMID:27213568

  12. Mycosis Inhibits Grasshopper Necrophagy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Necrophagy is common among the Acrididae and the tettigonid, Anabrus simplex; these behaviors have been proposed as mechanisms for the horizontal transmission of Microsporida and entomopathogenic fungi. After anecdotal observations that Melanoplus sanguinipes and A. simplex did not eat cadavers tha...

  13. Mechanisms of bacterial pathogenicity

    PubMed Central

    Wilson, J; Schurr, M; LeBlanc, C; Ramamurthy, R; Buchanan, K; Nickerson, C

    2002-01-01

    Pathogenic bacteria utilise a number of mechanisms to cause disease in human hosts. Bacterial pathogens express a wide range of molecules that bind host cell targets to facilitate a variety of different host responses. The molecular strategies used by bacteria to interact with the host can be unique to specific pathogens or conserved across several different species. A key to fighting bacterial disease is the identification and characterisation of all these different strategies. The availability of complete genome sequences for several bacterial pathogens coupled with bioinformatics will lead to significant advances toward this goal. PMID:11930024

  14. Disease Severity Is Associated with Differential Gene Expression at the Early and Late Phases of Infection in Nonhuman Primates Infected with Different H5N1 Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Muramoto, Yukiko; Shoemaker, Jason E.; Le, Mai Quynh; Itoh, Yasushi; Tamura, Daisuke; Sakai-Tagawa, Yuko; Imai, Hirotaka; Uraki, Ryuta; Takano, Ryo; Kawakami, Eiryo; Ito, Mutsumi; Okamoto, Kiyoko; Ishigaki, Hirohito; Mimuro, Hitomi; Sasakawa, Chihiro; Matsuoka, Yukiko; Noda, Takeshi; Fukuyama, Satoshi; Ogasawara, Kazumasa; Kitano, Hiroaki

    2014-01-01

    ABSTRACT Occasional transmission of highly pathogenic avian H5N1 influenza viruses to humans causes severe pneumonia with high mortality. To better understand the mechanisms via which H5N1 viruses induce severe disease in humans, we infected cynomolgus macaques with six different H5N1 strains isolated from human patients and compared their pathogenicity and the global host responses to the virus infection. Although all H5N1 viruses replicated in the respiratory tract, there was substantial heterogeneity in their replicative ability and in the disease severity induced, which ranged from asymptomatic to fatal. A comparison of global gene expression between severe and mild disease cases indicated that interferon-induced upregulation of genes related to innate immunity, apoptosis, and antigen processing/presentation in the early phase of infection was limited in severe disease cases, although interferon expression was upregulated in both severe and mild cases. Furthermore, coexpression analysis of microarray data, which reveals the dynamics of host responses during the infection, demonstrated that the limited expression of these genes early in infection led to a failure to suppress virus replication and to the hyperinduction of genes related to immunity, inflammation, coagulation, and homeostasis in the late phase of infection, resulting in a more severe disease. Our data suggest that the attenuated interferon-induced activation of innate immunity, apoptosis, and antigen presentation in the early phase of H5N1 virus infection leads to subsequent severe disease outcome. IMPORTANCE Highly pathogenic avian H5N1 influenza viruses sometimes transmit to humans and cause severe pneumonia with ca. 60% lethality. The continued circulation of these viruses poses a pandemic threat; however, their pathogenesis in mammals is not fully understood. We, therefore, investigated the pathogenicity of six H5N1 viruses and compared the host responses of cynomolgus macaques to the virus

  15. BACTERIAL WATERBORNE PATHOGENS

    EPA Science Inventory

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  16. Plant pathogen resistance

    DOEpatents

    Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

    2012-11-27

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  17. Plant pathogen resistance

    SciTech Connect

    Greenberg, Jean T.; Jung, Ho Won; Tschaplinski, Timothy

    2015-10-20

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  18. Emerging foodborne pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emergence of new foodborne pathogens is due to a number of factors. An important factor is the globalization of the food supply with the possibility of the introduction of foodborne pathogens from other countries. Animal husbandry, food production, food processing, and food distribution system...

  19. Monograph of the Afrotropical species of Scelio Latreille (Hymenoptera, Platygastridae), egg parasitoids of acridid grasshoppers (Orthoptera, Acrididae)

    PubMed Central

    Yoder, Matthew J.; Valerio, Alejandro A.; Polaszek, Andrew; van Noort, Simon; Masner, Lubomír; Johnson, Norman F.

    2014-01-01

    Abstract The genus Scelio is a cosmopolitan and speciose group of solitary parasitoids of the eggs of short-horned grasshoppers (Orthoptera: Acrididae). A number of these hosts are important pests, including plague locusts of the genus Schistocerca. Species of Scelio are recognized as potentially important biological control agents, but this possibility has yet to be fully realized, in part because the species-level taxonomy is still incompletely developed. The species of the pulchripennis group have been recently revised. As a continuation of this effort, here we revise the Afrotropical species of Scelio, excluding the pulchripennis species group. Sixty two (62) species are treated, 48 of which are new. Species are classified into the following species groups: ernstii (12 species, 9 new), howardi (23 species, 19 new), ipomeae (6 species, 5 new), irwini (4 species, 3 new), simoni (3 new species) and walkeri (12 species, 9 new). Keys to species groups and to the species within each group are provided. New species described are: S. albatus Yoder, sp. n., S. aphares Yoder, sp. n., S. apospastos Yoder, sp. n., S. ardelio Yoder, sp. n., S. aurantium Yoder, sp. n., S. balo Valerio & Yoder, sp. n., S. bayanga Yoder, sp. n., S. bubulo Yoder, sp. n., S. cano Yoder, sp. n., S. clypeatus Yoder, sp. n., S. concavus Yoder, sp. n., S. copelandi Yoder, sp. n., S. crepo Yoder, sp. n., S. destico Yoder, sp. n., S. dupondi Yoder, sp. n., S. effervesco Yoder, sp. n., S. erugatus Yoder, sp. n., S. exophthalmus Yoder, sp. n., S. fremo Valerio & Yoder, sp. n., S. gemo Yoder, sp. n., S. grunnio Yoder, sp. n., S. harinhalai Yoder, sp. n., S. igland Yoder, sp. n., S. impostor Yoder, sp. n., S. irwini Yoder, sp. n., S. janseni Yoder, sp. n., S. latro Yoder, sp. n., S. memorabilis Yoder, sp. n., S. modulus Yoder, sp. n., S. mutio Yoder, sp. n., S. ntchisii Yoder, sp. n., S. parkeri Yoder, sp. n., S. phaeoprora Yoder, sp. n., S. pilosilatus Yoder, sp. n., S. pipilo Yoder, sp. n., S

  20. Vaccine-induced pathogen strain replacement: what are the mechanisms?

    PubMed

    Martcheva, Maia; Bolker, Benjamin M; Holt, Robert D

    2008-01-01

    Host immune systems impose natural selection on pathogen populations, which respond by evolving different antigenic signatures. Like many evolutionary processes, pathogen evolution reflects an interaction between different levels of selection; pathogens can win in between-strain competition by taking over individual hosts (within-host level) or by infecting more hosts (population level). Vaccination, which intensifies and modifies selection by protecting hosts against one or more pathogen strains, can drive the emergence of new dominant pathogen strains-a phenomenon called vaccine-induced pathogen strain replacement. Here, we review reports of increased incidence of subdominant variants after vaccination campaigns and extend the current model for pathogen strain replacement, which assumes that pathogen strain replacement occurs only through the differential effectiveness of vaccines against different pathogen strains. Based on a recent theoretical study, we suggest a broader range of possible mechanisms, some of which allow pathogen strain replacement even when vaccines are perfect-that is, they protect all vaccinated individuals completely against all pathogen strains. We draw an analogy with ecological and evolutionary explanations for competitive dominance and coexistence that allow for tradeoffs between different competitive and life-history traits. PMID:17459810

  1. Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis

    PubMed Central

    Zhang, Yuping; Liu, Yaoming; Zhang, Jianzhen; Guo, Yaping; Ma, Enbo

    2015-01-01

    Heat shock proteins (Hsps) are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78), Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR) was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd) stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h), were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination. PMID:26135744

  2. Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis.

    PubMed

    Zhang, Yuping; Liu, Yaoming; Zhang, Jianzhen; Guo, Yaping; Ma, Enbo

    2015-01-01

    Heat shock proteins (Hsps) are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78), Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR) was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd) stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h), were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination. PMID:26135744

  3. Pathogenicity of entamoeba histolytica.

    PubMed

    Kagan, I G

    1975-01-01

    The pathogenicity of Entamoeba histolytica is discussed from an immunologic point of view. The evidence that there is some "trigger" mechanism which converts a commensal dwelling organism into a tissue invasive pathogen is rejected as inadequate. The number of liver abscess cases in comparison with the number of intestinal amebic infections in a population is so low that this in itself suggests that tissue invasion is a rare event in the life history of the ameba. A review is made of the experimental evidence that some type of sensitization is necessary before ameba can invade tissue. In postulating an immunologic basis for the pathogenicity of ameba, a parallel between the behavior of malignant cells in the body and an amebic infection in the gut is made. An appealing hypothesis which deserves further research effort is that an altered immune response is the basis for the pathogenic mechanism in the host. PMID:171223

  4. Physical mapping of 18S and 5S rDNA loci and histone H3 gene in grasshopper species of the subfamily Gomphocerinae (Acrididae).

    PubMed

    Silva-Neto, L C; Bernardino, A C S; Loreto, V; Moura, R C

    2015-01-01

    In this study, fluorescence in situ hybridization (FISH) analysis was used to determine and compare the numbers and chromosomal locations of two multigene families (rDNA and histone H3) in four Neotropical species of gomphocerine grasshoppers. FISH using the 18S rDNA probe identified a single site on the S9 chromosome of Amblytropidia sp and Cauratettix borelli, a single site on chromosome M6 of Compsacris pulcher, and two sites (chromosomes L1 and L2) in Orphulella punctata. By contrast, FISH with a 5S rDNA probe identified dispersion of this sequence in the genomes of the four species, with evidence of intraspecific variations. Amblytropidia sp had six to eight FISH signals on autosomal chromosomes, while C. pulcher exhibited a signal only on the M5 bivalent. The histone H3 gene was less variable and was restricted to a single pair in all species. The conservation of the numbers and locations of 18S rDNA and H3 genes in conjunction with data from the literature was useful for evaluating karyotype evolution in this subfamily. The variation in the number and sizes of 5S rDNA sites indicates a process of recent dispersion that might have been mediated by transposition. PMID:26634462

  5. Biomonitoring of the genotoxic effects and oxidative potentials of commercial edible dung beetles (Onitis sp.), grasshopper (Caelifera sp.) and mole crickets (Gryllotalpa sp.) in vitro.

    PubMed

    Koc, Kubra; Incekara, Umit; Turkez, Hasan

    2014-09-01

    In this investigation, the genotoxic and oxidative effects of water soluble extracts of dung beetles, flying grasshopper and mole crickets have been assessed on cultured human blood cells. The extracts were added to the culture tubes at 12 different concentrations (0-2000 ppm). Micronucleus test was used to monitor the DNA and the chromosomal damage produced by aqueous extracts in vitro. In addition, to assess the oxidative effects, total antioxidant capacity (TAC) and total oxidant status (TOS) levels were also measured. Our results indicated that these extracts did not show genotoxic effects at the tested concentrations. However, the extracts caused dose-dependent alterations in both TAC and TOS levels. Based on the findings, it was concluded that the studied insects can be consumed safely, but it is necessary to consider the cellular damages which are likely to appear depending on oxidative stress at higher concentrations. It has also been suggested that this in vitro approach for oxidative and genotoxicity assessments may be useful to evaluate the potential health risks of edible insects.

  6. Physical mapping of 18S and 5S rDNA loci and histone H3 gene in grasshopper species of the subfamily Gomphocerinae (Acrididae).

    PubMed

    Silva-Neto, L C; Bernardino, A C S; Loreto, V; Moura, R C

    2015-11-25

    In this study, fluorescence in situ hybridization (FISH) analysis was used to determine and compare the numbers and chromosomal locations of two multigene families (rDNA and histone H3) in four Neotropical species of gomphocerine grasshoppers. FISH using the 18S rDNA probe identified a single site on the S9 chromosome of Amblytropidia sp and Cauratettix borelli, a single site on chromosome M6 of Compsacris pulcher, and two sites (chromosomes L1 and L2) in Orphulella punctata. By contrast, FISH with a 5S rDNA probe identified dispersion of this sequence in the genomes of the four species, with evidence of intraspecific variations. Amblytropidia sp had six to eight FISH signals on autosomal chromosomes, while C. pulcher exhibited a signal only on the M5 bivalent. The histone H3 gene was less variable and was restricted to a single pair in all species. The conservation of the numbers and locations of 18S rDNA and H3 genes in conjunction with data from the literature was useful for evaluating karyotype evolution in this subfamily. The variation in the number and sizes of 5S rDNA sites indicates a process of recent dispersion that might have been mediated by transposition.

  7. B chromosomes in the grasshopper Eyprepocnemis plorans are present in all body parts analyzed and show extensive variation for rDNA copy number.

    PubMed

    Ruiz-Estévez, Mercedes; Cabrero, Josefa; Camacho, Juan Pedro M; López-León, María Dolores

    2014-01-01

    B chromosomes in the grasshopper Eyprepocnemis plorans are considered to be mitotically stable, because all meiotic (primary spermatocytes and oocytes) or mitotic (embryos, ovarioles, and gastric caecum) cells analyzed within the same individual show the same B chromosome number. Nothing is known, however, about body parts with somatic tissues with no mitotic activity in adult individuals, constituting the immense majority of their body. Therefore, we investigated whether B chromosomes are present in 8 non-mitotically active somatic body parts from both sexes in addition to ovarioles and testes by PCR analysis of 2 B-specific molecular markers. We also elucidated the number of B chromosomes that an individual carried through quantifying the B-located rDNA copy number by qPCR. Our results indicated the amplification of both B-specific markers in all analyzed body parts. However, we found high variation between males for the estimated number of rDNA units in the B chromosomes. These results demonstrate the presence of B chromosomes in all body parts from the same individual and suggest a high variation in the rDNA content of the B chromosomes carried by different individuals from the same population, presumably due to unequal crossovers during meiosis.

  8. Pathogenicity islands and the evolution of bacterial pathogens.

    PubMed

    Lee, C A

    1996-01-01

    The term pathogenicity island has been used to refer to large chromosomal regions in pathogenic bacteria that encode virulence genes. This article reviews the recent history of this term and considers what characteristics define a pathogenicity island. It appears that pathogenicity islands can confer complex virulence phenotypes and were acquired by bacteria from unrelated organisms, leading to interesting hypotheses about how bacterial pathogens evolved. It is likely that mechanisms that generate pathogenicity islands continue to operate and may contribute to the emergence of bacterial pathogens with new virulence properties.

  9. Stomata and pathogens

    PubMed Central

    Gudesblat, Gustavo E; Torres, Pablo S

    2009-01-01

    Bacteria and fungi are capable of triggering stomatal closure through pathogen-associated molecular patterns (PAMPs), which prevents penetration through these pores. Therefore, the stomata can be considered part of the plant innate immune response. Some pathogens have evolved mechanisms to evade stomatal defense. The bacterial pathogen Xanthomonas campestris pv. campestris (Xcc), which infects plants of the Brassicaceae family mainly through hydathodes, has also been reported to infect plants through stomata. A recent report shows that penetration of Xcc in Arabidopsis leaves through stomata depends on a secreted small molecule whose synthesis is under control of the rpf/diffusible signal factor (DSF) cell-to-cell signaling system, which also controls genes involved in biofilm formation and pathogenesis. The same reports shows that Arabidopsis ROS- and PAMP-activated MAP kinase 3 (MPK3) is essential for stomatal innate response. Other recent and past findings about modulation of stomatal behaviour by pathogens are also discussed. In all, these findings support the idea that PAMP-triggered stomatal closure might be a more effective and widespread barrier against phytopathogens than previously thought, which has in turn led to the evolution in pathogens of several mechanisms to evade stomatal defense. PMID:20514224

  10. Mitochondrial DNA variation in the grasshopper Sinipta dalmani: application of long-PCR to the development of a homologous probe.

    PubMed

    Pensel, S M; Vilardi, J C; Remis, M I

    2005-12-01

    RFLP analysis of mtDNA in natural populations is a valuable tool for phylogeographic and population genetic studies. The amplification of long DNA fragments using universal primers may contribute to the development of novel homologous probes in species for which no previous genomic information is available. Here we report how we obtained the complete mtDNA genome of Sinipta dalmani (Orthoptera) in 2 fragments (7 and 9 kb) using primers of conserved regions. The specificity of the PCR reactions was ultimately confirmed by several lines of evidence. These fragments were used as a probe for a mtDNA RFLP study in S. dalmani that analyzed the pattern of haplotype distribution and nucleotide diversity within and among chromosomally differentiated natural populations. Our results suggest that the restriction in gene flow detected at the molecular level may explain the chromosome differentiation detected previously and the maintenance of chromosome polymorphism in some areas of S. dalmani geographic distribution.

  11. Bioterrorism: pathogens as weapons.

    PubMed

    Anderson, Peter D; Bokor, Gyula

    2012-10-01

    Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern.

  12. Bioterrorism: pathogens as weapons.

    PubMed

    Anderson, Peter D; Bokor, Gyula

    2012-10-01

    Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern. PMID:23011963

  13. Highly pathogenic avian influenza.

    PubMed

    Swayne, D E; Suarez, D L

    2000-08-01

    Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

  14. Comparative proteomics lends insight into genotype-specific pathogenicity.

    PubMed

    Guarnieri, Michael T

    2013-09-01

    Comparative proteomic analyses have emerged as a powerful tool for the identification of unique biomarkers and mechanisms of pathogenesis. In this issue of Proteomics, Murugaiyan et al. utilize difference gel electrophoresis (DIGE) to examine differential protein expression between nonpathogenic and pathogenic genotypes of Prototheca zopfii, a causative agent in bovine enteritis and mastitis. Their findings provide insights into molecular mechanisms of infection and evolutionary adaptation of pathogenic genotypes, demonstrating the power of comparative proteomic analyses. PMID:23925996

  15. Plant-pathogenic bacteria as biological weapons - real threats?

    PubMed

    Young, J M; Allen, C; Coutinho, T; Denny, T; Elphinstone, J; Fegan, M; Gillings, M; Gottwald, T R; Graham, J H; Iacobellis, N S; Janse, J D; Jacques, M-A; Lopez, M M; Morris, C E; Parkinson, N; Prior, P; Pruvost, O; Neto, J Rodrigues; Scortichini, M; Takikawa, Y; Upper, C D

    2008-10-01

    At present, much attention is being given to the potential of plant pathogens, including plant-pathogenic bacteria, as biological weapons/bioterror weapons. These two terms are sometimes used interchangeably and there is need for care in their application. It has been claimed that clandestine introduction of certain plant-pathogenic bacteria could cause such crop losses as to impact so significantly on a national economy and thus constitute a threat to national security. As a separate outcome, it is suggested that they could cause serious public alarm, perhaps constituting a source of terror. Legislation is now in place to regulate selected plant-pathogenic bacteria as potential weapons. However, we consider it highly doubtful that any plant-pathogenic bacterium has the requisite capabilities to justify such a classification. Even if they were so capable, the differentiation of pathogens into a special category with regulations that are even more restrictive than those currently applied in quarantine legislation of most jurisdictions offers no obvious benefit. Moreover, we believe that such regulations are disadvantageous insofar as they limit research on precisely those pathogens most in need of study. Whereas some human and animal pathogens may have potential as biological or bioterror weapons, we conclude that it is unlikely that any plant-pathogenic bacterium realistically falls into this category.

  16. Bloodborne Pathogens Program

    NASA Technical Reports Server (NTRS)

    Blasdell, Sharon

    1993-01-01

    The final rule on the Occupational Exposure to Bloodborne Pathogens was published in the Federal Register on Dec. 6, 1991. This Standard, 29 CFR Part 1910.130, is expected to prevent 8,900 hepatitis B infections and nearly 200 deaths a year in healthcare workers in the U.S. The Occupational Medicine and Environmental Health Services at KSC has been planning to implement this standard for several years. Various aspects of this standard and its Bloodborne Pathogens Program at KSC are discussed.

  17. Waterborne Pathogens: The Protozoans.

    PubMed

    Moss, Joseph Anthony

    2016-09-01

    Waterborne diseases associated with polluted recreational and potable waters have been documented for more than a century. Key microbial protozoan parasites, such as Cryptosporidium and Giardia, are causative agents for gastrointestinal disease worldwide. Although not a first-line diagnostic approach for these diseases, medical imaging, such as radiography, computed tomography, magnetic resonance imaging, ultrasonography, and nuclear medicine technologies, can be used to evaluate patients with long-term effects. This article describes protozoan pathogens that affect human health, treatment of common waterborne pathogen-related diseases, and associated medical imaging. PMID:27601690

  18. Particle size and pathogenicity in the respiratory tract

    PubMed Central

    Thomas, Richard James

    2013-01-01

    Particle size dictates where aerosolized pathogens deposit in the respiratory tract, thereafter the pathogens potential to cause disease is influenced by tissue tropism, clearance kinetics and the host immunological response. This interplay brings pathogens into contact with a range of tissues spanning the respiratory tract and associated anatomical structures. In animal models, differential deposition within the respiratory tract influences infection kinetics for numerous select agents. Greater numbers of pathogens are required to infect the upper (URT) compared with the lower respiratory tract (LRT), and in comparison the URT infections are protracted with reduced mortality. Pathogenesis in the URT is characterized by infection of the URT lymphoid tissues, cervical lymphadenopathy and septicemia, closely resembling reported human infections of the URT. The olfactory, gastrointestinal, and ophthalmic systems are also infected in a pathogen-dependent manner. The relevant literature is reviewed with respect to particle size and infection of the URT in animal models and humans. PMID:24225380

  19. PATHOGEN EQUIVALENCY COMMITTEE (PEC)

    EPA Science Inventory

    The U.S. Environmental Protection Agency created the PEC in 1985 to make recommendations to EPA and State managers on the equivalency of unproven sewage sludge disinfection technologies/processes to either a Process to Significantly Reduce Pathogens (PSRP) or a Process to Further...

  20. DISINFECTION OF EMERGING PATHOGENS

    EPA Science Inventory

    There is a growing awareness of the need to control waterborne microbial pathogens. This presentation will concentate on the role of chemical inactivation, using chlorine, chloramines and ozone as a means of controlling bacterial and protozoan species. Information will be present...

  1. Leafhopper viral pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four newly discovered viral pathogens in leafhopper vectors of Pierce’s disease of grapes, have been shown to replicate in sharpshooter leafhoppers; the glassy-winged sharpshooter, GWSS, Homalodisca vitripennis, and Oncometopia nigricans (Hemiptera: Cicadellidae). The viruses were classified as memb...

  2. [Salmonella pathogenicity islands].

    PubMed

    Sırıken, Belgin

    2013-01-01

    Salmonella species are facultative intracellular pathogenic bacteria. They can invade macrophages, dendritic and epithelial cells. The responsible virulence genes for invasion, survival, and extraintestinal spread are located in Salmonella pathogenicity islands (SPIs). SPIs are thought to be acquired by horizontal gene transfer. Some of the SPIs are conserved throughout the Salmonella genus, and some of them are specific for certain serovars. There are differences between Salmonella serotypes in terms of adaptation to host cell, virulence factors and the resulting infection according to SPA presence and characteristics. The most important Salmonella virulence gene clusters are located in 12 pathogenicity islands. Virulence genes that are involved in the intestinal phase of infection are located in SPI-1 and SPI-2 and the remaining SPIs are required for intracellular survival, fimbrial expression, magnesium and iron uptake, multiple antibiotic resistance and the development of systemic infections. In addition SPIs, Sigma ss (RpoS) factors and adaptive acid tolerance response (ATR) are the other two important virulence factors. RpoS and ATR found in virulent Salmonella strains help the bacteria to survive under inappropriate conditions such as gastric acidity, bile salts, inadequate oxygen concentration, lack of nutrients, antimicrobial peptides, mucus and natural microbiota and also to live in phagosomes or phagolysosomes. This review article summarizes the data related to pathogenicity islands in Salmonella serotypes and some factors which play role in the regulation of virulence genes.

  3. Bacterial genomes: evolution of pathogenicity.

    PubMed

    Arnold, Dawn L; Jackson, Robert W

    2011-08-01

    Bacterial pathogens continue to pose a major threat to economically important plant resources. Disease outbreaks can occur through rapid evolution of a pathogen to overcome host defences. The advent of genome sequencing, especially next-generation technologies, has seen a revolution in the study of plant pathogen evolution over the past five years. This review highlights recent developments in understanding bacterial plant pathogen evolution, enabled by genomics and specifically focusing on type III protein effectors. The genotypic changes and mechanisms involved in pathogen evolution are now much better understood. However, there is still much to be learned about the drivers of pathogen evolution, both in terms of plant resistance and bacterial lifestyle.

  4. Resequencing Pathogen Microarray (RPM) for prospective detection and identification of emergent pathogen strains and variants

    NASA Astrophysics Data System (ADS)

    Tibbetts, Clark; Lichanska, Agnieszka M.; Borsuk, Lisa A.; Weslowski, Brian; Morris, Leah M.; Lorence, Matthew C.; Schafer, Klaus O.; Campos, Joseph; Sene, Mohamadou; Myers, Christopher A.; Faix, Dennis; Blair, Patrick J.; Brown, Jason; Metzgar, David

    2010-04-01

    High-density resequencing microarrays support simultaneous detection and identification of multiple viral and bacterial pathogens. Because detection and identification using RPM is based upon multiple specimen-specific target pathogen gene sequences generated in the individual test, the test results enable both a differential diagnostic analysis and epidemiological tracking of detected pathogen strains and variants from one specimen to the next. The RPM assay enables detection and identification of pathogen sequences that share as little as 80% sequence similarity to prototype target gene sequences represented as detector tiles on the array. This capability enables the RPM to detect and identify previously unknown strains and variants of a detected pathogen, as in sentinel cases associated with an infectious disease outbreak. We illustrate this capability using assay results from testing influenza A virus vaccines configured with strains that were first defined years after the design of the RPM microarray. Results are also presented from RPM-Flu testing of three specimens independently confirmed to the positive for the 2009 Novel H1N1 outbreak strain of influenza virus.

  5. Multiplex detection of agricultural pathogens

    DOEpatents

    Siezak, Thomas R.; Gardner, Shea; Torres, Clinton; Vitalis, Elizabeth; Lenhoff, Raymond J.

    2013-01-15

    Described are kits and methods useful for detection of agricultural pathogens in a sample. Genomic sequence information from agricultural pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay and/or an array assay to successfully identify the presence or absence of pathogens in a sample.

  6. Multiplex detection of agricultural pathogens

    DOEpatents

    McBride, Mary Teresa; Slezak, Thomas Richard; Messenger, Sharon Lee

    2010-09-14

    Described are kits and methods useful for detection of seven agricultural pathogens (BPSV; BHV; BVD; FMDV; BTV; SVD; and VESV) in a sample. Genomic sequence information from 7 agricultural pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay to successfully identify the presence or absence of pathogens in a sample.

  7. Opportunistic Pathogenic Yeasts

    NASA Astrophysics Data System (ADS)

    Banerjee, Uma

    Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

  8. Extraintestinal pathogenic Escherichia coli.

    PubMed

    Smith, James L; Fratamico, Pina M; Gunther, Nereus W

    2007-01-01

    Extraintestinal pathogenic Escherichia coli (ExPEC) possesses virulence traits that allow it to invade, colonize, and induce disease in bodily sites outside of the gastrointestinal tract. Human diseases caused by ExPEC include urinary tract infections, neonatal meningitis, sepsis, pneumonia, surgical site infections, as well as infections in other extraintestinal locations. ExPEC-induced diseases represent a large burden in terms of medical costs and productivity losses. In addition to human illnesses, ExPEC strains also cause extraintestinal infections in domestic animals and pets. A commonality of virulence factors has been demonstrated between human and animal ExPEC, suggesting that the organisms are zoonotic pathogens. ExPEC strains have been isolated from food products, in particular from raw meats and poultry, indicating that these organisms potentially represent a new class of foodborne pathogens. This review discusses various aspects of ExPEC, including its presence in food products, in animals used for food or as companion pets; the diseases ExPEC can cause; and the virulence factors and virulence mechanisms that cause disease.

  9. Pathogenicity islands in bacterial pathogenesis.

    PubMed

    Schmidt, Herbert; Hensel, Michael

    2004-01-01

    In this review, we focus on a group of mobile genetic elements designated pathogenicity islands (PAI). These elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. Characteristic molecular features of PAI of important human pathogens and their role in pathogenesis are described. The availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a unique opportunity for the identification of novel pathogen-specific genomic islands. However, this knowledge has to be complemented by improved model systems for the analysis of virulence functions of bacterial pathogens. PAI apparently have been acquired during the speciation of pathogens from their nonpathogenic or environmental ancestors. The acquisition of PAI not only is an ancient evolutionary event that led to the appearance of bacterial pathogens on a timescale of millions of years but also may represent a mechanism that contributes to the appearance of new pathogens within a human life span. The acquisition of knowledge about PAI, their structure, their mobility, and the pathogenicity factors they encode not only is helpful in gaining a better understanding of bacterial evolution and interactions of pathogens with eukaryotic host cells but also may have important practical implications such as providing delivery systems for vaccination, tools for cell biology, and tools for the development of new strategies for therapy of bacterial infections.

  10. Pathogenicity Islands in Bacterial Pathogenesis

    PubMed Central

    Schmidt, Herbert; Hensel, Michael

    2004-01-01

    In this review, we focus on a group of mobile genetic elements designated pathogenicity islands (PAI). These elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. Characteristic molecular features of PAI of important human pathogens and their role in pathogenesis are described. The availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a unique opportunity for the identification of novel pathogen-specific genomic islands. However, this knowledge has to be complemented by improved model systems for the analysis of virulence functions of bacterial pathogens. PAI apparently have been acquired during the speciation of pathogens from their nonpathogenic or environmental ancestors. The acquisition of PAI not only is an ancient evolutionary event that led to the appearance of bacterial pathogens on a timescale of millions of years but also may represent a mechanism that contributes to the appearance of new pathogens within a human life span. The acquisition of knowledge about PAI, their structure, their mobility, and the pathogenicity factors they encode not only is helpful in gaining a better understanding of bacterial evolution and interactions of pathogens with eukaryotic host cells but also may have important practical implications such as providing delivery systems for vaccination, tools for cell biology, and tools for the development of new strategies for therapy of bacterial infections. PMID:14726454

  11. Single-Cell Genomics Unveils Critical Regulators of Th17 Cell Pathogenicity.

    PubMed

    Gaublomme, Jellert T; Yosef, Nir; Lee, Youjin; Gertner, Rona S; Yang, Li V; Wu, Chuan; Pandolfi, Pier Paolo; Mak, Tak; Satija, Rahul; Shalek, Alex K; Kuchroo, Vijay K; Park, Hongkun; Regev, Aviv

    2015-12-01

    Extensive cellular heterogeneity exists within specific immune-cell subtypes classified as a single lineage, but its molecular underpinnings are rarely characterized at a genomic scale. Here, we use single-cell RNA-seq to investigate the molecular mechanisms governing heterogeneity and pathogenicity of Th17 cells isolated from the central nervous system (CNS) and lymph nodes (LN) at the peak of autoimmune encephalomyelitis (EAE) or differentiated in vitro under either pathogenic or non-pathogenic polarization conditions. Computational analysis relates a spectrum of cellular states in vivo to in-vitro-differentiated Th17 cells and unveils genes governing pathogenicity and disease susceptibility. Using knockout mice, we validate four new genes: Gpr65, Plzp, Toso, and Cd5l (in a companion paper). Cellular heterogeneity thus informs Th17 function in autoimmunity and can identify targets for selective suppression of pathogenic Th17 cells while potentially sparing non-pathogenic tissue-protective ones. PMID:26607794

  12. Genetics-based interactions among plants, pathogens, and herbivores define arthropod community structure.

    PubMed

    Busby, Posy E; Lamit, Louis J; Keith, Arthur R; Newcombe, George; Gehring, Catherine A; Whitham, Thomas G; Dirzo, Rodolfo

    2015-07-01

    Plant resistance to pathogens or insect herbivores is common, but its potential for indirectly influencing plant-associated communities is poorly known. Here, we test whether pathogens' indirect effects on arthropod communities and herbivory depend on plant resistance to pathogens and/or herbivores, and address the overarching interacting foundation species hypothesis that genetics-based interactions among a few highly interactive species can structure a much larger community. In a manipulative field experiment using replicated genotypes of two Populus species and their interspecific hybrids, we found that genetic variation in plant resistance to both pathogens and insect herbivores modulated the strength of pathogens' indirect effects on arthropod communities and insect herbivory. First, due in part to the pathogens' differential impacts on leaf biomass among the two Populus species and the hybrids, the pathogen most strongly impacted arthropod community composition, richness, and abundance on the pathogen-susceptible tree species. Second, we found similar patterns comparing pathogen-susceptible and pathogen-resistant genotypes within species. Third, within a plant species, pathogens caused a fivefold greater reduction in herbivory on insect-herbivore-susceptible plant genotypes than on herbivore-resistant genotypes, demonstrating that the pathogen-herbivore interaction is genotype dependent. We conclude that interactions among plants, pathogens, and herbivores can structure multitrophic communities, supporting the interacting foundation species hypothesis. Because these interactions are genetically based, evolutionary changes in genetic resistance could result in ecological changes in associated communities, which may in turn feed back to affect plant fitness.

  13. BK polyomavirus: emerging pathogen.

    PubMed

    Bennett, Shauna M; Broekema, Nicole M; Imperiale, Michael J

    2012-08-01

    BK polyomavirus (BKPyV) is a small double-stranded DNA virus that is an emerging pathogen in immunocompromised individuals. BKPyV is widespread in the general population, but primarily causes disease when immune suppression leads to reactivation of latent virus. Polyomavirus-associated nephropathy and hemorrhagic cystitis in renal and bone marrow transplant patients, respectively, are the most common diseases associated with BKPyV reactivation and lytic infection. In this review, we discuss the clinical relevance, effects on the host, virus life cycle, and current treatment protocols. PMID:22402031

  14. Portable pathogen detection system

    SciTech Connect

    Colston, Billy W.; Everett, Matthew; Milanovich, Fred P.; Brown, Steve B.; Vendateswaran, Kodumudi; Simon, Jonathan N.

    2005-06-14

    A portable pathogen detection system that accomplishes on-site multiplex detection of targets in biological samples. The system includes: microbead specific reagents, incubation/mixing chambers, a disposable microbead capture substrate, and an optical measurement and decoding arrangement. The basis of this system is a highly flexible Liquid Array that utilizes optically encoded microbeads as the templates for biological assays. Target biological samples are optically labeled and captured on the microbeads, which are in turn captured on an ordered array or disordered array disposable capture substrate and then optically read.

  15. The Keystone Pathogen Hypothesis

    PubMed Central

    Hajishengallis, George; Darveau, Richard P.; Curtis, Michael A.

    2012-01-01

    Recent studies have highlighted the importance of the human microbiome in host health and disease. However, for the most part the mechanisms by which the microbiome mediates disease, or protection from it, remain poorly understood. The “keystone pathogen” hypothesis holds that certain low-abundance microbial pathogens can orchestrate inflammatory disease by remodelling a normally benign microbiota into a dysbiotic one. In this Opinion, we critically assess the available literature in support of this hypothesis, which may provide a novel conceptual basis for the development of targeted diagnostic and treatment modalities for complex dysbiotic diseases. PMID:22941505

  16. Life-style transitions in plant pathogenic Colletotrichum fungi deciphered by genome and transcriptome analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colletotrichum species are devastating fungal pathogens of major crop plants worldwide. Infection involves differentiation of specialized cell-types associated with host surface penetration, growth inside living host cells (biotrophy) and tissue destruction (necrotrophy). Here we report genome and t...

  17. Modeling of pathogen survival during simulated gastric digestion.

    PubMed

    Koseki, Shige; Mizuno, Yasuko; Sotome, Itaru

    2011-02-01

    The objective of the present study was to develop a mathematical model of pathogenic bacterial inactivation kinetics in a gastric environment in order to further understand a part of the infectious dose-response mechanism. The major bacterial pathogens Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp. were examined by using simulated gastric fluid adjusted to various pH values. To correspond to the various pHs in a stomach during digestion, a modified logistic differential equation model and the Weibull differential equation model were examined. The specific inactivation rate for each pathogen was successfully described by a square-root model as a function of pH. The square-root models were combined with the modified logistic differential equation to obtain a complete inactivation curve. Both the modified logistic and Weibull models provided a highly accurate fitting of the static pH conditions for every pathogen. However, while the residuals plots of the modified logistic model indicated no systematic bias and/or regional prediction problems, the residuals plots of the Weibull model showed a systematic bias. The modified logistic model appropriately predicted the pathogen behavior in the simulated gastric digestion process with actual food, including cut lettuce, minced tuna, hamburger, and scrambled egg. Although the developed model enabled us to predict pathogen inactivation during gastric digestion, its results also suggested that the ingested bacteria in the stomach would barely be inactivated in the real digestion process. The results of this study will provide important information on a part of the dose-response mechanism of bacterial pathogens. PMID:21131530

  18. Development of methodology to prioritise wildlife pathogens for surveillance.

    PubMed

    McKenzie, Joanna; Simpson, Helen; Langstaff, Ian

    2007-09-14

    We developed and evaluated a methodology to prioritise pathogens for a wildlife disease surveillance strategy in New Zealand. The methodology, termed 'rapid risk analysis' was based on the import risk analysis framework recommended by the Office Internationale des Epizooties (OIE), and involved: hazard identification, risk estimation, and ranking of 48 exotic and 34 endemic wildlife pathogens. The risk assessment was more rapid than a full quantitative assessment through the use of a semi-quantitative approach to score pathogens for probability of entry to NZ (release assessment), likelihood of spread (exposure assessment) and consequences in free-living wildlife, captive wildlife, humans, livestock and companion animals. Risk was estimated by multiplying the scores for the probability of entry to New Zealand by the likelihood of spread by the consequences for free-living wildlife, humans and livestock. The rapid risk analysis methodology produced scores that were sufficiently differentiated between pathogens to be useful for ranking them on the basis of risk. Ranking pathogens on the basis of the risk estimate for each population sector provided an opportunity to identify the priorities within each sector alone thus avoiding value-laden comparisons between sectors. Ranking pathogens across all three population sectors by summing the risk estimate for each sector provided a comparison of total risk which may be useful for resource allocation decisions at national level. Ranking pathogens within each wildlife taxonomic group using the total risk estimate was most useful for developing specific surveillance strategies for each group. PMID:17482697

  19. Tick vaccines and the control of tick-borne pathogens.

    PubMed

    Merino, Octavio; Alberdi, Pilar; Pérez de la Lastra, José M; de la Fuente, José

    2013-01-01

    Ticks are obligate hematophagous ectoparasites that transmit a wide variety of pathogens to humans and animals. The incidence of tick-borne diseases has increased worldwide in both humans and domestic animals over the past years resulting in greater interest in the study of tick-host-pathogen interactions. Advances in vector and pathogen genomics and proteomics have moved forward our knowledge of the vector-pathogen interactions that take place during the colonization and transmission of arthropod-borne microbes. Tick-borne pathogens adapt from the vector to the mammalian host by differential gene expression thus modulating host processes. In recent years, studies have shown that targeting tick proteins by vaccination can not only reduce tick feeding and reproduction, but also the infection and transmission of pathogens from the tick to the vertebrate host. In this article, we review the tick-protective antigens that have been identified for the formulation of tick vaccines and the effect of these vaccines on the control of tick-borne pathogens.

  20. Tick vaccines and the control of tick-borne pathogens

    PubMed Central

    Merino, Octavio; Alberdi, Pilar; Pérez de la Lastra, José M.; de la Fuente, José

    2013-01-01

    Ticks are obligate hematophagous ectoparasites that transmit a wide variety of pathogens to humans and animals. The incidence of tick-borne diseases has increased worldwide in both humans and domestic animals over the past years resulting in greater interest in the study of tick-host-pathogen interactions. Advances in vector and pathogen genomics and proteomics have moved forward our knowledge of the vector-pathogen interactions that take place during the colonization and transmission of arthropod-borne microbes. Tick-borne pathogens adapt from the vector to the mammalian host by differential gene expression thus modulating host processes. In recent years, studies have shown that targeting tick proteins by vaccination can not only reduce tick feeding and reproduction, but also the infection and transmission of pathogens from the tick to the vertebrate host. In this article, we review the tick-protective antigens that have been identified for the formulation of tick vaccines and the effect of these vaccines on the control of tick-borne pathogens. PMID:23847771

  1. Pathogenic Network Analysis Predicts Candidate Genes for Cervical Cancer

    PubMed Central

    Zhang, Yun-Xia

    2016-01-01

    Purpose. The objective of our study was to predicate candidate genes in cervical cancer (CC) using a network-based strategy and to understand the pathogenic process of CC. Methods. A pathogenic network of CC was extracted based on known pathogenic genes (seed genes) and differentially expressed genes (DEGs) between CC and normal controls. Subsequently, cluster analysis was performed to identify the subnetworks in the pathogenic network using ClusterONE. Each gene in the pathogenic network was assigned a weight value, and then candidate genes were obtained based on the weight distribution. Eventually, pathway enrichment analysis for candidate genes was performed. Results. In this work, a total of 330 DEGs were identified between CC and normal controls. From the pathogenic network, 2 intensely connected clusters were extracted, and a total of 52 candidate genes were detected under the weight values greater than 0.10. Among these candidate genes, VIM had the highest weight value. Moreover, candidate genes MMP1, CDC45, and CAT were, respectively, enriched in pathway in cancer, cell cycle, and methane metabolism. Conclusion. Candidate pathogenic genes including MMP1, CDC45, CAT, and VIM might be involved in the pathogenesis of CC. We believe that our results can provide theoretical guidelines for future clinical application. PMID:27034707

  2. Cryptosporidium Pathogenicity and Virulence

    PubMed Central

    Bouzid, Maha; Chalmers, Rachel M.; Tyler, Kevin M.

    2013-01-01

    Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence. PMID:23297262

  3. Differentiated Staffing.

    ERIC Educational Resources Information Center

    Geisinger, Robert W.; And Others

    This report describes school operation changes in scheduling, curriculum, decisionmaking powers, and individualization of instruction that are concurrent with the adoption of differentiated staffing. The author defines differentiated staffing, explains where and at what levels it has been utilized, provides descriptions of results achieved, gives…

  4. Differential games.

    NASA Technical Reports Server (NTRS)

    Varaiya, P. P.

    1972-01-01

    General discussion of the theory of differential games with two players and zero sum. Games starting at a fixed initial state and ending at a fixed final time are analyzed. Strategies for the games are defined. The existence of saddle values and saddle points is considered. A stochastic version of a differential game is used to examine the synthesis problem.

  5. Clostridium difficile Is an Autotrophic Bacterial Pathogen

    PubMed Central

    Köpke, Michael; Straub, Melanie; Dürre, Peter

    2013-01-01

    During the last decade, Clostridium difficile infection showed a dramatic increase in incidence and virulence in the Northern hemisphere. This incessantly challenging disease is the leading cause of antibiotic-associated and nosocomial infectious diarrhea and became life-threatening especially among elderly people. It is generally assumed that all human bacterial pathogens are heterotrophic organisms, being either saccharolytic or proteolytic. So far, this has not been questioned as colonization of the human gut gives access to an environment, rich in organic nutrients. Here, we present data that C. difficile (both clinical and rumen isolates) is also able to grow on CO2+H2 as sole carbon and energy source, thus representing the first identified autotrophic bacterial pathogen. Comparison of several different strains revealed high conservation of genes for autotrophic growth and showed that the ability to use gas mixtures for growth decreases or is lost upon prolonged culturing under heterotrophic conditions. The metabolic flexibility of C. difficile (heterotrophic growth on various substrates as well as autotrophy) could allow the organism in the gut to avoid competition by niche differentiation and contribute to its survival when stressed or in unfavorable conditions that cause death to other bacteria. This may be an important trait for the pathogenicity of C. difficile. PMID:23626782

  6. Tomato transcriptional responses to a foliar and a vascular fungal pathogen are distinct.

    PubMed

    van Esse, H Peter; Fradin, Emilie F; de Groot, Philip J; de Wit, Pierre J G M; Thomma, Bart P H J

    2009-03-01

    Plant activation of host defense against pathogenic microbes requires significant host transcriptional reprogramming. In this study, we compared transcriptional changes in tomato during compatible and incompatible interactions with the foliar fungal pathogen Cladosporium fulvum and the vascular fungal pathogen Verticillium dahliae. Although both pathogens colonize different host tissues, they display distinct commonalities in their infection strategy; both pathogens penetrate natural openings and grow strictly extracellular. Furthermore, resistance against both pathogens is conveyed by the same class of resistance proteins, the receptor-like proteins. For each individual pathogen, the expression profile of the compatible and incompatible interaction largely overlaps. However, when comparing between the two pathogens, the C. fulvum-induced transcriptional changes show little overlap with those induced by V. dahliae. Moreover, within the subset of genes that are regulated by both pathogens, many genes show inverse regulation. With pathway reconstruction, networks of tomato genes implicated in photorespiration, hypoxia, and glycoxylate metabolism were identified that are repressed upon infection with C. fulvum and induced by V. dahliae. Similarly, auxin signaling is differentially affected by the two pathogens. Thus, differentially regulated pathways were identified with novel strategies that allowed the use of state-of-the-art tools, even though tomato is not a genetic model organism.

  7. [Streptococcus pyogenes pathogenic factors].

    PubMed

    Bidet, Ph; Bonacorsi, S

    2014-11-01

    The pathogenicity of ß-hemolytic group A streptococcus (GAS) is particularly diverse, ranging from mild infections, such as pharyngitis or impetigo, to potentially debilitating poststreptococcal diseases, and up to severe invasive infections such as necrotizing fasciitis or the dreaded streptococcal toxic shock syndrome. This variety of clinical expressions, often radically different in individuals infected with the same strain, results from a complex interaction between the bacterial virulence factors, the mode of infection and the immune system of the host. Advances in comparative genomics have led to a better understanding of how, following this confrontation, GAS adapts to the immune system's pressure, either peacefully by reducing the expression of certain virulence factors to achieve an asymptomatic carriage, or on the contrary, by overexpressing them disproportionately, resulting in the most severe forms of invasive infection. PMID:25456681

  8. Flagella and bacterial pathogenicity.

    PubMed

    Duan, Qiangde; Zhou, Mingxu; Zhu, Liqian; Zhu, Guoqiang

    2013-01-01

    As locomotive organelles, flagella allow bacteria to move toward favorable environments. A flagellum consists of three parts: the basal structure (rotary motor), the hook (universal joint), and the filament (helical propeller). For ages, flagella have been generally regarded as important virulence factors, mainly because of their motility property. However, flagella are getting recognized to play multiple roles with more functions besides motility and chemotaxis. Recent evidence has pinpointed that the bacterial flagella participate in many additional processes including adhesion, biofilm formation, virulence factor secretion, and modulation of the immune system of eukaryotic cells. This mini-review summarizes data from recent studies that elucidated how flagella, as a virulence factor, contribute to bacterial pathogenicity.

  9. Flagella and bacterial pathogenicity.

    PubMed

    Duan, Qiangde; Zhou, Mingxu; Zhu, Liqian; Zhu, Guoqiang

    2013-01-01

    As locomotive organelles, flagella allow bacteria to move toward favorable environments. A flagellum consists of three parts: the basal structure (rotary motor), the hook (universal joint), and the filament (helical propeller). For ages, flagella have been generally regarded as important virulence factors, mainly because of their motility property. However, flagella are getting recognized to play multiple roles with more functions besides motility and chemotaxis. Recent evidence has pinpointed that the bacterial flagella participate in many additional processes including adhesion, biofilm formation, virulence factor secretion, and modulation of the immune system of eukaryotic cells. This mini-review summarizes data from recent studies that elucidated how flagella, as a virulence factor, contribute to bacterial pathogenicity. PMID:22359233

  10. Pathogenic effects of asbestos.

    PubMed

    Kannerstein, M; Churg, J; McCaughey, E; Selikoff, I J

    1977-12-01

    The enormous increase in the use of asbestos during this century has necessitated the intensive study of its pathogenic effects. The occurrence of pulmonary parenchymal and pleural fibrosis and an increased prevalence of pulmonary and gastrointestinal carcinoma and of pleural and peritoneal mesothelioma have been established. A relationship, also, to laryngeal carcinoma is probable. Mesothelioma has been associated with indirect occupational, domestic, and neighborhood exposure, and the possibility of a similar correlation of pulmonary carcinoma with low exposure has been suggested. Pulmonary fibrosis and pleural plaques have been demonstrated under these circumstances. The physical characteristics of the asbestos fiber appear to be the principal factors in its carcinogenic action. The ability of fine, short fibers, especially fragmented chrysotile, to reach the pleura would appear to account for many of the pathogenetic and anatomical features of asbestos-related disease.

  11. Rapid Detection of Pathogens

    SciTech Connect

    David Perlin

    2005-08-14

    Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development

  12. Fungal pathogens of Proteaceae.

    PubMed

    Crous, P W; Summerell, B A; Swart, L; Denman, S; Taylor, J E; Bezuidenhout, C M; Palm, M E; Marincowitz, S; Groenewald, J Z

    2011-12-01

    Species of Leucadendron, Leucospermum and Protea (Proteaceae) are in high demand for the international floriculture market due to their brightly coloured and textured flowers or bracts. Fungal pathogens, however, create a serious problem in cultivating flawless blooms. The aim of the present study was to characterise several of these pathogens using morphology, culture characteristics, and DNA sequence data of the rRNA-ITS and LSU genes. In some cases additional genes such as TEF 1-α and CHS were also sequenced. Based on the results of this study, several novel species and genera are described. Brunneosphaerella leaf blight is shown to be caused by three species, namely B. jonkershoekensis on Protea repens, B. nitidae sp. nov. on Protea nitida and B. protearum on a wide host range of Protea spp. (South Africa). Coniothyrium-like species associated with Coniothyrium leaf spot are allocated to other genera, namely Curreya grandicipis on Protea grandiceps, and Microsphaeropsis proteae on P. nitida (South Africa). Diaporthe leucospermi is described on Leucospermum sp. (Australia), and Diplodina microsperma newly reported on Protea sp. (New Zealand). Pyrenophora blight is caused by a novel species, Pyrenophora leucospermi, and not Drechslera biseptata or D. dematoidea as previously reported. Fusicladium proteae is described on Protea sp. (South Africa), Pestalotiopsis protearum on Leucospermum cuneiforme (Zimbabwe), Ramularia vizellae and R. stellenboschensis on Protea spp. (South Africa), and Teratosphaeria capensis on Protea spp. (Portugal, South Africa). Aureobasidium leaf spot is shown to be caused by two species, namely A. proteae comb. nov. on Protea spp. (South Africa), and A. leucospermi sp. nov. on Leucospermum spp. (Indonesia, Portugal, South Africa). Novel genera and species elucidated in this study include Gordonomyces mucovaginatus and Pseudopassalora gouriqua (hyphomycetes), and Xenoconiothyrium catenata (coelomycete), all on Protea spp. (South Africa).

  13. Multiplex detection of respiratory pathogens

    DOEpatents

    McBride, Mary; Slezak, Thomas; Birch, James M.

    2012-07-31

    Described are kits and methods useful for detection of respiratory pathogens (influenza A (including subtyping capability for H1, H3, H5 and H7 subtypes) influenza B, parainfluenza (type 2), respiratory syncytial virus, and adenovirus) in a sample. Genomic sequence information from the respiratory pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay to successfully identify the presence or absence of pathogens in a sample.

  14. Host Specificity of Bacterial Pathogens

    PubMed Central

    Bäumler, Andreas; Fang, Ferric C.

    2013-01-01

    Most pathogens are able to infect multiple hosts but some are highly adapted to a single-host species. A detailed understanding of the basis of host specificity can provide important insights into molecular pathogenesis, the evolution of pathogenic microbes, and the potential for pathogens to cross the species barrier to infect new hosts. Comparative genomics and the development of humanized mouse models have provided important new tools with which to explore the basis of generalism and specialism. This review will examine host specificity of bacterial pathogens with a focus on generalist and specialist serovars of Salmonella enterica. PMID:24296346

  15. DIFFERENTIAL ANALYZER

    DOEpatents

    Sorensen, E.G.; Gordon, C.M.

    1959-02-10

    Improvements in analog eomputing machines of the class capable of evaluating differential equations, commonly termed differential analyzers, are described. In general form, the analyzer embodies a plurality of basic computer mechanisms for performing integration, multiplication, and addition, and means for directing the result of any one operation to another computer mechanism performing a further operation. In the device, numerical quantities are represented by the rotation of shafts, or the electrical equivalent of shafts.

  16. Sexual differentiation.

    PubMed

    Sinisi, A A; Pasquali, D; Notaro, A; Bellastella, A

    2003-01-01

    In humans, like as in other mammals, the gonads, the internal genital ducts, and the external genital structures all develop from bipotential embryologic tissues. Male or female phenotype develops through a cascade of processes which initiate with sex determination and follow with sex differentiation. The karyotype (46, XY or 46, XX) of the embryo (genetic sex) determines whether primordial gonad differentiates into a testis or an ovary, respectively (gonadal differentiation). A Y-related gene, SRY, acts as a switch signal for testis differentiation. Testis development process involves several steps controlled by other non-OY-linked genes, such as Wilms tumor gene 1 (WT1), EMX2, LIM1, steroidogenic factor 1(SF-1), SRY box-related gene 9 (SOX9). Since other genes, such as Wnt-4 and DAX-1, are necessary for the initiation of female pathway in sex determination, female development cannot be considered a default process. Hormonal production of differentiated gonads is relevant for differentiation of the internal and external genitalia during fetal life, and for the development of secondary sex characteristics at puberty. Antimullerian hormone (AMH) secreted by Sertoli cells inhibits the development of female internal genitalia (tube, uterus, upper part of vagina); testosterone secreted by Leydig cells induces stabilization of wolffian ducts and development of internal male genitalia. Differentiation of external male genitalia requires the transformation of testosterone to dihydrotestosterone by 5alpha reductase type 2 expressed in genital skin and urogenital sinus. The effects of androgens occur in presence of functional androgen receptor (AR) protein. Mutations of genes coding for steroidogenic enzymes, AMH, AMH receptor, AR and 5alpha reductase are all associated with impairment of sex differentiation and result in genital ambiguity. PMID:12834017

  17. Richness and composition of niche-assembled viral pathogen communities.

    PubMed

    Seabloom, Eric W; Borer, Elizabeth T; Lacroix, Christelle; Mitchell, Charles E; Power, Alison G

    2013-01-01

    The pathogen and parasite community that inhabits every free-living organism can control host vital rates including lifespan and reproductive output. To date, however, there have been few experiments examining pathogen community assembly replicated at large-enough spatial scales to inform our understanding of pathogen dynamics in natural systems. Pathogen community assembly may be driven by neutral stochastic colonization and extinction events or by niche differentiation that constrains pathogen distributions to particular environmental conditions, hosts, or vectors. Here, we present results from a regionally-replicated experiment investigating the community of barley and cereal yellow dwarf viruses (B/CYDV's) in over 5000 experimentally planted individuals of six grass species along a 700 km latitudinal gradient along the Pacific coast of North America (USA) in response to experimentally manipulated nitrogen and phosphorus supplies. The composition of the virus community varied predictably among hosts and across nutrient-addition treatments, indicating niche differentiation among virus species. There were some concordant responses among the viral species. For example, the prevalence of most viral species increased consistently with perennial grass cover, leading to a 60% increase in the richness of the viral community within individual hosts (i.e., coinfection) in perennial-dominated plots. Furthermore, infection rates of the six host species in the field were highly correlated with vector preferences assessed in laboratory trials. Our results reveal the importance of niche differentiation in structuring virus assemblages. Virus species distributions reflected a combination of local host community composition, host species-specific vector preferences, and virus responses to host nutrition. In addition, our results suggest that heterogeneity among host species in their capacity to attract vectors or support pathogens between growing seasons can lead to positive

  18. Pathogenic agents in freshwater resources

    NASA Astrophysics Data System (ADS)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  19. Promiscuous Pathogenicity Islands and Phylogeny of Pathogenic Streptomyces spp.

    PubMed

    Zhang, Yucheng; Bignell, Dawn R D; Zuo, Ran; Fan, Qiurong; Huguet-Tapia, Jose C; Ding, Yousong; Loria, Rosemary

    2016-08-01

    Approximately 10 Streptomyces species cause disease on underground plant structures. The most economically important of these is potato scab, and the most studied of these pathogens is Streptomyces scabiei (syn. S. scabies). The main pathogenicity determinant of scab-causing Streptomyces species is a nitrated diketopiperazine, known as thaxtomin A (ThxA). In the pathogenic species Streptomyces turgidiscabies, ThxA biosynthetic genes reside on a mobile pathogenicity island (PAI). However, the mobilization of PAIs in other Streptomyces species remains uncharacterized. Here, we investigated the mobilization of the PAI of S. scabiei 87-22. Based on whole genome sequences, we inferred the evolutionary relationships of pathogenic Streptomyces species and discovered that Streptomyces sp. strain 96-12, a novel pathogenic species isolated from potatoes in Egypt, was phylogenetically grouped with nonpathogenic species rather than with known pathogenic species. We also found that Streptomyces sp. strain 96-12 contains a PAI that is almost identical to the PAI in S. scabiei 87-22, despite significant differences in their genome sequences. This suggested direct or indirect in vivo mobilization of the PAI between S. scabiei and nonpathogenic Streptomyces species. To test whether the S. scabiei 87-22 PAI could, indeed, be mobilized, S. scabiei 87-22 deletion mutants containing antibiotic resistance markers in the PAI were mated with Streptomyces diastatochromogenes, a nonpathogenic species. The PAI of S. scabiei was site-specifically inserted into the aviX1 gene of S. diastatochromogenes and conferred pathogenicity in radish seedling assays. Our results demonstrated that S. scabiei, the earliest described Streptomyces pathogen, could be the source of a PAI responsible for the emergence of novel pathogenic species. PMID:27502745

  20. Virulence-specific cell cycle and morphogenesis connections in pathogenic fungi.

    PubMed

    Pérez-Martín, José; Bardetti, Paola; Castanheira, Sónia; de la Torre, Antonio; Tenorio-Gómez, María

    2016-09-01

    To initiate pathogenic development, pathogenic fungi respond to a set of inductive cues. Some of them are of an extracellular nature (environmental signals), while others are intracellular (developmental signals). These signals must be integrated into a single response whose major outcome is changes in the morphogenesis of the fungus. The regulation of the cell cycle is pivotal during these cellular differentiation steps; therefore, cell cycle regulation would likely provide control points for infectious development by fungal pathogens. Here, we provide clues to understanding how the control of the cell cycle is integrated with the morphogenesis program in pathogenic fungi, and we review current examples that support these connections. PMID:27032479

  1. How Salmonella became a pathogen.

    PubMed

    Groisman, E A; Ochman, H

    1997-09-01

    In many pathogens, virulence can be conferred by a single region of the genome. In contrast, the facultative intracellular lifestyle of Salmonella demands a large number of genes distributed around the chromosome. The evolution of Salmonella has been marked by the acquisition of several 'pathogenicity islands', each contributing to the unique virulence properties of this microorganism.

  2. Common themes in microbial pathogenicity.

    PubMed Central

    Finlay, B B; Falkow, S

    1989-01-01

    A bacterial pathogen is a highly adapted microorganism which has the capacity to cause disease. The mechanisms used by pathogenic bacteria to cause infection and disease usually include an interactive group of virulence determinants, sometimes coregulated, which are suited for the interaction of a particular microorganism with a specific host. Because pathogens must overcome similar host barriers, common themes in microbial pathogenesis have evolved. However, these mechanisms are diverse between species and not necessarily conserved; instead, convergent evolution has developed several different mechanisms to overcome host barriers. The success of a bacterial pathogen can be measured by the degree with which it replicates after entering the host and reaching its specific niche. Successful microbial infection reflects persistence within a host and avoidance or neutralization of the specific and nonspecific defense mechanisms of the host. The degree of success of a pathogen is dependent upon the status of the host. As pathogens pass through a host, they are exposed to new environments. Highly adapted pathogenic organisms have developed biochemical sensors exquisitely designed to measure and respond to such environmental stimuli and accordingly to regulate a cascade of virulence determinants essential for life within the host. The pathogenic state is the product of dynamic selective pressures on microbial populations. PMID:2569162

  3. USEPA PATHOGEN EQUIVALENCY COMMITTEE RETREAT

    EPA Science Inventory

    The Pathogen Equivalency Committee held its retreat from September 20-21, 2005 at Hueston Woods State Park in College Corner, Ohio. This presentation will update the PEC’s membership on emerging pathogens, analytical methods, disinfection techniques, risk analysis, preparat...

  4. Physical constraints for pathogen movement.

    PubMed

    Schwarz, Ulrich S

    2015-10-01

    In this pedagogical review, we discuss the physical constraints that pathogens experience when they move in their host environment. Due to their small size, pathogens are living in a low Reynolds number world dominated by viscosity. For swimming pathogens, the so-called scallop theorem determines which kinds of shape changes can lead to productive motility. For crawling or gliding cells, the main resistance to movement comes from protein friction at the cell-environment interface. Viruses and pathogenic bacteria can also exploit intracellular host processes such as actin polymerization and motor-based transport, if they present the appropriate factors on their surfaces. Similar to cancer cells that also tend to cross various barriers, pathogens often combine several of these strategies in order to increase their motility and therefore their chances to replicate and spread.

  5. Production of Eicosanoids and Other Oxylipins by Pathogenic Eukaryotic Microbes

    PubMed Central

    Noverr, Mairi C.; Erb-Downward, John R.; Huffnagle, Gary B.

    2003-01-01

    Oxylipins are oxygenated metabolites of fatty acids. Eicosanoids are a subset of oxylipins and include the prostaglandins and leukotrienes, which are potent regulators of host immune responses. Host cells are one source of eicosanoids and oxylipins during infection; however, another potential source of eicosanoids is the pathogen itself. A broad range of pathogenic fungi, protozoa, and helminths produce eicosanoids and other oxylipins by novel synthesis pathways. Why do these organisms produce oxylipins? Accumulating data suggest that phase change and differentiation in these organisms are controlled by oxylipins, including prostaglandins and lipoxygenase products. The precise role of pathogen-derived eicosanoids in pathogenesis remains to be determined, but the potential link between pathogen eicosanoids and the development of TH2 responses in the host is intriguing. Mammalian prostaglandins and leukotrienes have been studied extensively, and these molecules can modulate Th1 versus Th2 immune responses, chemokine production, phagocytosis, lymphocyte proliferation, and leukocyte chemotaxis. Thus, eicosanoids and oxylipins (host or microbe) may be mediators of a direct host-pathogen “cross-talk” that promotes chronic infection and hypersensitivity disease, common features of infection by eukaryotic pathogens. PMID:12857780

  6. Host-Pathogen Interactions

    PubMed Central

    English, Patricia D.; Jurale, Joseph Byrne; Albersheim, Peter

    1971-01-01

    The effect of a number of physiological variables on the secretion of polysaccharide-degrading enzymes by culture-grown Colletotrichum lindemuthianum (Saccardo and Magnus) Scribner was determined. The number of spores used to inoculate cultures grown on isolated bean hypocotyl cell walls affects the time after inoculation at which enzyme secretion occurs, but has no significant effect on the maximal amount of enzyme ultimately secreted. Cell walls isolated from bean leaves, first internodes, or hypocotyls (susceptible to C. lindemuthianum infection), when used as carbon source for C. lindemuthianum growth, stimulate the fungus to secrete more α-galactosidase than do cell walls isolated from roots (resistant to infection). The concentration of carbon source used for fungal growth determines the final level of enzyme activity in the culture fluid. The level of enzyme secretion is not proportional to fungal growth; rather, enzyme secretion is induced. Maximal α-galactosidase activity in the culture medium is found when the concentration of cell walls used as carbon source is 1% or greater. A higher concentration of cell walls is necessary for maximal α-arabinosidase activity. Galactose, when used as the carbon source, stimulates α-galactosidase secretion but, at comparable concentrations, is less effective in doing so than are cell walls. Polysaccharide-degrading enzymes are secreted by C. lindemuthianum at different times during growth of the pathogen on isolated cell walls. Pectinase and α-arabinosidase are secreted first, followed by β-xylosidase and cellulase, then β-glucosidase, and, finally, α-galactosidase. PMID:16657562

  7. Opportunistic Premise Plumbing Pathogens: Increasingly Important Pathogens in Drinking Water.

    PubMed

    Falkinham, Joseph O; Pruden, Amy; Edwards, Marc

    2015-06-09

    Opportunistic premise plumbing pathogens are responsible for a significant number of infections whose origin has been traced to drinking water. These opportunistic pathogens represent an emerging water borne disease problem with a major economic cost of at least $1 billion annually. The common features of this group of waterborne pathogens include: disinfectant-resistance, pipe surface adherence and biofilm formation, growth in amoebae, growth on low organic concentrations, and growth at low oxygen levels. Their emergence is due to the fact that conditions resulting from drinking water treatment select for them. As such, there is a need for novel approaches to reduce exposure to these pathogens. In addition to much-needed research, controls to reduce numbers and human exposure can be instituted independently by utilities and homeowners and hospital- and building-operators.

  8. Opportunistic Premise Plumbing Pathogens: Increasingly Important Pathogens in Drinking Water

    PubMed Central

    Falkinham, Joseph O.; Pruden, Amy; Edwards, Marc

    2015-01-01

    Opportunistic premise plumbing pathogens are responsible for a significant number of infections whose origin has been traced to drinking water. These opportunistic pathogens represent an emerging water borne disease problem with a major economic cost of at least $1 billion annually. The common features of this group of waterborne pathogens include: disinfectant-resistance, pipe surface adherence and biofilm formation, growth in amoebae, growth on low organic concentrations, and growth at low oxygen levels. Their emergence is due to the fact that conditions resulting from drinking water treatment select for them. As such, there is a need for novel approaches to reduce exposure to these pathogens. In addition to much-needed research, controls to reduce numbers and human exposure can be instituted independently by utilities and homeowners and hospital- and building-operators. PMID:26066311

  9. Bacterial differentiation.

    PubMed

    Shapiro, L; Agabian-Keshishian, N; Bendis, I

    1971-09-01

    The foregoing studies are intended to define a differentiation process and to permit genetic access to the mechanisms that control this process. In order to elucidate the basic mechanisms whereby a cell dictates its own defined morphogenic changes, we have found it helpful to study an organism that can be manipulated both biochemically and genetically. We have attempted to develop the studies initiated by Poindexter,Stove and Stanier, and Schmidt and Stanier (16, 17, 20) with the Caulobacter genus so that these bacteria can serve as a model system for prokaryotic differentiation. The Caulobacter life cycle, defined in synchronously growing cultures, includes a sequential series of morphological changes that occur at specific times in the cycle and at specific locations in the cell. Six distinct cellular characteristics, which are peculiar to these bacteria, have been defined and include (i) the synthesis of a polar organelle which may be membranous (21-23), (ii) a satellite DNA in the stalked cell (26), (iii) pili to which RNA bacteriophage specifically adsorb (16, 33), (iv) a single polar flagellum(17), (v) a lipopolysaccharide phage receptor site (27), and (vi) new cell wall material at the flagellated pole of the cell giving rise to a stalk (19, 20). Cell division, essential for the viability of the organism, is dependent on the irreversible differentiation of a flagellated swarmer cell to a mature stalked cell. The specific features of the Caulobacter system which make it a system of choice for studies of the control of sequential events resulting in cellular differentiation can be summarized as follows. 1) Cell populations can be synchronized, and homogeneous populations at each stage in the differentiation cycle can thus be obtained. 2) A specific technique has been developed whereby the progress of the differentiation cycle can be accurately measured by adsorption of labeled RNA phage or penetration of labeled phage DNA into specific cell forms. This

  10. Maize-Pathogen Interactions: An Ongoing Combat from a Proteomics Perspective

    PubMed Central

    Pechanova, Olga; Pechan, Tibor

    2015-01-01

    Maize (Zea mays L.) is a host to numerous pathogenic species that impose serious diseases to its ear and foliage, negatively affecting the yield and the quality of the maize crop. A considerable amount of research has been carried out to elucidate mechanisms of maize-pathogen interactions with a major goal to identify defense-associated proteins. In this review, we summarize interactions of maize with its agriculturally important pathogens that were assessed at the proteome level. Employing differential analyses, such as the comparison of pathogen-resistant and susceptible maize varieties, as well as changes in maize proteomes after pathogen challenge, numerous proteins were identified as possible candidates in maize resistance. We describe findings of various research groups that used mainly mass spectrometry-based, high through-put proteomic tools to investigate maize interactions with fungal pathogens Aspergillus flavus, Fusarium spp., and Curvularia lunata, and viral agents Rice Black-streaked Dwarf Virus and Sugarcane Mosaic Virus. PMID:26633370

  11. Development of Genomic Resources for a thraustochytrid Pathogen and Investigation of Temperature Influences on Gene Expression

    PubMed Central

    Garcia-Vedrenne, Ana Elisa; Groner, Maya; Page-Karjian, Annie; Siegmund, Gregor-Fausto; Singhal, Sonia; Sziklay, Jamie; Roberts, Steven

    2013-01-01

    Understanding how environmental changes influence the pathogenicity and virulence of infectious agents is critical for predicting epidemiological patterns of disease. Thraustochytrids, part of the larger taxonomic class Labyrinthulomycetes, contain several highly pathogenic species, including the hard clam pathogen quahog parasite unknown (QPX). QPX has been associated with large-scale mortality events along the northeastern coast of North America. Growth and physiology of QPX is temperature-dependent, and changes in local temperature profiles influence pathogenicity. In this study we characterize the partial genome of QPX and examine the influence of temperature on gene expression. Genes involved in several biological processes are differentially expressed upon temperature change, including those associated with altered growth and metabolism and virulence. The genomic and transcriptomic resources developed in this study provide a foundation for better understanding virulence, pathogenicity and life history of thraustochytrid pathogens. PMID:24069279

  12. Functional genomics of pathogenic bacteria.

    PubMed Central

    Moxon, E R; Hood, D W; Saunders, N J; Schweda, E K H; Richards, J C

    2002-01-01

    Microbial diseases remain the commonest cause of global mortality and morbidity. Automated-DNA sequencing has revolutionized the investigation of pathogenic microbes by making the immense fund of information contained in their genomes available at reasonable cost. The challenge is how this information can be used to increase current understanding of the biology of commensal and virulence behaviour of pathogens with particular emphasis on in vivo function and novel approaches to prevention. One example of the application of whole-genome-sequence information is afforded by investigations of the pathogenic role of Haemophilus influenzae lipopolysaccharide and its candidacy as a vaccine. PMID:11839188

  13. Lectins in human pathogenic fungi.

    PubMed

    Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

    2014-01-01

    Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

  14. Pathogen detection using engineered bacteriophages.

    PubMed

    Smartt, Abby E; Xu, Tingting; Jegier, Patricia; Carswell, Jessica J; Blount, Samuel A; Sayler, Gary S; Ripp, Steven

    2012-04-01

    Bacteriophages, or phages, are bacterial viruses that can infect a broad or narrow range of host organisms. Knowing the host range of a phage allows it to be exploited in targeting various pathogens. Applying phages for the identification of microorganisms related to food and waterborne pathogens and pathogens of clinical significance to humans and animals has a long history, and there has to some extent been a recent revival in these applications as phages have become more extensively integrated into novel detection, identification, and monitoring technologies. Biotechnological and genetic engineering strategies applied to phages are responsible for some of these new methods, but even natural unmodified phages are widely applicable when paired with appropriate innovative detector platforms. This review highlights the use of phages as pathogen detector interfaces to provide the reader with an up-to-date inventory of phage-based biodetection strategies.

  15. Molecular Soybean-Pathogen Interactions.

    PubMed

    Whitham, Steven A; Qi, Mingsheng; Innes, Roger W; Ma, Wenbo; Lopes-Caitar, Valéria; Hewezi, Tarek

    2016-08-01

    Soybean hosts a wide variety of pathogens that cause significant yield losses. The importance of soybean as a major oilseed crop has led to research focused on its interactions with pathogens, such as Soybean mosaic virus, Pseudomonas syringae, Phytophthora sojae, Phakopsora pachyrhizi, and Heterodera glycines. Pioneering work on soybean's interactions with these organisms, which represent the five major pathogen groups (viruses, bacteria, oomycetes, fungi, and nematodes), has contributed to our understanding of the molecular mechanisms underlying virulence and immunity. These mechanisms involve conserved and unique features that validate the need for research in both soybean and homologous model systems. In this review, we discuss identification of effectors and their functions as well as resistance gene-mediated recognition and signaling. We also point out areas in which model systems and recent advances in resources and tools have provided opportunities to gain deeper insights into soybean-pathogen interactions. PMID:27359370

  16. Lectins in human pathogenic fungi.

    PubMed

    Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

    2014-01-01

    Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). PMID:24270074

  17. Continuous-Flow Detector for Rapid Pathogen Identification

    SciTech Connect

    Barrett, Louise M.; Skulan, Andrew J.; Singh, Anup K.; Cummings, Eric B.; Fiechtner, Gregory J.

    2006-09-01

    This report describes the continued development of a low-power, portable detector for the rapid identification of pathogens such as B. anthracis and smallpox. Based on our successful demonstration of the continuous filter/concentrator inlet, we believe strongly that the inlet section will enable differentiation between viable and non-viable populations, between types of cells, and between pathogens and background contamination. Selective, continuous focusing of particles in a microstream enables highly selective and sensitive identification using fluorescently labeled antibodies and other receptors such as peptides, aptamers, or small ligands to minimize false positives. Processes such as mixing and lysing will also benefit from the highly localized particle streams. The concentrator is based on faceted prisms to contract microfluidic flows while maintaining uniform flowfields. The resulting interfaces, capable of high throughput, serve as high-, low-, and band-pass filters to direct selected bioparticles to a rapid, affinity-based detection system. The proposed device is superior to existing array-based detectors as antibody-pathogen binding can be accomplished in seconds rather than tens of minutes or even hours. The system is being designed to interface with aerosol collectors under development by the National Laboratories or commercial systems. The focused stream is designed to be interrogated using diode lasers to differentiate pathogens by light scattering. Identification of particles is done using fluorescently labeled antibodies to tag the particles, followed by multiplexed laser-induced fluorescence (LIF) detection (achieved by labeling each antibody with a different dye).

  18. Identification of meat-associated pathogens via Raman microspectroscopy.

    PubMed

    Meisel, Susann; Stöckel, Stephan; Rösch, Petra; Popp, Jürgen

    2014-04-01

    The development of fast and reliable sensing techniques to detect food-borne microorganisms is a permanent concern in food industry and health care. For this reason, Raman microspectroscopy was applied to rapidly detect pathogens in meat, which could be a promising supplement to currently established methods. In this context, a spectral database of 19 species of the most important harmful and non-pathogenic bacteria associated with meat and poultry was established. To create a meat-like environment the microbial species were prepared on three different agar types. The whole amount of Raman data was taken as a basis to build up a three level classification model by means of support vector machines. Subsequent to a first classifier that differentiates between Raman spectra of Gram-positive and Gram-negative bacteria, two decision knots regarding bacterial genus and species follow. The different steps of the classification model achieved accuracies in the range of 90.6%-99.5%. This database was then challenged with independently prepared test samples. By doing so, beef and poultry samples were spiked with different pathogens associated with food-borne diseases and then identified. The test samples were correctly assigned to their genus and for the most part down to the species-level i.e. a differentiation from closely-related non-pathogenic members was achieved.

  19. [Non-pathogenic intestinal amoebae: a clinical-analytical overview].

    PubMed

    Sard, Bárbara Gomila; Navarro, Rafael Toledo; Esteban Sanchis, J Guillermo

    2011-03-01

    Human beings can be parasitized by various species of intestinal amoebae. Entamoeba histolytica is the only intestinal amoeba recognized to be pathogenic, while other amoeba species, E. dispar, E. moshkovskii, E. hartmanni, E. coli, E. polecki, Endolimax nana and Iodamoeba buetschlii are considered to be non-pathogenic. The aim of this review is to synthesize the main morphological characteristics of the trophozoite and cyst stages of each amoeba as the basis for precise microscopical diagnosis. The difficulty of morphological differentiation among species included in the so-called "Entamoeba complex" entails the use of immunological and molecular diagnoses. In addition, a summary of basic epidemiological, therapeutic and prophylactic aspects of these non-pathogenic amoebae is provided. All of these aspects are crucial since these amoebae are usually found to be present in human coproparasitological analyses and must be differentiated from the pathogenic species E. histolytica. Furthermore, they can be used as suitable biological tags of the hygienic state of the environment and the health and hygiene measures of the population. PMID:21458707

  20. DNA methylation profiling to assess pathogenicity of BRCA1 unclassified variants in breast cancer

    PubMed Central

    Flower, Kirsty J; Shenker, Natalie S; El-Bahrawy, Mona; Goldgar, David E; Parsons, Michael T; Spurdle, Amanda B; Morris, Joanna R; Brown, Robert; Flanagan, James M

    2015-01-01

    Germline pathogenic mutations in BRCA1 increase risk of developing breast cancer. Screening for mutations in BRCA1 frequently identifies sequence variants of unknown pathogenicity and recent work has aimed to develop methods for determining pathogenicity. We previously observed that tumor DNA methylation can differentiate BRCA1-mutated from BRCA1-wild type tumors. We hypothesized that we could predict pathogenicity of variants based on DNA methylation profiles of tumors that had arisen in carriers of unclassified variants. We selected 150 FFPE breast tumor DNA samples [47 BRCA1 pathogenic mutation carriers, 65 BRCAx (BRCA1-wild type), 38 BRCA1 test variants] and analyzed a subset (n=54) using the Illumina 450K methylation platform, using the remaining samples for bisulphite pyrosequencing validation. Three validated markers (BACH2, C8orf31, and LOC654342) were combined with sequence bioinformatics in a model to predict pathogenicity of 27 variants (independent test set).  Predictions were compared with standard multifactorial likelihood analysis. Prediction was consistent for c.5194-12G>A (IVS 19-12 G>A) (P>0.99); 13 variants were considered not pathogenic or likely not pathogenic using both approaches. We conclude that tumor DNA methylation data alone has potential to be used in prediction of BRCA1 variant pathogenicity but is not independent of estrogen receptor status and grade, which are used in current multifactorial models to predict pathogenicity. PMID:26727311

  1. Waterborne pathogens in urban watersheds.

    PubMed

    Arnone, Russell D; Walling, Joyce Perdek

    2007-03-01

    A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combined sewer overflows and sanitary sewer overflows. Pathogens in US ambient water bodies are regulated under the Clean Water Act (CWA), while pathogens in drinking water supplies are regulated under the Safe Drinking Water Act. Total maximum daily loads (TMDLs) are developed in accordance with CWA regulations for ambient water bodies with bacterial concentrations exceeding the water quality standard, which generally is a measure of a bacterial indicator organism. However, developing a TMDL for a supplementary indicator or pathogen is also required if a use impairment would still exist even after the water body is in compliance with the standard. This occurs because indicator organisms do not reflect the presence of pathogen contamination with complete certainty. The evaluation of pathogen indicators and summary of epidemiological studies presented are resources for those developing TMDLs to achieve water quality standards and restore water bodies to their intended uses. PMID:17402286

  2. Genome sequence of the necrotrophic plant pathogen Pythium ultimum reveals original pathogenicity mechanisms and effector repertoire

    PubMed Central

    2010-01-01

    Background Pythium ultimum is a ubiquitous oomycete plant pathogen responsible for a variety of diseases on a broad range of crop and ornamental species. Results The P. ultimum genome (42.8 Mb) encodes 15,290 genes and has extensive sequence similarity and synteny with related Phytophthora species, including the potato blight pathogen Phytophthora infestans. Whole transcriptome sequencing revealed expression of 86% of genes, with detectable differential expression of suites of genes under abiotic stress and in the presence of a host. The predicted proteome includes a large repertoire of proteins involved in plant pathogen interactions, although, surprisingly, the P. ultimum genome does not encode any classical RXLR effectors and relatively few Crinkler genes in comparison to related phytopathogenic oomycetes. A lower number of enzymes involved in carbohydrate metabolism were present compared to Phytophthora species, with the notable absence of cutinases, suggesting a significant difference in virulence mechanisms between P. ultimum and more host-specific oomycete species. Although we observed a high degree of orthology with Phytophthora genomes, there were novel features of the P. ultimum proteome, including an expansion of genes involved in proteolysis and genes unique to Pythium. We identified a small gene family of cadherins, proteins involved in cell adhesion, the first report of these in a genome outside the metazoans. Conclusions Access to the P. ultimum genome has revealed not only core pathogenic mechanisms within the oomycetes but also lineage-specific genes associated with the alternative virulence and lifestyles found within the pythiaceous lineages compared to the Peronosporaceae. PMID:20626842

  3. The Quantitative Basis of the Arabidopsis Innate Immune System to Endemic Pathogens Depends on Pathogen Genetics

    PubMed Central

    Corwin, Jason A.; Copeland, Daniel; Feusier, Julie; Subedy, Anushriya; Eshbaugh, Robert; Palmer, Christine; Maloof, Julin; Kliebenstein, Daniel J.

    2016-01-01

    The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabidopsis-Botrytis pathosystem to explore the quantitative genetic architecture underlying host innate immune system in a population of Arabidopsis thaliana. By infecting a diverse panel of Arabidopsis accessions with four phenotypically and genotypically distinct isolates of the fungal necrotroph B. cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence of pathogen genetic variation in analyzing host quantitative resistance. While known resistance genes, such as receptor-like kinases (RLKs) and nucleotide-binding site leucine-rich repeat proteins (NLRs), were found to be enriched among associated genes, they only account for a small fraction of the total genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance, including defense hormone signaling and ROS production, as well as novel processes, such as leaf development. Validation of single gene T-DNA knockouts in a Col-0 background demonstrate a high success rate (60%) when accounting for differences in environmental and Botrytis genetic variation. This study shows that the genetic architecture underlying host innate immune system is extremely complex and is likely able to sense and respond to differential virulence among pathogen genotypes. PMID:26866607

  4. The Quantitative Basis of the Arabidopsis Innate Immune System to Endemic Pathogens Depends on Pathogen Genetics.

    PubMed

    Corwin, Jason A; Copeland, Daniel; Feusier, Julie; Subedy, Anushriya; Eshbaugh, Robert; Palmer, Christine; Maloof, Julin; Kliebenstein, Daniel J

    2016-02-01

    The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabidopsis-Botrytis pathosystem to explore the quantitative genetic architecture underlying host innate immune system in a population of Arabidopsis thaliana. By infecting a diverse panel of Arabidopsis accessions with four phenotypically and genotypically distinct isolates of the fungal necrotroph B. cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence of pathogen genetic variation in analyzing host quantitative resistance. While known resistance genes, such as receptor-like kinases (RLKs) and nucleotide-binding site leucine-rich repeat proteins (NLRs), were found to be enriched among associated genes, they only account for a small fraction of the total genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance, including defense hormone signaling and ROS production, as well as novel processes, such as leaf development. Validation of single gene T-DNA knockouts in a Col-0 background demonstrate a high success rate (60%) when accounting for differences in environmental and Botrytis genetic variation. This study shows that the genetic architecture underlying host innate immune system is extremely complex and is likely able to sense and respond to differential virulence among pathogen genotypes.

  5. Pathogens in Dairy Farming: Source Characterization and Groundwater Impacts

    NASA Astrophysics Data System (ADS)

    Atwill, E. R.; Watanabe, N.; Li, X.; Hou, L.; Harter, T.; Bergamaschi, B.

    2007-12-01

    Intense animal husbandry is of growing concern as a potential contamination source of enteric pathogens as well as antibiotics. To assess the public health risk from pathogens and their hydrologic pathways, we hypothesize that the animal farm is not a homogeneous diffuse source, but that pathogen loading to the soil and, therefore, to groundwater varies significantly between the various management units of a farm. A dairy farm, for example, may include an area with calf hutches, corrals for heifers of various ages, freestalls and exercise yards for milking cows, separate freestalls for dry cows, a hospital barn, a yard for collection of solid manure, a liquid manure storage lagoon, and fields receiving various amounts of liquid and solid manure. Pathogen shedding and, hence, therapeutic and preventive pharmaceutical treatments vary between these management units. We are implementing a field reconnaissance program to determine the occurrence of three different pathogens ( E. coli, Salmonella, Campylobacter) and one indicator organism ( Enterococcus) at the ground-surface and in shallow groundwater of seven different management units on each of two farms, and in each of four seasons (spring/dry season, summer/irrigation season, fall/dry season, winter/rainy season). Initial results indicate that significant differences exist in the occurrence of these pathogens between management units and between organisms. These differences are weakly reflected in their occurrence in groundwater, despite the similarity of the shallow geologic environment across these sites. Our results indicate the importance of differentiating sources within a dairy farm and the importance of understanding subsurface transport processes for these pathogens.

  6. Genomic and Phenomic Study of Mammary Pathogenic Escherichia coli

    PubMed Central

    Blum, Shlomo E.; Heller, Elimelech D.; Sela, Shlomo; Elad, Daniel; Edery, Nir; Leitner, Gabriel

    2015-01-01

    Escherichia coli is a major etiological agent of intra-mammary infections (IMI) in cows, leading to acute mastitis and causing great economic losses in dairy production worldwide. Particular strains cause persistent IMI, leading to recurrent mastitis. Virulence factors of mammary pathogenic E. coli (MPEC) involved pathogenesis of mastitis as well as those differentiating strains causing acute or persistent mastitis are largely unknown. This study aimed to identify virulence markers in MPEC through whole genome and phenome comparative analysis. MPEC strains causing acute (VL2874 and P4) or persistent (VL2732) mastitis were compared to an environmental strain (K71) and to the genomes of strains representing different E. coli pathotypes. Intra-mammary challenge in mice confirmed experimentally that the strains studied here have different pathogenic potential, and that the environmental strain K71 is non-pathogenic in the mammary gland. Analysis of whole genome sequences and predicted proteomes revealed high similarity among MPEC, whereas MPEC significantly differed from the non-mammary pathogenic strain K71, and from E. coli genomes from other pathotypes. Functional features identified in MPEC genomes and lacking in the non-mammary pathogenic strain were associated with synthesis of lipopolysaccharide and other membrane antigens, ferric-dicitrate iron acquisition and sugars metabolism. Features associated with cytotoxicity or intra-cellular survival were found specifically in the genomes of strains from severe and acute (VL2874) or persistent (VL2732) mastitis, respectively. MPEC genomes were relatively similar to strain K-12, which was subsequently shown here to be possibly pathogenic in the mammary gland. Phenome analysis showed that the persistent MPEC was the most versatile in terms of nutrients metabolized and acute MPEC the least. Among phenotypes unique to MPEC compared to the non-mammary pathogenic strain were uric acid and D-serine metabolism. This study

  7. Genomic and Phenomic Study of Mammary Pathogenic Escherichia coli.

    PubMed

    Blum, Shlomo E; Heller, Elimelech D; Sela, Shlomo; Elad, Daniel; Edery, Nir; Leitner, Gabriel

    2015-01-01

    Escherichia coli is a major etiological agent of intra-mammary infections (IMI) in cows, leading to acute mastitis and causing great economic losses in dairy production worldwide. Particular strains cause persistent IMI, leading to recurrent mastitis. Virulence factors of mammary pathogenic E. coli (MPEC) involved pathogenesis of mastitis as well as those differentiating strains causing acute or persistent mastitis are largely unknown. This study aimed to identify virulence markers in MPEC through whole genome and phenome comparative analysis. MPEC strains causing acute (VL2874 and P4) or persistent (VL2732) mastitis were compared to an environmental strain (K71) and to the genomes of strains representing different E. coli pathotypes. Intra-mammary challenge in mice confirmed experimentally that the strains studied here have different pathogenic potential, and that the environmental strain K71 is non-pathogenic in the mammary gland. Analysis of whole genome sequences and predicted proteomes revealed high similarity among MPEC, whereas MPEC significantly differed from the non-mammary pathogenic strain K71, and from E. coli genomes from other pathotypes. Functional features identified in MPEC genomes and lacking in the non-mammary pathogenic strain were associated with synthesis of lipopolysaccharide and other membrane antigens, ferric-dicitrate iron acquisition and sugars metabolism. Features associated with cytotoxicity or intra-cellular survival were found specifically in the genomes of strains from severe and acute (VL2874) or persistent (VL2732) mastitis, respectively. MPEC genomes were relatively similar to strain K-12, which was subsequently shown here to be possibly pathogenic in the mammary gland. Phenome analysis showed that the persistent MPEC was the most versatile in terms of nutrients metabolized and acute MPEC the least. Among phenotypes unique to MPEC compared to the non-mammary pathogenic strain were uric acid and D-serine metabolism. This study

  8. In Vitro Th Differentiation Protocol.

    PubMed

    Sekiya, Takashi; Yoshimura, Akihiko

    2016-01-01

    CD4(+) T cells play central roles in adaptive immunity, driving appropriate immune responses to invading pathogens of diverse types. Four major CD4(+) T cell subsets, Th1, Th2, Th17, and Treg cells are differentiated from naïve CD4(+) T cells upon ligation of their T cell receptors with antigens, depending on the cytokines they receive. Th1 cells, which are induced by IL-12 and IFN-γ, mediate host defense against intracellular pathogens by exclusively expressing IFN-γ. Th2 cells, which are induced by IL4, secrete IL-4, IL-5, and IL-13, and protect hosts from helminths. IL-6 plus TGF-β induces Th17 cells, another Th subset identified relatively recently, express IL-17 and play important roles in the eradication of extracellular bacteria and fungi. Treg cells, which play central roles in immune suppression, are composed of either thymus-derived Treg cells (tTreg cells), which are directly developed from CD4-single positive (CD4-SP) cells in the thymus, or peripherally derived Treg cells (pTreg cells), which are induced by TGF-β plus IL-2 from naïve CD4(+) T cells. Although the regulated induction of Th cells results in proper eradication of pathogens, their excess activation results in various immune-associated diseases. For example, aberrant activation of Th1 and Th17 has been implicated in autoimmune diseases, excess Th2 activity causes atopic diseases, and impaired function of Treg cells due to abrogation of Foxp3 has been shown to cause fatal inflammatory disorders both in human and in mouse. The methods for in vitro differentiation of each Th subset described above are presented here. We hope these methods will facilitate understanding of differentiation and function of CD4(+) T cells and pathogenesis of various inflammatory diseases. PMID:26520124

  9. Characterization of Pathogenicity, Virulence and Host-Pathogen Interractions

    SciTech Connect

    Krishnan, A; Folta, P

    2006-07-27

    The threats of bio-terrorism and newly emerging infectious diseases pose serious challenges to the national security infrastructure. Rapid detection and diagnosis of infectious disease in human populations, as well as characterizing pathogen biology, are critical for reducing the morbidity and mortality associated with such threats. One of the key challenges in managing an infectious disease outbreak, whether through natural causes or acts of overt terrorism, is detection early enough to initiate effective countermeasures. Much recent attention has been directed towards the utility of biomarkers or molecular signatures that result from the interaction of the pathogen with the host for improving our ability to diagnose and mitigate the impact of a developing infection during the time window when effective countermeasures can be instituted. Host responses may provide early signals in blood even from localized infections. Multiple innate and adaptive immune molecules, in combination with other biochemical markers, may provide disease-specific information and new targets for countermeasures. The presence of pathogen specific markers and an understanding of the molecular capabilities and adaptations of the pathogen when it interacts with its host may likewise assist in early detection and provide opportunities for targeting countermeasures. An important question that needs to be addressed is whether these molecular-based approaches will prove useful for early diagnosis, complement current methods of direct agent detection, and aid development and use of countermeasures. Lawrence Livermore National Laboratory (LLNL) will host a workshop to explore the utility of host- and pathogen-based molecular diagnostics, prioritize key research issues, and determine the critical steps needed to transition host-pathogen research to tools that can be applied towards a more effective national bio-defense strategy. The workshop will bring together leading researchers/scientists in the

  10. Compositions and methods for pathogen transport

    DOEpatents

    El-Etr, Sahar; Farquar, George R.

    2016-01-26

    This disclosure provides a method for transporting a pathogen under ambient conditions, by culturing the pathogen with an amoeba under conditions that favor the incorporation of the pathogen into a trophozoite, starving the amoeba until it encysts, then culturing under conditions that favor conversion of the amoeba back to a trophozoite. In one aspect, the conditions that favor incorporation of the pathogen into the cyst of the amoeba comprises contacting the pathogen with the amoeba in an iron rich environment. Virus and/or bacteria are pathogens that can be transported by the disclosed method. Amoeba that are useful in the disclosed methods include, without limitation Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria gruberi. The disclosed methods have utility in: transporting pathogens from military field hospitals and clinics to the laboratory; transporting pathogens from global satellite laboratories to clinical laboratories; long term storage of pathogens; enriching contaminated patient samples for pathogens of interest; biosurveillance and detection efforts.

  11. Pathogen evolution and the immunological niche

    PubMed Central

    Cobey, Sarah

    2014-01-01

    Host immunity is a major driver of pathogen evolution and thus a major determinant of pathogen diversity. Explanations for pathogen diversity traditionally assume simple interactions between pathogens and the immune system, a view encapsulated by the susceptible–infected–recovered (SIR) model. However, there is growing evidence that the complexity of many host–pathogen interactions is dynamically important. This revised perspective requires broadening the definition of a pathogen's immunological phenotype, or what can be thought of as its immunological niche. After reviewing evidence that interactions between pathogens and host immunity drive much of pathogen evolution, I introduce the concept of a pathogen's immunological phenotype. Models that depart from the SIR paradigm demonstrate the utility of this perspective and show that it is particularly useful in understanding vaccine-induced evolution. This paper highlights questions in immunology, evolution, and ecology that must be answered to advance theories of pathogen diversity. PMID:25040161

  12. Infectious pathogens and bronchiolitis outcomes.

    PubMed

    Hasegawa, Kohei; Mansbach, Jonathan M; Camargo, Carlos A

    2014-07-01

    Bronchiolitis is a common early childhood illness and an important cause of morbidity, it is the number one cause of hospitalization among US infants. Bronchiolitis is also an active area of research, and recent studies have advanced our understanding of this illness. Although it has long been the conventional wisdom that the infectious etiology of bronchiolitis does not affect outcomes, a growing number of studies have linked specific pathogens of bronchiolitis (e.g., rhinovirus) to short- and long-term outcomes, such as future risk of developing asthma. The authors review the advent of molecular diagnostic techniques that have demonstrated diverse pathogens in bronchiolitis, and they review recent studies on the complex link between infectious pathogens of bronchiolitis and the development of childhood asthma.

  13. The Main Aeromonas Pathogenic Factors

    PubMed Central

    Tomás, J. M.

    2012-01-01

    The members of the Aeromonas genus are ubiquitous, water-borne bacteria. They have been isolated from marine waters, rivers, lakes, swamps, sediments, chlorine water, water distribution systems, drinking water and residual waters; different types of food, such as meat, fish, seafood, vegetables, and processed foods. Aeromonas strains are predominantly pathogenic to poikilothermic animals, and the mesophilic strains are emerging as important pathogens in humans, causing a variety of extraintestinal and systemic infections as well as gastrointestinal infections. The most commonly described disease caused by Aeromonas is the gastroenteritis; however, no adequate animal model is available to reproduce this illness caused by Aeromonas. The main pathogenic factors associated with Aeromonas are: surface polysaccharides (capsule, lipopolysaccharide, and glucan), S-layers, iron-binding systems, exotoxins and extracellular enzymes, secretion systems, fimbriae and other nonfilamentous adhesins, motility and flagella. PMID:23724321

  14. Differential gearing

    SciTech Connect

    Tamiya, S.

    1986-07-29

    A differential for motor vehicles is described and the like comprising, an input drive shaft, a pair of coaxially spaced drive gears simultaneously driven by the input shaft in a same direction at a same speed of rotation about a common axis of rotation, a driven gear driven peripherally by the pair of drive gears for transmission of power from the input drive shaft, two coaxial opposed bevel sun gears having an axis of rotation concentric with an axis of rotation of the driven gear, two planetary gears disposed between the sun gears for differential driving thereof during turns of the vehicle to the right and to the left of each meshing with the sun gears for driving the suns gears. Each planetary gear has a separate axis of rotation carried by the driven gear disposed therein radially and symmetrically relative to the axis of rotation of the sun gears, and each sun gear having a respective power output shaft connected thereto for rotation therewith.

  15. Xylella Genomics and Bacterial Pathogenicity to Plants

    PubMed Central

    Dow, J. M.

    2000-01-01

    Xylella fastidiosa, a pathogen of citrus, is the first plant pathogenic bacterium for which the complete genome sequence has been published. Inspection of the sequence reveals high relatedness to many genes of other pathogens, notably Xanthomonas campestris. Based on this, we suggest that Xylella possesses certain easily testable properties that contribute to pathogenicity. We also present some general considerations for deriving information on pathogenicity from bacterial genomics. PMID:11119303

  16. From multiple pathogenicity islands to a unique organized pathogenicity archipelago

    PubMed Central

    Bouyioukos, Costas; Reverchon, Sylvie; Képès, François

    2016-01-01

    Pathogenicity islands are sets of successive genes in a genome that determine the virulence of a bacterium. In a growing number of studies, bacterial virulence appears to be determined by multiple islands scattered along the genome. This is the case in a family of seven plant pathogens and a human pathogen that, under KdgR regulation, massively secrete enzymes such as pectinases that degrade plant cell wall. Here we show that their multiple pathogenicity islands form together a coherently organized, single “archipelago” at the genome scale. Furthermore, in half of the species, most genes encoding secreted pectinases are expressed from the same DNA strand (transcriptional co-orientation). This genome architecture favors DNA conformations that are conducive to genes spatial co-localization, sometimes complemented by co-orientation. As proteins tend to be synthetized close to their encoding genes in bacteria, we propose that this architecture would favor the efficient funneling of pectinases at convergent points within the cell. The underlying functional hypothesis is that this convergent funneling of the full blend of pectinases constitutes a crucial strategy for successful degradation of the plant cell wall. Altogether, our work provides a new approach to describe and predict, at the genome scale, the full virulence complement. PMID:27302835

  17. Host ecotype generates evolutionary and epidemiological divergence across a pathogen metapopulation

    PubMed Central

    Laine, Anna-Liisa; Burdon, Jeremy J.; Nemri, Adnane; Thrall, Peter H.

    2014-01-01

    The extent and speed at which pathogens adapt to host resistance varies considerably. This presents a challenge for predicting when—and where—pathogen evolution may occur. While gene flow and spatially heterogeneous environments are recognized to be critical for the evolutionary potential of pathogen populations, we lack an understanding of how the two jointly shape coevolutionary trajectories between hosts and pathogens. The rust pathogen Melampsora lini infects two ecotypes of its host plant Linum marginale that occur in close proximity yet in distinct populations and habitats. In this study, we found that within-population epidemics were different between the two habitats. We then tested for pathogen local adaptation at host population and ecotype level in a reciprocal inoculation study. Even after controlling for the effect of spatial structure on infection outcome, we found strong evidence of pathogen adaptation at the host ecotype level. Moreover, sequence analysis of two pathogen infectivity loci revealed strong genetic differentiation by host ecotype but not by distance. Hence, environmental variation can be a key determinant of pathogen population genetic structure and coevolutionary dynamics and can generate strong asymmetry in infection risks through space. PMID:24870042

  18. Pathogenic and Genetic Variation in the Japanese Strains of Fusarium oxysporum f. sp. melonis.

    PubMed

    Namiki, F; Shiomi, T; Nishi, K; Kayamura, T; Tsuge, T

    1998-08-01

    ABSTRACT Pathogenic variation among 41 Japanese strains of Fusarium oxysporum f. sp. melonis was analyzed by pathogenicity tests with muskmelon, oriental melon, and oriental pickling melon cultivars. Based on pathogenicity to muskmelon cvs. Amus and Ohi and oriental melon cv. Ogon 9, 41 strains were divided into 3 groups that corresponded completely to Risser's races 0, 2, and 1,2y. To further characterize pathogenic variation within the forma specialis and races, strains were assayed for pathogenicity to 42 additional muskmelon, oriental melon, and oriental pickling melon cultivars. All strains of race 1,2y were pathogenic to all cultivars tested. Strains of race 0 were divided into six variants based on differences in pathogenicity to three muskmelon cultivars; strains of race 2 also were classified into six variants based on differences in pathogenicity to two muskmelon cultivars and one oriental melon cultivar. Genetic variation among strains was analyzed by DNA fingerprinting with four repetitive DNA sequences: FOLR1 to FOLR4. Thirty-six fingerprint types were detected among forty-one strains by pooling results of fingerprinting with four probes. Cluster analysis showed distinct genetic groups correlated with races: the fingerprint types detected in each of races 2 and 1,2y were grouped into a single cluster, and two distinct genetic groups were found in race 0. However, pathogenic variation detected within races 0 and 2 could not be differentiated based on the nuclear markers examined. PMID:18944886

  19. The extinction differential induced virulence macroevolution

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Xu, Liufang; Wang, Jin

    2014-04-01

    We apply the potential-flux landscape theory to deal with the large fluctuation induced extinction phenomena. We quantify the most probable extinction pathway on the landscape and measure the extinction risk by the landscape topography. In this Letter, we investigate the disease extinction through an epidemic model described by a set of chemical reaction. We found the virulence-differential-dependent symbioses between mother and daughter pathogen species: mutualism and parasitism. The symbioses, whether mutualism or parasitism, benefit the higher virulence species. This implies that speciation towards lower virulence is an effective strategy for a pathogen species to reduce its extinction risk.

  20. New trends in emerging pathogens.

    PubMed

    Skovgaard, Niels

    2007-12-15

    The emergence of pathogens is the result of a number of impact in all parts of the food chain. The emerging technologies in food production explain how new pathogens can establish themselves in the food chain and compromise food safety. The impact of the food technology is analysed for several bacteria, such as Yersinia, Campylobacter, Arcobacter, Helicobacter pullorum, Enterobacter sakazakii, Mycobacterium avium spp. paratuberculosis, prions related to vCJD and others. The importance of the ability of many microbes to form VBNC forms is elaborated on. Research on culture independent methods may address this outstanding issue to the better understanding of emerging pathogens. The "demerging" of pathogens also occur, and examples of this are explained. The reaction of bacteria to stresses and sublethal treatments, and how exposure to one stress factor can confer resistance to other stresses, literally speaking causing contagious resistance, are explained. The implication of this e.g. in modern approaches of food preservation, such as Minimally processed Foods, is considerable. Intestinal colonization of EHEC may be regulated by Quorum sensing, and this ability of microbes plays an important role in the colonization of microbes in food and on food processing equipment, an important factor in the emergence of pathogens. The emergence of Saccharomyces cerevisiae, as an opportunistic human pathogen, used for centuries for food and production of alcoholic beverages, calls for research in molecular tools to distinguish between probiotic and clinical strains. Cyclospora cayetanensis and Norovirus outbreaks can no longer be designated as emerging pathogens, they share however one characteristic in the epidemiology of emerging nature, the importance of the hygiene in the primary production stage, including supply of potable water, and the application of GMP and the HACCP principles in the beginning of the food chain. Hepatitis E virus is a potential emerging food borne

  1. New trends in emerging pathogens.

    PubMed

    Skovgaard, Niels

    2007-12-15

    The emergence of pathogens is the result of a number of impact in all parts of the food chain. The emerging technologies in food production explain how new pathogens can establish themselves in the food chain and compromise food safety. The impact of the food technology is analysed for several bacteria, such as Yersinia, Campylobacter, Arcobacter, Helicobacter pullorum, Enterobacter sakazakii, Mycobacterium avium spp. paratuberculosis, prions related to vCJD and others. The importance of the ability of many microbes to form VBNC forms is elaborated on. Research on culture independent methods may address this outstanding issue to the better understanding of emerging pathogens. The "demerging" of pathogens also occur, and examples of this are explained. The reaction of bacteria to stresses and sublethal treatments, and how exposure to one stress factor can confer resistance to other stresses, literally speaking causing contagious resistance, are explained. The implication of this e.g. in modern approaches of food preservation, such as Minimally processed Foods, is considerable. Intestinal colonization of EHEC may be regulated by Quorum sensing, and this ability of microbes plays an important role in the colonization of microbes in food and on food processing equipment, an important factor in the emergence of pathogens. The emergence of Saccharomyces cerevisiae, as an opportunistic human pathogen, used for centuries for food and production of alcoholic beverages, calls for research in molecular tools to distinguish between probiotic and clinical strains. Cyclospora cayetanensis and Norovirus outbreaks can no longer be designated as emerging pathogens, they share however one characteristic in the epidemiology of emerging nature, the importance of the hygiene in the primary production stage, including supply of potable water, and the application of GMP and the HACCP principles in the beginning of the food chain. Hepatitis E virus is a potential emerging food borne

  2. Pathogenic rickettsiae as bioterrorism agents.

    PubMed

    Azad, Abdu F

    2007-07-15

    Because of their unique biological characteristics, such as environmental stability, small size, aerosol transmission, persistence in infected hosts, low infectious dose, and high associated morbidity and mortality, Rickettsia prowazekii and Coxiella burnetii have been weaponized. These biological attributes would make the pathogenic rickettsiae desirable bioterrorism agents. However, production of highly purified, virulent, weapon-quality rickettsiae is a daunting task that requires expertise and elaborate, state-of-the art laboratory procedures to retain rickettsial survival and virulence. Another drawback to developing rickettsial pathogens as biological weapons is their lack of direct transmission from host to host and the availability of very effective therapeutic countermeasures against these obligate intracellular bacteria.

  3. Thermally Dimorphic Human Fungal Pathogens--Polyphyletic Pathogens with a Convergent Pathogenicity Trait.

    PubMed

    Sil, Anita; Andrianopoulos, Alex

    2015-08-01

    Fungi are adept at changing their cell shape and developmental program in response to signals in their surroundings. Here we focus on a group of evolutionarily related fungal pathogens of humans known as the thermally dimorphic fungi. These organisms grow in a hyphal form in the environment but shift their morphology drastically within a mammalian host. Temperature is one of the main host signals that initiates their conversion to the "host" form and is sufficient in the laboratory to trigger establishment of this host-adapted developmental program. Here we discuss the major human pathogens in this group, which are Blastomyces dermatiditis, Coccidioides immitis/posadasii, Histoplasma capsulatum, Paracoccidioides brasiliensis/lutzii, Sporothrix schenckii, and Talaromyces marneffei (formerly known as Penicillium marneffei). The majority of these organisms are primary pathogens, with the ability to cause disease in healthy humans who encounter them in endemic areas. PMID:25384771

  4. Modeling the U.S. national distribution of waterborne pathogen concentrations with application to Cryptosporidium parvum

    NASA Astrophysics Data System (ADS)

    Crainiceanu, Ciprian M.; Stedinger, Jery R.; Ruppert, David; Behr, Christopher T.

    2003-09-01

    This paper provides a general statistical methodology for modeling environmental pathogen concentrations in natural waters. A hierarchical model of pathogen concentrations captures site and regional random effects as well as random laboratory recovery rates. Recovery rates were modeled by a generalized linear mixed model. Two classes of pathogen concentration models are differentiated according to their ultimate purpose: water quality prediction or health risk analysis. A fully Bayesian analysis using Markov chain Monte Carlo (MCMC) simulation is used for statistical inference. The applicability of this methodology is illustrated by the analysis of a national survey of Cryptosporidium parvum concentrations, in which 93% of the observations were zero counts.

  5. Pathogen pollution and the emergence of a deadly amphibian pathogen.

    PubMed

    McKenzie, Valerie J; Peterson, Anna C

    2012-11-01

    Imagine a single pathogen that is responsible for mass mortality of over a third of an entire vertebrate class. For example, if a single pathogen were causing the death, decline and extinction of 30% of mammal species (including humans), the entire world would be paying attention. This is what has been happening to the world's amphibians - the frogs, toads and salamanders that are affected by the chytrid fungal pathogen, Batrachochytrium dendrobatidis (referred to as Bd), which are consequently declining at an alarming rate. It has aptly been described as the worst pathogen in history in terms of its effects on biodiversity (Kilpatrick et al. 2010). The pathogen was only formally described about 13 years ago (Longcore et al. 1999), and scientists are still in the process of determining where it came from and investigating the question: why now? Healthy debate has ensued as to whether Bd is a globally endemic organism that only recently started causing high mortality due to shifting host responses and/or environmental change (e.g. Pounds et al. 2006) or whether a virulent strain of the pathogen has rapidly disseminated around the world in recent decades, affecting new regions with a vengeance (e.g. Morehouse et al. 2003; Weldon et al. 2004; Lips et al. 2008). We are finally beginning to shed more light on this question, due to significant discoveries that have emerged as a result of intensive DNA-sequencing methods comparing Bd isolates from different amphibian species across the globe. Evidence is mounting that there is indeed a global panzootic lineage of Bd (BdGPL) in addition to what appear to be more localized endemic strains (Fisher et al. 2009; James et al. 2009; Farrer et al. 2011). Additionally, BdGPL appears to be a hypervirulent strain that has resulted from the hybridization of different Bd strains that came into contact in recent decades, and is now potentially replacing the less-virulent endemic strains of the pathogen (Farrer et al. 2011

  6. Pathogen pollution and the emergence of a deadly amphibian pathogen.

    PubMed

    McKenzie, Valerie J; Peterson, Anna C

    2012-11-01

    Imagine a single pathogen that is responsible for mass mortality of over a third of an entire vertebrate class. For example, if a single pathogen were causing the death, decline and extinction of 30% of mammal species (including humans), the entire world would be paying attention. This is what has been happening to the world's amphibians - the frogs, toads and salamanders that are affected by the chytrid fungal pathogen, Batrachochytrium dendrobatidis (referred to as Bd), which are consequently declining at an alarming rate. It has aptly been described as the worst pathogen in history in terms of its effects on biodiversity (Kilpatrick et al. 2010). The pathogen was only formally described about 13 years ago (Longcore et al. 1999), and scientists are still in the process of determining where it came from and investigating the question: why now? Healthy debate has ensued as to whether Bd is a globally endemic organism that only recently started causing high mortality due to shifting host responses and/or environmental change (e.g. Pounds et al. 2006) or whether a virulent strain of the pathogen has rapidly disseminated around the world in recent decades, affecting new regions with a vengeance (e.g. Morehouse et al. 2003; Weldon et al. 2004; Lips et al. 2008). We are finally beginning to shed more light on this question, due to significant discoveries that have emerged as a result of intensive DNA-sequencing methods comparing Bd isolates from different amphibian species across the globe. Evidence is mounting that there is indeed a global panzootic lineage of Bd (BdGPL) in addition to what appear to be more localized endemic strains (Fisher et al. 2009; James et al. 2009; Farrer et al. 2011). Additionally, BdGPL appears to be a hypervirulent strain that has resulted from the hybridization of different Bd strains that came into contact in recent decades, and is now potentially replacing the less-virulent endemic strains of the pathogen (Farrer et al. 2011

  7. Bloodborne Pathogens Exposure Control Plan.

    ERIC Educational Resources Information Center

    National Child Care Association, Atlanta, GA.

    This sample exposure control plan is a guide to assist child care providers in complying with the blood-borne pathogens standard issued by the Occupational Safety and Health Administration (OSHA). The standard requires employers to establish a written exposure control plan by May 5, 1992 (for exposure to microorganisms in human blood that cause…

  8. Asian citrus psyllid viral pathogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A newly discovered viral pathogen of Asian citrus psyllid, AsCP, Diaphorina citri, Kuwayama (Psyllidae: Hemiptera) was classified as a Reoviridae. This virus may serve as a biological control agent for AsCP. The AsCP is an efficient vector of the plant-infecting bacterium (Candidatus Liberibacter as...

  9. Biosignatures of Pathogen and Host

    SciTech Connect

    Fitch, J P; Chromy, B A; Forde, C E; Garcia, E; Gardner, S N; Gu, P P; Kuczmarksi, T A; Melius, C F; McCutchen-Maloney, S L; Milanovich, F P; Motin, V L; Ott, L L; Quong, A A; Quong, J N; Rocco, J M; Slezak, T R; Sokhansanj, B A; Vitalis, E A; Zemla, A T; McCready, P M

    2002-08-27

    In information theory, a signature is characterized by the information content as well as noise statistics of the communication channel. Biosignatures have analogous properties. A biosignature can be associated with a particular attribute of a pathogen or a host. However, the signature may be lost in backgrounds of similar or even identical signals from other sources. In this paper, we highlight statistical and signal processing challenges associated with identifying good biosignatures for pathogens in host and other environments. In some cases it may be possible to identify useful signatures of pathogens through indirect but amplified signals from the host. Discovery of these signatures requires new approaches to modeling and data interpretation. For environmental biosignal collections, it is possible to use signal processing techniques from other applications (e.g., synthetic aperture radar) to track the natural progression of microbes over large areas. We also present a computer-assisted approach to identify unique nucleic-acid based microbial signatures. Finally, an understanding of host-pathogen interactions will result in better detectors as well as opportunities in vaccines and therapeutics.

  10. Microbial Forensics and Plant Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New awareness of the vulnerability of a nation's agricultural infrastructure to the intentional introduction of pathogens or pests has led to the enhancement of programs for prevention and preparedness. A necessary component of a balanced bio-security plan is the capability to determine whether an ...

  11. Ustilago maydis as a Pathogen.

    PubMed

    Brefort, Thomas; Doehlemann, Gunther; Mendoza-Mendoza, Artemio; Reissmann, Stefanie; Djamei, Armin; Kahmann, Regine

    2009-01-01

    The Ustilago maydis-maize pathosystem has emerged as the current model for plant pathogenic basidiomycetes and as one of the few models for a true biotrophic interaction that persists throughout fungal development inside the host plant. This is based on the highly advanced genetic system for both the pathogen and its host, the ability to propagate U. maydis in axenic culture, and its unique capacity to induce prominent disease symptoms (tumors) on all aerial parts of maize within less than a week. The corn smut pathogen, though economically not threatening, will continue to serve as a model for related obligate biotrophic fungi such as the rusts, but also for closely related smut species that induce symptoms only in the flower organs of their hosts. In this review we describe the most prominent features of the U. maydis-maize pathosystem as well as genes and pathways most relevant to disease. We highlight recent developments that place this system at the forefront of understanding the function of secreted effectors in eukaryotic pathogens and describe the expected spin-offs for closely related species exploiting comparative genomics approaches.

  12. USEPA PERSPECTIVE ON CONTROLLING PATHOGENS

    EPA Science Inventory

    EPA minimizes the risk of infectious diseases from the beneficial use of sludge by requiring its treatment to reduce pathogen levels below the detection limit. How new treatment processes can be shown equivalent to ones specified in 40CFR503 will be discussed together with ways t...

  13. The Evolution of Foodborne Pathogens

    NASA Astrophysics Data System (ADS)

    Abu-Ali, Galeb S.; Manning, Shannon D.

    Despite continuous advances in food safety and disease surveillance, control, and prevention, foodborne bacterial infections remain a major public health concern. Because foodborne pathogens are commonly exposed to multiple environmental stressors, such as low pH and antibiotics, most have evolved specific mechanisms to facilitate survival in adverse environments.

  14. MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

    EPA Science Inventory

    This presentation is a summary of the EPA National Risk Management Research Laboratory (NRMRL) publication entitled Managing Urban Watershed Pathogen Contamination, EPA/600/R-03/111 (September 2003). It is available on the internet at http://www.epa.gov/ednnrmrl/repository/water...

  15. Proteomics of foodborne bacterial pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter focuses on recent research on foodborne bacterial pathogens that use mass spectrometry-based proteomic techniques as well as protein microarrays. Mass spectrometry ionization techniques (e.g. electrospray ionization and matrix-assisted laser desorption/ionization), analyzers (e.g. ion ...

  16. EXTRAINTESTINAL PATHOGENIC ESCHERICHIA COLI (EXPEC)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extraintestinal pathogenic Escherichia coli (ExPEC) possess virulence traits that allow them to invade, colonize, and induce disease in bodily sites outside of the gastrointestinal tract. Human diseases caused by ExPEC include urinary tract infections, neonatal meningitis, sepsis, pneumonia, surgic...

  17. Regulation of virulence gene expression in pathogenic Listeria.

    PubMed

    Brehm, K; Kreft, J; Ripio, M T; Vázquez-Boland, J A

    1996-06-01

    Dynamic interactions between host and pathogen are characteristic of infections caused by intracellular bacteria. This has favoured the evolution of highly effective control systems by which these pathogens regulate the expression of different virulence factors during sequential steps of the infection process. In the case of the facultative intracellular bacterium Listeria monocytogenes, these steps involve internalization by eukaryotic cells, lysis of the resulting phagosome, replication as well as movement within the host cytoplasm, direct cell-to-cell spread, and subsequent lysis of a double-membrane vacuole when entering neighbouring cells. Virulence factors which are involved in each of these steps have been identified and the expression of these factors is subject to a co-ordinate and differential control exerted by the major listerial virulence regulator PrfA. This protein belongs to the Crp/Fnr-family of transcriptional activators and recognizes specific target sequences in promoter regions of several listerial virulence genes. Differential expression of these genes during sequential steps of the infection seems to be at least partially mediated by different binding affinities of PrfA to its target sequences. Activity of PrfA-dependent genes and of prfA itself is under the control of several environmental variables which are used by the pathogen to recognize its transition from the free environment into a eukaryotic host.

  18. Sensitive detection of multiple pathogens using a single DNA probe.

    PubMed

    Nordin, Noordiana; Yusof, Nor Azah; Abdullah, Jaafar; Radu, Son; Hushiarian, Roozbeh

    2016-12-15

    A simple but promising electrochemical DNA nanosensor was designed, constructed and applied to differentiate a few food-borne pathogens. The DNA probe was initially designed to have a complementary region in Vibrio parahaemolyticus (VP) genome and to make different hybridization patterns with other selected pathogens. The sensor was based on a screen printed carbon electrode (SPCE) modified with polylactide-stabilized gold nanoparticles (PLA-AuNPs) and methylene blue (MB) was employed as the redox indicator binding better to single-stranded DNA. The immobilization and hybridization events were assessed using differential pulse voltammetry (DPV). The fabricated biosensor was able to specifically distinguish complementary, non-complementary and mismatched oligonucleotides. DNA was measured in the range of 2.0×10(-9)-2.0×10(-13)M with a detection limit of 5.3×10(-12)M. The relative standard deviation for 6 replications of DPV measurement of 0.2µM complementary DNA was 4.88%. The fabricated DNA biosensor was considered stable and portable as indicated by a recovery of more than 80% after a storage period of 6 months at 4-45°C. Cross-reactivity studies against various food-borne pathogens showed a reliably sensitive detection of VP. PMID:27414245

  19. Variation between pathogenic serovars within Salmonella pathogenicity islands.

    PubMed

    Amavisit, P; Lightfoot, D; Browning, G F; Markham, P F

    2003-06-01

    Although four of the five Salmonella pathogenicity islands (SPIs) have been characterized in detail for Salmonella enterica serovar Typhimurium, and the fifth has been characterized for Salmonella enterica serovar Dublin, there have been limited studies to examine them in detail in a range of pathogenic serovars of S. enterica. The aim of this study was to examine these regions, shown to be crucial in virulence, in pathogenic serovars to identify any major deletions or insertions that may explain variation in virulence and provide further understanding of the elements involved in the evolution of these regions. Multiple strains of each of the 13 serovars were compared by Southern blot hybridization using a series of probes that together encompassed the full length of all five SPIs. With the exception of serovar Typhimurium, all strains of the same serovar were identical in all five SPIs. Those serovars that differed from serovar Typhimurium in SPI-1 to SPI-4 and from serovar Dublin in SPI-5 were examined in more detail in the variant regions by PCR, and restriction endonuclease digestion and/or DNA sequencing. While most variation in hybridization patterns was attributable to loss or gain of single restriction endonuclease cleavage sites, three regions, in SPI-1, SPI-3, and SPI-5, had differences due to major insertions or deletions. In SPI-1 the avrA gene was replaced by a 200-base fragment in three serovars, as reported previously. In SPI-5, two serovars had acquired an insertion with similarity to the pagJ and pagK genes between pipC and pipD. In SPI-3 the genes sugR and rhuM were deleted in most serovars and in some were replaced by sequences that were very similar to either the Escherichia coli fimbrial operon, flanked by two distinct insertion sequence elements, or to the E. coli retron phage PhiR73. The distribution of these differences suggests that there have been a number of relatively recent horizontal transfers of genes into S. enterica and that in some

  20. Automated Separation of C. elegans Variably Colonized by a Bacterial Pathogen

    PubMed Central

    Twumasi-Boateng, Kwame; Berg, Maureen; Shapira, Michael

    2014-01-01

    The wormsorter is an instrument analogous to a FACS machine that is used in studies of Caenorhabditis elegans, typically to sort worms based on expression of a fluorescent reporter. Here, we highlight an alternative usage of this instrument, for sorting worms according to their degree of colonization by a GFP-expressing pathogen. This new usage allowed us to address the relationship between colonization of the worm intestine and induction of immune responses. While C. elegans immune responses to different pathogens have been documented, it is still unknown what initiates them. The two main possibilities (which are not mutually exclusive) are recognition of pathogen-associated molecular patterns, and detection of damage caused by infection. To differentiate between the two possibilities, exposure to the pathogen must be dissociated from the damage it causes. The wormsorter enabled separation of worms that were extensively-colonized by the Gram-negative pathogen Pseudomonas aeruginosa, with the damage likely caused by pathogen load, from worms that were similarly exposed, but not, or marginally, colonized. These distinct populations were used to assess the relationship between pathogen load and the induction of transcriptional immune responses. The results suggest that the two are dissociated, supporting the possibility of pathogen recognition. PMID:24686453

  1. Stress Signaling Pathways for the Pathogenicity of Cryptococcus

    PubMed Central

    Jung, Kwang-Woo

    2013-01-01

    Sensing, responding, and adapting to the surrounding environment are crucial for all living organisms to survive, proliferate, and differentiate in their biological niches. This ability is also essential for Cryptococcus neoformans and its sibling species Cryptococcus gattii, as these pathogens have saprobic and parasitic life cycles in natural and animal host environments. The ability of Cryptococcus to cause fatal meningoencephalitis is highly related to its capability to remodel and optimize its metabolic and physiological status according to external cues. These cues act through multiple stress signaling pathways through a panoply of signaling components, including receptors/sensors, small GTPases, secondary messengers, kinases, transcription factors, and other miscellaneous adaptors or regulators. In this minireview, we summarize and highlight the importance of several stress signaling pathways that influence the pathogenicity of Cryptococcus and discuss future challenges in these areas. PMID:24078305

  2. Perspective: Adhesion Mediated Signal Transduction in Bacterial Pathogens.

    PubMed

    Moorthy, Sudha; Keklak, Julia; Klein, Eric A

    2016-01-01

    During the infection process, pathogenic bacteria undergo large-scale transcriptional changes to promote virulence and increase intrahost survival. While much of this reprogramming occurs in response to changes in chemical environment, such as nutrient availability and pH, there is increasing evidence that adhesion to host-tissue can also trigger signal transduction pathways resulting in differential gene expression. Determining the molecular mechanisms of adhesion-mediated signaling requires disentangling the contributions of chemical and mechanical stimuli. Here we highlight recent work demonstrating that surface attachment drives a transcriptional response in bacterial pathogens, including uropathogenic Escherichia coli (E. coli), and discuss the complexity of experimental design when dissecting the specific role of adhesion-mediated signaling during infection.

  3. Perspective: Adhesion Mediated Signal Transduction in Bacterial Pathogens

    PubMed Central

    Moorthy, Sudha; Keklak, Julia; Klein, Eric A.

    2016-01-01

    During the infection process, pathogenic bacteria undergo large-scale transcriptional changes to promote virulence and increase intrahost survival. While much of this reprogramming occurs in response to changes in chemical environment, such as nutrient availability and pH, there is increasing evidence that adhesion to host-tissue can also trigger signal transduction pathways resulting in differential gene expression. Determining the molecular mechanisms of adhesion-mediated signaling requires disentangling the contributions of chemical and mechanical stimuli. Here we highlight recent work demonstrating that surface attachment drives a transcriptional response in bacterial pathogens, including uropathogenic Escherichia coli (E. coli), and discuss the complexity of experimental design when dissecting the specific role of adhesion-mediated signaling during infection. PMID:26901228

  4. ERD Research on Nutrient and Pathogen Dynamics

    EPA Science Inventory

    Slide presentation giving an overview on the ERD research on nutrient and pathogen dynamics. Focus is on characterizing the dynamics of pathogen and nutrient stressors in the environment to support water quality objectives.

  5. Innate Defense against Fungal Pathogens.

    PubMed

    Drummond, Rebecca A; Gaffen, Sarah L; Hise, Amy G; Brown, Gordon D

    2014-11-10

    Human fungal infections have been on the rise in recent years and proved increasingly difficult to treat as a result of the lack of diagnostics, effective antifungal therapies, and vaccines. Most pathogenic fungi do not cause disease unless there is a disturbance in immune homeostasis, which can be caused by modern medical interventions, disease-induced immunosuppression, and naturally occurring human mutations. The innate immune system is well equipped to recognize and destroy pathogenic fungi through specialized cells expressing a broad range of pattern recognition receptors (PRRs). This review will outline the cells and PRRs required for effective antifungal immunity, with a special focus on the major antifungal cytokine IL-17 and recently characterized antifungal inflammasomes.

  6. APDS: Autonomous Pathogen Detection System

    SciTech Connect

    Langlois, R G; Brown, S; Burris, L; Colston, B; Jones, L; Makarewicz, T; Mariella, R; Masquelier, D; McBride, M; Milanovich, F; Masarabadi, S; Venkateswaran, K; Marshall, G; Olson, D; Wolcott, D

    2002-02-14

    An early warning system to counter bioterrorism, the Autonomous Pathogen Detection System (APDS) continuously monitors the environment for the presence of biological pathogens (e.g., anthrax) and once detected, it sounds an alarm much like a smoke detector warns of a fire. Long before September 11, 2001, this system was being developed to protect domestic venues and events including performing arts centers, mass transit systems, major sporting and entertainment events, and other high profile situations in which the public is at risk of becoming a target of bioterrorist attacks. Customizing off-the-shelf components and developing new components, a multidisciplinary team developed APDS, a stand-alone system for rapid, continuous monitoring of multiple airborne biological threat agents in the environment. The completely automated APDS samples the air, prepares fluid samples in-line, and performs two orthogonal tests: immunoassay and nucleic acid detection. When compared to competing technologies, APDS is unprecedented in terms of flexibility and system performance.

  7. Antimicrobial resistance of mastitis pathogens.

    PubMed

    Oliver, Stephen P; Murinda, Shelton E

    2012-07-01

    Antibiotics are used extensively in the dairy industry to combat disease and to improve animal performance. Antibiotics such as penicillin, cephalosporin, streptomycin, and tetracycline are used for the treatment and prevention of diseases affecting dairy cows caused by a variety of gram-positive and gram-negative bacteria. Antibiotics are often administrated routinely to entire herds to prevent mastitis during the dry period. An increase in the incidence of disease in a herd generally results in increased use of antimicrobials, which in turn increases the potential for antibiotic residues in milk and the potential for increased bacterial resistance to antimicrobials. Continued use of antibiotics in the treatment and prevention of diseases of dairy cows will continue to be scrutinized. It is clear that strategies employing the prudent use of antimicrobials are needed. This clearly illustrates the importance of effective herd disease prevention and control programs. Based on studies published to date, scientific evidence does not support widespread, emerging resistance among mastitis pathogens to antibacterial drugs even though many of these antibiotics have been used in the dairy industry for treatment and prevention of disease for several decades. However, it is clear that use of antibiotics in dairy cows can contribute to increased antimicrobial resistance. While antimicrobial resistance does occur, we are of the opinion that the advantages of using antibiotics for the treatment of mastitis far outweigh the disadvantages. The clinical consequences of antimicrobial resistance of dairy pathogens affecting humans appear small. Antimicrobial resistance among dairy pathogens, particularly those found in milk, is likely not a human health concern as long as the milk is pasteurized. However, there are an increasing number of people who choose to consume raw milk. Transmission of an antimicrobial-resistant mastitis pathogen and/or foodborne pathogen to humans could occur

  8. Bacteriophage biocontrol of foodborne pathogens.

    PubMed

    Kazi, Mustafa; Annapure, Uday S

    2016-03-01

    Bacteriophages are viruses that only infect bacterial cells. Phages are categorized based on the type of their life cycle, the lytic cycle cause lysis of the bacterium with the release of multiple phage particles where as in lysogenic phase the phage DNA is incorporated into the bacterial genome. Lysogeny does not result in lysis of the host. Lytic phages have several potential applications in the food industry as biocontrol agents, biopreservatives and as tools for detecting pathogens. They have also been proposed as alternatives to antibiotics in animal health. Two unique features of phage relevant for food safety are that they are harmless to mammalian cells and high host specificity, keeping the natural microbiota undisturbed. However, the recent approval of bacteriophages as food additives has opened the discussion about 'edible viruses'. This article reviews in detail the application of phages for the control of foodborne pathogens in a process known as "biocontrol". PMID:27570260

  9. Resistant Pathogens, Fungi, and Viruses

    PubMed Central

    Guidry, Christopher A.; Mansfield, Sara A.; Sawyer, Robert G.; Cook, Charles H.

    2014-01-01

    The first reports of antibiotic pathogens occurred a few short years after the introduction of these powerful new agents, heralding a new kind of war between medicine and pathogens. Although originally described in Staphylococcus aureus, resistance among bacteria has now become a grim race to determine which classes of bacteria will become more resistant, pitting the Gram positive staphylococci, enterococci, and streptococci against the increasingly resistant Gram negative pathogens, e. g., carbapenemase-resistant enterobacteriaceae. In addition, the availability of antibacterial agents has allowed the development of whole new kinds of diseases caused by non-bacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. All of these organisms are becoming more prevalent and, ultimately, more clinically relevant for surgeons. It is ironic that despite their ubiquity in our communities, there is seldom a second thought given to viral infections in patients with surgical illness. The extent of most surgeon’s interest in viral infections ends with hepatitis and HIV, no doubt related to transmissibility as well as the implications that these viruses might have in a patient’s hepatic or immune functions. There are chapters and even textbooks written about these viruses so these will not be considered here. Instead, we will present the growing body of knowledge of the herpes family viruses and their occurrence and consequences in patients with concomitant surgical disease or critical illness. We have also chosen to focus this chapter on previously immune competent patients, as the impact of herpes family viruses in immunosuppressed patients such as transplant or AIDS patients has received thorough treatment elsewhere. PMID:25440119

  10. Plant innate immunity against human bacterial pathogens

    PubMed Central

    Melotto, Maeli; Panchal, Shweta; Roy, Debanjana

    2014-01-01

    Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens. PMID:25157245

  11. Taxonomy of bacterial fish pathogens

    PubMed Central

    2011-01-01

    Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens. PMID:21314902

  12. Molecular Mechanisms of Bacterial Pathogenicity

    NASA Astrophysics Data System (ADS)

    Fuchs, Thilo Martin

    Cautious optimism has arisen over recent decades with respect to the long struggle against bacteria, viruses, and parasites. This has been offset, however, by a fatal complacency stemming from previous successes such as the development of antimicrobial drugs, the eradication of smallpox, and global immunization programs. Infectious diseases nevertheless remain the world's leading cause of death, killing at least 17 million persons annually [61]. Diarrheal diseases caused by Vibrio cholerae or Shigella dysenteriae kill about 3 million persons every year, most of them young children: Another 4 million die of tuberculosis or tetanus. Outbreaks of diphtheria in Eastern Europe threatens the population with a disease that had previously seemed to be overcome. Efforts to control infectious diseases more comprehensively are undermined not only by socioeconomic conditions but also by the nature of the pathogenic organisms itself; some isolates of Staphylococcus aureus and Enterobacter have become so resistant to drugs by horizontal gene transfer that they are almost untreatable. In addition, the mechanism of genetic variability helps pathogens to evade the human immune system, thus compromising the development of powerful vaccines. Therefore detailed knowledge of the molecular mechanisms of microbial pathogenicity is absolutely necessary to develop new strategies against infectious diseases and thus to lower their impact on human health and social development.

  13. Emerging water-borne pathogens.

    PubMed

    Sharma, S; Sachdeva, P; Virdi, J S

    2003-06-01

    Emerging water-borne pathogens constitute a major health hazard in both developed and developing nations. A new dimension to the global epidemiology of cholera-an ancient scourge-was provided by the emergence of Vibrio cholerae O139. Also, water-borne enterohaemorrhagic Escherichia coli ( E. coli O157:H7), although regarded as a problem of the industrialized west, has recently caused outbreaks in Africa. Outbreaks of chlorine-resistant Cryptosporidium have motivated water authorities to reassess the adequacy of current water-quality regulations. Of late, a host of other organisms, such as hepatitis viruses (including hepatitis E virus), Campylobacter jejuni, microsporidia, cyclospora, Yersinia enterocolitica, calciviruses and environmental bacteria like Mycobacterium spp, aeromonads, Legionella pneumophila and multidrug-resistant Pseudomonas aeruginosa have been associated with water-borne illnesses. This review critically examines the potential of these as emerging water-borne pathogens. It also examines the possible reasons, such as an increase in the number of immunocompromised individuals, urbanization and horizontal gene transfer, that may underlie their emergence. Further, measures required to face the challenge posed by these pathogens are also discussed.

  14. Taxonomy of bacterial fish pathogens.

    PubMed

    Austin, Brian

    2011-02-02

    Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens.

  15. Pathogens in septage in Vietnam.

    PubMed

    Yen-Phi, Vo Thi; Rechenburg, Andrea; Vinneras, Björn; Clemens, Joachim; Kistemann, Thomas

    2010-04-01

    Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 oval(-1), and were detected in all septage sludge samples with an average of 16,000 oval(-1). Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.

  16. [Cultivation of pathogenic free-living amoebae].

    PubMed

    Peng, Heng; Zhu, Huai-Min

    2009-08-01

    The isolation and culture of pathogenic free-living amoebae are useful in the diagnosis and research. This review focuses on the methods of isolation and cultivation of pathogenic free-living amoebae, including sample treatment, culture conditions, passage culture, pathogen detection, and maintenance.

  17. Pathogenicity islands and the evolution of microbes.

    PubMed

    Hacker, J; Kaper, J B

    2000-01-01

    Virulence factors of pathogenic bacteria (adhesins, toxins, invasins, protein secretion systems, iron uptake systems, and others) may be encoded by particular regions of the prokaryotic genome termed pathogenicity islands. Pathogenicity islands were first described in human pathogens of the species Escherichia coli, but have recently been found in the genomes of various pathogens of humans, animals, and plants. Pathogenicity islands comprise large genomic regions [10-200 kilobases (kb) in size] that are present on the genomes of pathogenic strains but absent from the genomes of nonpathogenic members of the same or related species. The finding that the G+C content of pathogenicity islands often differs from that of the rest of the genome, the presence of direct repeats at their ends, the association of pathogenicity islands with transfer RNA genes, the presence of integrase determinants and other mobility loci, and their genetic instability argue for the generation of pathogenicity islands by horizontal gene transfer, a process that is well known to contribute to microbial evolution. In this article we review these and other aspects of pathogenicity islands and discuss the concept that they represent a subclass of genomic islands. Genomic islands are present in the majority of genomes of pathogenic as well as nonpathogenic bacteria and may encode accessory functions which have been previously spread among bacterial populations.

  18. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  19. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate.

  20. Pathogen evolution under host avoidance plasticity

    PubMed Central

    McLeod, David V.; Day, Troy

    2015-01-01

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host–pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. PMID:26336170

  1. Contamination of water resources by pathogenic bacteria

    PubMed Central

    2014-01-01

    Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed. PMID:25006540

  2. Contamination of water resources by pathogenic bacteria.

    PubMed

    Pandey, Pramod K; Kass, Philip H; Soupir, Michelle L; Biswas, Sagor; Singh, Vijay P

    2014-01-01

    Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed.

  3. Internalization of fresh produce by foodborne pathogens.

    PubMed

    Erickson, Marilyn C

    2012-01-01

    Recent studies addressing the internalization of fresh produce by foodborne pathogens arose in response to the growing number of recent and high profile outbreaks involving fresh produce. Because chemical sanitizing agents used during harvest and minimal processing are unlikely to reach enteric pathogens residing within plant tissue, it is imperative that paths for pathogen entry be recognized and minimized. Using both microscopy and microbial enumeration tools, enteric pathogens have been shown to enter plant tissues through both natural apertures (stomata, lateral junctions of roots, flowers) and damaged (wounds, cut surfaces) tissue. In studies revealing preharvest internalization via plant roots or leaf stomata, experimental conditions have primarily involved exposure of plants to high pathogen concentrations (≥ 6 log g⁻¹ soil or 6 log ml⁻¹ water), but those pathogens internalized appear to have short-term persistence. Postharvest internalization of pathogens via cut surfaces may be minimized by maintaining effective levels of sanitizing agents in waters during harvesting and minimal processing.

  4. [Pathogenicity and pneumococcal capsular genes].

    PubMed

    García, E; García, P; López, R

    1994-01-01

    Pneumococci remain to be one of the most prominent human pathogens. Increasing efforts are being dedicated to the development of improved vaccines with wider specificity. Since a clear understanding of the genetics of capsular types in Streptococcus pneumoniae is missing, our efforts are oriented to characterize, at the molecular level, the genes involved in capsular polysaccharide biosynthesis. We have cloned and sequenced a chromosomal DNA fragment of a clinical isolate of type 3 pneumococcus and showed that it contains a type 3 specific gene as well as genes common to other serotypes.

  5. Molecular Epidemiology of Foodborne Pathogens

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Brown, Eric; Knabel, Stephen J.

    The purpose of this chapter is to describe the basic principles and advancements in the molecular epidemiology of foodborne pathogens. Epidemiology is the study of the distribution and determinants of infectious diseases and/or the dynamics of disease transmission. The goals of epidemiology include the identification of physical sources, routes of transmission of infectious agents, and distribution and relationships of different subgroups. Molecular epidemiology is the study of epidemiology at the molecular level. It has been defined as "a science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution and prevention of diseases within families and across populations".

  6. The Autonomous Pathogen Detection System

    SciTech Connect

    Dzenitis, J M; Makarewicz, A J

    2009-01-13

    We developed, tested, and now operate a civilian biological defense capability that continuously monitors the air for biological threat agents. The Autonomous Pathogen Detection System (APDS) collects, prepares, reads, analyzes, and reports results of multiplexed immunoassays and multiplexed PCR assays using Luminex{copyright} xMAP technology and flow cytometer. The mission we conduct is particularly demanding: continuous monitoring, multiple threat agents, high sensitivity, challenging environments, and ultimately extremely low false positive rates. Here, we introduce the mission requirements and metrics, show the system engineering and analysis framework, and describe the progress to date including early development and current status.

  7. Hyphal chemotropism in fungal pathogenicity.

    PubMed

    Turrà, David; Nordzieke, Daniela; Vitale, Stefania; El Ghalid, Mennat; Di Pietro, Antonio

    2016-09-01

    The ability to grow as filamentous hyphae defines the lifestyle of fungi. Hyphae are exposed to a variety of chemical stimuli such as nutrients or signal molecules from mating partners and host organisms. How fungi sense and process this chemical information to steer hyphal growth is poorly understood. Saccharomyces cerevisiae and Neurospora crassa have served as genetic models for the identification of cellular components functioning in chemotropism. A recent study in the pathogen Fusarium oxysporum revealed distinct MAPK pathways governing hyphal growth towards nutrient sources and sex pheromones or plant signals, suggesting an unanticipated complexity of chemosensing during fungus-host interactions. PMID:27150623

  8. Isolate Identity Determines Plant Tolerance to Pathogen Attack in Assembled Mycorrhizal Communities

    PubMed Central

    Lewandowski, Thaddeus J.; Dunfield, Kari E.; Antunes, Pedro M.

    2013-01-01

    Arbuscular mycorrhizal fungi (AMF) are widespread soil microorganisms that associate mutualistically with plant hosts. AMF receive photosynthates from the host in return for various benefits. One of such benefits is in the form of enhanced pathogen tolerance. However, this aspect of the symbiosis has been understudied compared to effects on plant growth and its ability to acquire nutrients. While it is known that increased AMF species richness positively correlates with plant productivity, the relationship between AMF diversity and host responses to pathogen attack remains obscure. The objective of this study was to test whether AMF isolates can differentially attenuate the deleterious effects of a root pathogen on plant growth, whether the richest assemblage of AMF isolates provides the most tolerance against the pathogen, and whether AMF-induced changes to root architecture serve as a mechanism for improved plant disease tolerance. In a growth chamber study, we exposed the plant oxeye daisy (Leucanthemum vulgare) to all combinations of three AMF isolates and to the plant root pathogen Rhizoctonia solani. We found that the pathogen caused an 81% reduction in shoot and a 70% reduction in root biomass. AMF significantly reduced the highly deleterious effect of the pathogen. Mycorrhizal plants infected with the pathogen produced 91% more dry shoot biomass and 72% more dry root biomass relative to plants solely infected with R. solani. AMF isolate identity was a better predictor of AMF-mediated host tolerance to the pathogen than AMF richness. However, the enhanced tolerance response did not result from AMF-mediated changes to root architecture. Our data indicate that AMF communities can play a major role in alleviating host pathogen attack but this depends primarily on the capacity of individual AMF isolates to provide this benefit. PMID:23620744

  9. Diverse intracellular pathogens activate type III interferon expression from peroxisomes.

    PubMed

    Odendall, Charlotte; Dixit, Evelyn; Stavru, Fabrizia; Bierne, Helene; Franz, Kate M; Durbin, Ann Fiegen; Boulant, Steeve; Gehrke, Lee; Cossart, Pascale; Kagan, Jonathan C

    2014-08-01

    Type I interferon responses are considered the primary means by which viral infections are controlled in mammals. Despite this view, several pathogens activate antiviral responses in the absence of type I interferons. The mechanisms controlling type I interferon-independent responses are undefined. We found that RIG-I like receptors (RLRs) induce type III interferon expression in a variety of human cell types, and identified factors that differentially regulate expression of type I and type III interferons. We identified peroxisomes as a primary site of initiation of type III interferon expression, and revealed that the process of intestinal epithelial cell differentiation upregulates peroxisome biogenesis and promotes robust type III interferon responses in human cells. These findings highlight the importance of different intracellular organelles in specific innate immune responses.

  10. Pathotypes of Bacterial Spot Pathogen Infecting Capsicum Peppers in Korea

    PubMed Central

    Wai, Khin Pa Pa; Siddique, Muhammad Irfan; Mo, Hwang-Sung; Yoo, Hee Ju; Byeon, Si-Eun; Jegal, Yoonhyuk; Mekuriaw, Alebel A.; Kim, Byung-Soo

    2015-01-01

    Sixty-seven isolates of bacterial spot pathogen (Xanthomonas spp.) collected from six provinces of Korea were tested for the identification of their pathotypes and determination of their distribution throughout Korea in an effort to genetically manage the disease. Near isogenic lines of Early Calwonder (Capsicum annuum) pepper plants carrying Bs1, Bs2 and Bs3, and PI235047 (C. pubescens) were used as differential hosts. Race P1 was found to be predominant, followed by race P7, and races P3 and P8 were also observed. This is the first report of races P7 and P8 in Korea. The races P7 and P8 were differentiated from the former races P1 and P3, respectively, on the basis of their ability to elicit hypersensitive reactions to PI235047. PMID:26674555

  11. Diverse intracellular pathogens activate Type III Interferon expression from peroxisomes

    PubMed Central

    Odendall, Charlotte; Dixit, Evelyn; Stavru, Fabrizia; Bierne, Helene; Franz, Kate M.; Fiegen, Ann; Boulant, Steeve; Gehrke, Lee; Cossart, Pascale; Kagan, Jonathan C.

    2014-01-01

    Type I Interferon (IFN) responses are considered the primary means by which viral infections are controlled in mammals. Despite this view, several pathogens activate antiviral responses in the absence of Type I IFNs. The mechanisms controlling Type I IFN-independent responses are undefined. We have found that RIG-I like Receptors (RLRs) induce Type III IFN expression in a variety of human cell types, and identified factors that differentially regulate Type I and III IFN expression. We identified peroxisomes as a primary site that initiates Type III IFN expression, and revealed that the process of intestinal epithelial cell differentiation upregulates peroxisome biogenesis and promotes robust Type III IFN responses in human cells. These findings highlight the interconnections between innate immunity and cell biology. PMID:24952503

  12. Computational models in plant-pathogen interactions: the case of Phytophthora infestans

    PubMed Central

    2009-01-01

    Background Phytophthora infestans is a devastating oomycete pathogen of potato production worldwide. This review explores the use of computational models for studying the molecular interactions between P. infestans and one of its hosts, Solanum tuberosum. Modeling and conclusion Deterministic logistics models have been widely used to study pathogenicity mechanisms since the early 1950s, and have focused on processes at higher biological resolution levels. In recent years, owing to the availability of high throughput biological data and computational resources, interest in stochastic modeling of plant-pathogen interactions has grown. Stochastic models better reflect the behavior of biological systems. Most modern approaches to plant pathology modeling require molecular kinetics information. Unfortunately, this information is not available for many plant pathogens, including P. infestans. Boolean formalism has compensated for the lack of kinetics; this is especially the case where comparative genomics, protein-protein interactions and differential gene expression are the most common data resources. PMID:19909526

  13. mTOR Regulation of Lymphoid Cells in Immunity to Pathogens.

    PubMed

    Keating, Rachael; McGargill, Maureen Ann

    2016-01-01

    Immunity to pathogens exists as a fine balance between promoting activation and expansion of effector cells, while simultaneously limiting normal and aberrant responses. These seemingly opposing functions are kept in check by immune regulators. The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that senses nutrient availability and, in turn, regulates cell metabolism, growth, and survival accordingly. mTOR plays a pivotal role in facilitating immune defense against invading pathogens by regulating the differentiation, activation, and effector functions of lymphoid cells. Here, we focus on the emerging and sometimes contradictory roles of mTOR in orchestrating lymphoid cell-mediated host immune responses to pathogens. A thorough understanding of how mTOR impacts lymphoid cells in pathogen defense will provide the necessary base for developing therapeutic interventions for infectious diseases. PMID:27242787

  14. mTOR Regulation of Lymphoid Cells in Immunity to Pathogens

    PubMed Central

    Keating, Rachael; McGargill, Maureen Ann

    2016-01-01

    Immunity to pathogens exists as a fine balance between promoting activation and expansion of effector cells, while simultaneously limiting normal and aberrant responses. These seemingly opposing functions are kept in check by immune regulators. The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that senses nutrient availability and, in turn, regulates cell metabolism, growth, and survival accordingly. mTOR plays a pivotal role in facilitating immune defense against invading pathogens by regulating the differentiation, activation, and effector functions of lymphoid cells. Here, we focus on the emerging and sometimes contradictory roles of mTOR in orchestrating lymphoid cell-mediated host immune responses to pathogens. A thorough understanding of how mTOR impacts lymphoid cells in pathogen defense will provide the necessary base for developing therapeutic interventions for infectious diseases. PMID:27242787

  15. Isolation and Characterization of Trichoderma spp. for Antagonistic Activity Against Root Rot and Foliar Pathogens.

    PubMed

    Kumar, Krishna; Amaresan, N; Bhagat, S; Madhuri, K; Srivastava, R C

    2012-06-01

    Trichoderma, soil-borne filamentous fungi, are capable of parasitising several plant pathogenic fungi. Twelve isolates of Trichoderma spp. isolated from different locations of South Andaman were characterized for their cultural, morphological and antagonistic activity against soil borne and foliar borne pathogens. The sequencing of these isolates showed seven different species. The isolates revealed differential reaction patterns against th