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Sample records for lepidopteran host ranges

  1. Broad host range plasmids.

    PubMed

    Jain, Aayushi; Srivastava, Preeti

    2013-11-01

    Plasmids are and will remain important cloning vehicles for biotechnology. They have also been associated with the spread of a number of diseases and therefore are a subject of environmental concern. With the advent of sequencing technologies, the database of plasmids is increasing. It will be of immense importance to identify the various bacterial hosts in which the plasmid can replicate. The present review article describes the features that confer broad host range to the plasmids, the molecular basis of plasmid host range evolution, and applications in recombinant DNA technology and environment.

  2. Determining larval host plant use by a polyphagous lepidopteran through analysis of adult moths for plant secondary metabolites.

    PubMed

    Orth, Robert G; Head, Graham; Mierkowski, Mary

    2007-06-01

    Many polyphagous insect species are important economic pests on one or more of their crop hosts. For most important insect pests, the common crop hosts are well-known, but knowledge of weedy and unmanaged hosts is limited. Furthermore, the relative contribution of different hosts to local and regional populations has rarely been ascertained because this requires having some way to determine which plant hosts are the source of the adult moths observed ovipositing in a crop field at a given place and time. One way of determining the larval host of polyphagous pest species is to analyze for several plant-derived chemicals that are each specific to a different small set of related plant species and are preserved in detectable amounts in adult moths. In this paper, we describe novel methods for analyzing adults of the polyphagous lepidopteran, the tobacco budworm (TBW) Heliothis virescens (F.), for plant secondary metabolites, specifically cotinine and gossypol, which are diagnostic for larval feeding on tobacco and cotton, respectively. Cotinine was extracted from individual TBW moths with acetic acid and methanol, then concentrated and analyzed directly by gas chromatography/mass spectrometry (GC/MS). The same moths then were analyzed for bound gossypol by creating a Schiff's base that used aniline, and the resulting dianilino-gossypol complex was quantified using high pressure chromatography coupled with a triple quadrupole mass spectrometer (MS) as the detector. Based on analysis of standards, the detection limit for the cotinine was less than 1.5 ppb by dry weight. Comparable standards were not available for the gossypol derivative so a quantitative limit of detection could not be calculated. When TBW moths reared on known hosts were analyzed for gossypol and/or cotinine, all of the moths reared on tobacco or cotton were correctly identified, although some false positives were recorded with the gossypol method. Analysis of TBW moths of various ages and at various

  3. Accidental genetic engineers: horizontal sequence transfer from parasitoid wasps to their Lepidopteran hosts.

    PubMed

    Schneider, Sean E; Thomas, James H

    2014-01-01

    We show here that 105 regions in two Lepidoptera genomes appear to derive from horizontally transferred wasp DNA. We experimentally verified the presence of two of these sequences in a diverse set of silkworm (Bombyx mori) genomes. We hypothesize that these horizontal transfers are made possible by the unusual strategy many parasitoid wasps employ of injecting hosts with endosymbiotic polydnaviruses to minimize the host's defense response. Because these virus-like particles deliver wasp DNA to the cells of the host, there has been much interest in whether genetic information can be permanently transferred from the wasp to the host. Two transferred sequences code for a BEN domain, known to be associated with polydnaviruses and transcriptional regulation. These findings represent the first documented cases of horizontal transfer of genes between two organisms by a polydnavirus. This presents an interesting evolutionary paradigm in which host species can acquire new sequences from parasitoid wasps that attack them. Hymenoptera and Lepidoptera diverged ∼300 MYA, making this type of event a source of novel sequences for recipient species. Unlike many other cases of horizontal transfer between two eukaryote species, these sequence transfers can be explained without the need to invoke the sequences 'hitchhiking' on a third organism (e.g. retrovirus) capable of independent reproduction. The cellular machinery necessary for the transfer is contained entirely in the wasp genome. The work presented here is the first such discovery of what is likely to be a broader phenomenon among species affected by these wasps.

  4. Intraspecific variation of host plant and locality influence the lepidopteran-parasitoid system of Brassica oleracea crops.

    PubMed

    Santolamazza-Carbone, S; Velasco, P; Selfa, J; Soengas, P; Cartea, M E

    2013-06-01

    The aim of the study was to investigate the attractiveness to herbivores and parasitoids of two cultivars of Brassica oleracea L., namely, B. oleracea variety acephala (kale) and B. oleracea variety capitata (cabbage), that exhibit differences of morphological and biochemical traits. To this end, field samplings were replicated at seven localities in Galicia (northwestern Spain). Three specialist and three generalist lepidopteran species were sampled. In total, 7,050 parasitoids were obtained, belonging to 18 genera and 22 species. The results showed that 1) parasitism rate and parasitoid species richness changed with locality and was higher in cabbage, although this crop had lower herbivore abundance; 2) the proportion of specialist herbivores was higher in cabbage crops, whereas generalists dominated in kale crops; 3) the abundance of the parasitoids Telenomus sp. (Hymenoptera, Scelionidae), Cotesia glomerata L. (Hymenoptera: Braconidae), and Diadegma fenestrale (Holmgren) (Hymenoptera: Ichneumonidae) was higher in kale crops; and 4) parasitism rate of Pieris rapae larvae and pupae and Mamestra brassicae eggs were higher in kale crops. In contrast with the notion that plant structural complexity provides physical refuge to the hosts and can interfere with parasitoid foraging, parasitism rate was higher on cabbage plants, which form heads of overlapped leaves. Possibly, different chemical profiles of cultivars also influenced the host-parasitoid relationship. These results suggest that top-down and bottom-up forces may enhance cabbage crops to better control herbivore pressure during the studied season. In Spain, information on natural occurring parasitoid guilds of Brassica crops is still scarce. The data provided here also represent a critical first step for conservation biological control plans of these cultivations.

  5. Electroantennogram (EAG) responses of Microplitis croceipes and Cotesia marginiventris and their lepidopteran hosts to a wide array of odor stimuli: correlation between EAG response and degree of host specificity?

    PubMed

    Ngumbi, Esther; Chen, Li; Fadamiro, Henry

    2010-09-01

    In order to test whether the electroantennogram (EAG) response spectrum of an insect correlates to its degree of host specificity, we recorded EAG responses of two parasitoid species with different degrees of host specificity, Microplitis croceipes (specialist) and Cotesia marginiventris (generalist), to a wide array of odor stimuli including compounds representing green leaf volatiles (GLVs), herbivore-induced plant volatiles (HIPV), ecologically irrelevant (not used by the parasitoid species and their hosts for host location) plant volatiles, and host-specific odor stimuli (host sex pheromones, and extracts of host caterpillar body and frass). We also tested the EAG responses of female moths of the caterpillar hosts of the parasitoids, Heliothis virescens and Spodoptera exigua, to some of the odor stimuli. We hypothesized that the specialist parasitoid will have a narrower EAG response spectrum than the generalist, and that the two lepidopteran species, which are similar in their host plant use, will show similar EAG response spectra to plant volatiles. As predicted, the specialist parasitoid showed greater EAG responses than the generalist to host-specific odor and one HIPV (cis-3-hexenyl butyrate), whereas the generalist showed relatively greater EAG responses to the GLVs and unrelated plant volatiles. We detected no differences in the EAG responses of H. virescens and S. exigua to any of the tested odor.

  6. Cowpox: reservoir hosts and geographic range.

    PubMed Central

    Chantrey, J.; Meyer, H.; Baxby, D.; Begon, M.; Bown, K. J.; Hazel, S. M.; Jones, T.; Montgomery, W. I.; Bennett, M.

    1999-01-01

    It is generally accepted that the reservoir hosts of cowpox virus are wild rodents, although direct evidence for this is lacking for much of the virus's geographic range. Here, through a combination of serology and PCR, we demonstrate conclusively that the main hosts in Great Britain are bank voles, wood mice and short-tailed field voles. However, we also suggest that wood mice may not be able to maintain infection alone, explaining the absence of cowpox from Ireland where voles are generally not found. Infection in wild rodents varies seasonally, and this variation probably underlies the marked seasonal incidence of infection in accidental hosts such as humans and domestic cats. PMID:10459650

  7. Host Range and Emerging and Reemerging Pathogens

    PubMed Central

    Gowtage-Sequeria, Sonya

    2005-01-01

    An updated literature survey identified 1,407 recognized species of human pathogen, 58% of which are zoonotic. Of the total, 177 are regarded as emerging or reemerging. Zoonotic pathogens are twice as likely to be in this category as are nonzoonotic pathogens. Emerging and reemerging pathogens are not strongly associated with particular types of nonhuman hosts, but they are most likely to have the broadest host ranges. Emerging and reemerging zoonoses are associated with a wide range of drivers, but changes in land use and agriculture and demographic and societal changes are most commonly cited. However, although zoonotic pathogens do represent the most likely source of emerging and reemerging infectious disease, only a small minority have proved capable of causing major epidemics in the human population. PMID:16485468

  8. Host range, host specificity and hypothesized host shift events among viruses of lower vertebrates

    PubMed Central

    2011-01-01

    The successful replication of a viral agent in a host is a complex process that often leads to a species specificity of the virus and can make interspecies transmission difficult. Despite this difficulty, natural host switch seems to have been frequent among viruses of lower vertebrates, especially fish viruses, since there are several viruses known to be able to infect a wide range of species. In the present review we will focus on well documented reports of broad host range, variations in host specificity, and host shift events hypothesized for viruses within the genera Ranavirus, Novirhabdovirus, Betanodavirus, Isavirus, and some herpesvirus. PMID:21592358

  9. When History Repeats Itself: Exploring the Genetic Architecture of Host-Plant Adaptation in Two Closely Related Lepidopteran Species

    PubMed Central

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

    2013-01-01

    The genus Ostrinia includes two allopatric maize pests across Eurasia, namely the European corn borer (ECB, O. nubilalis) and the Asian corn borer (ACB, O. furnacalis). A third species, the Adzuki bean borer (ABB, O. scapulalis), occurs in sympatry with both the ECB and the ACB. The ABB mostly feeds on native dicots, which probably correspond to the ancestral host plant type for the genus Ostrinia. This situation offers the opportunity to characterize the two presumably independent adaptations or preadaptations to maize that occurred in the ECB and ACB. In the present study, we aimed at deciphering the genetic architecture of these two adaptations to maize, a monocot host plant recently introduced into Eurasia. To this end, we performed a genome scan analysis based on 684 AFLP markers in 12 populations of ECB, ACB and ABB. We detected 2 outlier AFLP loci when comparing French populations of the ECB and ABB, and 9 outliers when comparing Chinese populations of the ACB and ABB. These outliers were different in both countries, and we found no evidence of linkage disequilibrium between any two of them. These results suggest that adaptation or preadaptation to maize relies on a different genetic architecture in the ECB and ACB. However, this conclusion must be considered in light of the constraints inherent to genome scan approaches and of the intricate evolution of adaptation and reproductive isolation in the Ostrinia spp. complex. PMID:23874914

  10. Ecological consequences of ingestion of Bacillus cereus on Bacillus thuringiensis infections and on the gut flora of a lepidopteran host.

    PubMed

    Raymond, Ben; Lijek, Rebeccah S; Griffiths, Robert I; Bonsall, Michael B

    2008-09-01

    The Bacillus cereus group comprises a diverse array of non-pathogenic bacteria as well as pathogens such as Bacillus thuringiensis. Their spores are found together in soil and leaves and are therefore likely to commonly interact within hosts. Mixed infections of pathogenic B. thuringiensis and non-pathogenic strains have been little studied, despite their potential impact on biological control and the evolutionary ecology of virulence. Antibiotic secreting strains of B. cereus have been shown to be able to synergize B. thuringiensis (Bt) infections. We explored the ecology of these mixed infections more broadly in the diamondback moth (DBM). We tested whether antibiotic-expressing B. cereus can synergize Bt infections initiated with spores, investigated whether ingestion of antibiotic-expressing B. cereus had any consequences for the larval gut flora and whether synergistic interactions with B. cereus increase Bt reproduction. Ingestion of high-antibiotic secreting B. cereus synergized infections of B. thuringiensis in diamondback moth larvae, but at a lower level than previously reported. Coinfection also increased slightly the number of Bt spores found in cadavers. Culture independent analysis of gut homogenates indicated that ingestion of an antibiotic-expressing strain of B. cereus reduced the abundance of the gut flora and led to gut communities being dominated bacteria with DGGE profiles very similar to pure B. cereus cultures. Ingestion of B. cereus, regardless of genotype, reduced densities of an enteric isolate of Enterobacter sp. These findings support the hypothesis that antibiotic secretion in the gut synergizes B. thuringiensis infections by reducing the abundance of the commensal gut flora and facilitating invasion by bacteria in the B. cereus group.

  11. In vitro host range of feline morbillivirus

    PubMed Central

    SAKAGUCHI, Shoichi; KOIDE, Rie; MIYAZAWA, Takayuki

    2015-01-01

    Feline morbillivirus (FmoPV) is an emerging virus in cats, which is associated with tubulointerstitial nephritis. To study the in vitro host range of FmoPV, we inoculated FmoPV strain SS1 to 32 cell lines originated from 13 species and cultured for 2 weeks, followed by RNA extraction and reverse-transcription-polymerase chain reaction for FmoPV detection. As a result, only cell lines derived from cats and African green monkeys were susceptible to FmoPV. FmoPV infects diverse feline cell lines: epithelial, fibroblastic, lymphoid and glial cells. These results indicate that the receptor (s) for FmoPV are ubiquitously expressed in cats. No infectivity of FmoPV was observed in human cell lines, which suggests least threatening of cross-species transmission of FmoPV from cats to humans. PMID:26027844

  12. More Is Better: Selecting for Broad Host Range Bacteriophages

    PubMed Central

    Ross, Alexa; Ward, Samantha; Hyman, Paul

    2016-01-01

    Bacteriophages are viruses that infect bacteria. In this perspective, we discuss several aspects of a characteristic feature of bacteriophages, their host range. Each phage has its own particular host range, the range of bacteria that it can infect. While some phages can only infect one or a few bacterial strains, other phages can infect many species or even bacteria from different genera. Different methods for determining host range may give different results, reflecting the multiple mechanisms bacteria have to resist phage infection and reflecting the different steps of infection each method depends on. This makes defining host range difficult. Another difficulty in describing host range arises from the inconsistent use of the words “narrow” and especially “broad” when describing the breadth of the host range. Nearly all bacteriophages have been isolated using a single host strain of bacteria. While this procedure is fairly standard, it may more likely produce narrow rather than broad host range phage. Our results and those of others suggest that using multiple host strains during isolation can more reliably produce broader host range phages. This challenges the common belief that most bacteriophages have a narrow host range. We highlight the implications of this for several areas that are affected by host range including horizontal gene transfer and phage therapy. PMID:27660623

  13. Poxviruses and the Evolution of Host Range and Virulence

    PubMed Central

    Haller, Sherry L.; Peng, Chen; McFadden, Grant; Rothenburg, Stefan

    2013-01-01

    Poxviruses as a group can infect a large number of animals. However, at the level of individual viruses, even closely related poxviruses display highly diverse host ranges and virulence. For example, variola virus, the causative agent of smallpox, is human-specific and highly virulent only to humans, whereas related cowpox viruses naturally infect a broad spectrum of animals and only cause relatively mild disease in humans. The successful replication of poxviruses depends on their effective manipulation of the host antiviral responses, at the cellular-, tissue- and species-specific levels, which constitutes a molecular basis for differences in poxvirus host range and virulence. A number of poxvirus genes have been identified that possess host range function in experimental settings, and many of these host range genes target specific antiviral host pathways. Herein, we review the biology of poxviruses with a focus on host range, zoonotic infections, virulence, genomics and host range genes as well as the current knowledge about the function of poxvirus host range factors and how their interaction with the host innate immune system contributes to poxvirus host range and virulence. We further discuss the evolution of host range and virulence in poxviruses as well as host switches and potential poxvirus threats for human and animal health. PMID:24161410

  14. Host Range Specificity in Verticillium dahliae.

    PubMed

    Bhat, R G; Subbarao, K V

    1999-12-01

    ABSTRACT Verticillium dahliae isolates from artichoke, bell pepper, cabbage, cauliflower, chili pepper, cotton, eggplant, lettuce, mint, potato, strawberry, tomato, and watermelon and V. albo-atrum from alfalfa were evaluated for their pathogenicity on all 14 hosts. One-month-old seedlings were inoculated with a spore suspension of about 10(7) conidia per ml using a root-dip technique and incubated in the greenhouse. Disease incidence and severity, plant height, and root and shoot dry weights were recorded 6 weeks after inoculation. Bell pepper, cabbage, cauliflower, cotton, eggplant, and mint isolates exhibited host specificity and differential pathogenicity on other hosts, whereas isolates from artichoke, lettuce, potato, strawberry, tomato, and watermelon did not. Bell pepper was resistant to all Verticillium isolates except isolates from bell pepper and eggplant. Thus, host specificity exists in some isolates of V. dahliae. The same isolates were characterized for vegetative compatibility groups (VCGs) through complementation of nitrate nonutilizing (nit) mutants. Cabbage and cauliflower isolates did not produce nit mutants. The isolate from cotton belonged to VCG 1; isolates from bell pepper, eggplant, potato, and tomato, to VCG 4; and the remaining isolates, to VCG 2. These isolates were also analyzed using the random amplified polymorphic DNA (RAPD) method. Forty random primers were screened, and eighteen of them amplified DNA from Verticillium. Based on RAPD banding patterns, cabbage and cauliflower isolates formed a unique group, distinct from other V. dahliae and V. albo-atrum groups. Minor genetic variations were observed among V. dahliae isolates from other hosts, regardless of whether they were host specific or not. There was no correlation among pathogenicity, VCGs, and RAPD banding patterns. Even though the isolates belonged to different VCGs, they shared similar RAPD profiles. These results suggest that management of Verticillium wilt in some crops

  15. GENETICS OF HOST RANGE IN LEPIDOPTERA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic basis of complex, ecologically relevant traits is not well known for any organism. The question is particularly compelling where closely-related species have diverged radically in their adaptation to the environment. Differences in host plant use among moths and butterflies often provi...

  16. A survey of host range genes in poxvirus genomes

    PubMed Central

    Bratke, Kirsten A.; McLysaght, Aoife; Rothenburg, Stefan

    2014-01-01

    Poxviruses are widespread pathogens, which display extremely different host ranges. Whereas some poxviruses, including variola virus, display narrow host ranges, others such as cowpox viruses naturally infect a wide range of mammals. The molecular basis for differences in host range are poorly understood but apparently depend on the successful manipulation of the host antiviral response. Some poxvirus genes have been shown to confer host tropism in experimental settings and are thus called host range factors. Identified host range genes include vaccinia virus K1L, K3L, E3L, B5R, C7L and SPI-1, cowpox virus CP77/CHOhr, ectromelia virus p28 and 022, and myxoma virus T2, T4, T5, 11L, 13L, 062R and 063R. These genes encode for ankyrin repeat-containing proteins, tumor necrosis factor receptor II homologs, apoptosis inhibitor T4-related proteins, Bcl-2-related proteins, pyrin domain-containing proteins, cellular serine protease inhibitors (serpins), short complement-like repeats containing proteins, KilA-N/RING domain-containing proteins, as well as inhibitors of the double-stranded RNA-activated protein kinase PKR. We conducted a systematic survey for the presence of known host range genes and closely related family members in poxvirus genomes, classified them into subgroups based on their phylogenetic relationship and correlated their presence with the poxvirus phylogeny. Common themes in the evolution of poxvirus host range genes are lineage-specific duplications and multiple independent inactivation events. Our analyses yield new insights into the evolution of poxvirus host range genes. Implications of our findings for poxvirus host range and virulence are discussed. PMID:23268114

  17. The Poxvirus C7L Host Range Factor Superfamily

    PubMed Central

    Liu, Jia; Rothenburg, Stefan; McFadden, Grant

    2012-01-01

    Host range factors, expressed by the poxvirus family, determine the host tropism of species, tissue, and cell specificity. C7L family members exist in the genomes of most sequenced mammalian poxviruses, suggesting an evolutionarily conserved effort adapting to the hosts. In general, C7L orthologs influence the host tropism in mammalian cell culture, and for some poxviruses it is essential for the complete viral life cycle in vitro and in vivo. The C7L family members lack obvious sequence homology with any other known viral or cellular proteins. Here we review recent findings from an evolutionary perspective and summarize recent progress that broadens our view on the role of C7L family members in mediating poxvirus host range and antagonizing the host defense system. PMID:23103013

  18. Host Range of, and Plant Reaction to, Subanguina picridis

    PubMed Central

    Watson, A. K.

    1986-01-01

    The host range of the knapweed nematode, Subanguina picridis (Kirjanova) Brzeski, under controlled environmental conditions was extended to include, in addition to Russian knapweed, Acroptilon repens (L.) DC., plant species within the Centaureinae, and Carduinae subtribes of the Cynareae tribe of the Asteraceae family. Examination of host response to nematode infection revealed that Russian knapweed was the only highly susceptible host plant. Diffuse knapweed (Centaurea diffusa Lam.) was moderately susceptible, and other plants which formed galls were resistant to S. picridis. PMID:19294150

  19. Scale insect host ranges are broader in the tropics.

    PubMed

    Hardy, Nate B; Peterson, Daniel A; Normark, Benjamin B

    2015-12-01

    The specificity of the interactions between plants and their consumers varies considerably. The evolutionary and ecological factors underlying this variation are unclear. Several potential explanatory factors vary with latitude, for example plant species richness and the intensity of herbivory. Here, we use comparative phylogenetic methods to test the effect of latitude on host range in scale insects. We find that, on average, scale insects that occur in lower latitudes are more polyphagous. This result is at odds with the general pattern of greater host-plant specificity of insects in the tropics. We propose that this disparity reflects a high cost for host specificity in scale insects, stemming from unusual aspects of scale insect life history, for example, passive wind-driven dispersal. More broadly, the strong evidence for pervasive effects of geography on host range across insect groups stands in stark contrast to the weak evidence for constraints on host range due to genetic trade-offs.

  20. An Experimental Host Range of Triticum Mosaic Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Triticum mosaic virus (TriMV) is a newly discovered virus isolated from wheat. This study was conducted to determine an experimental host range for TriMV and identify species that could serve as differential hosts for isolating TriMV from Wheat streak mosaic virus (WSMV). Plants tested were mechan...

  1. Invasion success of a scarab beetle within its native range: host range expansion versus host-shift

    PubMed Central

    Boyer, Stéphane; De Romans, Saïana; Glare, Travis; Armstrong, Karen; Worner, Susan

    2014-01-01

    Only recently has it been formally acknowledged that native species can occasionally reach the status of ‘pest’ or ‘invasive species’ within their own native range. The study of such species has potential to help unravel fundamental aspects of biological invasions. A good model for such a study is the New Zealand native scarab beetle, Costelytra zealandica (White), which even in the presence of its natural enemies has become invasive in exotic pastures throughout the country. Because C. zealandica still occurs widely within its native habitat, we hypothesised that this species has only undergone a host range expansion (ability to use equally both an ancestral and new host) onto exotic hosts rather than a host shift (loss of fitness on the ancestral host in comparison to the new host). Moreover, this host range expansion could be one of the main drivers of its invasion success. In this study, we investigated the fitness response of populations of C. zealandica from native and exotic flora, to several feeding treatments comprising its main exotic host plant as well as one of its ancestral hosts. Our results suggest that our initial hypothesis was incorrect and that C. zealandica populations occurring in exotic pastures have experienced a host-shift rather than simply a host-range expansion. This finding suggests that an exotic plant introduction can facilitate the evolution of a distinct native host-race, a phenomenon often used as evidence for speciation in phytophagous insects and which may have been instrumental to the invasion success of C. zealandica. PMID:24795845

  2. Host compatibility rather than vector-host-encounter rate determines the host range of avian Plasmodium parasites.

    PubMed

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

    2013-06-07

    Blood-feeding arthropod vectors are responsible for transmitting many parasites between vertebrate hosts. While arthropod vectors often feed on limited subsets of potential host species, little is known about the extent to which this influences the distribution of vector-borne parasites in some systems. Here, we test the hypothesis that different vector species structure parasite-host relationships by restricting access of certain parasites to a subset of available hosts. Specifically, we investigate how the feeding patterns of Culex mosquito vectors relate to distributions of avian malaria parasites among hosts in suburban Chicago, IL, USA. We show that Plasmodium lineages, defined by cytochrome b haplotypes, are heterogeneously distributed across avian hosts. However, the feeding patterns of the dominant vectors (Culex restuans and Culex pipiens) are similar across these hosts, and do not explain the distributions of Plasmodium parasites. Phylogenetic similarity of avian hosts predicts similarity in their Plasmodium parasites. This effect was driven primarily by the general association of Plasmodium parasites with particular host superfamilies. Our results suggest that a mosquito-imposed encounter rate does not limit the distribution of avian Plasmodium parasites across hosts. This implies that compatibility between parasites and their avian hosts structure Plasmodium host range.

  3. Host plant utilization, host range oscillations and diversification in nymphalid butterflies: a phylogenetic investigation.

    PubMed

    Nylin, Sören; Slove, Jessica; Janz, Niklas

    2014-01-01

    It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the "oscillation hypothesis." In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies.

  4. Genome characteristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography

    PubMed Central

    Normand, Philippe; Lapierre, Pascal; Tisa, Louis S.; Gogarten, Johann Peter; Alloisio, Nicole; Bagnarol, Emilie; Bassi, Carla A.; Berry, Alison M.; Bickhart, Derek M.; Choisne, Nathalie; Couloux, Arnaud; Cournoyer, Benoit; Cruveiller, Stephane; Daubin, Vincent; Demange, Nadia; Francino, Maria Pilar; Goltsman, Eugene; Huang, Ying; Kopp, Olga R.; Labarre, Laurent; Lapidus, Alla; Lavire, Celine; Marechal, Joelle; Martinez, Michele; Mastronunzio, Juliana E.; Mullin, Beth C.; Niemann, James; Pujic, Pierre; Rawnsley, Tania; Rouy, Zoe; Schenowitz, Chantal; Sellstedt, Anita; Tavares, Fernando; Tomkins, Jeffrey P.; Vallenet, David; Valverde, Claudio; Wall, Luis G.; Wang, Ying; Medigue, Claudine; Benson, David R.

    2007-01-01

    Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N2-fixing root nodules on diverse and globally distributed angiosperms in the “actinorhizal” symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%–98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses. PMID:17151343

  5. Generating a host range-expanded recombinant baculovirus

    PubMed Central

    Wu, Chunfeng; Deng, Zihao; Long, Zhao; Cai, Yi; Ying, Zhongfu; Yin, Hanqi; Yuan, Meijin; Clem, Rollie J.; Yang, Kai; Pang, Yi

    2016-01-01

    As baculoviruses usually have a narrow insecticidal spectrum, knowing the mechanisms by which they control the host-range is prerequisite for improvement of their applications as pesticides. In this study, from supernatant of culture cells transfected with DNAs of an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) mutant lacking the antiapoptotic gene p35 (vAc∆P35) and a cosmid representing a fragment of Spodoptera exigua nucleopolyhedrovirus (SeMNPV), a viral strain was plaque-purified and named vAcRev. vAcRev had a broader host range than either vAc∆P35 or SeMNPV parental virus, being able to infect not only the permissive hosts of its parental viruses but also a nonpermissive host (Spodoptera litura). Genome sequencing indicated that vAcRev comprises a mixture of two viruses with different circular dsDNA genomes. One virus contains a genome similar to vAc∆P35, while in the other viral genome, a 24.4 kbp-fragment containing 10 essential genesis replaced with a 4 kbp-fragment containing three SeMNPV genes including a truncated Se-iap3 gene. RNA interference and ectopic expression assays found that Se-iap3 is responsible for the host range expansion of vAcRev, suggesting that Se-iap3 inhibits the progression of apoptosis initiated by viral infection and promotes viral propagation in hosts both permissive and non-permissive for AcMNPV and SeMNPV. PMID:27321273

  6. Phylogenetic signal in plant pathogen–host range

    PubMed Central

    Gilbert, Gregory S.; Webb, Campbell O.

    2007-01-01

    What determines which plant species are susceptible to a given plant pathogen is poorly understood. Experimental inoculations with fungal pathogens of plant leaves in a tropical rain forest show that most fungal pathogens are polyphagous but that most plant species in a local community are resistant to any given pathogen. The likelihood that a pathogen can infect two plant species decreases continuously with phylogenetic distance between the plants, even to ancient evolutionary distances. This phylogenetic signal in host range allows us to predict the likely host range of plant pathogens in a local community, providing an important tool for plant ecology, design of agronomic systems, quarantine regulations in international trade, and risk analysis of biological control agents. In particular, the results suggest that the rate of spread and ecological impacts of a disease through a natural plant community will depend strongly on the phylogenetic structure of the community itself and that current regulatory approaches strongly underestimate the local risks of global movement of plant pathogens or their hosts. PMID:17360396

  7. Brain infection and activation of neuronal repair mechanisms by the human pathogen Listeria monocytogenes in the lepidopteran model host Galleria mellonella.

    PubMed

    Mukherjee, Krishnendu; Hain, Torsten; Fischer, Rainer; Chakraborty, Trinad; Vilcinskas, Andreas

    2013-05-15

    Listeria monocytogenes the causative agent of the foodborne disease listeriosis in humans often involves fatal brainstem infections leading to meningitis and meningoencephalitis. We recently established the larvae of the greater wax moth (Galleria mellonella) as a model host for the investigation of L. monocytogenes pathogenesis and as a source of peptides exhibiting anti-Listeria-activity. Here we show that G. mellonella can be used to study brain infection and its impact on larval development as well as the activation of stress responses and neuronal repair mechanisms. The infection of G. mellonella larvae with L. monocytogenes elicits a cellular immune response involving the formation of melanized cellular aggregates (nodules) containing entrapped bacteria. These form under the integument and in the brain, resembling the symptoms found in human patients. We screened the G. mellonella transcriptome with marker genes representing stress responses and neuronal repair, and identified several modulated genes including those encoding heat shock proteins, growth factors, and regulators of neuronal stress. Remarkably, we discovered that L. monocytogenes infection leads to developmental shift in larvae and also modulates the expression of genes involved in the regulation of endocrine functions. We demonstrated that L. monocytogenes pathogenesis can be prevented by treating G. mellonella larvae with signaling inhibitors such as diclofenac, arachidonic acid, and rapamycin. Our data extend the utility of G. mellonella larvae as an ideal model for the high-throughput in vivo testing of potential compounds against listeriosis.

  8. Brain infection and activation of neuronal repair mechanisms by the human pathogen Listeria monocytogenes in the lepidopteran model host Galleria mellonella

    PubMed Central

    Mukherjee, Krishnendu; Hain, Torsten; Fischer, Rainer; Chakraborty, Trinad; Vilcinskas, Andreas

    2013-01-01

    Listeria monocytogenes the causative agent of the foodborne disease listeriosis in humans often involves fatal brainstem infections leading to meningitis and meningoencephalitis. We recently established the larvae of the greater wax moth (Galleria mellonella) as a model host for the investigation of L. monocytogenes pathogenesis and as a source of peptides exhibiting anti-Listeria-activity. Here we show that G. mellonella can be used to study brain infection and its impact on larval development as well as the activation of stress responses and neuronal repair mechanisms. The infection of G. mellonella larvae with L. monocytogenes elicits a cellular immune response involving the formation of melanized cellular aggregates (nodules) containing entrapped bacteria. These form under the integument and in the brain, resembling the symptoms found in human patients. We screened the G. mellonella transcriptome with marker genes representing stress responses and neuronal repair, and identified several modulated genes including those encoding heat shock proteins, growth factors, and regulators of neuronal stress. Remarkably, we discovered that L. monocytogenes infection leads to developmental shift in larvae and also modulates the expression of genes involved in the regulation of endocrine functions. We demonstrated that L. monocytogenes pathogenesis can be prevented by treating G. mellonella larvae with signaling inhibitors such as diclofenac, arachidonic acid, and rapamycin. Our data extend the utility of G. mellonella larvae as an ideal model for the high-throughput in vivo testing of potential compounds against listeriosis. PMID:23348912

  9. In vitro host range of the Hz-1 nonoccluded virus in insect cell lines.

    PubMed

    McIntosh, Arthur H; Grasela, James J; Ignoffo, Carlo M

    2007-01-01

    A total of 13 insect cell lines spanning 4 orders (Lepidoptera, Coleoptera, Diptera, and Homoptera) were tested for their ability to replicate the nonoccluded virus Hz-1. Only the Lepidopteran cell lines supported replication of the virus with TN-CL1 and BCIRL-HZ-AM1 producing the highest titers of 2.4 x 10(8) tissue culture infective dose (TCID)50/ml and 2.0 x 10(8) TCID50/ml, respectively. A codling moth cell line (CP-169) was the only Lepidopteran cell line that did not replicate the virus and transfection of this cell line with Hz-1 DNA failed to replicate the virus. Also, transfection with DNA from a recombinant baculovirus carrying the red fluorescent protein gene (AcMNPVhsp70 Red) was not expressed in CP-169 cells. The replication cycle of Hz-1 in BCIRL-HZ-AM1 cells showed that this virus replicated rapidly starting at 16 h postinoculation (p.i.) and reaching a peak titer of 1.0 x 10(8) TCID50/ml 56 h postinoculation. Hz-1 when compared with several other baculoviruses has the widest in vitro host spectrum.

  10. Host range, host ecology, and distribution of more than 11800 fish parasite species

    USGS Publications Warehouse

    Strona, Giovanni; Palomares, Maria Lourdes D.; Bailly, Nicholas; Galli, Paolo; Lafferty, Kevin D.

    2013-01-01

    Our data set includes 38 008 fish parasite records (for Acanthocephala, Cestoda, Monogenea, Nematoda, Trematoda) compiled from the scientific literature, Internet databases, and museum collections paired to the corresponding host ecological, biogeographical, and phylogenetic traits (maximum length, growth rate, life span, age at maturity, trophic level, habitat preference, geographical range size, taxonomy). The data focus on host features, because specific parasite traits are not consistently available across records. For this reason, the data set is intended as a flexible resource able to extend the principles of ecological niche modeling to the host–parasite system, providing researchers with the data to model parasite niches based on their distribution in host species and the associated host features. In this sense, the database offers a framework for testing general ecological, biogeographical, and phylogenetic hypotheses based on the identification of hosts as parasite habitat. Potential applications of the data set are, for example, the investigation of species–area relationships or the taxonomic distribution of host-specificity. The provided host–parasite list is that currently used by Fish Parasite Ecology Software Tool (FishPEST, http://purl.oclc.org/fishpest), which is a website that allows researchers to model several aspects of the relationships between fish parasites and their hosts. The database is intended for researchers who wish to have more freedom to analyze the database than currently possible with FishPEST. However, for readers who have not seen FishPEST, we recommend using this as a starting point for interacting with the database.

  11. Extension of the Avian Host Range of Collyriclosis in Europe.

    PubMed

    Tahas, Stamatios A; Diakou, Anastasia; Dressel, Monika; Frei, Samuel; Azevedo, Fábia M Pinto; Casero, Maria V Mena; Maia, Carla; Grest, Paula; Grimm, Felix; Sitko, Jiljí; Literak, Ivan

    2017-01-18

    We describe cases of collyriclosis in apodiform and passeriform birds in Portugal, Switzerland, and Germany. We extend the host range of Collyriculm faba to include apodiform birds ( Apus apus , Apus melba , and Apus pallidus ) and the passerine Sitta europaea (Eurasian Nuthatch). Infections varied in severity from an incidental finding to severe debilitation and death. The infection route remains unclear with the apparent absence from Germany, Portugal, and Switzerland of the first intermediate host of C. faba, the aquatic gastropod Bythinella austriaca, implying that other organisms might be involved in the parasite's life cycle. Furthermore, the detection of C. faba cysts in very young passerine birds may indicate an infection during the nestling stage and a rapid development of parasite-containing subcutaneous cysts. This series of cases highlights an increased geographic range into Portugal and the potential debilitating nature of a parasite of migratory birds in Europe. However, given the rarity of cases, collyriclosis does not seem to present an important threat to migratory species preservation.

  12. Ectomycorrhizal fungal richness declines towards the host species' range edge.

    PubMed

    Lankau, Richard A; Keymer, Daniel P

    2016-07-01

    Plant range boundaries are generally considered to reflect abiotic conditions; however, a rise in negative or decline in positive species interactions at range margins may contribute to these stable boundaries. While evidence suggests that pollinator mutualisms may decline near range boundaries, little is known about other important plant mutualisms, including microbial root symbionts. Here, we used molecular methods to characterize root-associated fungal communities in populations of two related temperate tree species from across the species' range in the eastern United States. We found that ectomycorrhizal fungal richness on plant roots declined with distance from the centre of the host species range. These patterns were not evident in nonmycorrhizal fungal communities on roots nor in fungal communities in bulk soil. Climatic and soil chemical variables could not explain these biogeographic patterns, although these abiotic gradients affected other components of the bulk soil and rhizosphere fungal community. Depauperate ectomycorrhizal fungal communities may represent an underappreciated challenge to marginal tree populations, especially as rapid climate change pushes these populations outside their current climate niche.

  13. Staphylococcus aureus Host Range and Human-Bovine Host Shift ▿†

    PubMed Central

    Sakwinska, Olga; Giddey, Marlyse; Moreillon, Martine; Morisset, Delphine; Waldvogel, Andreas; Moreillon, Philippe

    2011-01-01

    Staphylococcus aureus is a major agent of bovine mastitis. The concomitant emergence of pig-associated methicillin-resistant S. aureus (MRSA) in human carriage and infection requires a reexamination of the host range and specificity of human- and cow-associated S. aureus strains, something which has not been systematically studied previously. The genetic relatedness of 500 S. aureus isolates from bovine mastitis cases, 57 isolates from nasal carriage of farmers, and 133 isolates from nonfarmers was determined by amplified fragment length polymorphism (AFLP) analysis and spa typing. Multilocus sequence typing (MLST) was conducted on a subset of isolates to match AFLP clusters with MLST clonal complexes (CCs). This data set allowed us to study host range and host specificity and to estimate the extent of bovine-to-human transmission. The genotype compositions of S. aureus isolates from farmers and nonfarmers were very similar, while the mastitis isolates were quite distinct. Overall, transmission was low, but specific genotypes did show increased cow-to-human transmission. Unexpectedly, more than one-third of mastitis isolates belonged to CC8, a lineage which has not been considered to be bovine mastitis associated, but it is well known from human carriage and infection (i.e., USA300). Despite the fact that we did detect some transmission of other genotypes from cows to farmers, no transmission of CC8 isolates to farmers was detected, except for one tentative case. This was despite the close genetic relatedness of mastitis CC8 strains to nonfarmer carriage strains. These results suggest that the emergence of the new bovine-adapted genotype was due to a recent host shift from humans to cows concurrent with a loss of the ability to colonize humans. More broadly, our results indicate that host specificity is a lineage-specific trait that can rapidly evolve. PMID:21742927

  14. Evolution of host range in the follicle mite Demodex kutzeri.

    PubMed

    Palopoli, Michael F; Tra, VAN; Matoin, Kassey; Mac, Phuong D

    2016-11-29

    The sequences of four mitochondrial genes were determined for Demodex mites isolated from two distantly related species within the family Cervidae, and identified morphologically as belonging to the species Demodex kutzeri. The sequences were used to test the hypothesis that Demodex are strictly host-specific, and hence cospeciate with their hosts: (1) The estimated divergence time between mites found on elk vs humans agreed closely with a previous estimate of the time that these host species last shared a common ancestor, suggesting cospeciation of mites and hosts, at least over long evolutionary timescales. (2) The extremely low levels of sequence divergence between the mites found on elk vs mule deer hosts indicated that these mites belong to the same species, which suggests that Demodex are able to move across host species boundaries over shorter timescales. Together, the results are consistent with the model that Demodex mites are not strict host-specialists, but instead lose the ability to move between host lineages gradually.

  15. Novel application of species richness estimators to predict the host range of parasites.

    PubMed

    Watson, David M; Milner, Kirsty V; Leigh, Andrea

    2017-01-01

    Host range is a critical life history trait of parasites, influencing prevalence, virulence and ultimately determining their distributional extent. Current approaches to measure host range are sensitive to sampling effort, the number of known hosts increasing with more records. Here, we develop a novel application of results-based stopping rules to determine how many hosts should be sampled to yield stable estimates of the number of primary hosts within regions, then use species richness estimation to predict host ranges of parasites across their distributional ranges. We selected three mistletoe species (hemiparasitic plants in the Loranthaceae) to evaluate our approach: a strict host specialist (Amyema lucasii, dependent on a single host species), an intermediate species (Amyema quandang, dependent on hosts in one genus) and a generalist (Lysiana exocarpi, dependent on many genera across multiple families), comparing results from geographically-stratified surveys against known host lists derived from herbarium specimens. The results-based stopping rule (stop sampling bioregion once observed host richness exceeds 80% of the host richness predicted using the Abundance-based Coverage Estimator) worked well for most bioregions studied, being satisfied after three to six sampling plots (each representing 25 host trees) but was unreliable in those bioregions with high host richness or high proportions of rare hosts. Although generating stable predictions of host range with minimal variation among six estimators trialled, distribution-wide estimates fell well short of the number of hosts known from herbarium records. This mismatch, coupled with the discovery of nine previously unrecorded mistletoe-host combinations, further demonstrates the limited ecological relevance of simple host-parasite lists. By collecting estimates of host range of constrained completeness, our approach maximises sampling efficiency while generating comparable estimates of the number of primary

  16. Predictability of helminth parasite host range using information on geography, host traits and parasite community structure.

    PubMed

    Dallas, Tad; Park, Andrew W; Drake, John M

    2017-02-01

    Host-parasite associations are complex interactions dependent on aspects of hosts (e.g. traits, phylogeny or coevolutionary history), parasites (e.g. traits and parasite interactions) and geography (e.g. latitude). Predicting the permissive host set or the subset of the host community that a parasite can infect is a central goal of parasite ecology. Here we develop models that accurately predict the permissive host set of 562 helminth parasites in five different parasite taxonomic groups. We developed predictive models using host traits, host taxonomy, geographic covariates, and parasite community composition, finding that models trained on parasite community variables were more accurate than any other covariate group, even though parasite community covariates only captured a quarter of the variance in parasite community composition. This suggests that it is possible to predict the permissive host set for a given parasite, and that parasite community structure is an important predictor, potentially because parasite communities are interacting non-random assemblages.

  17. Fatty acid-amino acid conjugates diversification in lepidopteran caterpillars.

    PubMed

    Yoshinaga, Naoko; Alborn, Hans T; Nakanishi, Tomoaki; Suckling, David M; Nishida, Ritsuo; Tumlinson, James H; Mori, Naoki

    2010-03-01

    Fatty acid amino acid conjugates (FACs) have been found in noctuid as well as sphingid caterpillar oral secretions; in particular, volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and its biochemical precursor, N-linolenoyl-L-glutamine, are known elicitors of induced volatile emissions in corn plants. These induced volatiles, in turn, attract natural enemies of the caterpillars. In a previous study, we showed that N-linolenoyl-L-glutamine in larval Spodoptera litura plays an important role in nitrogen assimilation which might be an explanation for caterpillars synthesizing FACs despite an increased risk of attracting natural enemies. However, the presence of FACs in lepidopteran species outside these families of agricultural interest is not well known. We conducted FAC screening of 29 lepidopteran species, and found them in 19 of these species. Thus, FACs are commonly synthesized through a broad range of lepidopteran caterpillars. Since all FAC-containing species had N-linolenoyl-L-glutamine and/or N-linoleoyl-L-glutamine in common, and the evolutionarily earliest species among them had only these two FACs, these glutamine conjugates might be the evolutionarily older FACs. Furthermore, some species had glutamic acid conjugates, and some had hydroxylated FACs. Comparing the diversity of FACs with lepidopteran phylogeny indicates that glutamic acid conjugates can be synthesized by relatively primitive species, while hydroxylation of fatty acids is limited mostly to larger and more developed macrolepidopteran species.

  18. Cucumis melo endornavirus: Genome organization, host range and co-divergence with the host.

    PubMed

    Sabanadzovic, Sead; Wintermantel, William M; Valverde, Rodrigo A; McCreight, James D; Aboughanem-Sabanadzovic, Nina

    2016-03-02

    A high molecular weight dsRNA was isolated from a Cucumis melo L. plant (referred to as 'CL01') of an unknown cultivar and completely sequenced. Sequence analyses showed that dsRNA is associated with an endornavirus for which a name Cucumis melo endornavirus (CmEV) is proposed. The genome of CmEV-CL01 consists of 15,078 nt, contains a single, 4939 codons-long ORF and terminates with a stretch of 10 cytosine residues. Comparisons of the putative CmEV-encoded polyprotein with available references in protein databases revealed a unique genome organization characterized by the presence of the following domains: viral helicase Superfamily 1 (Hel-1), three glucosyltransferases (doublet of putative capsular polysaccharide synthesis proteins and a putative C_28_Glycosyltransferase), and an RNA-dependent RNA polymerase (RdRp). The presence of three glycome-related domains of different origin makes the genome organization of CmEV unique among endornaviruses. Phylogenetic analyses of viral RdRp domains showed that CmEV belongs to a specific lineage within the family Endornaviridae made exclusively of plant-infecting endornaviruses. An RT-PCR based survey demonstrated high incidence of CmEV among melon germplasm accession (>87% of tested samples). Analyses of partial genome sequences of CmEV isolates from 26 different melon genotypes suggest fine-tuned virus adaptation and co-divergence with the host. Finally, results of the present study revealed that CmEV is present in plants belonging to three different genera in the family Cucurbitaceae. Such diverse host range is unreported for known endornaviruses and suggests a long history of CmEV association with cucurbits predating their speciation.

  19. Endophytic Phomopsis species: host range and implications for diversity estimates.

    PubMed

    Murali, T S; Suryanarayanan, T S; Geeta, R

    2006-07-01

    Foliar endophyte assemblages of teak trees growing in dry deciduous and moist deciduous forests of Nilgiri Biosphere Reserve were compared. A species of Phomopsis dominated the endophyte assemblages of teak, irrespective of the location of the host trees. Internal transcribed spacer sequence analysis of 11 different Phomopsis isolates (ten from teak and one from Cassia fistula) showed that they fall into two groups, which are separated by a relatively long branch that is strongly supported. The results showed that this fungus is not host restricted and that it continues to survive as a saprotroph in teak leaf, possibly by exploiting senescent leaves as well as the litter. Although the endophyte assemblage of a teak tree growing about 500 km from the forests was also dominated by a Phomopsis sp., it separated into a different group based on internal transcribed spacer sequence analysis. Our results with an endophytic Phomopsis sp. reinforce the earlier conclusions reached by others for pathogenic Phomopsis sp., i.e., that this fungus is not host specific, and the species concept of Phomopsis needs to be redefined.

  20. Controls on pathogen species richness in plants introduced and native ranges: roles of residence time, range size and host traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction of hosts to new geographic regions allows them to escape many pathogens, raising two questions. How quickly do introduced hosts accumulate pathogens? Do the same factors control pathogen accumulation as in the native range? We analyzed fungal and viral pathogen species richness on 124 p...

  1. Geographic host use variabiliy and host range evolutionary dynamics in the phytophagous insect Apagomerella versicolor (Cerambycidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The high diversity of phytophagous insects has been explained by the tendency of the group towards specialization; however, generalism may be advantageous in some environments. The cerambycid Apagomerella versicolor exhibits intraspecific geographical variation in host use. In northern Argentina it ...

  2. Prevalence of Broad-Host-Range Lytic Bacteriophages of Sphaerotilus natans, Escherichia coli, and Pseudomonas aeruginosa

    PubMed Central

    Jensen, Ellen C.; Schrader, Holly S.; Rieland, Brenda; Thompson, Thomas L.; Lee, Kit W.; Nickerson, Kenneth W.; Kokjohn, Tyler A.

    1998-01-01

    Two bacteriophage collections were examined with regard to their ability to form plaques on multiple bacterial host species. Nine of 10 phages studied were found to be broad-host-range bacteriophages. These phages fell into two groups. Group 1, the SN series, was isolated from sewage treatment plant samples with Sphaerotilus natans ATCC 13338 as a host. The DNAs of these bacteriophages contained modified bases and were insensitive to cleavage by type I and II restriction endonucleases. The efficiency of plating of these bacteriophages was changed only slightly on the alternate host. Group 2, the BHR series, was isolated by a two-host enrichment protocol. These bacteriophages were sensitive to restriction, and their efficiency of plating was dramatically reduced on the alternate host. Our results suggest that a multiple-host enrichment protocol may be more effective for the isolation of broad-host-range bacteriophages by avoiding the selection bias inherent in single-host methods. At least two of the broad-host-range bacteriophages mediated generalized transduction. We suggest that broad-host-range bacteriophages play a key role in phage ecology and gene transfer in nature. PMID:9464396

  3. Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus

    PubMed Central

    Wolfe, Benjamin E; Pringle, Anne

    2012-01-01

    The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world. PMID:22134645

  4. Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus.

    PubMed

    Wolfe, Benjamin E; Pringle, Anne

    2012-04-01

    The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world.

  5. Host range of Caloptilia triadicae (Lepidoptera: Gracillariidae): an adventive herbivore of Chinese tallowtree (Malpighiales: Euphorbiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In its native range the invasive weed, Rhodomyrtus tomentosa is host to a suite of herbivores. One, Strepsicrates sp. (Lepidoptera: Tortricidae) was collected in China in 2014, introduced under quarantine in Florida, USA and tested against related species to determine its host range and suitability ...

  6. Biogeographic Variation in Host Range Phenotypes and Taxonomic Composition of Marine Cyanophage Isolates

    PubMed Central

    Hanson, China A.; Marston, Marcia F.; Martiny, Jennifer B. H.

    2016-01-01

    Despite the important role of phages in marine systems, little is understood about how their diversity is distributed in space. Biogeographic patterns of marine phages may be difficult to detect due to their vast genetic diversity, which may not be accurately represented by conserved marker genes. To investigate the spatial biogeographic structure of marine phages, we isolated over 400 cyanophages on Synechococcus host strain WH7803 at three coastal locations in the United States (Rhode Island, Washington, and southern California). Approximately 90% of the cyanophage isolates were myoviruses, while the other 10% were podoviruses. The diversity of isolates was further characterized in two ways: (i) taxonomically, using conserved marker genes and (ii) phenotypically, by testing isolates for their ability to infect a suite of hosts, or their “host range.” Because host range is a highly variable trait even among closely related isolates, we hypothesized that host range phenotypes of cyanophage isolates would vary more strongly among locations than would taxonomic composition. Instead, we found evidence for strong biogeographic variation both in taxonomic composition and host range phenotypes, with little taxonomic overlap among the three coastal regions. For both taxonomic composition and host range phenotypes, cyanophage communities from California and Rhode Island were the most dissimilar, while Washington communities exhibited similarity to each of the other two locations. These results suggest that selection imposed by spatial variation in host dynamics influence the biogeographic distribution of cyanophages. PMID:27446023

  7. Stepwise adaptation of murine cytomegalovirus to cells of a foreign host for identification of host range determinants.

    PubMed

    Ostermann, Eleonore; Pawletko, Kerstin; Indenbirken, Daniela; Schumacher, Uwe; Brune, Wolfram

    2015-06-01

    Ever since their first isolation 60 years ago, cytomegaloviruses have been recognized as being highly species specific. They replicate only in cells of their own or a closely related host species, while cells of phylogenetically more distant hosts are usually not permissive for viral replication. For instance, human cytomegalovirus replicates in human and chimpanzee fibroblasts but not in rodent cells, and murine cytomegalovirus (MCMV) replicates in cells of mice and rats but not in primate cells. However, the viral and cellular factors determining the narrow host range of cytomegaloviruses have remained largely unknown. We show that MCMV can be adapted stepwise to replicate in cultured human retinal pigment epithelial (RPE-1) cells and human fibroblasts. The human RPE-1 cells used for the initial adaptation step showed a pronounced contact inhibition and produced very low level of interferon-β transcripts upon cytomegalovirus infection, suggesting that these cells provide a particularly favorable environment for adaptation. By whole genome sequencing of the 230 kbp viral genomes of several adapted mutants, a limited number of mutations were detected. Comparison of several human cell-adapted MCMV clones and introduction of specific mutations into the wild-type MCMV genome by site-directed mutagenesis allows for the identification of viral host range determinants and provides the basis for elucidating the molecular basis of the cytomegalovirus host species specificity.

  8. Characterisation of Host Growth after Infection with a Broad-Range Freshwater Cyanopodophage

    PubMed Central

    Watkins, Siobhan C.; Smith, James R.; Hayes, Paul K.; Watts, Joy E. M.

    2014-01-01

    Freshwater cyanophages are poorly characterised in comparison to their marine counterparts, however, the level of genetic diversity that exists in freshwater cyanophage communities is likely to exceed that found in marine environments, due to the habitat heterogeneity within freshwater systems. Many cyanophages are specialists, infecting a single host species or strain; however, some are less fastidious and infect a number of different host genotypes within the same species or even hosts from different genera. Few instances of host growth characterisation after infection by broad host-range phages have been described. Here we provide an initial characterisation of interactions between a cyanophage isolated from a freshwater fishing lake in the south of England and its hosts. Designated ΦMHI42, the phage is able to infect isolates from two genera of freshwater cyanobacteria, Planktothrix and Microcystis. Transmission Electron Microscopy and Atomic Force Microscopy indicate that ΦMHI42 is a member of the Podoviridae, albeit with a larger than expected capsid. The kinetics of host growth after infection with ΦMHI42 differed across host genera, species and strains in a way that was not related to the growth rate of the uninfected host. To our knowledge, this is the first characterisation of the growth of cyanobacteria in the presence of a broad host-range freshwater cyanophage. PMID:24489900

  9. Narrow- and Broad-Host-Range Symbiotic Plasmids of Rhizobium spp. Strains That Nodulate Phaseolus vulgaris

    PubMed Central

    Brom, Susana; Martinez, Esperanza; Dávila, Guillermo; Palacios, Rafael

    1988-01-01

    Agrobacterium transconjugants containing symbiotic plasmids from different Rhizobium spp. strains that nodulate Phaseolus vulgaris were obtained. All transconjugants conserved the parental nodulation host range. Symbiotic (Sym) plasmids of Rhizobium strains isolated originally from P. vulgaris nodules, which had a broad nodulation host range, and single-copy nitrogenase genes conferred a Fix+ phenotype to the Agrobacterium transconjugants. A Fix− phenotype was obtained with Sym plasmids of strains isolated from P. vulgaris nodules that had a narrow host range and reiterated nif genes, as well as with Sym plasmids of strains isolated from other legumes that presented single nif genes and a broad nodulation host range. This indicates that different types of Sym plasmids can confer the ability to establish an effective symbiosis with P. vulgaris. Images PMID:16347637

  10. Host plant range of Raoiella indica (Acari: Tenuipalpidae) in areas of invasion of the New World.

    PubMed

    Carrillo, Daniel; Amalin, Divina; Hosein, Farzan; Roda, Amy; Duncan, Rita E; Peña, Jorge E

    2012-08-01

    Raoiella indica has spread rapidly through the Neotropical region where the mite damages economically and ecologically important plants. Three studies were conducted to determine the host plant range of R. indica, using the presence of colonies containing all life stages as an indicator of reproductive suitability. Periodic surveys at the Fairchild Tropical Botanic Garden (Miami Dade County, FL, USA) and the Royal Botanical Gardens (Port of Spain, Trinidad and Tobago) identified 27 new reproductive host plants. The reproductive suitability of two dicotyledonous species and three native Florida palm species was examined. An updated list of reproductive host plants of R. indica is presented. All reported reproductive hosts (91 plant species) of R. indica are monocots from the orders Arecales (Arecaceae), Zingiberales (Heliconiaceae, Musaceae, Strelitziaceae, Zingiberaceae) and Pandanales (Pandanaceae). Most are palms of the family Arecaceae that originated in areas of the Eastern Hemisphere; about one fourth of the reported hosts are native to the New World and could be considered new host associations of R. indica. Six years after the initial detection in the Caribbean, R. indica has expanded its host plant range. Here we report 27 new reproductive host of R. indica that represent 30% of increase on previous host plant records. As this mite continues spreading in the Neotropical region a great diversity of plants is potentially affected.

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

    PubMed

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

    2017-02-01

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

  12. Evolutionary interpretations of mycobacteriophage biodiversity and host-range through the analysis of codon usage bias

    PubMed Central

    Esposito, Lauren A.; Gupta, Swati; Streiter, Fraida; Prasad, Ashley

    2016-01-01

    In an genomics course sponsored by the Howard Hughes Medical Institute (HHMI), undergraduate students have isolated and sequenced the genomes of more than 1,150 mycobacteriophages, creating the largest database of sequenced bacteriophages able to infect a single host, Mycobacterium smegmatis, a soil bacterium. Genomic analysis indicates that these mycobacteriophages can be grouped into 26 clusters based on genetic similarity. These clusters span a continuum of genetic diversity, with extensive genomic mosaicism among phages in different clusters. However, little is known regarding the primary hosts of these mycobacteriophages in their natural habitats, nor of their broader host ranges. As such, it is possible that the primary host of many newly isolated mycobacteriophages is not M. smegmatis, but instead a range of closely related bacterial species. However, determining mycobacteriophage host range presents difficulties associated with mycobacterial cultivability, pathogenicity and growth. Another way to gain insight into mycobacteriophage host range and ecology is through bioinformatic analysis of their genomic sequences. To this end, we examined the correlations between the codon usage biases of 199 different mycobacteriophages and those of several fully sequenced mycobacterial species in order to gain insight into the natural host range of these mycobacteriophages. We find that UPGMA clustering tends to match, but not consistently, clustering by shared nucleotide sequence identify. In addition, analysis of GC content, tRNA usage and correlations between mycobacteriophage and mycobacterial codon usage bias suggests that the preferred host of many clustered mycobacteriophages is not M. smegmatis but other, as yet unknown, members of the mycobacteria complex or closely allied bacterial species. PMID:28348827

  13. Electrically and optically tunable plasmonic guest-host liquid crystals with long-range ordered nanoparticles.

    PubMed

    Liu, Qingkun; Yuan, Ye; Smalyukh, Ivan I

    2014-07-09

    Practical guest-host devices in which dichroic dye molecules follow electrical switching of a liquid crystal host remain elusive for decades despite promising efficient displays and emergent applications such as smart windows. This is mainly because of poor stability, surface precipitation, and limited means for property engineering of the dyes. To overcome these challenges, we develop plasmonic metal nanoparticle analogues of dichroic guest-host liquid crystals. Nematic dispersions of aligned anisotropic gold nanoparticles are obtained by polymer passivation of their surfaces to impose weak tangential boundary conditions for orientation of anisotropic host molecules. Control of the ensuing surface interactions leads to long-range ordered colloidal dispersions, allowing for collective optical and electrical switching of rod- and platelet-like nanoparticles. This facile control of mesostructured plasmonic medium's optical properties in visible and infrared spectral ranges is of interest for many applications.

  14. Host-range Characterization of Two Pratylenchus coffeae Isolates from Brazil

    PubMed Central

    Silva, R. A.; Inomoto, M. M.

    2002-01-01

    Two isolates of Pratylenchus coffeae were collected from coffee roots (in Marília, São Paulo State, Brazil) and Aglaonema (in Rio de Janeiro City, Rio de Janeiro State, Brazil) and maintained in the laboratory on alfalfa callus. Twenty-four plants were tested in the greenhouse to characterize the host preference of these isolates. The host ranges of the isolates differed from each other and, interestingly, coffee, banana, and citrus were not among the better hosts of either isolate. Rather, sorghum, maize, rice, millet, okra, melon, eggplant, and lettuce were the best hosts of the Marília isolate. Poor hosts included French marigold, Rangpur lime, banana, sesame, peanut, sunflower, cotton, French bean, onion, and small onion. The best hosts of the Rio de Janeiro isolate were sesame, soybean, sorghum, castor oil plant, watermelon, squash, eggplant, and melon; the poorest hosts were French marigold, coffee, Rangpur lime, banana, sunflower, peanut, maize, millet, French bean, cotton, onion, sweet pepper, lettuce, okra, and small onion. These isolates have important molecular and morphological differences, suggesting host preference is linked to these characteristics. PMID:19265921

  15. Structural basis for antagonizing a host restriction factor by C7 family of poxvirus host-range proteins

    PubMed Central

    Meng, Xiangzhi; Krumm, Brian; Li, Yongchao; Deng, Junpeng; Xiang, Yan

    2015-01-01

    Human sterile alpha motif domain-containing 9 (SAMD9) protein is a host restriction factor for poxviruses, but it can be overcome by some poxvirus host-range proteins that share homology with vaccinia virus C7 protein. To understand the mechanism of action for this important family of host-range factors, we determined the crystal structures of C7 and myxoma virus M64, a C7 family member that is unable to antagonize SAMD9. Despite their different functions and only 23% sequence identity, the two proteins have very similar overall structures, displaying a previously unidentified fold comprised of a compact 12-stranded antiparallel β-sandwich wrapped in two short α helices. Extensive structure-guided mutagenesis of C7 identified three loops clustered on one edge of the β sandwich as critical for viral replication and binding with SAMD9. The loops are characterized with functionally important negatively charged, positively charged, and hydrophobic residues, respectively, together forming a unique “three-fingered molecular claw.” The key residues of the claw are not conserved in two C7 family members that do not antagonize SAMD9 but are conserved in distantly related C7 family members from four poxvirus genera that infect diverse mammalian species. Indeed, we found that all in the latter group of proteins bind SAMD9. Taken together, our data indicate that diverse mammalian poxviruses use a conserved molecular claw in a C7-like protein to target SAMD9 and overcome host restriction. PMID:26578811

  16. Identification of FAM111A as an SV40 Host Range Restriction and Adenovirus Helper Factor

    PubMed Central

    Padi, Megha; Korkhin, Anna; James, Robert L.; Adelmant, Guillaume; Yoon, Rosa; Guo, Luxuan; Berrios, Christian; Zhang, Ying; Calderwood, Michael A.; Velmurgan, Soundarapandian; Cheng, Jingwei; Marto, Jarrod A.; Hill, David E.; Cusick, Michael E.; Vidal, Marc; Florens, Laurence; Washburn, Michael P.; Litovchick, Larisa; DeCaprio, James A.

    2012-01-01

    The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT) contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT. PMID:23093934

  17. Deep phylogeographical structure and parallel host range evolution in the leaf beetle Agelasa nigriceps.

    PubMed

    Kohyama, Tetsuo I; Matsumoto, Kazuma; Katakura, Haruo

    2014-02-01

    To understand the mechanisms behind the diversification of herbivorous insects through insect-plant interactions, it is important to know how the insects change their diet breadth in response to environmental changes. In this study, we investigated the phylogeographical pattern of the leaf beetle Agelasa nigriceps to infer the evolutionary history of its host range. While this beetle commonly uses Actinidia arguta (Actinidiaceae) as a host plant, it has been recorded recently on Pterostyrax hispidus (Styracaceae), which is now increasing in abundance at some localities in Japan due to the indirect effects of high population size of a mammalian herbivore. Considerable variation among populations in the ability of Ag. nigriceps to use P. hispidus suggests that P. hispidus is a newly acquired host plant for this beetle. Phylogenetic analyses using mitochondrial DNA sequences and amplified fragment length polymorphism (AFLP) revealed a high degree of phylogeographical structure in Ag. nigriceps throughout Japan, which is consistent with the hypothesis that several glacial refugia existed in the Japanese archipelago. In contrast, no genetic structure associated with the host plants was detected. Both the mitochondrial DNA and AFLP analyses showed that populations that can use P. hispidus are polyphyletic. These results and geographical variation in host use suggest that the host range expansion to a novel host, P. hispidus, is a very recent and possibly ongoing phenomenon and has occurred independently in several regions. Our study illustrates that the host range of herbivorous insects can evolve repeatedly in response to similar environmental changes.

  18. Effects of epistasis on infectivity range during host-parasite coevolution.

    PubMed

    Ashby, Ben; Gupta, Sunetra; Buckling, Angus

    2014-10-01

    Understanding how parasites adapt to changes in host resistance is crucial to evolutionary epidemiology. Experimental studies have demonstrated that parasites are more capable of adapting to gradual, rather than sudden changes in host phenotype, as the latter may require multiple mutations that are unlikely to arise simultaneously. A key, but as yet unexplored factor is precisely how interactions between mutations (epistasis) affect parasite evolution. Here, we investigate this phenomenon in the context of infectivity range, where parasites may experience selection to infect broader sets of genotypes. When epistasis is strongly positive, we find that parasites are unlikely to evolve broader infectivity ranges if hosts exhibit sudden, rather than gradual changes in phenotype, in close agreement with empirical observations. This is due to a low probability of fixing multiple mutations that individually confer no immediate advantage. When epistasis is weaker, parasites are more likely to evolve broader infectivity ranges if hosts make sudden changes in phenotype, which can be explained by a balance between mutation supply and selection. Thus, we demonstrate that both the rate of phenotypic change in hosts and the form of epistasis between mutations in parasites are crucial in shaping the evolution of infectivity range.

  19. Implications of a temperature increase for host plant range: predictions for a butterfly

    PubMed Central

    Audusseau, Hélène; Nylin, Sören; Janz, Niklas

    2013-01-01

    Although changes in phenology and species associations are relatively well-documented responses to global warming, the potential interactions between these phenomena are less well understood. In this study, we investigate the interactions between temperature, phenology (in terms of seasonal timing of larval growth) and host plant use in the polyphagous butterfly Polygonia c-album. We found that the hierarchy of larval performance on three natural host plants was not modified by a temperature increase as such. However, larval performance on each host plant and temperature treatment was affected by rearing season. Even though larvae performed better at the higher temperature regardless of the time of the rearing, relative differences between host plants changed with the season. For larvae reared late in the season, performance was always better on the herbaceous plant than on the woody plants. In this species, it is likely that a prolonged warming will lead to a shift from univoltinism to bivoltinism. The demonstrated interaction between host plant suitability and season means that such a shift is likely to lead to a shift in selective regime, favoring specialization on the herbaceous host. Based on our result, we suggest that host range evolution in response to temperature increase would in this species be highly contingent on whether the population undergoes a predicted shift from one to two generations. We discuss the effect of global warming on species associations and the outcome of asynchrony in rates of phenological change. PMID:24101991

  20. Implications of a temperature increase for host plant range: predictions for a butterfly.

    PubMed

    Audusseau, Hélène; Nylin, Sören; Janz, Niklas

    2013-09-01

    Although changes in phenology and species associations are relatively well-documented responses to global warming, the potential interactions between these phenomena are less well understood. In this study, we investigate the interactions between temperature, phenology (in terms of seasonal timing of larval growth) and host plant use in the polyphagous butterfly Polygonia c-album. We found that the hierarchy of larval performance on three natural host plants was not modified by a temperature increase as such. However, larval performance on each host plant and temperature treatment was affected by rearing season. Even though larvae performed better at the higher temperature regardless of the time of the rearing, relative differences between host plants changed with the season. For larvae reared late in the season, performance was always better on the herbaceous plant than on the woody plants. In this species, it is likely that a prolonged warming will lead to a shift from univoltinism to bivoltinism. The demonstrated interaction between host plant suitability and season means that such a shift is likely to lead to a shift in selective regime, favoring specialization on the herbaceous host. Based on our result, we suggest that host range evolution in response to temperature increase would in this species be highly contingent on whether the population undergoes a predicted shift from one to two generations. We discuss the effect of global warming on species associations and the outcome of asynchrony in rates of phenological change.

  1. Investigations of the Host Range of the Corn Cyst Nematode, Heterodera zeae, from Maryland

    PubMed Central

    Ringer, Chloe E.; Sardanelli, Sandra; Krusberg, Lorin R.

    1987-01-01

    The host range of the corn cyst nematode, Heterodera zeae, recently detected in Maryland, was investigated. A total of 269 plant entries, representing 68 families, 172 genera, and 204 species, was inoculated with cysts or a mixture of eggs and second-stage juveniles of H. zeae. The host range of the Maryland population of H. zeae was limited to plants of the Gramineae and included 11 tribes, 33 genera, 42 species, and 77 entries. All 22 corn (Zea mays) cultivars tested were hosts. Other economic hosts included certain cultivars of barley (Hordeum vulgare), oat (Arena sativa), rice (Oryza sativa), sorghum (Sorghum bicolor), sugar cane (Saccharum interspecific hybrid), and wheat (Triticum aestivum). Fall panicum (Panicum dichotomiflorum), a weed species common to cultivated fields in Maryland, was also a host for H. zeae. Other hosts included meadow foxtail (Alopecurus pratensis), Calamagrostis eipgeios, Job's tears (Coix Lachryma-Jobi), green sprangletop (Leptochloa dubia), witchgrass (Panicum capillare), broomcorn (Panicum miliaceum), fountain grass (Pennisetum rueppeli), reed canary grass (Phalaris arundinacea), common reed (Phragmites australis), eastern gamagrass (Tripsacum dactyloides), corn (Zea mays), and teosinte (Zea mexicana). PMID:19290286

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

    PubMed Central

    2013-01-01

    Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii), both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively). Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations. PMID:23390985

  3. Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts

    PubMed Central

    Ferreira, Luciana de Lima; Pereira, Marcos Horácio; Guarneri, Alessandra Aparecida

    2015-01-01

    Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts. PMID:26469403

  4. Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts.

    PubMed

    Ferreira, Luciana de Lima; Pereira, Marcos Horácio; Guarneri, Alessandra Aparecida

    2015-01-01

    Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts.

  5. Oxatub[4]arene: a molecular "transformer" capable of hosting a wide range of organic cations.

    PubMed

    Jia, Fei; Wang, Hao-Yi; Li, Dong-Hao; Yang, Liu-Pan; Jiang, Wei

    2016-04-28

    The molecular "transformer", oxatub[4]arene, was found to be able to host a wide range of organic cations. The strong binding ability is believed to originate from its four interconvertible and deep-cavity conformers. The binding behavior of such adaptable receptors may provide implications for molecular recognition in nature.

  6. Complete genome sequence of the broad-host-range strain Sinorhizobium fredii USDA257

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we announce the complete genome sequence of the symbiotic and nitrogen fixing bacterium Sinorhizobium fredii USDA257. The genome shares a high degree of similarity with the closely related broad-host-range strains S. fredii NGR234 and HH103. Most striking, the USDA257 genome encodes for a wealt...

  7. Draft genome sequence of Pseudomonas fuscovaginae, a broad-host-range pathogen of plants.

    PubMed

    Patel, Hitendra Kumar; da Silva, Daniel Passos; Devescovi, Giulia; Maraite, Henri; Paszkiewicz, Konrad; Studholme, David J; Venturi, Vittorio

    2012-05-01

    Pseudomonas fuscovaginae was first reported as a pathogen of rice causing sheath rot in plants grown at high altitudes. P. fuscovaginae is now considered a broad-host-range plant pathogen causing disease in several economically important plants. We report what is, to our knowledge, the first draft genome sequence of a P. fuscovaginae strain.

  8. Draft Genome Sequence of Pseudomonas fuscovaginae, a Broad-Host-Range Pathogen of Plants

    PubMed Central

    Patel, Hitendra Kumar; Passos da Silva, Daniel; Devescovi, Giulia; Maraite, Henri; Paszkiewicz, Konrad; Studholme, David J.

    2012-01-01

    Pseudomonas fuscovaginae was first reported as a pathogen of rice causing sheath rot in plants grown at high altitudes. P. fuscovaginae is now considered a broad-host-range plant pathogen causing disease in several economically important plants. We report what is, to our knowledge, the first draft genome sequence of a P. fuscovaginae strain. PMID:22535942

  9. Sugarcane aphid (Hemiptera: Aphididae): Host range and sorghum resistance including cross-resistance from greenbug sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The graminous host range, and sources of sorghum plant resistance including cross resistance from greenbug, Schizaphis graminum (Rond.) sorghums, [Sorghum bicolor L.) Moench], were studied for the newly emerging sugarcane aphid Melanaphis sacchari, (Zehntner) in greenhouse no-choice experiments and ...

  10. Evolution of specialization: a phylogenetic study of host range in the red milkweed beetle (Tetraopes tetraophthalmus).

    PubMed

    Rasmann, Sergio; Agrawal, Anurag A

    2011-06-01

    Specialization is common in most lineages of insect herbivores, one of the most diverse groups of organisms on earth. To address how and why specialization is maintained over evolutionary time, we hypothesized that plant defense and other ecological attributes of potential host plants would predict the performance of a specialist root-feeding herbivore (the red milkweed beetle, Tetraopes tetraophthalmus). Using a comparative phylogenetic and functional trait approach, we assessed the determinants of insect host range across 18 species of Asclepias. Larval survivorship decreased with increasing phylogenetic distance from the true host, Asclepias syriaca, suggesting that adaptation to plant traits drives specialization. Among several root traits measured, only cardenolides (toxic defense chemicals) correlated with larval survival, and cardenolides also explained the phylogenetic distance effect in phylogenetically controlled multiple regression analyses. Additionally, milkweed species having a known association with other Tetraopes beetles were better hosts than species lacking Tetraopes herbivores, and milkweeds with specific leaf area values (a trait related to leaf function and habitat affiliation) similar to those of A. syriaca were better hosts than species having divergent values. We thus conclude that phylogenetic distance is an integrated measure of phenotypic and ecological attributes of Asclepias species, especially defensive cardenolides, which can be used to explain specialization and constraints on host shifts over evolutionary time.

  11. Do-or-die life cycles and diverse post-infection resistance mechanisms limit the evolution of parasite host ranges.

    PubMed

    Sieber, Michael; Gudelj, Ivana

    2014-04-01

    In light of the dynamic nature of parasite host ranges and documented potential for rapid host shifts, the observed high host specificity of most parasites remains an ecological paradox. Different variants of host-use trade-offs have become a mainstay of theoretical explanations of the prevalence of host specialism, but empirical evidence for such trade-offs is rare. We propose an alternative theory based on basic features of the parasite life cycle: host selection and subsequent intrahost replication. We introduce a new concept of effective burst size that accounts for the fact that successful host selection does not guarantee intrahost replication. Our theory makes a general prediction that a parasite will expand its host range if its effective burst size is positive. An in silico model of bacteria-phage coevolution verifies our predictions and demonstrates that the tendency for relatively narrow host ranges in parasites can be explained even in the absence of trade-offs.

  12. Prevalence, Genetic Diversity, and Host Range of Tectiviruses among Members of the Bacillus cereus Group

    PubMed Central

    Gillis, Annika

    2014-01-01

    GIL01, Bam35, GIL16, AP50, and Wip1 are tectiviruses preying on the Bacillus cereus group. Despite the significant contributions of phages in different biological processes, little is known about the dealings taking place between tectiviruses and their Gram-positive bacterial hosts. Therefore, this work focuses on characterizing the interactions between tectiviruses and the B. cereus group by assessing their occurrence and genetic diversity and evaluating their host range. To study the occurrence of tectiviruses in the B. cereus group, 2,000 isolates were evaluated using primers designed to be specific to two variable regions detected in previously described elements. PCR and propagation tests revealed that tectivirus-like elements occurred in less than 3% of the isolates. Regardless of this limited distribution, several novel tectiviruses were found, and partial DNA sequencing indicated that a greater diversity exists within the family Tectiviridae. Analyses of the selected variable regions, along with their host range, showed that tectiviruses in the B. cereus group can be clustered mainly into two different groups: the ones infecting B. anthracis and those isolated from other B. cereus group members. In order to address the host range of some novel tectiviruses, 120 strains were tested for sensitivity. The results showed that all the tested tectiviruses produced lysis in at least one B. cereus sensu lato strain. Moreover, no simple relationship between the infection patterns of the tectiviruses and their diversity was found. PMID:24795369

  13. Prevalence, genetic diversity, and host range of tectiviruses among members of the Bacillus cereus group.

    PubMed

    Gillis, Annika; Mahillon, Jacques

    2014-07-01

    GIL01, Bam35, GIL16, AP50, and Wip1 are tectiviruses preying on the Bacillus cereus group. Despite the significant contributions of phages in different biological processes, little is known about the dealings taking place between tectiviruses and their Gram-positive bacterial hosts. Therefore, this work focuses on characterizing the interactions between tectiviruses and the B. cereus group by assessing their occurrence and genetic diversity and evaluating their host range. To study the occurrence of tectiviruses in the B. cereus group, 2,000 isolates were evaluated using primers designed to be specific to two variable regions detected in previously described elements. PCR and propagation tests revealed that tectivirus-like elements occurred in less than 3% of the isolates. Regardless of this limited distribution, several novel tectiviruses were found, and partial DNA sequencing indicated that a greater diversity exists within the family Tectiviridae. Analyses of the selected variable regions, along with their host range, showed that tectiviruses in the B. cereus group can be clustered mainly into two different groups: the ones infecting B. anthracis and those isolated from other B. cereus group members. In order to address the host range of some novel tectiviruses, 120 strains were tested for sensitivity. The results showed that all the tested tectiviruses produced lysis in at least one B. cereus sensu lato strain. Moreover, no simple relationship between the infection patterns of the tectiviruses and their diversity was found.

  14. Biocontrol potential of Steinernema thermophilum and its symbiont Xenorhabdus indica against lepidopteran pests: virulence to egg and larval stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under laboratory conditions, the biocontrol potential of Steinernema thermophilum was tested against eggs and larval stages of two important lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura (polyphagous pests), as well as Galleria mellonella (used as a model host) . In terms of ...

  15. Ecological Genetics and Host Range Expansion by Busseola fusca (Lepidoptera: Noctuidae).

    PubMed

    Assefa, Y; Conlong, D E; Van Den Berg, J; Martin, L A

    2015-08-01

    The host plant range of pests can have important consequences for its evolution, and plays a critical role in the emergence and spread of a new pest outbreak. This study addresses the ecological genetics of the indigenous African maize stem borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae), in an attempt to investigate the evolutionary forces that may be involved in the recent host range expansion and establishment of this species in Ethiopian and southern African sugarcane. We used populations from Ethiopia, Zimbabwe, and South Africa to examine whether the host range expansion patterns shared by the Ethiopian and the southern African populations of B. fusca have evolved independently. Base-pair differences in the cytochrome oxidase I (COI) gene were used to characterize haplotype diversity and phylogenetic relationships. There were seven haplotypes among the 30 sequenced individuals collected on four host plant species from 17 localities in the four countries. Of the seven COI haplotypes identified, the two major ones occurred in both sugarcane and maize. Genetic analyses revealed no detectable genetic differentiation between southern African B. fusca populations from maize and sugarcane (FST = 0.019; P = 0.24). However, there was strong evidence of variation in genetic composition between populations of the pest from different geographic regions (FST = 0.948; P < 0.001). The main implication of these findings is that the B. fusca populations in maize in southern Africa are more likely to shift to sugarcane, suggesting that ecological opportunity is an important factor in host plant range expansion by a pest.

  16. The Fleas (Siphonaptera) in Iran: Diversity, Host Range, and Medical Importance

    PubMed Central

    Maleki-Ravasan, Naseh; Solhjouy-Fard, Samaneh; Beaucournu, Jean-Claude; Laudisoit, Anne

    2017-01-01

    Background Flea-borne diseases have a wide distribution in the world. Studies on the identity, abundance, distribution and seasonality of the potential vectors of pathogenic agents (e.g. Yersinia pestis, Francisella tularensis, and Rickettsia felis) are necessary tools for controlling and preventing such diseases outbreaks. The improvements of diagnostic tools are partly responsible for an easier detection of otherwise unnoticed agents in the ectoparasitic fauna and as such a good taxonomical knowledge of the potential vectors is crucial. The aims of this study were to make an exhaustive inventory of the literature on the fleas (Siphonaptera) and range of associated hosts in Iran, present their known distribution, and discuss their medical importance. Methodology/Principal Findings The data were obtained by an extensive literature review related to medically significant fleas in Iran published before 31st August 2016. The flea-host specificity was then determined using a family and subfamily-oriented criteria to further realize and quantify the shared and exclusive vertebrate hosts of fleas among Iran fleas. The locations sampled and reported in the literature were primarily from human habitation, livestock farms, poultry, and rodents’ burrows of the 31 provinces of the country. The flea fauna were dominated by seven families, namely the Ceratophyllidae, Leptopsyllidae, Pulicidae, Ctenophthalmidae, Coptopsyllidae, Ischnopsyllidae and Vermipsyllidae. The hosts associated with Iran fleas ranged from the small and large mammals to the birds. Pulicidae were associated with 73% (56/77) of identified host species. Flea-host association analysis indicates that rodents are the common hosts of 5 flea families but some sampling bias results in the reduced number of bird host sampled. Analyses of flea-host relationships at the subfamily level showed that most vertebrates hosted fleas belgonging to 3 subfamilies namely Xenopsyllinae (n = 43), Ctenophthalminae (n = 20) and

  17. Does scavenging extend the host range of entomopathogenic nematodes (Nematoda: Steinernematidae)?

    PubMed

    Půza, Vladimír; Mrácek, Zdenĕk

    2010-05-01

    Living and freeze-killed natural and laboratory hosts, with different susceptibility to entomopathogenic nematodes, were exposed to the larvae of Steinernema affine and Steinernema kraussei in two different experimental arenas (Eppendorf tubes, Petri dishes), and the success of the colonisation and eventual progeny production were observed. Both nematodes were able to colonise both living and dead larvae of Galleria mellonella (Lepidoptera) and adult Blatella germanica (Blattodea) even though the progeny production in dead hosts was lower on average. Living carabid beetles, Poecilus cupreus, and elaterid larvae (Coleoptera) were resistant to the infection, however, both nematodes were able to colonise and multiply in several dead P. cupreus and in a majority of dead elaterid larvae. By scavenging, EPNs can utilise cadavers of insects that are naturally resistant to EPN infection, and so broaden their host range.

  18. Ant-lepidopteran associations along African forest edges.

    PubMed

    Dejean, Alain; Azémar, Frédéric; Libert, Michel; Compin, Arthur; Hérault, Bruno; Orivel, Jérôme; Bouyer, Thierry; Corbara, Bruno

    2017-02-01

    Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

  19. Ant-lepidopteran associations along African forest edges

    NASA Astrophysics Data System (ADS)

    Dejean, Alain; Azémar, Frédéric; Libert, Michel; Compin, Arthur; Hérault, Bruno; Orivel, Jérôme; Bouyer, Thierry; Corbara, Bruno

    2017-02-01

    Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

  20. Phylogenetic relationships and host range of Rhizobium spp. that nodulate Phaseolus vulgaris L.

    PubMed Central

    Hernandez-Lucas, I; Segovia, L; Martinez-Romero, E; Pueppke, S G

    1995-01-01

    We determined the nucleotide sequences of 16S rRNA gene segments from five Rhizobium strains that have been isolated from tropical legume species. All share the capacity to nodulate Phaseolus vulgaris L., the common bean. Phylogenetic analysis confirmed that these strains are of two different chromosomal lineages. We defined the host ranges of two strains of Rhizobium etli and three strains of R. tropici, comparing them with those of the two most divergently related new strains. Twenty-two of the 43 tested legume species were nodulated by three or more of these strains. All seven strains have broad host ranges that include woody species such as Albizia lebbeck, Gliricidia maculata, and Leucaena leucocephala. PMID:7618891

  1. Broad host range plasmids can invade an unexpectedly diverse fraction of a soil bacterial community

    PubMed Central

    Klümper, Uli; Riber, Leise; Dechesne, Arnaud; Sannazzarro, Analia; Hansen, Lars H; Sørensen, Søren J; Smets, Barth F

    2015-01-01

    Conjugal plasmids can provide microbes with full complements of new genes and constitute potent vehicles for horizontal gene transfer. Conjugal plasmid transfer is deemed responsible for the rapid spread of antibiotic resistance among microbes. While broad host range plasmids are known to transfer to diverse hosts in pure culture, the extent of their ability to transfer in the complex bacterial communities present in most habitats has not been comprehensively studied. Here, we isolated and characterized transconjugants with a degree of sensitivity not previously realized to investigate the transfer range of IncP- and IncPromA-type broad host range plasmids from three proteobacterial donors to a soil bacterial community. We identified transfer to many different recipients belonging to 11 different bacterial phyla. The prevalence of transconjugants belonging to diverse Gram-positive Firmicutes and Actinobacteria suggests that inter-Gram plasmid transfer of IncP-1 and IncPromA-type plasmids is a frequent phenomenon. While the plasmid receiving fractions of the community were both plasmid- and donor- dependent, we identified a core super-permissive fraction that could take up different plasmids from diverse donor strains. This fraction, comprising 80% of the identified transconjugants, thus has the potential to dominate IncP- and IncPromA-type plasmid transfer in soil. Our results demonstrate that these broad host range plasmids have a hitherto unrecognized potential to transfer readily to very diverse bacteria and can, therefore, directly connect large proportions of the soil bacterial gene pool. This finding reinforces the evolutionary and medical significances of these plasmids. PMID:25333461

  2. Short- and long-range cues used by ground-dwelling parasitoids to find their host

    NASA Astrophysics Data System (ADS)

    Goubert, C.; Josso, C.; Louâpre, P.; Cortesero, A. M.; Poinsot, D.

    2013-02-01

    Parasitoids of phytophagous insects face a detectability-reliability dilemma when foraging for hosts. Plant-related cues are easily detectable, but do not guarantee the presence of the host. Host-related cues are very reliable, but much harder to detect from a distance. Little is known in particular about the way coleopteran parasitoid females use these cues when foraging for a suitable place to lay their eggs. The question is of interest because, unlike hymenopteran larvae, coleopteran parasitoid larvae are highly mobile and able to forage for hosts on their own. We assessed whether females of the parasitoid rove beetle Aleochara bipustulata (L.) (Coleoptera: Staphylinidae) are attracted to plant (Swede roots, Brassica napus) and host-related cues [pupae of the cabbage root fly Delia radicum (L.) (Diptera: Anthomyiidae)]. In the field, A. bipustulata adult females were captured in selective pitfall traps containing pieces of roots damaged by D. radicum larvae, but not in traps containing pieces of healthy roots or D. radicum pupae. However, in the laboratory, the odour of D. radicum pupae attracted A. bipustulata females to mini-pitfalls. Video monitoring in the laboratory showed that foraging A. bipustulata females preferred a zone containing D. radicum pupae and larval tracks rather than one containing an extract of D. radicum-infested roots. Our results suggest a behavioural sequence where A. bipustulata females use plant-related cues at a distance, but then switch their preference to host-related cues at a close range. This would be the first observation of this behaviour in coleopteran parasitoids.

  3. Divergent Nod-Containing Bradyrhizobium sp. DOA9 with a Megaplasmid and its Host Range

    PubMed Central

    Teamtisong, Kamonluck; Songwattana, Pongpan; Noisangiam, Rujirek; Piromyou, Pongdet; Boonkerd, Nantakorn; Tittabutr, Panlada; Minamisawa, Kiwamu; Nantagij, Achara; Okazaki, Shin; Abe, Mikiko; Uchiumi, Toshiki; Teaumroong, Neung

    2014-01-01

    Bradyrhizobium sp. DOA9, a non-photosynthetic bacterial strain originally isolated from the root nodules of the legume Aeschynomene americana, is a divergent nod-containing strain. It exhibits a broad host range, being able to colonize and efficiently nodulate the roots of most plants from the Dalbergioid, Millettioid, and Robinioid tribes (7 species of Papilionoideae). In all cases, nodulation was determinate. The morphology and size of DOA9 bacteroids isolated from the nodules of various species of Papilionoideae were indistinguishable from the free-living form. However, they were spherical in Arachis hypogaea nodules. GusA-tagged DOA9 also colonized rice roots as endophytes. Since broad-host-range legume symbionts often carry multiple replicons in their genome, we analyzed the replicons for symbiosis genes by electrophoresis. DOA9 carried two replicons, a chromosome (cDOA9) and single megaplasmid (pDOA9) larger than 352 kb. The genes for nodulation (nodA, B, C) and nitrogen fixation (nifH) were localized on the megaplasmid. Southern blot hybridization revealed two copies of nodA on the megaplasmid, single copies of nodB and C on the megaplasmid, and one copy each of nifH on the chromosome and megaplasmid. These results suggested that Bradyrhizobium sp. DOA9 may have the unusual combination of a broad host range, bacteroid differentiation, and symbiosis-mediating replicons. PMID:25283477

  4. Cryptosporidium from a free-ranging marsupial host: bandicoots in urban Australia.

    PubMed

    Dowle, Matthew; Hill, Nichola J; Power, Michelle L

    2013-11-15

    Expansion of human settlement has increased the interface between people and bandicoots with implications for the emergence and spread of zoonotic parasites. The host status of bandicoots inhabiting suburban areas and their potential role in Cryptosporidium transmission remains unresolved. Our study aimed to determine the prevalence and identity of Cryptosporidium in two sympatric bandicoot species. Cryptosporidium signatures were detected in twelve bandicoot faecal samples (n=98) through amplification of the 18S rRNA. Phylogenetic inference placed the isolates in a clade with Cryptosporidium parvum, a species with a broad host range and zoonotic potential, or loosely related to Cryptosporidium hominis. However, the identity of the bandicoot isolates was not fully resolved and whether they were infected or simply passively transmitting oocysts is unknown. This study revealed that free-ranging bandicoots of northern Sydney were shedding Cryptosporidium oocysts at a prevalence of 12.2% (95% CI [6.76, 20.8]), similar to marsupial species that act as reservoirs for Cryptosporidium. Our findings expand the range of hosts known to shed Cryptosporidium in urban areas.

  5. The role of flagella and chemotaxis genes in host pathogen interaction of the host adapted Salmonella enterica serovar Dublin compared to the broad host range serovar S. Typhimurium

    PubMed Central

    2013-01-01

    Background The importance of flagella and chemotaxis genes in host pathogen interaction in Salmonella enterica is mainly based on studies of the broad host range serovar, S. Typhimurium, while little is known on the importance in host specific and host adapted serovars, such as S. Dublin. In the current study we have used previously characterized insertion mutants in flagella and chemotaxis genes to investigate this and possible differences in the importance between the two serovars. Results fliC (encoding the structural protein of the flagella) was essential for adhesion and fliC and cheB (CheB restores the chemotaxis system to pre-stimulus conformation) were essential for invasion of S. Dublin into epithelial Int407 cells. In S. Typhimurium, both lack of flagella (fliC/fljB double mutant) and cheB influenced adhesion, and invasion was influenced by lack of both cheA (the histidine-kinase of the chemotaxis system), fliC/fljB and cheB mutation. Uptake in J774A.1 macrophage cells was significantly reduced in cheA, cheB and fliC mutants of S. Dublin, while cheA was dispensable in S. Typhimurium. Removal of flagella in both serotypes caused an increased ability to propagate intracellular in J774 macrophage cells and decreased cytotoxicity toward these cells. Flagella and chemotaxis genes were found not to influence the oxidative response. The induction of IL-6 from J774A-1 cells depended on the presence of flagella in S. Typhimurium, whilst this was not the case following challenge with S. Dublin. Addition of fliC from S. Typhimurium in trans to a fliC mutant of S. Dublin increased cytotoxicity but it did not increase the IL-6 production. Flagella were demonstrated to contribute to the outcome of infection following oral challenge of mice in S. Dublin, while an S. Typhimurium fliC/fljB mutant showed increased virulence following intra peritoneal challenge. Conclusions The results showed that flagella and chemotaxis genes differed in their role in host pathogen

  6. Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Open-field host-specificity testing assesses the host-range of a biological control agent in a setting that permits the agent to use its full complement of host-seeking behaviors. This form of testing, particularly when it includes a no-choice phase in which the target weed is killed, may provide th...

  7. Feline Host Range of Canine parvovirus: Recent Emergence of New Antigenic Types in Cats

    PubMed Central

    Nakamura, Kazuya; Miyazawa, Takayuki; Tohya, Yukinobu; Takahashi, Eiji; Mochizuki, Masami

    2002-01-01

    Since the emergence of Canine parvovirus (CPV-2) in the late 1970s, CPV-2 has evolved consecutively new antigenic types, CPV-2a and 2b. Although CPV-2 did not have a feline host range, CPV-2a and 2b appear to have gained the ability to replicate in cats. Recent investigations demonstrate the prevalence of CPV-2a and 2b infection in a wide range of cat populations. We illustrate the pathogenic potential of CPV in cats and assesses the risk caused by CPV variants. PMID:11971764

  8. Different Mesorhizobium species associated with Caragana carry similar symbiotic genes and have common host ranges.

    PubMed

    Chen, Wen Feng; Guan, Su Hua; Zhao, Chun Tian; Yan, Xue Rui; Man, Chao Xin; Wang, En Tao; Chen, Wen Xin

    2008-06-01

    Fourteen strains representing 11 Caragana-nodulating Mesorhizobium genomic species were identified as representing Mesorhizobium amorphae, Mesorhizobium huakuii, Mesorhizobium septentrionale and groups related to Mesorhizobium plurifarium, Mesorhizobium temperatum, Mesorhizobium tianshanense and Mesorhizobium mediterraneum by sequencing of the 16S rRNA gene, 16S-23S internal transcribed spacer, partial housekeeping recA gene, and previously performed sodium dodecyl sulfate polyacrylamide gel electrophoresis of proteins and BOX-PCR fingerprinting. Despite their different taxonomic affiliation, highly similar symbiotic genes (>93% similarity for nodC and >91.8% similarity for nifH) were found among the Caragana strains and the three type strains for M. tianshanense, M. temperatum and M. septentrionale. Cross nodulation tests revealed that each of these 14 Caragana mesorhizobia and the three type strains mentioned above could effectively infect each of their original host plants, Caragana microphylla, Glycyrrhiza (host for M. tianshanense type strain) and Astragalus adsurgens (host for M. temperatum and M. septentrionale type strains). These results provide evidence that different Mesorhizobium species can nodulate with Caragana, and they have similar symbiotic genes (probably acquired by a phenomenon of lateral gene transfer) and common host ranges.

  9. Host-Range Dynamics of Cochliobolus lunatus: From a Biocontrol Agent to a Severe Environmental Threat

    PubMed Central

    Louis, Bengyella; Waikhom, Sayanika Devi; Roy, Pranab; Bhardwaj, Pardeep Kumar; Sharma, Chandradev K.; Singh, Mohendro Wakambam; Talukdar, Narayan Chandra

    2014-01-01

    We undertook an investigation to advance understanding of the host-range dynamics and biocontrol implications of Cochliobolus lunatus in the past decade. Potato (Solanum tuberosum L) farms were routinely surveyed for brown-to-black leaf spot disease caused by C. lunatus. A biphasic gene data set was assembled and databases were mined for reported hosts of C. lunatus in the last decade. The placement of five virulent strains of C. lunatus causing foliar necrosis of potato was studied with microscopic and phylogenetic tools. Analysis of morphology showed intraspecific variations in stromatic tissues among the virulent strains causing foliar necrosis of potato. A maximum likelihood inference based on GPDH locus separated C. lunatus strains into subclusters and revealed the emergence of unclustered strains. The evolving nutritional requirement of C. lunatus in the last decade is exhibited by the invasion of vertebrates, invertebrates, dicots, and monocots. Our results contribute towards a better understanding of the host-range dynamics of C. lunatus and provide useful implications on the threat posed to the environment when C. lunatus is used as a mycoherbicide. PMID:24987680

  10. Prediction of steps in the evolution of variola virus host range.

    PubMed

    Smithson, Chad; Purdy, Alex; Verster, Adrian J; Upton, Chris

    2014-01-01

    Variola virus, the agent of smallpox, has a severely restricted host range (humans) but a devastatingly high mortality rate. Although smallpox has been eradicated by a World Health Organization vaccination program, knowledge of the evolutionary processes by which human super-pathogens such as variola virus arise is important. By analyzing the evolution of variola and other closely related poxviruses at the level of single nucleotide polymorphisms we detected a hotspot of genome variation within the smallpox ortholog of the vaccinia virus O1L gene, which is known to be necessary for efficient replication of vaccinia virus in human cells. These mutations in the variola virus ortholog and the subsequent loss of the functional gene from camelpox virus and taterapox virus, the two closest relatives of variola virus, strongly suggest that changes within this region of the genome may have played a key role in the switch to humans as a host for the ancestral virus and the subsequent host-range restriction that must have occurred to create the phenotype exhibited by smallpox.

  11. Prediction of Steps in the Evolution of Variola Virus Host Range

    PubMed Central

    Smithson, Chad; Purdy, Alex; Verster, Adrian J.; Upton, Chris

    2014-01-01

    Variola virus, the agent of smallpox, has a severely restricted host range (humans) but a devastatingly high mortality rate. Although smallpox has been eradicated by a World Health Organization vaccination program, knowledge of the evolutionary processes by which human super-pathogens such as variola virus arise is important. By analyzing the evolution of variola and other closely related poxviruses at the level of single nucleotide polymorphisms we detected a hotspot of genome variation within the smallpox ortholog of the vaccinia virus O1L gene, which is known to be necessary for efficient replication of vaccinia virus in human cells. These mutations in the variola virus ortholog and the subsequent loss of the functional gene from camelpox virus and taterapox virus, the two closest relatives of variola virus, strongly suggest that changes within this region of the genome may have played a key role in the switch to humans as a host for the ancestral virus and the subsequent host-range restriction that must have occurred to create the phenotype exhibited by smallpox. PMID:24626337

  12. Eilat virus, a unique alphavirus with host range restricted to insects by RNA replication.

    PubMed

    Nasar, Farooq; Palacios, Gustavo; Gorchakov, Rodion V; Guzman, Hilda; Da Rosa, Amelia P Travassos; Savji, Nazir; Popov, Vsevolod L; Sherman, Michael B; Lipkin, W Ian; Tesh, Robert B; Weaver, Scott C

    2012-09-04

    Most alphaviruses and many other arboviruses are mosquito-borne and exhibit a broad host range, infecting many different vertebrates including birds, rodents, equids, humans, and nonhuman primates. Consequently, they can be propagated in most vertebrate and insect cell cultures. This ability of arboviruses to infect arthropods and vertebrates is usually essential for their maintenance in nature. However, several flaviviruses have recently been described that infect mosquitoes but not vertebrates, although the mechanism of their host restriction has not been determined. Here we describe a unique alphavirus, Eilat virus (EILV), isolated from a pool of Anopheles coustani mosquitoes from the Negev desert of Israel. Phylogenetic analyses placed EILV as a sister to the Western equine encephalitis antigenic complex within the main clade of mosquito-borne alphaviruses. Electron microscopy revealed that, like other alphaviruses, EILV virions were spherical, 70 nm in diameter, and budded from the plasma membrane of mosquito cells in culture. EILV readily infected a variety of insect cells with little overt cytopathic effect. However, in contrast to typical mosquito-borne alphaviruses, EILV could not infect mammalian or avian cell lines, and viral as well as RNA replication could not be detected at 37 °C or 28 °C. Evolutionarily, these findings suggest that EILV lost its ability to infect vertebrate cells. Thus, EILV seems to be mosquito-specific and represents a previously undescribed complex within the genus Alphavirus. Reverse genetic studies of EILV may facilitate the discovery of determinants of alphavirus host range that mediate disease emergence.

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

    PubMed Central

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

    2015-01-01

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

  14. A Single Residue in Ebola Virus Receptor NPC1 Influences Cellular Host Range in Reptiles

    PubMed Central

    Ndungo, Esther; Herbert, Andrew S.; Raaben, Matthijs; Obernosterer, Gregor; Biswas, Rohan; Miller, Emily Happy; Wirchnianski, Ariel S.; Carette, Jan E.; Brummelkamp, Thijn R.; Whelan, Sean P.

    2016-01-01

    ABSTRACT Filoviruses are the causative agents of an increasing number of disease outbreaks in human populations, including the current unprecedented Ebola virus disease (EVD) outbreak in western Africa. One obstacle to controlling these epidemics is our poor understanding of the host range of filoviruses and their natural reservoirs. Here, we investigated the role of the intracellular filovirus receptor, Niemann-Pick C1 (NPC1) as a molecular determinant of Ebola virus (EBOV) host range at the cellular level. Whereas human cells can be infected by EBOV, a cell line derived from a Russell’s viper (Daboia russellii) (VH-2) is resistant to infection in an NPC1-dependent manner. We found that VH-2 cells are resistant to EBOV infection because the Russell’s viper NPC1 ortholog bound poorly to the EBOV spike glycoprotein (GP). Analysis of panels of viper-human NPC1 chimeras and point mutants allowed us to identify a single amino acid residue in NPC1, at position 503, that bidirectionally influenced both its binding to EBOV GP and its viral receptor activity in cells. Significantly, this single residue change perturbed neither NPC1’s endosomal localization nor its housekeeping role in cellular cholesterol trafficking. Together with other recent work, these findings identify sequences in NPC1 that are important for viral receptor activity by virtue of their direct interaction with EBOV GP and suggest that they may influence filovirus host range in nature. Broader surveys of NPC1 orthologs from vertebrates may delineate additional sequence polymorphisms in this gene that control susceptibility to filovirus infection. IMPORTANCE Identifying cellular factors that determine susceptibility to infection can help us understand how Ebola virus is transmitted. We asked if the EBOV receptor Niemann-Pick C1 (NPC1) could explain why reptiles are resistant to EBOV infection. We demonstrate that cells derived from the Russell’s viper are not susceptible to infection because EBOV

  15. Host Range Specificity of Scymnus camptodromus (Coleoptera: Coccinellidae), A Predator of Hemlock Woolly Adelgid (Hemiptera: Adelgidae).

    PubMed

    Limbu, Samita; Cassidy, Katie; Keena, Melody; Tobin, Patrick; Hoover, Kelli

    2016-02-01

    Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae) was brought to the United States from China as a potential biological control agent for hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae). Scymnus camptodromus phenology is closely synchronized with that of A. tsugae and has several characteristics of a promising biological control agent. As a prerequisite to field release, S. camptodromus was evaluated for potential nontarget impacts. In host range studies, the predator was given the choice of sympatric adelgid and nonadelgid prey items. Nontarget testing showed that S. camptodromus will feed to some degree on other adelgid species, but highly prefers A. tsugae. We also evaluated larval development of S. camptodromus on pine bark adelgid (Pineus strobi (Hartig)) (Hemiptera: Adelgidae) and larch adelgid (Adelges laricis Vallot) (Hemiptera: Adelgidae); a small proportion of predator larvae was able to develop to adulthood on P. strobi or A. laricis alone. Scymnus camptodromus showed no interest in feeding on woolly alder aphid (Paraprociphilus tessellatus Fitch) (Hemiptera: Aphididae) or woolly apple aphid (Eriosoma lanigerum (Hausmann)) (Hemiptera: Aphididae), and minimal interest in cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) in choice and no-choice experiments. Scymnus camptodromus females did not oviposit on any host material other than A. tsugae-infested hemlock. Under the circumstances of the study, S. camptodromus appears to be a specific predator of A. tsugae, with minimal risk to nontarget species. Although the predator can develop on P. strobi, the likelihood that S. camptodromus would oviposit on pine hosts of this adelgid is small.

  16. Clarification on Host Range of Didymella pinodes the Causal Agent of Pea Ascochyta Blight

    PubMed Central

    Barilli, Eleonora; Cobos, Maria José; Rubiales, Diego

    2016-01-01

    Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum) worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates of D. fabae, D. rabiei, and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested. D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum, and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa, and V. articulata. DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here, D

  17. Reduced stability and intracellular transport of dsRNA contribute to poor RNAi response in lepidopteran insects

    PubMed Central

    Shukla, Jayendra Nath; Kalsi, Megha; Sethi, Amit; Narva, Kenneth E.; Fishilevich, Elane; Singh, Satnam; Mogilicherla, Kanakachari; Palli, Subba Reddy

    2016-01-01

    ABSTRACT RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects. PMID:27245473

  18. Reduced stability and intracellular transport of dsRNA contribute to poor RNAi response in lepidopteran insects.

    PubMed

    Shukla, Jayendra Nath; Kalsi, Megha; Sethi, Amit; Narva, Kenneth E; Fishilevich, Elane; Singh, Satnam; Mogilicherla, Kanakachari; Palli, Subba Reddy

    2016-07-02

    RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects.

  19. Temperature-dependent alterations in host use drive rapid range expansion in a butterfly.

    PubMed

    Pateman, Rachel M; Hill, Jane K; Roy, David B; Fox, Richard; Thomas, Chris D

    2012-05-25

    Responses of species to climate change are extremely variable, perhaps because of climate-related changes to interactions among species. We show that temperature-related changes in the dependence of the butterfly Aricia agestis on different larval host plants have facilitated rapid range expansion. Historically, the butterfly was largely restricted to a single plant species, Helianthemum nummularium, but recent warmer conditions have enabled the butterfly to increasingly use the more widespread plant species Geranium molle. This has resulted in a substantial increase in available habitat and rapid range expansion by the butterfly (79 kilometers northward in Britain in 20 years). Interactions among species are often seen as constraints on species' responses to climate change, but we show that temperature-dependent changes to interspecific interactions can also facilitate change.

  20. Genome degradation in Brucella ovis corresponds with narrowing of its host range and tissue tropism.

    PubMed

    Tsolis, Renee M; Seshadri, Rekha; Santos, Renato L; Sangari, Felix J; Lobo, Juan M García; de Jong, Maarten F; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M; Nelson, William C; Deboy, Robert T; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R; Mulligan, Stephanie; Walker, Richard L; Elzer, Philip E; Hassan, Karl A; Paulsen, Ian T

    2009-01-01

    Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis.

  1. Genome Degradation in Brucella ovis Corresponds with Narrowing of Its Host Range and Tissue Tropism

    PubMed Central

    Tsolis, Renee M.; Seshadri, Rekha; Santos, Renato L.; Sangari, Felix J.; Lobo, Juan M. García; de Jong, Maarten F.; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M.; Nelson, William C.; DeBoy, Robert T.; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R.; Mulligan, Stephanie; Walker, Richard L.; Elzer, Philip E.; Hassan, Karl A.; Paulsen, Ian T.

    2009-01-01

    Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis. PMID:19436743

  2. Mountain pine beetle host-range expansion threatens the boreal forest

    PubMed Central

    Cullingham, Catherine I; Cooke, Janice E K; Dang, Sophie; Davis, Corey S; Cooke, Barry J; Coltman, David W

    2011-01-01

    The current epidemic of the mountain pine beetle (MPB), an indigenous pest of western North American pine, has resulted in significant losses of lodgepole pine. The leading edge has reached Alberta where forest composition shifts from lodgepole to jack pine through a hybrid zone. The susceptibility of jack pine to MPB is a major concern, but there has been no evidence of host-range expansion, in part due to the difficulty in distinguishing the parentals and their hybrids. We tested the utility of a panel of microsatellite loci optimized for both species to classify lodgepole pine, jack pine and their hybrids using simulated data. We were able to accurately classify simulated individuals, and hence applied these markers to identify the ancestry of attacked trees. Here we show for the first time successful MPB attack in natural jack pine stands at the leading edge of the epidemic. This once unsuitable habitat is now a novel environment for MPB to exploit, a potential risk which could be exacerbated by further climate change. The consequences of host-range expansion for the vast boreal ecosystem could be significant. PMID:21457381

  3. “Candidatus Liberibacter asiaticus” Prophage Late Genes May Limit Host Range and Culturability

    PubMed Central

    Fleites, Laura A.; Jain, Mukesh; Zhang, Shujian

    2014-01-01

    “Candidatus Liberibacter asiaticus” is an uncultured alphaproteobacterium that systemically colonizes its insect host both inter- and intracellularly and also causes a severe, crop-destroying disease of citrus called huanglongbing, or citrus “greening.” In planta, “Ca. Liberibacter asiaticus” is also systemic but phloem limited. “Ca. Liberibacter asiaticus” strain UF506 carries two predicted prophages, SC1 and SC2. Bacteriophage particles have been observed in experimentally “Ca. Liberibacter asiaticus”-infected periwinkle but not in any other host. Comparative gene expression analysis of predicted SC1 late genes showed a much higher level of late gene expression, including holin transcripts (SC1_gp110), in “Ca. Liberibacter asiaticus”-infected periwinkle relative to “Ca. Liberibacter asiaticus”-infected citrus. To functionally characterize predicted holin and endolysin activity, SC1_gp110 and two predicted endolysins, one within SC1 (SC1_gp035) and another well outside the predicted prophage region (CLIBASIA_04790), were cloned and expressed in Escherichia coli. Both SC1 genes inhibited bacterial growth consistent with holin and endolysin function. The holin (SC1_gp110) promoter region was fused with a uidA reporter on pUFR071, a wide bacterial host range (repW) replicon, and used to transform Liberibacter crescens strain BT-1 by electroporation. BT-1 is the only liberibacter strain cultured to date and was used as a proxy for “Ca. Liberibacter asiaticus.” pUFR071 was >95% stable without selection in BT-1 for over 20 generations. The reporter construct exhibited strong constitutive glucuronidase (GUS) activity in culture-grown BT-1 cells. However, GUS reporter activity in BT-1 was suppressed in a dose-dependent manner by crude aqueous extracts from psyllids. Taken together with plant expression data, these observations indicate that “Ca. Liberibacter asiaticus” prophage activation may limit “Ca. Liberibacter asiaticus” host

  4. Characterization of novel virulent broad-host-range phages of Xylella fastidiosa and Xanthomonas.

    PubMed

    Ahern, Stephen J; Das, Mayukh; Bhowmick, Tushar Suvra; Young, Ry; Gonzalez, Carlos F

    2014-01-01

    The xylem-limited bacterium Xylella fastidiosa is the causal agent of several plant diseases, most notably Pierce's disease of grape and citrus variegated chlorosis. We report the isolation and characterization of the first virulent phages for X. fastidiosa, siphophages Sano and Salvo and podophages Prado and Paz, with a host range that includes Xanthomonas spp. Phages propagated on homologous hosts had observed adsorption rate constants of ~4 × 10(-12) ml cell(-1) min(-1) for X. fastidiosa strain Temecula 1 and ~5 × 10(-10) to 7 × 10(-10) ml cell(-1) min(-1) for Xanthomonas strain EC-12. Sano and Salvo exhibit >80% nucleotide identity to each other in aligned regions and are syntenic to phage BcepNazgul. We propose that phage BcepNazgul is the founding member of a novel phage type, to which Sano and Salvo belong. The lysis genes of the Nazgul-like phage type include a gene that encodes an outer membrane lipoprotein endolysin and also spanin gene families that provide insight into the evolution of the lysis pathway for phages of Gram-negative hosts. Prado and Paz, although exhibiting no significant DNA homology to each other, are new members of the phiKMV-like phage type, based on the position of the single-subunit RNA polymerase gene. The four phages are type IV pilus dependent for infection of both X. fastidiosa and Xanthomonas. The phages may be useful as agents for an effective and environmentally responsible strategy for the control of diseases caused by X. fastidiosa.

  5. Gyrodactylus proterorhini in its non-native range: distribution and ability to host-switch in freshwaters.

    PubMed

    Ondračková, Markéta

    2016-08-01

    Successful co-introduction of a parasite and its host relies not only on presence of the parasite on host individuals in the founder population but also on the ability of both host and parasite to persist in the new area. Gyrodactylus proterorhini (Monogenea) has been successfully co-introduced with its Ponto-Caspian goby hosts (Babka gymnotrachelus, Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, Proterorhinus semilunaris) to many freshwater systems in Europe and is now widely distributed over four large European river basins (Danube, Rhine, Scheldt and Vistula). Within Europe, higher infection levels are documented in sites further from the native host range. In North America, however, G. proterorhini appears to be absent. Host specificity of G. proterorhini tested under natural conditions showed accidental host-switching onto local fish species (native Perca fluviatilis and non-native Perccottus glenii) in the river Vistula. Further examination of host-switching under experimental conditions, however, showed that G. proterorhini were unable to survive on non-gobiid hosts longer than 24 h. Our results indicate extremely low potential for host-switching of introduced G. proterorhini to non-gobiid hosts, at least in the freshwater systems of Central and Western Europe.

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

    PubMed

    Stalažs, Arturs; Moročko-Bičevska, Inga

    2016-06-01

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

  7. Genetic diversity and host range variation of Ralstonia solanacearum strains entering North America.

    PubMed

    Norman, David J; Zapata, Mildred; Gabriel, Dean W; Duan, Y P; Yuen, Jeanne M F; Mangravita-Novo, Arianna; Donahoo, Ryan S

    2009-09-01

    Each year, large volumes of ornamental and food plant propagative stock are imported into the North America; occasionally, Ralstonia solanacearum is found systemically infecting this plant material. In this study, 107 new R. solanacearum strains were collected over a 10-year period from imported propagative stock and compared with 32 previously characterized R. solanacearum strains using repetitive polymerase chain reaction (rep-PCR) element (BOX, ERIC, and REP) primers. Additional strain comparisons were made by sequencing the endoglucanase and the cytochrome b561 genes. Using rep-PCR primers, populations could be distinguished by biovar and, to a limited extent, country of origin and original host. Similarity coefficients among rep-PCR clusters within biovars were relatively low in many cases, indicating that disease outbreaks over time may have been caused by different clonal populations. Similar population differentiations of R. solanacearum were obtained when comparing strain sequences using either the endoglucanase or cytochrome b561 genes. We found that most of the new biovar 1 strains of R. solanacearum entering the United States were genetically distinct from the biovar 1 strains currently found infecting vegetable production. These introduced biovar 1 strains also had a broader host range and could infect not only tomato, tobacco, and potato but also anthurium and pothos and cause symptoms on banana. All introductions into North America of race 3, biovar 2 strains in the last few years have been linked to geranium production and appeared to be clonal.

  8. Prevalence, host range, and spatial distribution of black band disease in the Maldivian Archipelago.

    PubMed

    Montano, Simone; Strona, Giovanni; Seveso, Davide; Galli, Paolo

    2013-07-09

    Little research has been conducted on diseases affecting reef-building corals in the central Indian Ocean. During 2010 and 2011, we performed a quantitative assessment of black band disease (BBD) in the central Republic of Maldives. Distribution, host range, and prevalence of BBD were investigated at 6 coral islands (Magoodhoo, Adanga, Ihuru, Vabbinfaru, Thudufushi, and Athuruga) belonging to 3 different atolls. BBD was found to be widespread among the atolls. All the islands showed a prevalence lower than 0.5%. Magoodhoo Island showed the highest mean disease prevalence. In the whole surveyed area, shallow sites showed higher overall mean BBD prevalence than deep ones. BBD was recorded from 6 scleractinian families (Acroporidae, Faviidae, Poritidae, Siderastreidae, Agariciidae, Fungiidae) and 13 scleractinian genera. Two of them, Gardineroseris and Sandalolitha, constitute new records for the disease. The siderastreid Psammocora (BBD prevalence: 5.33 ± 1.41%, mean ± SE) was the most affected genus, followed by Goniopora (2.7 ± 1.3%). BBD prevalence was positively correlated to the respective host density in both genera. Favites and Acropora were the less affected genera (both <0.1%). Although we observed an extremely low overall disease prevalence in the surveyed area (<1%), the large number of different scleractinian genera affected and the widespread distribution of BBD indicate a need for further investigation.

  9. Genetic diversity, host range, and distribution of tomato yellow leaf curl virus in Iran.

    PubMed

    Shirazi, M; Mozafari, J; Rakhshandehroo, F; Shams-Bakhsh, M

    2014-01-01

    Tomato yellow leaf curl virus (TYLCV) is considered one of the most important tomato pathogens in tropical and subtropical regions including Iran. During the years 2007 to 2009, a total number of 510 symptomatic and asymptomatic vegetable, ornamental and weed samples were collected from fields and greenhouses in ten provinces of Iran. Symptoms included stunting, yellowing, leaf curl and flower senescence. PCR with specific primers showed TYLCV infection in 184 samples (36%) such as cucumber, pepper, tomato and several weeds from seven provinces. Based on the geographical origin, host range and symptoms, twenty three representative isolates were selected for phylogenetic analysis. An amplicon with a size about 608 base pair (bp) comprising partial sequence of the coat (CP) and movement protein (MP) coding regions of the viral genome was sequenced and compared with the corresponding selected sequences available in GenBank for Iran and worldwide. Phylogenetic analyses on the basis of the nucleotide sequences indicated two geographically separated clades. Isolates collected from Hormozgan, Khuzestan and Kerman provinces were grouped together with other Iranian isolates including TYLCV-Ir2, TYLCV-Kahnooj, and an isolate from Oman. It was also revealed that isolates collected from Boushehr, Fars, Tehran, and Isfahan placed close to the Iranian isolate TYLCV-Abadeh and isolates from Israel and Egypt. No correlation was found between the genetic variation and the host species, but selected Iranian isolates were grouped on the basis of the geographical origins. Results of this study indicated a high genetic diversity among Iranian TYLCV isolates.

  10. In vitro and in vivo host range of Anopheles gambiae densovirus (AgDNV).

    PubMed

    Suzuki, Yasutsugu; Barik, Tapan K; Johnson, Rebecca M; Rasgon, Jason L

    2015-07-29

    AgDNV is a powerful gene transduction tool and potential biological control agent for Anopheles mosquitoes. Using a GFP reporter virus system, we investigated AgDNV host range specificity in four arthropod cell lines (derived from An. gambiae, Aedes albopictus and Drosophila melanogaster) and six mosquito species from 3 genera (An. gambiae, An. arabiensis, An. stephensi, Ae. albopictus, Ae. aegypti and Culex tarsalis). In vitro, efficient viral invasion, replication and GFP expression was only observed in MOS55 An. gambiae cells. In vivo, high levels of GFP were observed in An. gambiae mosquitoes. Intermediate levels of GFP were observed in the closely related species An. arabiensis. Low levels of GFP were observed in An. stephensi, Ae. albopictus, Ae. aegypti and Cx. tarsalis. These results suggest that AgDNV is a specific gene transduction tool for members of the An. gambiae species complex, and could be potentially developed into a biocontrol agent with minimal off-target effects.

  11. Evolution of broad host range in retroviruses leads to cell death mediated by highly cytopathic variants.

    PubMed

    Rainey, G Jonah A; Coffin, John M

    2006-01-01

    The ability of many retroviruses to cause disease can be correlated to their cytopathic effect (CPE) in tissue culture characterized by an acute period of cell death and viral DNA accumulation. Here, we show that mutants of a subgroup B avian retrovirus (Alpharetrovirus) cause a very dramatic CPE in certain susceptible avian cells that is coincident with elevated levels of apoptosis, as measured by nuclear morphology, and persistent viral DNA accumulation. These mutants also have a broadly extended host range that includes rodent, cat, dog, monkey, and human cells (31). Previously, we have shown that the mutants exhibit diminished resistance to superinfection. The results presented here have important implications for the process of evolution of retroviruses to use distinct cellular receptors.

  12. Host range and cellular tropism of the human exogenous gammaretrovirus XMRV.

    PubMed

    Stieler, Kristin; Schulz, Claudia; Lavanya, Madakasira; Aepfelbacher, Martin; Stocking, Carol; Fischer, Nicole

    2010-03-30

    Recently, the first human infection with an exogenous gammaretrovirus (XMRV) was reported. In its initial description, XMRV was confined to prostate stromal fibroblasts, although subsequent reports demonstrated XMRV protein expression in prostate epithelial cells. Most recently, XMRV has been detected in blood cells of patients with chronic fatigue syndrome. The aim of this study was to elucidate the transmission routes and tissue tropism of XMRV by comparing its host range, receptor usage and LTR functionality with other MLV isolates. We demonstrate using pseudotype experiments that XMRV Env mediates efficient infection of cells from different species. We show that replication competent XMRV infects various human cell types, including hematopoietic cell lines and prostate stromal fibroblasts. XMRV-LTR activity is significantly higher in the prostate cancer cell line LNCaP and in prostate stromal fibroblasts, compared to other cell types tested and could be one factor contributing to efficient viral spread in prostate tissue.

  13. Host range, growth property, and virulence of the smallpox vaccine: vaccinia virus Tian Tan strain.

    PubMed

    Fang, Qing; Yang, Lin; Zhu, Weijun; Liu, Li; Wang, Haibo; Yu, Wenbo; Xiao, Genfu; Tien, Po; Zhang, Linqi; Chen, Zhiwei

    2005-05-10

    Vaccinia Tian Tan (VTT) was used as a vaccine against smallpox in China for millions of people before 1980, yet the biological characteristics of the virus remain unclear. We have characterized VTT with respect to its host cell range, growth properties in vitro, and virulence in vivo. We found that 11 of the 12 mammalian cell lines studied are permissive to VTT infection whereas one, CHO-K1, is non-permissive. Using electron microscopy and sequence analysis, we found that the restriction of VTT replication in CHO-K1 is at a step before viral maturation probably due to the loss of the V025 gene. Moreover, VTT is significantly less virulent than vaccinia WR but remains neurovirulent in mice and causes significant body weight loss after intranasal inoculation. Our data demonstrate the need for further attenuation of VTT to serve either as a safer smallpox vaccine or as a live vaccine vector for other pathogens.

  14. Host range, growth property, and virulence of the smallpox vaccine: Vaccinia virus Tian Tan strain

    SciTech Connect

    Fang Qing; Yang Lin; Zhu Weijun; Liu Li; Wang Haibo; Yu Wenbo; Xiao Genfu; Tien Po; Zhang Linqi; Chen Zhiwei . E-mail: zchen@adarc.org

    2005-05-10

    Vaccinia Tian Tan (VTT) was used as a vaccine against smallpox in China for millions of people before 1980, yet the biological characteristics of the virus remain unclear. We have characterized VTT with respect to its host cell range, growth properties in vitro, and virulence in vivo. We found that 11 of the 12 mammalian cell lines studied are permissive to VTT infection whereas one, CHO-K1, is non-permissive. Using electron microscopy and sequence analysis, we found that the restriction of VTT replication in CHO-K1 is at a step before viral maturation probably due to the loss of the V025 gene. Moreover, VTT is significantly less virulent than vaccinia WR but remains neurovirulent in mice and causes significant body weight loss after intranasal inoculation. Our data demonstrate the need for further attenuation of VTT to serve either as a safer smallpox vaccine or as a live vaccine vector for other pathogens.

  15. In vitro and in vivo host range of Anopheles gambiae densovirus (AgDNV)

    PubMed Central

    Suzuki, Yasutsugu; Barik, Tapan K.; Johnson, Rebecca M.; Rasgon, Jason L.

    2015-01-01

    AgDNV is a powerful gene transduction tool and potential biological control agent for Anopheles mosquitoes. Using a GFP reporter virus system, we investigated AgDNV host range specificity in four arthropod cell lines (derived from An. gambiae, Aedes albopictus and Drosophila melanogaster) and six mosquito species from 3 genera (An. gambiae, An. arabiensis, An. stephensi, Ae. albopictus, Ae. aegypti and Culex tarsalis). In vitro, efficient viral invasion, replication and GFP expression was only observed in MOS55 An. gambiae cells. In vivo, high levels of GFP were observed in An. gambiae mosquitoes. Intermediate levels of GFP were observed in the closely related species An. arabiensis. Low levels of GFP were observed in An. stephensi, Ae. albopictus, Ae. aegypti and Cx. tarsalis. These results suggest that AgDNV is a specific gene transduction tool for members of the An. gambiae species complex, and could be potentially developed into a biocontrol agent with minimal off-target effects. PMID:26220140

  16. Canine and feline host ranges of canine parvovirus and feline panleukopenia virus: distinct host cell tropisms of each virus in vitro and in vivo.

    PubMed Central

    Truyen, U; Parrish, C R

    1992-01-01

    Canine parvovirus (CPV) emerged as an apparently new virus during the mid-1970s. The origin of CPV is unknown, but a variation from feline panleukopenia virus (FPV) or another closely related parvovirus is suspected. Here we examine the in vitro and in vivo canine and feline host ranges of CPV and FPV. Examination of three canine and six feline cell lines and mitogen-stimulated canine and feline peripheral blood lymphocytes revealed that CPV replicates in both canine and feline cells, whereas FPV replicates efficiently only in feline cells. The in vivo host ranges were unexpectedly complex and distinct from the in vitro host ranges. Inoculation of dogs with FPV revealed efficient replication in the thymus and, to some degree, in the bone marrow, as shown by virus isolation, viral DNA recovery, and Southern blotting and by strand-specific in situ hybridization. FPV replication could not be demonstrated in mesenteric lymph nodes or in the small intestine, which are important target tissues in CPV infection. Although CPV replicated well in all the feline cells tested in vitro, it did not replicate in any tissue of cats after intramuscular or intravenous inoculation. These results indicate that these viruses have complex and overlapping host ranges and that distinct tissue tropisms exist in the homologous and heterologous hosts. Images PMID:1323703

  17. Spatial variation in the phylogenetic structure of flea assemblages across geographic ranges of small mammalian hosts in the Palearctic.

    PubMed

    Krasnov, Boris R; Pilosof, Shai; Shenbrot, Georgy I; Khokhlova, Irina S

    2013-08-01

    We investigated spatial variation in the phylogenetic structure (measured as a degree of phylogenetic clustering) of flea assemblages across the geographic ranges of 11 Palearctic species of small mammalian hosts and asked whether the phylogenetic structure of the flea assemblage of a host in a locality is affected by (i) distance of this locality from the centre of the host's geographic range, (ii) geographic position of the locality (distance to the equator) and (iii) phylogenetic structure of the entire flea assemblage of the locality. Our results demonstrated that the key factor underlying spatial variation of the phylogenetic structure of the flea assemblage of a host was the distance from the centre of the host's geographic range. However, the pattern of this spatial variation differed between host species and might be explained by their species-specific immunogenetic and/or distributional patterns. Local flea assemblages may also, to some extent, be shaped by environmental filtering coupled with historical events. In addition, the phylogenetic structure of a local within-host flea assemblage may mirror the phylogenetic structure of the entire across-host flea assemblage in that locality and, thus, be affected by the availability of certain phylogenetic lineages.

  18. Characterization of a new iridovirus isolated from crickets and investigations on the host range

    PubMed

    Kleespies; Tidona; Darai

    1999-01-01

    Typical signs of an iridovirus infection were observed in two species of fatally diseased crickets, Gryllus campestris L. and Acheta domesticus L. (Orthoptera, Gryllidae). The infection was manifested by hypertrophy and bluish iridescence of the affected fat body cells. Electron microscope investigations led to the identification of a new iridovirus, which was termed cricket iridovirus (CrIV). In negatively stained preparations the size of the icosahedral virus particles ranged from 151 nm (side-side) to 167 nm (apex-apex). Assembly of virions occurred in the cytoplasm of hypertrophied fat body cells, where they often accumulated in paracrystalline arrays. Genetic analyses of purified viral DNA using a variety of restriction enzymes revealed that CrIV is distinct from all other known iridoviruses that have been isolated from insects and reported so far. In host range studies it was shown that CrIV can be transmitted perorally to other orthopteran species, causing characteristic symptoms and fatal disease. These species include Gryllus bimaculatus L. (Orthoptera, Gryllidae) and the African migratory locust Locusta migratoria migratorioides (R. & F.) (Orthoptera, Acrididae), which represents one of the most important pest insects in developing countries, as well as the cockroaches Blattella germanica L. and Blatta orientalis L. (both Orthoptera, Blattidae). Consequently, the isolation and characterization of this new cricket iridovirus is of particular interest in view of its possible use in biological or integrated control. Copyright 1999 Academic Press.

  19. Comparison of ranging behaviour in a multi-species complex of free-ranging hosts of bovine tuberculosis in relation to their use as disease sentinels.

    PubMed

    Yockney, I J; Nugent, G; Latham, M C; Perry, M; Cross, M L; Byrom, A E

    2013-07-01

    Sentinel species are increasingly used by disease managers to detect and monitor the prevalence of zoonotic diseases in wildlife populations. Characterizing home-range movements of sentinel hosts is thus important for developing improved disease surveillance methods, especially in systems where multiple host species co-exist. We studied ranging activity of major hosts of bovine tuberculosis (TB) in an upland habitat of New Zealand: we compared home-range coverage by ferrets (Mustela furo), wild deer (Cervus elaphus), feral pigs (Sus scrofa), brushtail possums (Trichosurus vulpecula) and free-ranging farmed cattle (Bos taurus). We also report in detail the proportional utilization of a seasonal (4-monthly) range area for the latter four species. Possums covered the smallest home range (<30 ha), ferrets covered ~100 ha, pigs ~4 km(2), deer and cattle both >30 km2. For any given weekly period, cattle, deer and pigs were shown to utilize 37–45% of their estimated 4-month range, while possums utilized 62% during any weekly period and 85% during any monthly period of their estimated 4-month range. We suggest that present means for estimating TB detection kernels, based on long-term range size estimates for possums and sentinel species, probably overstate the true local surveillance coverage per individual.

  20. Structure Function Studies of Vaccinia Virus Host Range Protein K1 Reveal a Novel Functional Surface for Ankyrin Repeat Proteins

    SciTech Connect

    Li, Yongchao; Meng, Xiangzhi; Xiang, Yan; Deng, Junpeng

    2010-06-15

    Poxvirus host tropism at the cellular level is regulated by virus-encoded host range proteins acting downstream of virus entry. The functioning mechanisms of most host range proteins are unclear, but many contain multiple ankyrin (ANK) repeats, a motif that is known for ligand interaction through a concave surface. We report here the crystal structure of one of the ANK repeat-containing host range proteins, the vaccinia virus K1 protein. The structure, at a resolution of 2.3 {angstrom}, showed that K1 consists entirely of ANK repeats, including seven complete ones and two incomplete ones, one each at the N and C terminus. Interestingly, Phe82 and Ser83, which were previously shown to be critical for K1's function, are solvent exposed and located on a convex surface, opposite the consensus ANK interaction surface. The importance of this convex surface was further supported by our additional mutagenesis studies. We found that K1's host range function was negatively affected by substitution of either Asn51 or Cys47 and completely abolished by substitution of both residues. Cys47 and Asn51 are also exposed on the convex surface, spatially adjacent to Phe82 and Ser83. Altogether, our data showed that K1 residues on a continuous convex ANK repeat surface are critical for the host range function, suggesting that K1 functions through ligand interaction and does so with a novel ANK interaction surface.

  1. Species Boundaries and Host Range of Tortoise Mites (Uropodoidea) Phoretic on Bark Beetles (Scolytinae), Using Morphometric and Molecular Markers

    PubMed Central

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

    2012-01-01

    Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea) are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae), but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1) morphologically defined species are supported by molecular data, and that (2) bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI) and nuclear large subunit ribosomal DNA (28S). Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella) collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists. PMID:23071768

  2. Seasonal Alterations in Host Range and Fidelity in the Polyphagous Mirid Bug, Apolygus lucorum (Heteroptera: Miridae)

    PubMed Central

    Pan, Hongsheng; Liu, Bing; Lu, Yanhui; Wyckhuys, Kris A. G.

    2015-01-01

    In herbivorous insects, host plant switching is commonly observed and plays an important role in their annual life cycle. However, much remains to be learned about seasonal host switching of various pestiferous arthropods under natural conditions. From 2006 until 2012, we assessed Apolygus lucorum (Meyer-Dür) host plant use in successive spring, summer and winter seasons at one single location (Langfang, China). Data were used to quantify changes in host plant breadth and host fidelity between seasons. Host fidelity of A. lucorum differed between seasons, with 87.9% of spring hosts also used in the summer and 36.1% of summer hosts used in winter. In contrast, as little as 25.6% host plant species were shared between winter and spring. Annual herbaceous plants are most often used for overwintering, while perennial woody plants are relatively important for initial population build-up in the spring. Our study contributes to an improved understanding of evolutionary interactions between A. lucorum and its host plants and lays the groundwork for the design of population management strategies for this important pest in myriad crops. PMID:25692969

  3. Host range and community structure of avian nest parasites in the genus Philornis (Diptera: Muscidae) on the island of Trinidad

    PubMed Central

    Bulgarella, Mariana; Heimpel, George E

    2015-01-01

    Parasite host range can be influenced by physiological, behavioral, and ecological factors. Combining data sets on host–parasite associations with phylogenetic information of the hosts and the parasites involved can generate evolutionary hypotheses about the selective forces shaping host range. Here, we analyzed associations between the nest-parasitic flies in the genus Philornis and their host birds on Trinidad. Four of ten Philornis species were only reared from one species of bird. Of the parasite species with more than one host bird species, P. falsificus was the least specific and P. deceptivus the most specific attacking only Passeriformes. Philornis flies in Trinidad thus include both specialists and generalists, with varying degrees of specificity within the generalists. We used three quantities to more formally compare the host range of Philornis flies: the number of bird species attacked by each species of Philornis, a phylogenetically informed host specificity index (Poulin and Mouillot's STD), and a branch length-based STD. We then assessed the phylogenetic signal of these measures of host range for 29 bird species. None of these measures showed significant phylogenetic signal, suggesting that clades of Philornis did not differ significantly in their ability to exploit hosts. We also calculated two quantities of parasite species load for the birds – the parasite species richness, and a variant of the STD index based on nodes rather than on taxonomic levels – and assessed the signal of these measures on the bird phylogeny. We did not find significant phylogenetic signal for the parasite species load or the node-based STD index. Finally, we calculated the parasite associations for all bird pairs using the Jaccard index and regressed these similarity values against the number of nodes in the phylogeny separating bird pairs. This analysis showed that Philornis on Trinidad tend to feed on closely related bird species more often than expected by

  4. Relative geographic range of sibling species of host damselflies does not reliably predict differential parasitism by water mites

    PubMed Central

    2013-01-01

    related hosts species, no such differences were found between other related host species. Differences in geographic range of related host species does not reliably explain differential levels of parasitism by water mites. PMID:24351055

  5. Modulation of pPS10 Host Range by Plasmid-Encoded RepA Initiator Protein

    PubMed Central

    Maestro, Beatriz; Sanz, Jesús M.; Díaz-Orejas, Ramón; Fernández-Tresguerres, Elena

    2003-01-01

    We report here the isolation and analysis of novel repA host range mutants of pPS10, a plasmid originally found in Pseudomonas savastanoi. Upon hydroxylamine treatment, five plasmid mutants were selected for their establishment in Escherichia coli at 37°C, a temperature at which the wild-type form cannot be established. The mutations were located in different functional regions of the plasmid RepA initiation protein, and the mutants differ in their stable maintenance, copy number, and ability to interact with sequences of the basic replicon. Four of them have broadened their host range, and one of them, unable to replicate in Pseudomonas, has therefore changed its host range. Moreover, the mutants also have increased their replication efficiency in strains other than E. coli such as Pseudomonas putida and Alcaligenes faecalis. None of these mutations drastically changed the structure or thermal stability of the wild-type RepA protein, but in all cases an enhanced interaction with host-encoded DnaA protein was detected by gel filtration chromatography. The effects of the mutations on the functionality of RepA protein are discussed in the framework of a three-dimensional model of the protein. We propose possible explanations for the host range effect of the different repA mutants, including the enhancement of limiting interactions of RepA with specific host replication factors such as DnaA. PMID:12562807

  6. Role of larval host plants in the climate-driven range expansion of the butterfly Polygonia c-album.

    PubMed

    Braschler, Brigitte; Hill, Jane K

    2007-05-01

    1. Some species have expanded their ranges during recent climate warming and the availability of breeding habitat and species' dispersal ability are two important factors determining expansions. The exploitation of a wide range of larval host plants should increase an herbivorous insect species' ability to track climate by increasing habitat availability. Therefore we investigated whether the performance of a species on different host plants changed towards its range boundary, and under warmer temperatures. 2. We studied the polyphagous butterfly Polygonia c-album, which is currently expanding its range in Britain and apparently has altered its host plant preference from Humulus lupulus to include other hosts (particularly Ulmus glabra and Urtica dioica). We investigated insect performance (development time, larval growth rate, adult size, survival) and adult flight morphology on these host plants under four rearing temperatures (18-28.5 degrees C) in populations from core and range margin sites. 3. In general, differences between core and margin populations were small compared with effects of rearing temperature and host plant. In terms of insect performance, host plants were generally ranked U. glabra > or = U. dioica > H. lupulus at all temperatures. Adult P. c-album can either enter diapause or develop directly and higher temperatures resulted in more directly developing adults, but lower survival rates (particularly on the original host H. lupulus) and smaller adult size. 4. Adult flight morphology of wild-caught individuals from range margin populations appeared to be related to increased dispersal potential relative to core populations. However, there was no difference in laboratory reared individuals, and conflicting results were obtained for different measures of flight morphology in relation to larval host plant and temperature effects, making conclusions about dispersal potential difficult. 5. Current range expansion of P. c-album is associated with the

  7. Avian host range of Chlamydophila spp. based on isolation, antigen detection and serology.

    PubMed

    Kaleta, E F; Taday, Eva M A

    2003-10-01

    Published reports and our own diagnostic data on the avian host range of avian Chlamydophila spp. are presented in an attempt to provide evidence for the large number of bird species that have been naturally infected with chlamydia. The term 'chlamydia-positive' is based on either isolation of the organism and antigen detection or on serological detection of circulating antibodies. The list of chlamydia-positive birds contains the six major domestic species (chicken, turkey, Pekin duck, Muscovy duck, goose, and pigeon), the three minor domestic species (Japanese quail, bobwhite quail, and peafowl) and a total of 460 free-living or pet bird species in 30 orders. The order Psittaciformes contains by far the most (153 of 342; 45%) chlamydia-positive bird species. More than 20% of all species per order are positive for chlamydia in the orders Lariformes (gulls, 26 of 92 species; 28%), Alciformes (alks, six of 23 species; 26%), Sphenisciformes (penguins, four of 16 species; 25%), and Anseriformes (ducks and geese, 33 of 157 species; 21%). Only 5% of all bird species (14 of 259 species) in the order Phasianiformes (gallinaceus birds) are chlamydia-positive. The different percentages of chlamydia-positive bird species reflect: (i) a high rate of investigations (e.g. of domestic birds) compared with infrequent testing (e.g. of Charadriiformes or Cuculiformes), (ii) frequent zoonotic implications (e.g. psittacine and columbiform birds), and (iii) an assumed high susceptibility to infection and subsequent seroconversion (e.g. waterfowl).

  8. The avian and mammalian host range of highly pathogenic avian H5N1 influenza.

    PubMed

    Kaplan, Bryan S; Webby, Richard J

    2013-12-05

    Highly pathogenic H5N1 influenza viruses have been isolated from a number of avian and mammalian species. Despite intensive control measures the number of human and animal cases continues to increase. A more complete understanding of susceptible species and of contributing environmental and molecular factors is crucial if we are to slow the rate of new cases. H5N1 is currently endemic in domestic poultry in only a handful of countries with sporadic and unpredictable spread to other countries. Close contact of terrestrial bird or mammalian species with infected poultry/waterfowl or their biological products is the major route for interspecies transmission. Intra-species transmission of H5N1 in mammals, including humans, has taken place on a limited scale though it remains to be seen if this will change; recent laboratory studies suggest that it is indeed possible. Here we review the avian and mammalian species that are naturally susceptible to H5N1 infection and the molecular factors associated with its expanded host range.

  9. A T3 and T7 Recombinant Phage Acquires Efficient Adsorption and a Broader Host Range

    PubMed Central

    Lin, Tiao-Yin; Lo, Yi-Haw; Tseng, Pin-Wei; Chang, Shun-Fu; Lin, Yann-Tsyr; Chen, Ton-Seng

    2012-01-01

    It is usually thought that bacteriophage T7 is female specific, while phage T3 can propagate on male and female Escherichia coli. We found that the growth patterns of phages T7M and T3 do not match the above characteristics, instead showing strain dependent male exclusion. Furthermore, a T3/7 hybrid phage exhibits a broader host range relative to that of T3, T7, as well as T7M, and is able to overcome the male exclusion. The T7M sequence closely resembles that of T3. T3/7 is essentially T3 based, but a DNA fragment containing part of the tail fiber gene 17 is replaced by the T7 sequence. T3 displays inferior adsorption to strains tested herein compared to T7. The T3 and T7 recombinant phage carries altered tail fibers and acquires better adsorption efficiency than T3. How phages T3 and T7 recombine was previously unclear. This study is the first to show that recombination can occur accurately within only 8 base-pair homology, where four-way junction structures are identified. Genomic recombination models based on endonuclease I cleavages at equivalent and nonequivalent sites followed by strand annealing are proposed. Retention of pseudo-palindromes can increase recombination frequency for reviving under stress. PMID:22347414

  10. The Role of Flavonoids in Nodulation Host-Range Specificity: An Update

    PubMed Central

    Liu, Cheng-Wu; Murray, Jeremy D.

    2016-01-01

    Flavonoids are crucial signaling molecules in the symbiosis between legumes and their nitrogen-fixing symbionts, the rhizobia. The primary function of flavonoids in the interaction is to induce transcription of the genes for biosynthesis of the rhizobial signaling molecules called Nod factors, which are perceived by the plant to allow symbiotic infection of the root. Many legumes produce specific flavonoids that only induce Nod factor production in homologous rhizobia, and therefore act as important determinants of host range. Despite a wealth of evidence on legume flavonoids, relatively few have proven roles in rhizobial infection. Recent studies suggest that production of key “infection” flavonoids is highly localized at infection sites. Furthermore, some of the flavonoids being produced at infection sites are phytoalexins and may have a role in the selection of compatible symbionts during infection. The molecular details of how flavonoid production in plants is regulated during nodulation have not yet been clarified, but nitrogen availability has been shown to play a role. PMID:27529286

  11. A T3 and T7 recombinant phage acquires efficient adsorption and a broader host range.

    PubMed

    Lin, Tiao-Yin; Lo, Yi-Haw; Tseng, Pin-Wei; Chang, Shun-Fu; Lin, Yann-Tsyr; Chen, Ton-Seng

    2012-01-01

    It is usually thought that bacteriophage T7 is female specific, while phage T3 can propagate on male and female Escherichia coli. We found that the growth patterns of phages T7M and T3 do not match the above characteristics, instead showing strain dependent male exclusion. Furthermore, a T3/7 hybrid phage exhibits a broader host range relative to that of T3, T7, as well as T7M, and is able to overcome the male exclusion. The T7M sequence closely resembles that of T3. T3/7 is essentially T3 based, but a DNA fragment containing part of the tail fiber gene 17 is replaced by the T7 sequence. T3 displays inferior adsorption to strains tested herein compared to T7. The T3 and T7 recombinant phage carries altered tail fibers and acquires better adsorption efficiency than T3. How phages T3 and T7 recombine was previously unclear. This study is the first to show that recombination can occur accurately within only 8 base-pair homology, where four-way junction structures are identified. Genomic recombination models based on endonuclease I cleavages at equivalent and nonequivalent sites followed by strand annealing are proposed. Retention of pseudo-palindromes can increase recombination frequency for reviving under stress.

  12. A novel expression system based on host-range expansion of baculovirus.

    PubMed

    Zhu, Y; Qi, Y; Liu, D; Joshua, M N; Wang, Y

    1998-12-01

    A host range expanded recombinant Autographa californica multiple-nucleocapsid nucleopolyhedrosis virus AcMNPV/r2 was obtained by cotransfection of the bacmid DNA from Escherichia coli DH10Bac along with a plasmid pBmH-M containing HindIII M fragment of Bombyx mori nuclear polyhedrosis virus (BmNPV) genomic DNA. A recombinant transposon vector carrying a mutant green fluorescent protein gene (GFP) and a polyhedrin gene was constructed. Transposition was carried out in both E. coli DH10Bac and E. coli DH10BmH, which contains AcMNPV/r2 and a helper plasmid. Recombinant DNAs were transfected into Sf-9 cells to generate recombinant virus AcMNPV/r3 and AcMNPV/r4 respectively. Viral stock of AcMNPV/r4 was then infected into Bombyx mori cells (BmN) and Bombyx mori larvae (silkworm). Analysis shows that GFP was highly expressed in Bombyx mori larvae. This expression system, is practicable therefore for mass production of foreign gene products.

  13. The avian and mammalian host range of highly pathogenic avian H5N1 influenza

    PubMed Central

    Kaplan, Bryan S.; Webby, Richard J.

    2013-01-01

    Highly pathogenic H5N1 influenza viruses have been isolated from a number of avian and mammalian species. Despite intensive control measures the number of human and animal cases continues to increase. A more complete understanding of susceptible species and of contributing environmental and molecular factors is crucial if we are to slow the rate of new cases. H5N1 is currently endemic in domestic poultry in only a handful of countries with sporadic and unpredictable spread to other countries. Close contact of terrestrial bird or mammalian species with infected poultry/waterfowl or their biological products is the major route for interspecies transmission. Intra-species transmission of H5N1 in mammals, including humans, has taken place on a limited scale though it remains to be seen if this will change; recent laboratory studies suggest that it is indeed possible. Here we review the avian and mammalian species that are naturally susceptible to H5N1 infection and the molecular factors associated with its expanded host range. PMID:24025480

  14. Host and geographic range extensions of the North American strain of viral hemorrhagic septicemia virus

    USGS Publications Warehouse

    Hedrick, R.P.; Batts, W.N.; Yun, S.; Traxler, G.S.; Kaufman, J.; Winton, J.R.

    2003-01-01

    Viral hemorrhagic septicemia virus (VHSV) was isolated from populations of Pacific sardine Sardinops sagaxfrom the coastal waters of Vancouver Island, British Columbia, Canada, and central and southern California, USA. The virus was also isolated from Pacific mackerel Scomber japonicus in southern California, from eulachon or smeltThaleichthys pacificus, and surf smelt Hypomesus pretiosus pretiosus from Oregon, USA. Mortality and skin lesions typical of viral hemorrhagic septicemia in other marine fish species were observed among sardine in Canada and in a few surf smelt from Oregon, but the remaining isolates of VHSV were obtained from healthy appearing fish. The prevalence of VHSV among groups of apparently healthy sardine, mackerel and smelt ranged from 4 to 8% in California and Oregon. A greater prevalence of infection (58%) occurred in groups of sardine sampled in Canada that sustained a naturally occurring epidemic during 1998-99. A captive group of surf smelt in Oregon exhibited an 81% prevalence of infection with clinical signs in only a few fish. The new isolates were confirmed as North American VHSV and were closely related based on comparisons of the partial nucleotide sequence of the glycoprotein (G) gene. The VHSV isolates from sardine in Canada and California were the most closely related, differing from isolates obtained from other marine fish species and salmonids in British Columbia, Canada, Alaska and Washington, USA. These new virus isolations extend both the known hosts (sardine, mackerel and 2 species of smelt) and geographic range (Oregon and California, USA) of VHSV.

  15. A simple procedure to determine the infectivity and host range of viruses infecting anaerobic and hyperthermophilic microorganisms.

    PubMed

    Gorlas, Aurore; Geslin, Claire

    2013-03-01

    Plaque assay is the method traditionally used to isolate and purify lytic viruses, to determine the viral titer and host range. Whereas most bacterioviruses are either temperate or lytic, the majority of known archeoviruses are not lytic (i.e. they are temperate or chronic). In view of the widespread occurrence of such viruses in extreme environments, we designed an original method, called the inverted spot test, to determine the host range and infectivity of viruses isolated from anaerobic hyperthermophilic and sulfur-reducing microorganisms. Here, we used this approach to prove for the first time the infectivity of Pyrococcus abyssi virus 1 (PAV1) and to confirm the host range of Thermococcus prieurii virus 1 (TPV1), the only two viruses isolated so far from any of the described marine hyperthermophilic archaea (Euryarchaeota phylum, Thermococcales order).

  16. Host Range Assessment of Helicotylenchus pseudorobustus (Tylenchida: Hoplolaimidae) on Pasture Species

    PubMed Central

    Davis, L. T.; Bell, N. L.; Watson, R.N.; Rohan, T. C.

    2004-01-01

    The host status of 15 commonly occurring pasture species for Helicotylenchus pseudorobustus was tested in a greenhouse trial. Only tall fescue, with and without Neotyphodium endophyte infection, was a good host (Pf/Pi = final/initial population > 1). Inoculation survival was tested in a second trial, which showed that only 10% of the H. pseudorobustus nematodes survived the first 7 days after inoculation. When the Pf/Pi was adjusted to account for a 10% survival, all of the grass and clover hosts tested had a Pf/Pi > 1. Both trials showed a positive correlation between increased numbers of H. pseudorobustus and free-living nematodes. PMID:19262829

  17. Construction and characterization of regulated L-arabinose-inducible broad host range expression vectors in Xanthomonas.

    PubMed

    Sukchawalit, R; Vattanaviboon, P; Sallabhan, R; Mongkolsuk, S

    1999-12-15

    Several versions of broad host range (BHR), L-arabinose-inducible expression vectors were constructed. These expression vectors were based on a high copy number BHR pBBR1MCS-4 replicon that could replicate in both enteric and non-enteric Gram-negative bacteria. Two versions of expression cassettes containing multiple cloning sites either with or without a ribosome binding site were placed under transcriptional control of the Escherichia coli BAD promoter and araC gene. Three versions of vectors containing ampicillin or kanamycin or tetracycline resistance genes as selectable markers were constructed. In all six new L-arabinose-inducible BHR expression vectors containing many unique cloning sites, selectable markers were made to facilitate cloning and expression of genes in various Gram-negative bacteria. A Tn9 chloramphenicol acetyl transferase (cat) gene was cloned into an expression vector, resulting in pBBad18Acat that was used to establish optimal expression conditions (addition of 0.02% L-arabinose to mid-exponential phase cells for at least 1 h) in a Xanthomonas campestris pv. phaseoli. Comparison of the Cat enzyme activities between uninduced and a 180-min L-arabinose-induced culture showed a greater than 150-fold increased Cat specific activity. In addition, L-arabinose induction of exponential phase cells harboring pBBad18Acat gave a higher amount of Cat than similarly treated stationary phase cells. The usefulness of the expression vector was also demonstrated in both enteric and non-enteric Gram-negative bacteria.

  18. A rabbitpox virus serpin gene controls host range by inhibiting apoptosis in restrictive cells.

    PubMed Central

    Brooks, M A; Ali, A N; Turner, P C; Moyer, R W

    1995-01-01

    Poxviruses are unique among viruses in encoding members of the serine proteinase inhibitor (serpin) superfamily. Orthopoxviruses contain three serpins, designated SPI-1, SPI-2, and SPI-3. SPI-1 encodes a 40-kDa protein that is required for the replication of rabbitpox virus (RPV) in PK-15 or A549 cells in culture (A. N. Ali, P. C. Turner, M. A. Brooks, and R. W. Moyer, Virology 202:305-314, 1994). Examination of nonpermissive human A549 cells infected with an RPV mutant disrupted in the SPI-1 gene (RPV delta SPI-1) suggests there are no gross defects in protein or DNA synthesis. The proteolytic processing of late viral structural proteins, a feature of orthopoxvirus infections associated with the maturation of virus particles, also appears relatively normal. However, very few mature virus particles of any kind are produced compared with the level found in infections with wild-type RPV. Morphological examination of RPV delta SPI-1-infected A549 cells, together with an observed fragmentation of cellular DNA, suggests that the host range defect is associated with the onset of apoptosis. Apoptosis is seen only in RPV delta SPI-1 infection of nonpermissive (A549 or PK-15) cells and is absent in all wild-type RPV infections and RPV delta SPI-2 mutant infections examined to date. Although the SPI-1 gene is expressed early, before DNA replication, the triggering apoptotic event occurs late in the infection, as RPV delta SPI-1-infected A549 cells do not undergo apoptosis when infections are carried out in the presence of cytosine arabinoside. While the SPI-2 (crmA) gene, when transfected into cells, has been shown to inhibit apoptosis, our experiments provide the first indication that a poxvirus serpin protein can inhibit apoptosis during a poxvirus infection. PMID:7494278

  19. Laboratory and realized host ranges of Chaetorellia succinea (Diptera: Tephritidae), an unintentionally introduced natural enemy of yellow starthistle.

    PubMed

    Balciunas, Joe K; Villegas, Baldo

    2007-08-01

    In 1999, we reported our discovery, in California and Oregon, of Chaetorellia succinea (Costa) (Diptera: Tephritidae) destroying the seeds of yellow starthistle, Centaurea solstitialis L., one of the worst weeds in the western United States. This fly, an unintentional introduction from Greece, dispersed rapidly throughout California and the northwest, and there is interest in using this adventive fly as a classical biological control agent for this weed. Because the host range of Ch. succinea has not been studied, this fly might pose a risk to other members of the thistle tribe Cardueae, especially the many thistle species native to California and other parts of the western United States. We determined the physiological host range of this fly in the laboratory by exposing it under no-choice conditions to 14 potential Cardueae hosts. Two introduced weed species and the native American basketflower (Centaurea americana Nuttall) were laboratory hosts. Under less restrictive choice test conditions, yellow starthistle was highly preferred, but there was a small amount of oviposition, and a few adult Ch. succinea emerged from all three of these plant species. Because Ch. succinea is now widespread throughout California, we collected flower heads from 24 potential host plant species at 111 sites to determine the realized host range in the field. These collections did not include American basketflower, which does not occur naturally in California. Ch. succinea emerged only from the other two known hosts: Ce. melitensis and Ce. sulfurea. Our results suggest that American basketflower growing in the southwestern United States may be at risk if Ch. succinea expands its range into that region.

  20. Use of wide-host-range bacteriophages to reduce Salmonella on poultry products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteriophages used to treat infections are typically amplified in a pathogenic host. However, this practice introduces the risk of administering any remaining bacteriophage-resistant pathogen during bacteriophage application if separate techniques are less than perfect. In this study, bacteriopha...

  1. Expansion of Groundnut ringspot virus host and geographic ranges in solanaceous vegetables in peninsular Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report provides a timely account of Groundnut ringspot virus infection of additional hosts (pepper, tomatillo and eggplant) and in additional locations to growers, Extension personnel, crop consultants, and state and Federal regulatory and research scientists....

  2. Pristionchus uniformis, should I stay or should I go? Recent host range expansion in a European nematode

    PubMed Central

    D'Anna, Isabella; Sommer, Ralf J

    2011-01-01

    Pristionchus pacificus has been developed as a model system in evolutionary developmental biology, evolutionary ecology, and population genetics. This species has a well-known ecological association with scarab beetles. Generally, Pristionchus nematodes have a necromenic association with their beetle hosts. Arrested dauer larvae invade the insect and wait for the host's death to resume development. Only one Pristionchus species is known to frequently associate with a non-scarab beetle. Pristionchus uniformis has been isolated from the chrysomelid Leptinotarsa decemlineata, also known as the Colorado potato beetle, in Europe and North America, but is also found on scarab beetles. This unusual pattern of association with two unrelated groups of beetles on two continents requires the involvement of geographical and host range expansion events. Here, we characterized a collection of 81 P. uniformis isolates from North America and Europe and from both scarab beetles and L. decemlineata. We used population genetic and phylogenetic analyses of the mitochondrial gene nd2 to reconstruct the genetic history of P. uniformis and its beetle association. Olfactory tests on beetles chemical extracts showed that P. uniformis has a unique chemoattractive profile toward its beetle hosts. Our results provide evidence for host range expansion through host-switching events in Europe where P. uniformis was originally associated with scarab beetles and the nematode's subsequent invasion of North America. PMID:22393515

  3. 76 FR 60448 - Syngenta Biotechnology, Inc.; Determination of Nonregulated Status for Lepidopteran-Resistant Cotton

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... protect cotton plants from lepidopteran insect damage, is no longer considered a regulated article under... cotton plants from lepidopteran insect damage. The petition stated that cotton event COT67B is...

  4. Eop1 from a Rubus strain of Erwinia amylovora functions as a host-range limiting factor.

    PubMed

    Asselin, J E; Bonasera, J M; Kim, J F; Oh, C-S; Beer, S V

    2011-08-01

    Strains of Erwinia amylovora, the bacterium causing the disease fire blight of rosaceous plants, are separated into two groups based on host range: Spiraeoideae and Rubus strains. Spiraeoideae strains have wide host ranges, infecting plants in many rosaceous genera, including apple and pear. In the field, Rubus strains infect the genus Rubus exclusively, which includes raspberry and blackberry. Based on comparisons of limited sequence data from a Rubus and a Spiraeoideae strain, the gene eop1 was identified as unusually divergent, and it was selected as a possible host specificity factor. To test this, eop1 genes from a Rubus strain and a Spiraeoideae strain were cloned and mutated. Expression of the Rubus-strain eop1 reduced the virulence of E. amylovora in immature pear fruit and in apple shoots. Sequencing the orfA-eop1 regions of several strains of E. amylovora confirmed that forms of eop1 are conserved among strains with similar host ranges. This work provides evidence that eop1 from a Rubus-specific strain can function as a determinant of host specificity in E. amylovora.

  5. Phylogenetics and genetic diversity of the Cotesia flavipes complex of parasitoid wasps (Hymenoptera: Braconidae), biological control agents of lepidopteran stemborers.

    PubMed

    Muirhead, Kate A; Murphy, Nicholas P; Sallam, Nader; Donnellan, Stephen C; Austin, Andrew D

    2012-06-01

    The Cotesia flavipes complex of parasitoid wasps (Hymenoptera: Braconidae) are economically important for the biological control of lepidopteran stemboring pests associated with gramineous crops. Some members of the complex successfully parasitize numerous stemborer pest species, however certain geographic populations have demonstrated variation in the range of hosts that they parasitize. In addition, the morphology of the complex is highly conserved and considerable confusion surrounds the identity of species and host-associated biotypes. We generated nucleotide sequence data for two mtDNA genes (COI, 16S) and three anonymous nuclear loci (CfBN, CfCN, CfEN) for the C. flavipes complex. To analyze genetic variation and relationships among populations we used (1) concatenated mtDNA and nDNA data, (2) a nDNA multilocus network approach, and (3) two species tree inference methods, i.e. Bayesian estimation of species trees (BEST) and Bayesian inference of species trees from multilocus data with (*)BEAST. All phylogenetic analyses provide strong support for monophyly of the complex and the presence of at least four species, C. chilonis (from China and Japan), C. sesamiae (from Africa), C. flavipes (originating from the Indo-Asia region but introduced into Africa and the New World), and C. nonagriae (from Australia and Papua New Guinea). Haplotype diversity of geographic populations relates to historical biogeographic barriers and biological control introductions, and reflects previous reports of ecological variation in these species. Strong discordance was found between the mitochondrial and nuclear markers in the Papua New Guinea haplotypes, which may be an outcome of hybridization and introgression of C. flavipes and C. nonagriae. The position of Cotesia flavipes from Japan was not well supported in any analysis and was the sister taxon to C. nonagriae (mtDNA, (*)BEAST), C. flavipes (nDNA) or C. flavipes+C. nonagriae (BEST) and, may represent a cryptic species. The

  6. Host growth temperature and a conservative amino acid substitution in the replication protein of pPS10 influence plasmid host range.

    PubMed Central

    Fernández-Tresguerres, M E; Martín, M; García de Viedma, D; Giraldo, R; Díaz-Orejas, R

    1995-01-01

    pPS10 is a replicon isolated from Pseudomonas syringe pv. savastanoi that can be established at 37 degrees C efficiently in Pseudomonas aeruginosa but very inefficiently in Escherichia coli. The establishment of the wild-type pPS10 replicon in E. coli is favored at low temperatures (30 degrees C or below). RepA protein of pPS10 promotes in vitro plasmid replication in extracts from E. coli, and this replication depends on host proteins DnaA, DnaB, DnaG, and SSB. Mutant plasmids able to efficiently replicate in E. coli at 37 degrees C were obtained. Three of four mutants whose mutations were mapped show a conservative Ala-->Val change in the amino-terminal region of the replication protein RepA. Plasmids carrying this mutation maintain the capacity to replicate in P. aeruginosa and have a fourfold increase in copy number in this host. The mutation does not substantially alter the autoregulation mediated by RepA. These results show that the physiological conditions of the host as well as subtle changes in the plasmid replication protein can modulate the host range of the pPS10 replicon. PMID:7635822

  7. Identification from diverse mammalian poxviruses of host-range regulatory genes functioning equivalently to vaccinia virus C7L.

    PubMed

    Meng, Xiangzhi; Chao, Jie; Xiang, Yan

    2008-03-15

    Vaccinia virus (VACV) C7L is a host-range gene that regulates cellular tropism of VACV. Distantly related C7L homologues are encoded by nearly all mammalian poxviruses, but whether they are host-range genes functioning similar to VACV C7L has not been determined. Here, we used VACV as a model system to analyze five different C7L homologues from diverse mammalian poxviruses for their abilities to regulate poxvirus cellular tropism. Three C7L homologues (myxoma virus M63R, M64R and cowpox virus 020), when expressed with an epitope tag and from a VACV mutant lacking the host-range genes K1L and C7L (vK1L-C7L-), failed to support productive viral replication in human and murine cells. In nonpermissive cells, these viruses did not synthesize viral late proteins, expressed a reduced level of the early protein E3L, and were defective at suppressing cellular PKR activation. In contrast, two other C7L homologues, myxoma virus (MYXV) M62R and yaba-like disease virus (YLDV) 67R, when expressed with an epitope tag and from vK1L(-)C7L(-), supported normal viral replication in human and murine cells and restored the ability of the virus to suppress PKR activation. Furthermore, M62R rescued the defect of vK1L(-)C7L(-) at replicating and disseminating in mice following intranasal inoculation. These results show that MYXV M62R and YLDV 67R function equivalently to C7L at supporting VACV replication in mammalian hosts and suggest that a C7L-like host-range gene is essential for the replication of many mammalian poxviruses in mammalian hosts.

  8. The N-terminus of vaccinia virus host range protein C7L is essential for function

    PubMed Central

    Terajima, Masanori; Urban, Stina L.; Leporati, Anita M.

    2012-01-01

    Vaccinia virus (VACV), a member of the Poxviridae family of large double-stranded DNA viruses, is being used as a smallpox vaccine as well as an expression vector for immunization against other infectious diseases and cancer. The host range of wild type VACV is very broad among mammalian cells. C7L is a host range gene identified in VACV and is well conserved in mammalian poxviruses except for parapoxviruses and molluscum contagiosum virus. The molecular mechanisms by which the C7L gene exerts host range function are not well understood. The C7L protein does not have any known conserved domains or show sequence similarity to cellular proteins or viral proteins other than the C7L homologues in mammalian poxviruses. We generated recombinant vaccinia viruses carrying deletion mutants of the C7L gene using NYVAC as a parental strain and found that the N-terminus is essential for host range function of C7L, which is consistent with a previous report that showed homology among C7L homologues are greater near the N-terminus than the C-terminus. PMID:23001690

  9. Biology and host range of Heterapoderopsis bicallosicollis; a potential biological control agent for Chinese tallow Triadica sebifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chinese tallow, Triadica sebifera, is an invasive weed that infests natural and agricultural areas of the southeastern USA. A candidate for biological control of Chinese tallow has been studied under quarantine conditions. The biology and host range of a primitive leaf feeding beetle, Heterapoderops...

  10. Complexity and Variability of Gut Commensal Microbiota in Polyphagous Lepidopteran Larvae

    PubMed Central

    Vogel, Heiko; Ping, Liyan; Shao, Yongqi; Cordero, Erika Arias; Andersen, Gary; Westermann, Martin; Heckel, David G.; Boland, Wilhelm

    2012-01-01

    Background The gut of most insects harbours nonpathogenic microorganisms. Recent work suggests that gut microbiota not only provide nutrients, but also involve in the development and maintenance of the host immune system. However, the complexity, dynamics and types of interactions between the insect hosts and their gut microbiota are far from being well understood. Methods/Principal Findings To determine the composition of the gut microbiota of two lepidopteran pests, Spodoptera littoralis and Helicoverpa armigera, we applied cultivation-independent techniques based on 16S rRNA gene sequencing and microarray. The two insect species were very similar regarding high abundant bacterial families. Different bacteria colonize different niches within the gut. A core community, consisting of Enterococci, Lactobacilli, Clostridia, etc. was revealed in the insect larvae. These bacteria are constantly present in the digestion tract at relatively high frequency despite that developmental stage and diet had a great impact on shaping the bacterial communities. Some low-abundant species might become dominant upon loading external disturbances; the core community, however, did not change significantly. Clearly the insect gut selects for particular bacterial phylotypes. Conclusions Because of their importance as agricultural pests, phytophagous Lepidopterans are widely used as experimental models in ecological and physiological studies. Our results demonstrated that a core microbial community exists in the insect gut, which may contribute to the host physiology. Host physiology and food, nevertheless, significantly influence some fringe bacterial species in the gut. The gut microbiota might also serve as a reservoir of microorganisms for ever-changing environments. Understanding these interactions might pave the way for developing novel pest control strategies. PMID:22815679

  11. [Trichogramma species (Hymenoptera: Trichogrammatidae) parasitoids of Lepidopteran eggs in Lara State, Venezuela].

    PubMed

    Morales, José; Vásquez, Carlos; Pérez B, Nieves L; Valera, Neicy; Ríos, Yolmar; Arrieche, Norayda; Querino, Ranyse B

    2007-01-01

    This work was conducted to determine the occurrence of Trichogramma wasp species in Lara State, Venezuela. Lepidopteran egg samples collected from various crop leaves were observed daily under laboratory conditions for emergence of Trichogramma species adult wasps. Trichogramma were also obtained from traps containing eggs from the hosts Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). In the laboratory, specimens of Trichogramma species were mounted on microscope slides to show male genitalia and other morphological characters used for its identification. Trichogramma atopovirilia Oatman y Platner emerged from S. frugiperda eggs collected in a cornfield at La Palomera, Humocaro Alto and at El Parchal, Humocaro Bajo, Municipio Morán. T. atopovirilia also emerged from S. frugiperda eggs collected in a cornfield at Sabana Grande and from S. cerealella eggs used as traps in a pepper culture at Tintinal, Municipio Andrés Eloy Blanco. T. exiguum Pinto y Platner emerged from S. frugiperda eggs used as traps or collected in cornfield at Totumito and at La Palomera, Humocaro Alto. T. pretiosum Riley emerged from Phthorimaea operculella Zeller eggs collected on stored potatoes at Monte Carmelo, Sanare. The identification of Trichogramma species in Lara State would be useful in the development of biological control programs for lepidopteran pests.

  12. Variations in type III effector repertoires, pathological phenotypes and host range of Xanthomonas citri pv. citri pathotypes.

    PubMed

    Escalon, Aline; Javegny, Stéphanie; Vernière, Christian; Noël, Laurent D; Vital, Karine; Poussier, Stéphane; Hajri, Ahmed; Boureau, Tristan; Pruvost, Olivier; Arlat, Matthieu; Gagnevin, Lionel

    2013-06-01

    The mechanisms determining the host range of Xanthomonas are still undeciphered, despite much interest in their potential roles in the evolution and emergence of plant pathogenic bacteria. Xanthomonas citri pv. citri (Xci) is an interesting model of host specialization because of its pathogenic variants: pathotype A strains infect a wide range of Rutaceous species, whereas pathotype A*/A(W) strains have a host range restricted to Mexican lime (Citrus aurantifolia) and alemow (Citrus macrophylla). Based on a collection of 55 strains representative of Xci worldwide diversity assessed by amplified fragment length polymorphism (AFLP), we investigated the distribution of type III effectors (T3Es) in relation to host range. We examined the presence of 66 T3Es from xanthomonads in Xci and identified a repertoire of 28 effectors, 26 of which were shared by all Xci strains, whereas two (xopAG and xopC1) were present only in some A*/A(W) strains. We found that xopAG (=avrGf1) was present in all A(W) strains, but also in three A* strains genetically distant from A(W) , and that all xopAG-containing strains induced the hypersensitive response (HR) on grapefruit and sweet orange. The analysis of xopAD and xopAG suggested horizontal transfer between X. citri pv. bilvae, another citrus pathogen, and some Xci strains. A strains were genetically less diverse, induced identical phenotypic responses and possessed indistinguishable T3E repertoires. Conversely, A*/A(W) strains exhibited a wider genetic diversity in which clades correlated with geographical origin and T3E repertoire, but not with pathogenicity, according to T3E deletion experiments. Our data outline the importance of taking into account the heterogeneity of Xci A*/A(W) strains when analysing the mechanisms of host specialization.

  13. Transforming Lepidopteran Insect Cells for Improved Protein Processing and Expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The lepidopteran insect cells used with the baculovirus expression vector system (BEVS) are capable of synthesizing and accurately processing foreign proteins. However, proteins expressed in baculovirus-infected cells often fail to be completely processed, or are not processed in a manner that meet...

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

    PubMed Central

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

    2013-01-01

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

  15. Amerindian Helicobacter pylori Strains Go Extinct, as European Strains Expand Their Host Range

    PubMed Central

    Domínguez-Bello, Maria G.; Pérez, Maria E.; Bortolini, Maria C.; Salzano, Francisco M.; Pericchi, Luis R.; Zambrano-Guzmán, Orlisbeth; Linz, Bodo

    2008-01-01

    We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori strains would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes) of 131 strains: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all strains that had been cultured from Africans were African strains (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori strains were hspAmerind. Strains hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination). The lower genetic structure in hpEurope strains is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear. This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts. PMID:18830403

  16. Novel Papillomaviruses in Free-Ranging Iberian Bats: No Virus–Host Co-evolution, No Strict Host Specificity, and Hints for Recombination

    PubMed Central

    García-Pérez, Raquel; Ibáñez, Carlos; Godínez, Jose M.; Aréchiga, Nidia; Garin, Inazio; Pérez-Suárez, Gonzalo; de Paz, Oscar; Juste, Javier; Echevarría, Juan E.; Bravo, Ignacio G.

    2014-01-01

    Papillomaviruses (PVs) are widespread pathogens. However, the extent of PV infections in bats remains largely unknown. This work represents the first comprehensive study of PVs in Iberian bats. We identified four novel PVs in the mucosa of free-ranging Eptesicus serotinus (EserPV1, EserPV2, and EserPV3) and Rhinolophus ferrumequinum (RferPV1) individuals and analyzed their phylogenetic relationships within the viral family. We further assessed their prevalence in different populations of E. serotinus and its close relative E. isabellinus. Although it is frequent to read that PVs co-evolve with their host, that PVs are highly species-specific, and that PVs do not usually recombine, our results suggest otherwise. First, strict virus–host co-evolution is rejected by the existence of five, distantly related bat PV lineages and by the lack of congruence between bats and bat PVs phylogenies. Second, the ability of EserPV2 and EserPV3 to infect two different bat species (E. serotinus and E. isabellinus) argues against strict host specificity. Finally, the description of a second noncoding region in the RferPV1 genome reinforces the view of an increased susceptibility to recombination in the E2-L2 genomic region. These findings prompt the question of whether the prevailing paradigms regarding PVs evolution should be reconsidered. PMID:24391150

  17. Novel papillomaviruses in free-ranging Iberian bats: no virus-host co-evolution, no strict host specificity, and hints for recombination.

    PubMed

    García-Pérez, Raquel; Ibáñez, Carlos; Godínez, Jose M; Aréchiga, Nidia; Garin, Inazio; Pérez-Suárez, Gonzalo; de Paz, Oscar; Juste, Javier; Echevarría, Juan E; Bravo, Ignacio G

    2014-01-01

    Papillomaviruses (PVs) are widespread pathogens. However, the extent of PV infections in bats remains largely unknown. This work represents the first comprehensive study of PVs in Iberian bats. We identified four novel PVs in the mucosa of free-ranging Eptesicus serotinus (EserPV1, EserPV2, and EserPV3) and Rhinolophus ferrumequinum (RferPV1) individuals and analyzed their phylogenetic relationships within the viral family. We further assessed their prevalence in different populations of E. serotinus and its close relative E. isabellinus. Although it is frequent to read that PVs co-evolve with their host, that PVs are highly species-specific, and that PVs do not usually recombine, our results suggest otherwise. First, strict virus-host co-evolution is rejected by the existence of five, distantly related bat PV lineages and by the lack of congruence between bats and bat PVs phylogenies. Second, the ability of EserPV2 and EserPV3 to infect two different bat species (E. serotinus and E. isabellinus) argues against strict host specificity. Finally, the description of a second noncoding region in the RferPV1 genome reinforces the view of an increased susceptibility to recombination in the E2-L2 genomic region. These findings prompt the question of whether the prevailing paradigms regarding PVs evolution should be reconsidered.

  18. Limits to the host range of the highly polyphagous tephritid fruit fly Anastrepha ludens in its natural habitat.

    PubMed

    Birke, A; Acosta, E; Aluja, M

    2015-12-01

    Anastepha ludens (Diptera: Tephritidae) is a highly polyphagous fruit fly that is able to develop in a wide range of hosts. Understanding the limits of this pest's host range could provide valuable information for pest management and plant breeding for pest resistance. Previous studies have shown that guavas (Psidium guajava (Myrtaceae) L.), are not attacked under natural conditions by A. ludens. To understand this phenomenon, guavas were exposed to natural infestation by A. ludens and to other fruit fly species that infest guavas in nature (Anastrepha striata Schiner, Anastepha fraterculus (Wiedemann), Anastepha obliqua (Macquart)). Once the susceptible phenological stage of guavas was determined, fruit infestation levels were compared between A. ludens and A. striata. Choice and non-choice tests were performed under field-cage conditions. Under field conditions, guavas were susceptible to A. striata and A. fraterculus attack all the way from when fruit was undeveloped to when fruit began to ripen. No infestation by A. ludens was recorded under natural conditions. Similar results were obtained when forced exposures were performed, indicating that unripe guavas were preferred by A. striata over ripe fruit, and that infestation rates were higher at early fruit maturity stages. Under forced oviposition conditions, A. ludens larvae were unable to develop in unripe guavas but did so in fully ripe fruit. However, A. ludens fitness parameters were dramatically affected, exhibiting reduced survival and reduced pupal weight compared to conspecifics that developed in a natural host, grapefruit. We confirm that P. guajava should not be treated as a natural host of this pestiferous species, and suggest that both behavioral aspects and the fact that larvae are unable to adequately develop in this fruit, indeed represent clear limits to A. ludens's broad host range.

  19. M062 is a host range factor essential for myxoma virus pathogenesis and functions as an antagonist of host SAMD9 in human cells.

    PubMed

    Liu, Jia; Wennier, Sonia; Zhang, Leiliang; McFadden, Grant

    2011-04-01

    Myxoma virus (MYXV) M062R is a functional homolog of the C7L family of host range genes from orthopoxviruses. We constructed a targeted M062R-knockout-MYXV (vMyxM062-KO) and characterized its properties in vitro and in vivo. In European rabbits, infection by vMyxM062-KO was completely asymptomatic. The surviving rabbits did not gain full protection against the subsequent lethal-dose challenge with wild-type MYXV. We also looked for cellular tropism defects in a variety of cultured cells. In all of the rabbit cells tested, vMyxM062-KO conducts an abortive infection, although it initiates viral DNA replication. In many, but not all, human cancer cells that are permissive for wild-type MYXV, vMyxM062-KO exhibited a profound replication defect. We categorized human cells tested into two groups: (i) type A, which support productive replication for wild-type MYXV but are unable to produce significant levels of progeny virus by vMyxM062-KO, and (ii) type B, which are permissive to infections by both wild-type MYXV and vMyxM062-KO. Furthermore, using proteomic strategies, we identified sterile α motif domain containing 9 (SAMD9), an interferon-regulated cellular protein implicated in human inflammatory disorders, as a unique host binding partner of M062 in human cells. Significantly, knocking down SAMD9 in type A human cancer cells led to a substantial rescue of vMyxM062-KO infection. In summary, M062 is a novel host range factor that controls productive MYXV replication in rabbit cells and in a wide variety of human cells. M062 also binds and antagonizes cellular SAMD9 in human cells, suggesting that SAMD9 is a novel innate antiviral factor against poxviruses.

  20. Genome Analysis of a Novel Broad Host Range Proteobacteria Phage Isolated from a Bioreactor Treating Industrial Wastewater

    PubMed Central

    de Leeuw, Marina; Baron, Maayan; Brenner, Asher; Kushmaro, Ariel

    2017-01-01

    Bacteriophages are viruses that infect bacteria, and consequently they have a major impact on the development of a microbial population. In this study, the genome of a novel broad host range bacteriophage, Aquamicrobium phage P14, isolated from a wastewater treatment plant, was analyzed. The Aquamicrobium phage P14 was found to infect members of different Proteobacteria classes (Alphaproteobacteria and Betaproteobacteria). This phage contains a 40,551 bp long genome and 60% of its genes had blastx hits. Furthermore, the bacteriophage was found to share more than 50% of its genes with several podoviruses and has the same gene order as other polyvalent bacteriophages. The results obtained in this study led to the conclusion that indeed general features of the genome of the Aquamicrobium phage P14 are shared with other broad host range bacteriophages, however further analysis of the genome is needed in order to identify the specific mechanisms which enable the bacteriophage to infect both Alphaproteobacteria and Betaproteobacteria. PMID:28106814

  1. The Presence of Two Receptor-Binding Proteins Contributes to the Wide Host Range of Staphylococcal Twort-Like Phages

    PubMed Central

    Takeuchi, Ippei; Osada, Keita; Azam, Aa Haeruman; Asakawa, Hiroaki; Miyanaga, Kazuhiko

    2016-01-01

    ABSTRACT Thanks to their wide host range and virulence, staphylococcal bacteriophages (phages) belonging to the genus Twortlikevirus (staphylococcal Twort-like phages) are regarded as ideal candidates for clinical application for Staphylococcus aureus infections due to the emergence of antibiotic-resistant bacteria of this species. To increase the usability of these phages, it is necessary to understand the mechanism underlying host recognition, especially the receptor-binding proteins (RBPs) that determine host range. In this study, we found that the staphylococcal Twort-like phage ΦSA012 possesses at least two RBPs. Genomic analysis of five mutant phages of ΦSA012 revealed point mutations in orf103, in a region unique to staphylococcal Twort-like phages. Phages harboring mutated ORF103 could not infect S. aureus strains in which wall teichoic acids (WTAs) are glycosylated with α-N-acetylglucosamine (α-GlcNAc). A polyclonal antibody against ORF103 also inhibited infection by ΦSA012 in the presence of α-GlcNAc, suggesting that ORF103 binds to α-GlcNAc. In contrast, a polyclonal antibody against ORF105, a short tail fiber component previously shown to be an RBP, inhibited phage infection irrespective of the presence of α-GlcNAc. Immunoelectron microscopy indicated that ORF103 is a tail fiber component localized at the bottom of the baseplate. From these results, we conclude that ORF103 binds α-GlcNAc in WTAs, whereas ORF105, the primary RBP, is likely to bind the WTA backbone. These findings provide insight into the infection mechanism of staphylococcal Twort-like phages. IMPORTANCE Staphylococcus phages belonging to the genus Twortlikevirus (called staphylococcal Twort-like phages) are considered promising agents for control of Staphylococcus aureus due to their wide host range and highly lytic capabilities. Although staphylococcal Twort-like phages have been studied widely for therapeutic purposes, the host recognition process of staphylococcal Twort

  2. Wide Host Ranges of Herbivorous Beetles? Insights from DNA Bar Coding

    PubMed Central

    Kishimoto-Yamada, Keiko; Kamiya, Koichi; Meleng, Paulus; Diway, Bibian; Kaliang, Het; Chong, Lucy; Itioka, Takao; Sakai, Shoko; Ito, Motomi

    2013-01-01

    There are very few studies that have investigated host-specificity among tropical herbivorous insects. Indeed, most of the trophic interactions of herbivorous insects in Southeast Asian tropical rainforests remain unknown, and whether polyphagous feeding is common in the herbivores of this ecosystem has not been determined. The present study employed DNA bar coding to reveal the trophic associations of adult leaf-chewing chrysomelid beetles in a Bornean rainforest. Plant material ingested by the adults was retrieved from the bodies of the insects, and a portion of the chloroplast rbcL sequence was then amplified from this material. The plants were identified at the family level using an existing reference database of chloroplast DNA. Our DNA-based diet analysis of eleven chrysomelid species successfully identified their host plant families and indicated that five beetle species fed on more than two families within the angiosperms, and four species fed on several families of gymnosperms and/or ferns together with multiple angiosperm families. These findings suggest that generalist chrysomelid beetles associated with ecologically and taxonomically distant plants constitute a part of the plant-insect network of the Bornean rainforest. PMID:24073210

  3. Second site mutation in the virus envelope expands the host range of a cytopathic variant of Moloney murine leukemia virus.

    PubMed

    Ferrarone, John; Knoper, Ryan C; Li, Randolph; Kozak, Christine A

    2012-11-10

    Spl574 MLV (murine leukemia virus) is a variant of Moloney ecotropic MLV (MoMLV) that is cytopathic in Mus dunni cells and restricted by other mouse cells. Its host range and cytopathicity are due to a mutation, S82F, at a site critical for binding to the CAT-1 receptor. To identify residues that affect affinity for receptor variants, virus with S82F was passed in restrictive cells. The env genes of the adapted viruses contained 18 novel mutations, including one, E114G, present in 6 of 30 sequenced envs. MoMLV-E114G efficiently infected all mouse cells as well as ecotropic MLV resistant Chinese hamster cells. Virus with E114G and S82F induced large multinucleated syncytia in NIH 3T3 and SC-1 cells as well as M. dunni cells. Inoculation of Mo-S82F,E114G into mice produced lymphomas typical of MoMLV. Residues at env position 114 are thus important determinants of host range, and E114G suppresses host range restriction due to S82F, but does not affect S82F-governed cytopathicity.

  4. Differentiation of polyvalent bacteriophages specific to uropathogenic Proteus mirabilis strains based on the host range pattern and RFLP.

    PubMed

    Maszewska, Agnieszka; Wójcik, Ewelina; Ciurzyńska, Aneta; Wojtasik, Arkadiusz; Piątkowska, Iwona; Dastych, Jarosław; Różalski, Antoni

    2016-01-01

    Urinary tract infections (UTIs) caused by P. mirabilis are difficult to cure because of the increasing antimicrobial resistance of these bacteria. Phage therapy is proposed as an alternative infection treatment. The aim of this study was to isolate and differentiate uropathogenic P. mirabilis strain specific polyvalent bacteriophages producing polysaccharide depolymerases (PDs). 51 specific phages were obtained. The plaques of 29 bacteriophages were surrounded by halos, which indicated that they produced PDs. The host range analysis showed that, except phages 58B and 58C, the phage host range profiles differed from each other. Phages 35 and 45 infected all P. mirabilis strains tested. Another 10 phages lysed more than 90% of isolates. Among these phages, 65A, 70, 66 and 66A caused a complete lysis of the bacterial lawn formed by 62% to 78% of strains. Additionally, phages 39A and 70 probably produced PDs. The phages' DNA restriction fragment length polymorphism (RFLP) analysis demonstrated that genomes of 51 isolated phages represented 34 different restriction profiles. DNA of phage 58A seemed to be resistant to selected EcoRV endonuclease. The 33 RFLP-EcoRV profiles showed a Dice similarity index of 38.8%. 22 RFLP patterns were obtained from single phage isolates. The remaining 12 restriction profiles consisted of 2 to 4 viruses. The results obtained from phage characterization based on the pattern of phage host range in combination with the RFLP method enabled effective differentiation of the studied phages and selection of PD producing polyvalent phages for further study.

  5. Climate Change May Alter Breeding Ground Distributions of Eastern Migratory Monarchs (Danaus plexippus) via Range Expansion of Asclepias Host Plants

    PubMed Central

    Lemoine, Nathan P.

    2015-01-01

    Climate change can profoundly alter species’ distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  6. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus) via range expansion of Asclepias host plants.

    PubMed

    Lemoine, Nathan P

    2015-01-01

    Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  7. Roles of host plants in boll weevil range expansion beyond tropical Mesoamerica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New findings on boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), biology and ecology have had repercussions on the current level of understanding about short- and long-range boll weevil dispersal, and range expansion from its original tropical Mesoamerican habitat. The w...

  8. Host Range and Distribution of the Clover Root-knot Nematode, Meloidogyne trifoliophila

    PubMed Central

    Bernard, E. C.; Jennings, P. L.

    1997-01-01

    The ability of Meloidogyne trifoliophila to gall 230 species and cultivars of plants was determined in a greenhouse. All clovers (Trifolium spp.) were severely galled regardless of species or cultivar. Most soybean cultivars were moderately to severely galled. Among other legumes, broad bean, garden pea, Korean lespedeza, sweetclover, and common vetch were good hosts, but alfalfa, bird's-foot trefoil, peanut, and pole bean were poor or nonhosts. Among other plant families, most Apiaceae (Umbelliferae) and Brassicaceae (Cruciferae) were galled, but Cucurbitaceae, Iridaceae, Malvaceae, Poaceae, and Solanaceae were rarely or never galled. Results for Amaryllidaceae, Asteraceae, Lamiaceae, and Liliaceae were variable. This nematode was not found in a survey of pasture and soybean fields in southwestern Tennessee. PMID:19274266

  9. A Multivalent Adsorption Apparatus Explains the Broad Host Range of Phage phi92: a Comprehensive Genomic and Structural Analysis

    PubMed Central

    Buettner, Falk F. R.; Browning, Christopher; Nazarov, Sergey; Rabsch, Wolfgang; Bethe, Andrea; Oberbeck, Astrid; Bowman, Valorie D.; Stummeyer, Katharina; Mühlenhoff, Martina; Gerardy-Schahn, Rita

    2012-01-01

    Bacteriophage phi92 is a large, lytic myovirus isolated in 1983 from pathogenic Escherichia coli strains that carry a polysialic acid capsule. Here we report the genome organization of phi92, the cryoelectron microscopy reconstruction of its virion, and the reinvestigation of its host specificity. The genome consists of a linear, double-stranded 148,612-bp DNA sequence containing 248 potential open reading frames and 11 putative tRNA genes. Orthologs were found for 130 of the predicted proteins. Most of the virion proteins showed significant sequence similarities to proteins of myoviruses rv5 and PVP-SE1, indicating that phi92 is a new member of the novel genus of rv5-like phages. Reinvestigation of phi92 host specificity showed that the host range is not limited to polysialic acid-encapsulated Escherichia coli but includes most laboratory strains of Escherichia coli and many Salmonella strains. Structure analysis of the phi92 virion demonstrated the presence of four different types of tail fibers and/or tailspikes, which enable the phage to use attachment sites on encapsulated and nonencapsulated bacteria. With this report, we provide the first detailed description of a multivalent, multispecies phage armed with a host cell adsorption apparatus resembling a nanosized Swiss army knife. The genome, structure, and, in particular, the organization of the baseplate of phi92 demonstrate how a bacteriophage can evolve into a multi-pathogen-killing agent. PMID:22787233

  10. A wide host-range metagenomic library from a waste water treatment plant yields a novel alcohol/aldehyde dehydrogenase.

    PubMed

    Wexler, Margaret; Bond, Philip L; Richardson, David J; Johnston, Andrew W B

    2005-12-01

    Using DNA obtained from the metagenome of an anaerobic digestor in a waste water treatment plant, we constructed a gene library cloned in the wide host-range cosmid pLAFR3. One cosmid enabled Rhizobium leguminosarum to grow on ethanol as sole carbon and energy source, this being due to the presence of a gene, termed adhEMeta. The AdhEMeta protein most closely resembles the AdhE alcohol dehydrogenase of Clostridium acetobutylicum, where it catalyses the formation of ethanol and butanol in a two-step reductive process. However, cloned adhEMeta did not confer ethanol utilization ability to Escherichia coli or to Pseudomonas aeruginosa, even though it was transcribed in both these hosts. Further, cell-free extracts of E. coli and R. leguminosarum containing cloned adhEMeta had butanol and ethanol dehydrogenase activities when assayed in vitro. In contrast to the well-studied AdhE proteins of C. acetobutylicum and E. coli, the enzyme specified by adhEMeta is not inactivated by oxygen and it enables alcohol to be catabolized. Cloned adhEMeta did, however, confer one phenotype to E. coli. AdhE- mutants of E. coli fail to ferment glucose and introduction of adhEMeta restored the growth of such mutants when grown under fermentative conditions. These observations show that the use of wide host-range vectors enhances the efficacy with which metagenomic libraries can be screened for genes that confer novel functions.

  11. Host Range Restriction of Insect-Specific Flaviviruses Occurs at Several Levels of the Viral Life Cycle.

    PubMed

    Junglen, Sandra; Korries, Marvin; Grasse, Wolfgang; Wieseler, Janett; Kopp, Anne; Hermanns, Kyra; León-Juárez, Moises; Drosten, Christian; Kümmerer, Beate Mareike

    2017-01-01

    The genus Flavivirus contains emerging arthropod-borne viruses (arboviruses) infecting vertebrates, as well as insect-specific viruses (ISVs) (i.e., viruses whose host range is restricted to insects). ISVs are evolutionary precursors to arboviruses. Knowledge of the nature of the ISV infection block in vertebrates could identify functions necessary for the expansion of the host range toward vertebrates. Mapping of host restrictions by complementation of ISV and arbovirus genome functions could generate knowledge critical to predicting arbovirus emergence. Here we isolated a novel flavivirus, termed Niénokoué virus (NIEV), from mosquitoes sampled in Côte d'Ivoire. NIEV groups with insect-specific flaviviruses (ISFs) in phylogeny and grows in insect cells but not in vertebrate cells. We generated an infectious NIEV cDNA clone and a NIEV reporter replicon to study growth restrictions of NIEV in comparison to yellow fever virus (YFV), for which the same tools are available. Efficient RNA replication of the NIEV reporter replicon was observed in insect cells but not in vertebrate cells. Initial translation of the input replicon RNA in vertebrate cells was functional, but RNA replication did not occur. Chimeric YFV carrying the envelope proteins of NIEV was recovered via electroporation in C6/36 insect cells but did not infect vertebrate cells, indicating a block at the level of entry. Since the YF/NIEV chimera readily produced infectious particles in insect cells but not in vertebrate cells despite efficient RNA replication, restriction is also determined at the level of assembly/release. Taking the results together, the ability of ISF to infect vertebrates is blocked at several levels, including attachment/entry and RNA replication as well as assembly/release. IMPORTANCE Most viruses of the genus Flavivirus, e.g., YFV and dengue virus, are mosquito borne and transmitted to vertebrates during blood feeding of mosquitoes. Within the last decade, an increasing number

  12. Host Range Restriction of Insect-Specific Flaviviruses Occurs at Several Levels of the Viral Life Cycle

    PubMed Central

    Junglen, Sandra; Korries, Marvin; Grasse, Wolfgang; Wieseler, Janett; Kopp, Anne; Hermanns, Kyra; León-Juárez, Moises; Drosten, Christian

    2017-01-01

    ABSTRACT The genus Flavivirus contains emerging arthropod-borne viruses (arboviruses) infecting vertebrates, as well as insect-specific viruses (ISVs) (i.e., viruses whose host range is restricted to insects). ISVs are evolutionary precursors to arboviruses. Knowledge of the nature of the ISV infection block in vertebrates could identify functions necessary for the expansion of the host range toward vertebrates. Mapping of host restrictions by complementation of ISV and arbovirus genome functions could generate knowledge critical to predicting arbovirus emergence. Here we isolated a novel flavivirus, termed Niénokoué virus (NIEV), from mosquitoes sampled in Côte d’Ivoire. NIEV groups with insect-specific flaviviruses (ISFs) in phylogeny and grows in insect cells but not in vertebrate cells. We generated an infectious NIEV cDNA clone and a NIEV reporter replicon to study growth restrictions of NIEV in comparison to yellow fever virus (YFV), for which the same tools are available. Efficient RNA replication of the NIEV reporter replicon was observed in insect cells but not in vertebrate cells. Initial translation of the input replicon RNA in vertebrate cells was functional, but RNA replication did not occur. Chimeric YFV carrying the envelope proteins of NIEV was recovered via electroporation in C6/36 insect cells but did not infect vertebrate cells, indicating a block at the level of entry. Since the YF/NIEV chimera readily produced infectious particles in insect cells but not in vertebrate cells despite efficient RNA replication, restriction is also determined at the level of assembly/release. Taking the results together, the ability of ISF to infect vertebrates is blocked at several levels, including attachment/entry and RNA replication as well as assembly/release. IMPORTANCE Most viruses of the genus Flavivirus, e.g., YFV and dengue virus, are mosquito borne and transmitted to vertebrates during blood feeding of mosquitoes. Within the last decade, an

  13. Biology and preliminary host range assessment of two potential kudzu biological control agents.

    PubMed

    Frye, Matthew J; Hough-Goldstein, Judith; Sun, Jiang-Hua

    2007-12-01

    Two insect species from China, Gonioctena tredecimmaculata (Jacoby) (Coleoptera: Chrysomelidae) and Ornatalcides (Mesalcidodes) trifidus (Pascoe) (Coleoptera: Curculionidae), were studied in quarantine in the United States as potential biological control agents for kudzu, Pueraria montana variety lobata (Willd.) Maesen and S. Almeida. Adults of G. tredecimmaculata were ovoviviparous and reproduced throughout the summer, producing offspring that had an obligate adult diapause. In no-choice tests, adult and larval G. tredecimmaculata rejected most of the plant species tested, but consumed foliage and completed their life cycle on soybean (Glycine max L. Merr.) and on a native woodland plant, hog-peanut (Amphicarpaea bracteata L. Fernald), which are in the same subtribe as kudzu (Glycininae). Insects showed similar responses to field- and greenhouse-grown soybean and kudzu foliage, despite measurable differences in leaf traits: field-grown foliage of both plants had greater leaf toughness, higher total carbon content, higher trichome density, and lower water content than greenhouse foliage. O. trifidus adults also rejected most of the plants tested but fed on and severely damaged potted soybean and hog-peanut plants in addition to kudzu. Further tests in China are needed to determine whether these species will accept nontarget host plants under open-field conditions.

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

    PubMed

    Stenger, Brianna L S; Clark, Mark E; Kváč, Martin; Khan, Eakalak; Giddings, Catherine W; Prediger, Jitka; McEvoy, John M

    2015-12-01

    Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American tree squirrels and ground squirrels host zoonotic Cryptosporidium species and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three tree squirrel and three ground squirrel species. In tree squirrels, Cryptosporidium was identified in 40.5% (17/42) of American red squirrels (Tamiasciurus hudsonicus), 40.4% (55/136) of eastern gray squirrels (Sciurus carolinensis), and 28.6% (2/7) of fox squirrels (Sciurus niger). Human-pathogenic Cryptosporidium ubiquitum and Cryptosporidium skunk genotype were the most prevalent species/genotypes in tree squirrels. Because tree squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium species/genotypes, they may be a significant reservoir of infection in humans. In ground squirrels, Cryptosporidium was detected in 70.2% (33/47) of 13-lined ground squirrels (Ictidomys tridecemlineatus), 35.1% (27/77) of black-tailed prairie dogs (Cynomys ludovicianus), and the only golden-mantled ground squirrel (Callospermophilus lateralis) that was sampled. Cryptosporidium rubeyi and ground squirrel genotypes I, II, and III were identified in isolates from these ground squirrel species. In contrast to the Cryptosporidium infecting tree squirrels, these species/genotypes appear to be specific for ground squirrels and are not associated with human disease.

  15. All five host-range variants of Xanthomonas citri carry one pthA homolog with 17.5 repeats that determines pathogenicity on citrus, but none determine host-range variation.

    PubMed

    Al-Saadi, Abdulwahid; Reddy, Joseph D; Duan, Yong P; Brunings, Asha M; Yuan, Qiaoping; Gabriel, Dean W

    2007-08-01

    Citrus canker disease is caused by five groups of Xanthomonas citri strains that are distinguished primarily by host range: three from Asia (A, A*, and A(w)) and two that form a phylogenetically distinct clade and originated in South America (B and C). Every X. citri strain carries multiple DNA fragments that hybridize with pthA, which is essential for the pathogenicity of wide-host-range X. citri group A strain 3213. DNA fragments that hybridized with pthA were cloned from a representative strain from all five groups. Each strain carried one and only one pthA homolog that functionally complemented a knockout mutation of pthA in 3213. Every complementing homolog was of identical size to pthA and carried 17.5 nearly identical, direct tandem repeats, including three new genes from narrow-host-range groups C (pthC), A(w) (pthAW), and A* (pthA*). Every noncomplementing paralog was of a different size; one of these was sequenced from group A* (pthA*-2) and was found to have an intact promoter and full-length reading frame but with 15.5 repeats. None of the complementing homologs nor any of the noncomplementing paralogs conferred avirulence to 3213 on grapefruit or suppressed avirulence of a group A* strain on grapefruit. A knockout mutation of pthC in a group C strain resulted in loss of pathogenicity on lime, but the strain was unaffected in ability to elicit an HR on grapefruit. This pthC- mutant was fully complemented by pthA, pthB, or pthC. Analysis of the predicted amino-acid sequences of all functional pthA homologs and nonfunctional paralogs indicated that the specific sequence of the 17th repeat may be essential for pathogenicity of X. citri on citrus.

  16. Diversity of lepidopteran stem borers on monocotyledonous plants in eastern Africa and the islands of Madagascar and Zanzibar revisited.

    PubMed

    Le Ru, B P; Ong'amo, G O; Moyal, P; Ngala, L; Musyoka, B; Abdullah, Z; Cugala, D; Defabachew, B; Haile, T A; Matama, T Kauma; Lada, V Y; Negassi, B; Pallangyo, K; Ravolonandrianina, J; Sidumo, A; Omwega, C O; Schulthess, F; Calatayud, P A; Silvain, J F

    2006-12-01

    Surveys were completed in Eritrea, Ethiopia, Kenya, Madagascar, Mozambique, Tanzania, Uganda and Zanzibar to assess the lepidopteran stem borer species diversity on wild host plants. A total of 24,674 larvae belonging to 135 species were collected from 75 species of wild host plants belonging to the Poaceae, Cyperaceae and Typhaceae. Amongst them were 44 noctuid species belonging to at least nine genera, 33 crambids, 15 pyralids, 16 Pyraloidea species not yet identified, 25 tortricids and three cossids. The noctuid larvae represented 73.6% of the total number of larvae collected, with 66.3, 3.5 and 3.8% found on Poaceae, Cyperaceae and Typhaceae, respectively. The Crambidae, Pyralidae, Tortricidae and Cossidae represented 19.8, 1.9, 2.5 and 0.1% of the total larvae collected, respectively, with 90.4% of the Crambidae and Pyralidae collected from Poaceae, and 99.7% of the Tortricidae collected from Cyperaceae. The lepidopteran stem borer species diversity in the wild host plants was far more diverse than previously reported.

  17. Dead-end hollow-fiber ultrafiltration for concentration and enumeration of Escherichia coli and broad-host-range plasmid DNA from wastewater

    PubMed Central

    Asfahl, Kyle L.; Savin, Mary C.

    2012-01-01

    Broad-host-range plasmids can facilitate dissemination of antibiotic resistance determinants among diverse bacterial populations. We evaluated hollow-fiber ultrafiltration for increases in detection efficiency of broad-host-range plasmids and Escherichia coli DNA in wastewater. Ultrafiltration followed by PCR showed limited increases in DNA detection and quantification in effluent compared with membrane filtration alone. PMID:22251424

  18. Broad-Host-Range Plasmids from Agricultural Soils Have IncP-1 Backbones with Diverse Accessory Genes▿

    PubMed Central

    Sen, Diya; Van der Auwera, Geraldine A.; Rogers, Linda M.; Thomas, Christopher M.; Brown, Celeste J.; Top, Eva M.

    2011-01-01

    Broad-host-range plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to antibiotics and heavy metals or degradation of pollutants. Although some broad-host-range plasmids have been extensively studied, their evolutionary history and genetic diversity remain largely unknown. The goal of this study was to analyze and compare the genomes of 12 broad-host-range plasmids that were previously isolated from Norwegian soils by exogenous plasmid isolation and that encode mercury resistance. Complete nucleotide sequencing followed by phylogenetic analyses based on the relaxase gene traI showed that all the plasmids belong to one of two subgroups (β and ε) of the well-studied incompatibility group IncP-1. A diverse array of accessory genes was found to be involved in resistance to antimicrobials (streptomycin, spectinomycin, and sulfonamides), degradation of herbicides (2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenoxypropionic acid), and a putative new catabolic pathway. Intramolecular transposition of insertion sequences followed by deletion was found to contribute to the diversity of some of these plasmids. The previous observation that the insertion sites of a Tn501-related element are identical in four IncP-1β plasmids (pJP4, pB10, R906, and R772) was further extended to three more IncP-1β plasmids (pAKD15, pAKD18, and pAKD29). We proposed a hypothesis for the evolution of these Tn501-bearing IncP-1β plasmids that predicts recent diversification followed by worldwide spread. Our study increases the available collection of complete IncP-1 plasmid genome sequences by 50% and will aid future studies to enhance our understanding of the evolution and function of this important plasmid family. PMID:21948829

  19. Characterization of Extended-Host-Range Pseudo-T-Even Bacteriophage Kpp95 Isolated on Klebsiella pneumoniae▿

    PubMed Central

    Wu, Lii-Tzu; Chang, Shu-Ying; Yen, Ming-Ren; Yang, Tsuey-Ching; Tseng, Yi-Hsiung

    2007-01-01

    Kpp95, isolated on Klebsiella pneumoniae, is a bacteriophage with the morphology of T4-type phages and is capable of rapid lysis of host cells. Its double-stranded genomic DNA (ca. 175 kb, estimated by pulsed-field gel electrophoresis) can be cut only by restriction endonucleases with a cleavage site flanked either by A and T or by T, as tested, suggesting that it contains the modified derivative(s) of G and/or C. Over 26 protein bands were visualized upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the virion proteins. N-terminal sequencing indicated that the most abundant band (46 kDa) is the major coat protein (gp23) which has been cleaved from a signal peptide likely with a length similar to that of T4. Phylogenetic analyses based on the sequences of the central region (263 amino acid residues) of gp23 and the full length of gp18 and gp19 placed Kpp95 among the pseudo-T-even subgroup, most closely related to the coliphage JS98. In addition to being able to lyse many extended-spectrum β-lactamase strains of K. pneumoniae, Kpp95 can lyse Klebsiella oxytoca, Enterobacter agglomerans, and Serratia marcescens cells. Thus, Kpp95 deserves further studies for development as a component of a therapeutic cocktail, owing to its high efficiencies of host lysis plus extended host range. PMID:17337566

  20. Multilocus sequence analysis of Anaplasma phagocytophilum reveals three distinct lineages with different host ranges in clinically ill French cattle.

    PubMed

    Chastagner, Amélie; Dugat, Thibaud; Vourc'h, Gwenaël; Verheyden, Hélène; Legrand, Loïc; Bachy, Véronique; Chabanne, Luc; Joncour, Guy; Maillard, Renaud; Boulouis, Henri-Jean; Haddad, Nadia; Bailly, Xavier; Leblond, Agnès

    2014-12-09

    Molecular epidemiology represents a powerful approach to elucidate the complex epidemiological cycles of multi-host pathogens, such as Anaplasma phagocytophilum. A. phagocytophilum is a tick-borne bacterium that affects a wide range of wild and domesticated animals. Here, we characterized its genetic diversity in populations of French cattle; we then compared the observed genotypes with those found in horses, dogs, and roe deer to determine whether genotypes of A. phagocytophilum are shared among different hosts. We sampled 120 domesticated animals (104 cattle, 13 horses, and 3 dogs) and 40 wild animals (roe deer) and used multilocus sequence analysis on nine loci (ankA, msp4, groESL, typA, pled, gyrA, recG, polA, and an intergenic region) to characterize the genotypes of A. phagocytophilum present. Phylogenic analysis revealed three genetic clusters of bacterial variants in domesticated animals. The two principal clusters included 98% of the bacterial genotypes found in cattle, which were only distantly related to those in roe deer. One cluster comprised only cattle genotypes, while the second contained genotypes from cattle, horses, and dogs. The third contained all roe deer genotypes and three cattle genotypes. Geographical factors could not explain this clustering pattern. These results suggest that roe deer do not contribute to the spread of A. phagocytophilum in cattle in France. Further studies should explore if these different clusters are associated with differing disease severity in domesticated hosts. Additionally, it remains to be seen if the three clusters of A. phagocytophilum genotypes in cattle correspond to distinct epidemiological cycles, potentially involving different reservoir hosts.

  1. Randomly Amplified Polymorphic DNA Differs with Burrowing Nematode Collection Site, but not with Host Range.

    PubMed

    Marin, D H; Kaplan, D T; Opperman, C H

    1999-06-01

    The genetic variability of 12 burrowing nematode (Radopholus sp.) isolates from Central America, the Caribbean, and Florida, and one isolate from Ivory Coast were compared with RAPD analysis. A high degree of genetic similarity (>0.82) was determined for isolates from the Western Hemisphere. Genome similarity was greatest among isolates collected within a country. Among isolates collected in Central America and the Caribbean, burrowing nematodes from Belize and Guatemala were genetically more distant. However, the genome of the isolate from Ivory Coast was most dissimilar (>0.30). These results suggest that African and American burrowing-nematode isolates may have had different origins or that they have been geographically isolated for a sufficient amount of time to have accumulated genetic changes detectable by RAPD analysis. No relationship was found between the genomic similarity and extent of reproduction or damage to banana or citrus roots. Morphometric analysis involving eight of the isolates indicated that they were morphologically identical and values for morphometric parameters were well within the range previously published for banana and citrusparasitic burrowing nematodes.

  2. Free-ranging Eurasian lynx (Lynx lynx) as host of Toxoplasma gondii in Finland.

    PubMed

    Jokelainen, Pikka; Deksne, Gunita; Holmala, Katja; Näreaho, Anu; Laakkonen, Juha; Kojola, Ilpo; Sukura, Antti

    2013-07-01

    We investigated the presence of Toxoplasma gondii infections in Eurasian lynx (Lynx lynx) in Finland by analyzing samples from 337 lynx that were legally hunted during the 2010-2011 season and by performing a retrospective nationwide database search of postmortem toxoplasmosis diagnoses in this species. We detected specific anti-T. gondii IgG antibodies in 290 (86.1%) of the 337 lynx. The method used was a direct agglutination test, and samples positive at the used dilution 1:40 were defined as antibody positive. Older lynx had 14.3 times higher odds of being antibody-positive than did lynx of the presumed age of 7-10 mo, and lynx weighing >15 kg had 16.7 times higher odds of being antibody positive than did those ≤ 15 kg. Lynx from the southwest were more often antibody positive, with an odds ratio 6.3, than lynx from the northeast. None of the 332 fecal samples available was positive for the presence of T. gondii-like oocysts with a quantitative MgSO4 flotation technique, and none of the 167 free-ranging Eurasian lynx examined postmortem by veterinary pathologists from January 2000 to May 2010 had died from toxoplasmosis. Although Finnish lynx were confirmed to commonly encounter T. gondii, we found no evidence of an ongoing contribution to the environmental oocyst burden nor of the lynx dying from the infection.

  3. Complete Genome Sequence of the Broad-Host-Range Vibriophage KVP40: Comparative Genomics of a T4-Related Bacteriophage

    PubMed Central

    Miller, Eric S.; Heidelberg, John F.; Eisen, Jonathan A.; Nelson, William C.; Durkin, A. Scott; Ciecko, Ann; Feldblyum, Tamara V.; White, Owen; Paulsen, Ian T.; Nierman, William C.; Lee, Jong; Szczypinski, Bridget; Fraser, Claire M.

    2003-01-01

    The complete genome sequence of the T4-like, broad-host-range vibriophage KVP40 has been determined. The genome sequence is 244,835 bp, with an overall G+C content of 42.6%. It encodes 386 putative protein-encoding open reading frames (CDSs), 30 tRNAs, 33 T4-like late promoters, and 57 potential rho-independent terminators. Overall, 92.1% of the KVP40 genome is coding, with an average CDS size of 587 bp. While 65% of the CDSs were unique to KVP40 and had no known function, the genome sequence and organization show specific regions of extensive conservation with phage T4. At least 99 KVP40 CDSs have homologs in the T4 genome (Blast alignments of 45 to 68% amino acid similarity). The shared CDSs represent 36% of all T4 CDSs but only 26% of those from KVP40. There is extensive representation of the DNA replication, recombination, and repair enzymes as well as the viral capsid and tail structural genes. KVP40 lacks several T4 enzymes involved in host DNA degradation, appears not to synthesize the modified cytosine (hydroxymethyl glucose) present in T-even phages, and lacks group I introns. KVP40 likely utilizes the T4-type sigma-55 late transcription apparatus, but features of early- or middle-mode transcription were not identified. There are 26 CDSs that have no viral homolog, and many did not necessarily originate from Vibrio spp., suggesting an even broader host range for KVP40. From these latter CDSs, an NAD salvage pathway was inferred that appears to be unique among bacteriophages. Features of the KVP40 genome that distinguish it from T4 are presented, as well as those, such as the replication and virion gene clusters, that are substantially conserved. PMID:12923095

  4. Adaptation of Chimeric Retroviruses In Vitro and In Vivo: Isolation of Avian Retroviral Vectors with Extended Host Range

    PubMed Central

    Barsov, Eugene V.; Payne, William S.; Hughes, Stephen H.

    2001-01-01

    We have designed and characterized two new replication-competent avian sarcoma/leukosis virus-based retroviral vectors with amphotropic and ecotropic host ranges. The amphotropic vector RCASBP-M2C(797-8), was obtained by passaging the chimeric retroviral vector RCASBP-M2C(4070A) (6) in chicken embryos. The ecotropic vector, RCASBP(Eco), was created by replacing the env-coding region in the retroviral vector RCASBP(A) with the env region from an ecotropic murine leukemia virus. It replicates efficiently in avian DFJ8 cells that express murine ecotropic receptor. For both vectors, permanent cell lines that produce viral stocks with titers of about 5 × 106 CFU/ml on mammalian cells can be easily established by passaging transfected avian cells. Some chimeric viruses, for example, RCASBP(Eco), replicate efficiently without modifications. For those chimeric viruses that do require modification, adaptation by passage in vitro or in vivo is a general strategy. This strategy has been used to prepare vectors with altered host range and could potentially be used to develop vectors that would be useful for targeted gene delivery. PMID:11333876

  5. Adaptation of chimeric retroviruses in vitro and in vivo: isolation of avian retroviral vectors with extended host range.

    PubMed

    Barsov, E V; Payne, W S; Hughes, S H

    2001-06-01

    We have designed and characterized two new replication-competent avian sarcoma/leukosis virus-based retroviral vectors with amphotropic and ecotropic host ranges. The amphotropic vector RCASBP-M2C(797-8), was obtained by passaging the chimeric retroviral vector RCASBP-M2C(4070A) (6) in chicken embryos. The ecotropic vector, RCASBP(Eco), was created by replacing the env-coding region in the retroviral vector RCASBP(A) with the env region from an ecotropic murine leukemia virus. It replicates efficiently in avian DFJ8 cells that express murine ecotropic receptor. For both vectors, permanent cell lines that produce viral stocks with titers of about 5 x 10(6) CFU/ml on mammalian cells can be easily established by passaging transfected avian cells. Some chimeric viruses, for example, RCASBP(Eco), replicate efficiently without modifications. For those chimeric viruses that do require modification, adaptation by passage in vitro or in vivo is a general strategy. This strategy has been used to prepare vectors with altered host range and could potentially be used to develop vectors that would be useful for targeted gene delivery.

  6. Emerging Trends in Molecular Interactions between Plants and the Broad Host Range Fungal Pathogens Botrytis cinerea and Sclerotinia sclerotiorum

    PubMed Central

    Mbengue, Malick; Navaud, Olivier; Peyraud, Rémi; Barascud, Marielle; Badet, Thomas; Vincent, Rémy; Barbacci, Adelin; Raffaele, Sylvain

    2016-01-01

    Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum, the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi. PMID:27066056

  7. Phenolic Compounds and Their Fates In Tropical Lepidopteran Larvae: Modifications In Alkaline Conditions.

    PubMed

    Vihakas, Matti; Gómez, Isrrael; Karonen, Maarit; Tähtinen, Petri; Sääksjärvi, Ilari; Salminen, Juha-Pekka

    2015-09-01

    Lepidopteran larvae encounter a variety of phenolic compounds while consuming their host plants. Some phenolics may oxidize under alkaline conditions prevailing in the larval guts, and the oxidation products may cause oxidative stress to the larvae. In this study, we aimed to find new ways to predict how phenolic compounds may be modified in the guts of herbivorous larvae. To do so, we studied the ease of oxidation of phenolic compounds from 12 tropical tree species. The leaf extracts were incubated in vitro in alkaline conditions, and the loss of total phenolics during incubation was used to estimate the oxidizability of extracts. The phenolic profiles of the leaf extracts before and after incubation were compared, revealing that some phenolic compounds were depleted during incubation. The leaves of the 12 tree species were each fed to 12 species of lepidopteran larvae that naturally feed on these trees. The phenolic profiles of larval frass were compared to those of in vitro incubated leaf extracts. These comparisons showed that the phenolic profiles of alkali-treated samples and frass samples were similar in many cases. This suggested that certain phenolics, such as ellagitannins, proanthocyanidins, and galloylquinic acid derivatives were modified by the alkaline pH of the larval gut. In other cases, the chromatographic profiles of frass and in vitro incubated leaf extracts were not similar, and new modifications of phenolics were detected in the frass. We conclude that the actual fates of phenolics in vivo are often more complicated than can be predicted by a simple in vitro method.

  8. An interaction domain in human SAMD9 is essential for myxoma virus host-range determinant M062 antagonism of host anti-viral function.

    PubMed

    Nounamo, Bernice; Li, Yibo; O'Byrne, Peter; Kearney, Aoife M; Khan, Amir; Liu, Jia

    2017-03-01

    In humans, deleterious mutations in the sterile α motif domain protein 9 (SAMD9) gene are associated with cancer, inflammation, weakening of the immune response, and developmental arrest. However, the biological function of SAMD9 and its sequence-structure relationships remain to be characterized. Previously, we found that an essential host range factor, M062 protein from myxoma virus (MYXV), antagonized the function of human SAMD9. In this study, we examine the interaction between M062 and human SAMD9 to identify regions that are critical to SAMD9 function. We also characterize the in vitro kinetics of the interaction. In an infection assay, exogenous expression of SAMD9 N-terminus leads to a potent inhibition of wild-type MYXV infection. We reason that this effect is due to the sequestration of viral M062 by the exogenously expressed N-terminal SAMD9 region. Our studies reveal the first molecular insight into viral M062-dependent mechanisms that suppress human SAMD9-associated antiviral function.

  9. Genome sequence and analysis of a broad-host range lytic bacteriophage that infects the Bacillus cereus group

    PubMed Central

    2013-01-01

    Background Comparatively little information is available on members of the Myoviridae infecting low G+C content, Gram-positive host bacteria of the family Firmicutes. While numerous Bacillus phages have been isolated up till now only very few Bacillus cereus phages have been characterized in detail. Results Here we present data on the large, virulent, broad-host-range B. cereus phage vB_BceM_Bc431v3 (Bc431v3). Bc431v3 features a 158,618 bp dsDNA genome, encompassing 239 putative open reading frames (ORFs) and, 20 tRNA genes encoding 17 different amino acids. Since pulsed-field gel electrophoresis indicated that the genome of this phage has a mass of 155-158 kb Bc431v3 DNA appears not to contain long terminal repeats that are found in the genome of Bacillus phage SPO1. Conclusions Bc431v3 displays significant sequence similarity, at the protein level, to B. cereus phage BCP78, Listeria phage A511 and Enterococcus phage ØEF24C and other morphologically related phages infecting Firmicutes such as Staphylococcus phage K and Lactobacillus phage LP65. Based on these data we suggest that Bc431v3 should be included as a member of the Spounavirinae; however, because of all the diverse taxonomical information has been addressed recently, it is difficult to determine the genus. The Bc431v3 phage contains some highly unusual genes such as gp143 encoding putative tRNAHis guanylyltransferase. In addition, it carries some genes that appear to be related to the host sporulation regulators. These are: gp098, which encodes a putative segregation protein related to FstK/SpoIIIE DNA transporters; gp105, a putative segregation protein; gp108, RNA polymerase sigma factor F/B; and, gp109 encoding RNA polymerase sigma factor G. PMID:23388049

  10. Discovery of a polyomavirus in European badgers (Meles meles) and the evolution of host range in the family Polyomaviridae.

    PubMed

    Hill, Sarah C; Murphy, Aisling A; Cotten, Matthew; Palser, Anne L; Benson, Phillip; Lesellier, Sandrine; Gormley, Eamonn; Richomme, Céline; Grierson, Sylvia; Bhuachalla, Deirdre Ni; Chambers, Mark; Kellam, Paul; Boschiroli, María-Laura; Ehlers, Bernhard; Jarvis, Michael A; Pybus, Oliver G

    2015-06-01

    Polyomaviruses infect a diverse range of mammalian and avian hosts, and are associated with a variety of symptoms. However, it is unknown whether the viruses are found in all mammalian families and the evolutionary history of the polyomaviruses is still unclear. Here, we report the discovery of a novel polyomavirus in the European badger (Meles meles), which to our knowledge represents the first polyomavirus to be characterized in the family Mustelidae, and within a European carnivoran. Although the virus was discovered serendipitously in the supernatant of a cell culture inoculated with badger material, we subsequently confirmed its presence in wild badgers. The European badger polyomavirus was tentatively named Meles meles polyomavirus 1 (MmelPyV1). The genome is 5187 bp long and encodes proteins typical of polyomaviruses. Phylogenetic analyses including all known polyomavirus genomes consistently group MmelPyV1 with California sea lion polyomavirus 1 across all regions of the genome. Further evolutionary analyses revealed phylogenetic discordance amongst polyomavirus genome regions, possibly arising from evolutionary rate heterogeneity, and a complex association between polyomavirus phylogeny and host taxonomic groups.

  11. Salmonella phages isolated from dairy farms in Thailand show wider host range than a comparable set of phages isolated from U.S. dairy farms.

    PubMed

    Wongsuntornpoj, Sarach; Moreno Switt, Andrea I; Bergholz, Peter; Wiedmann, Martin; Chaturongakul, Soraya

    2014-08-06

    Salmonella is a zoonotic pathogen with globally distributed serovars as well as serovars predominantly found in certain regions; for example, serovar Weltevreden is rarely isolated in the U.S., but is common in Thailand. Relative to our understanding of Salmonella diversity, our understanding of the global diversity of Salmonella phages is limited. We hypothesized that the serovar diversity in a given environment and farming system will affect the Salmonella phage diversity associated with animal hosts. We thus isolated and characterized Salmonella phages from 15 small-scale dairy farms in Thailand and compared the host ranges of the 62 Salmonella phage isolates obtained with host range diversity for 129 phage isolates obtained from dairy farms in the U.S. The 62 phage isolates from Thailand represented genome sizes ranging from 40 to 200 kb and showed lysis of 6-25 of the 26 host strains tested (mean number of strain lysed=19). By comparison, phage isolates previously obtained in a survey of 15 U.S. dairy farms showed a narrow host range (lysis of 1-17; mean number of strains lysed=4); principal coordinate analysis also confirmed U.S. and Thai phages had distinct host lysis profiles. Our data indicate that dairy farms that differ in management practices and are located on different continents can yield phage isolates that differ in their host ranges, providing an avenue for isolation of phages with desirable host range characteristics for commercial applications. Farming systems characterized by coexistence of different animals may facilitate presence of Salmonella phages with wide host ranges.

  12. Construction of broad-host-range cosmid cloning vectors: identification of genes necessary for growth of Methylobacterium organophilum on methanol

    SciTech Connect

    Allen, L.N.; Hanson, R.S.

    1985-03-01

    Four new cloning vectors have been constructed from the broad-host-range cloning vector pRK290. These vectors, pLA2901, pLA2905, pLA2910, and pLA2917, confer resistance to kanamycin and tetracycline. The latter two are cosmid derivatives of pLA2901. The new vectors can be mobilized into, and are stably maintained in, a variety of gram-negative bacteria. A Sau3A genomic bank of Methylobacterium organophilum strain xx DNA has been constructed in pLA2917, and complementation analysis, with a variety of mutants unable to grow on methanol, revealed at least five separate regions necessary for growth on methanol. Complementation analysis and Tn5 mutagenesis data suggest that at least three genes are responsible for expression of active methanol dehydrogenase.

  13. Update on monitoring of resistance to Bt cotton in key lepidopteran pests in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers sprayed more Bollgard II to control target lepidopteran pests in 2010 than in previous years, and therefore concerns have been expressed that the susceptibility of the target lepidopteran pests to the Bt Cry1Ac and Cry2Ab proteins in Bollgard II has significantly decreased. However, resist...

  14. Heterologous expression of Paranosema (Antonospora) locustae hexokinase in lepidopteran, Sf9, cells is followed by accumulation of the microsporidian protein in insect cell nuclei.

    PubMed

    Timofeev, Sergey A; Senderskiy, Igor V; Tsarev, Alexander A; Tokarev, Yuri S; Dolgikh, Viacheslav V

    2017-02-01

    Paranosema (Nosema, Antonospora) locustae is the only microsporidium produced as a commercial product for biological control. Molecular mechanisms of the effects of this pathogen and other invertebrate microsporidia on host cells remain uncharacterized. Previously, we immunolocalized P. locustae hexokinase in nuclei of Locusta migratoria infected adipocytes. Here, the microsporidian protein was expressed in the yeast Pichia pastoris and in lepidopteran Sf9 cells. During heterologous expression, P. locustae hexokinase was accumulated in the nuclei of insect cells but not in yeast cell nuclei. This confirms nuclear localization of hexokinase secreted by microsporidia into infected host cells and suggests convenient model for its further study.

  15. Host ranges of gregarious muscoid fly parasitoids: Muscidifurax raptorellus (Hymenoptera: Pteromalidae), Tachinaephagus zealandicus (Hymenoptera: Encyrtidae), and Trichopria nigra (Hymenoptera: Diapriidae).

    PubMed

    Geden, Christopher J; Moon, Roger D

    2009-06-01

    Attack rates, progeny production, sex ratios, and host utilization efficiency of Muscidifurax raptorellus (Kogan and Legner) (Hymenoptera: Pteromalidae), Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae), and Trichopria nigra (Nees) (Hymenoptera: Diapriidae) were evaluated in laboratory bioassays with five dipteran hosts: house fly (Musca domestica L.), stable fly (Stomoxys calcitrans L.), horn fly (Hematobia irritans L.), black dump fly [Hydrotaea aenescens (Weidemann)] (Diptera: Muscidae), and a flesh fly (Sarcophaga bullata Parker) (Diptera: Sarcophagidae). M. raptorellus killed and successfully parasitized all five host species and produced an average 2.6 parasitoid progeny from each host. Host attack rates were highest on stable fly and lowest on horn fly; there were no differences among hosts in the total number of progeny produced. T. zealandicus killed larvae of all fly host species in similar numbers, but parasitism was most successful on H. aenescens and S. bullata and least successful on horn fly and house fly hosts. Significantly more parasitoid progeny emerged from S. bullata (10.2 parasitoids per host) than the other hosts; only 2.5 progeny were produced from parasitized horn fly hosts. Most of the killed puparia that produced neither adult flies nor parasitoids ("duds") contained dead parasitoids; in house fly, stable fly, and horn fly hosts, >30% of these dudded pupae contained adult wasps that failed to eclose. T. nigra successfully parasitized pupae of all host species except house fly and was most successful on stable fly. Significantly more parasitoid progeny emerged from S. bullata (30.6 parasitoids per host) than the other hosts; only 5.7 progeny were produced from horn fly hosts.

  16. Promoters of the Broad Host Range Plasmid Rk2: Analysis of Transcription (Initiation) in Five Species of Gram-Negative Bacteria

    PubMed Central

    Greener, A.; Lehman, S. M.; Helinski, D. R.

    1992-01-01

    A broad host range cloning vector was constructed, suitable for monitoring promoter activity in diverse Gram-negative bacteria. This vector, derived from plasmid RSF1010, utilized the firefly luciferase gene as the reporter, since the assay for its bioluminescent product is sensitive, and measurements can be made without background from the host. Twelve DNA fragments with promoter activity were obtained from broad host range plasmid RK2 and inserted into the RSF1010 derived vector. The relative luciferase activities were determined for these fragments in five species of Gram-negative bacteria. In addition, four promoters were analyzed by primer extension to locate transcriptional start sites in each host. The results show that several of the promoters vary substantially in relative strengths or utilize different transcriptional start sites in different bacteria. Other promoters exhibited similar activities and identical start sites in the five hosts examined. PMID:1732166

  17. Characterization of an Ancient Lepidopteran Lateral Gene Transfer

    PubMed Central

    Wheeler, David; Redding, Amanda J.; Werren, John H.

    2013-01-01

    Bacteria to eukaryote lateral gene transfers (LGT) are an important potential source of material for the evolution of novel genetic traits. The explosion in the number of newly sequenced genomes provides opportunities to identify and characterize examples of these lateral gene transfer events, and to assess their role in the evolution of new genes. In this paper, we describe an ancient lepidopteran LGT of a glycosyl hydrolase family 31 gene (GH31) from an Enterococcus bacteria. PCR amplification between the LGT and a flanking insect gene confirmed that the GH31 was integrated into the Bombyx mori genome and was not a result of an assembly error. Database searches in combination with degenerate PCR on a panel of 7 lepidopteran families confirmed that the GH31 LGT event occurred deep within the Order approximately 65–145 million years ago. The most basal species in which the LGT was found is Plutella xylostella (superfamily: Yponomeutoidea). Array data from Bombyx mori shows that GH31 is expressed, and low dN/dS ratios indicates the LGT coding sequence is under strong stabilizing selection. These findings provide further support for the proposition that bacterial LGTs are relatively common in insects and likely to be an underappreciated source of adaptive genetic material. PMID:23533610

  18. Host range and cell cycle activation properties of polyomavirus large T-antigen mutants defective in pRB binding

    SciTech Connect

    Freund, R.; Bauer, P.H.; Benjamin, T.L.; Crissman, H.A.; Bradbury, E.M. |

    1994-11-01

    The authors have examined the growth properties of polyomavirus large T-antigen mutants that ar unable to bind pRB, the product of the retinoblastoma tumor suppressor gene. These mutants grow poorly on primary mouse cells yet grow well on NIH 3T3 and other established mouse cell lines. Preinfection of primary baby mouse kidney (BMK) epithelial cells with wild-type simian virus 40 renders these cells permissive to growth of pRB-binding polyomavirus mutants. Conversely, NIH 3T3 cells transfected by and expressing wild-type human pRB become nonpermissive. Primary fibroblasts for mouse embryos that carry a homozygous knockout of the RB gene are permissive, while those from normal littermates are nonpermissive. The host range of polyomavirus pRB-binding mutants is thus determined by expression or lack of expression of functional pRB by the host. These results demonstrate the importance of pRB binding by large T antigen for productive viral infection in primary cells. Failure of pRB-binding mutants to grow well in BMK cells correlates with their failure to induce progression from G{sub 0} or G{sub 1} through the S phase of the cell cycle. Time course studies show delayed synthesis and lower levels of accumulation of large T antigen, viral DNA, and VP1 in mutant compared with wild-type virus-infected BMK cells. These results support a model in which productive infection by polyomavirus in normal mouse cells is tightly coupled to the induction and progression of the cell cycle. 48 refs., 6 figs., 5 tabs.

  19. Genetic structure of Aegilops cylindrica Host in its native range and in the United States of America.

    PubMed

    Gandhi, Harish T; Vales, M Isabel; Mallory-Smith, Carol; Riera-Lizarazu, Oscar

    2009-10-01

    Chloroplast and nuclear microsatellite markers were used to study genetic diversity and genetic structure of Aegilops cylindrica Host collected in its native range and in adventive sites in the USA. Our analysis suggests that Ae. cylindrica, an allotetraploid, arose from multiple hybridizations between Ae. markgrafii (Greuter) Hammer. and Ae. tauschii Coss. presumably along the Fertile Crescent, where the geographic distributions of its diploid progenitors overlap. However, the center of genetic diversity of this species now encompasses a larger area including northern Iraq, eastern Turkey, and Transcaucasia. Although the majority of accessions of Ae. cylindrica (87%) had D-type plastomes derived from Ae. tauschii, accessions with C-type plastomes (13%), derived from Ae. markgrafii, were also observed. This corroborates a previous study suggesting the dimaternal origin of Ae. cylindrica. Model-based and genetic distance-based clustering using both chloroplast and nuclear markers indicated that Ae. tauschii ssp. tauschii contributed one of its D-type plastomes and its D genome to Ae. cylindrica. Analysis of genetic structure using nuclear markers suggested that Ae. cylindrica accessions could be grouped into three subpopulations (arbitrarily named N-K1, N-K2, and N-K3). Members of the N-K1 subpopulation were the most numerous in its native range and members of the N-K2 subpopulation were the most common in the USA. Our analysis also indicated that Ae. cylindrica accessions in the USA were derived from a few founder genotypes. The frequency of Ae. cylindrica accessions with the C-type plastome in the USA (approximately 24%) was substantially higher than in its native range of distribution (approximately 3%) and all C-type Ae. cylindrica in the USA except one belonged to subpopulation N-K2. The high frequency of the C-type plastome in the USA may reflect a favorable nucleo-cytoplasmic combination.

  20. Predicting the host range of Nystalea ebalea: secondary plant chemistry and host selection by a surrogate biological control agent of Schinus terebinthifolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The safety of weed biological control depends upon the selection and utilization of the target weed by the agent while causing minimal harm to non-target species. Selection of weed species by biological control agents is determined by the presence of behavioral cues, generally host secondary plant c...

  1. Production of high-titer helper virus-free retroviral vectors by cocultivation of packaging cells with different host ranges.

    PubMed Central

    Lynch, C M; Miller, A D

    1991-01-01

    The titer of retroviral vectors can be increased by cocultivation of retrovirus packaging cells that produce a vector with packaging cells having a different host range. Multiple rounds of infection occur in such cultures, producing an amplification of vector copy number and titer. Production of a vector with a very high titer of over 10(10) CFU per ml of conditioned medium has been reported, although replication-competent helper virus was also present. Since helper-free virus is a requirement for many applications of retroviral vectors, we repeated this procedure with a modified vector and achieved a 2- to 10-fold amplification of vector titer in the absence of helper virus, up to 2 x 10(7) CFU/ml. We have also repeated these experiments with the same vector and methods described previously or have assayed virus from the high-titer vector-producing cell line reported previously and observed maximum titers of 10(8) CFU/ml, invariably accompanied by helper virus. Thus, while amplification of vector titer in the absence of helper virus is possible, some unexplained difference in the assays for virus titer must account for our inability to obtain the exceptionally high vector titers that were reported previously. PMID:2041097

  2. Coexpression of the simian immunodeficiency virus Env and Rev proteins by a recombinant human adenovirus host range mutant.

    PubMed Central

    Cheng, S M; Lee, S G; Ronchetti-Blume, M; Virk, K P; Mizutani, S; Eichberg, J W; Davis, A; Hung, P P; Hirsch, V M; Chanock, R M

    1992-01-01

    Recombinant human adenoviruses (Ads) that replicate in the intestinal tract offer a novel, yet practical, means of immunoprophylaxis against a wide variety of viral and bacterial pathogens. For some infectious agents such as human immunodeficiency virus (HIV), the potential for residual infectious material in vaccine preparations must be eliminated. Therefore, recombinant human Ads that express noninfectious HIV or other microbial proteins are attractive vaccine candidates. To test such an approach for HIV, we chose an experimental model of AIDS based on simian immunodeficiency virus (SIV) infection of macaques. Our data demonstrate that the SIV Env gene products are expressed in cultured cells after infection with a recombinant Ad containing both SIV env and rev genes. An E3 deletion vector derived from a mutant of human Ad serotype 5 that efficiently replicates in both human and monkey cells was used to bypass the usual host range restriction of Ad infection. In addition, we show that the SIV rev gene is properly spliced from a single SIV subgenomic DNA fragment and that the Rev protein is expressed in recombinant Ad-SIV-infected human as well as monkey cells. The expression of SIV gene products in suitable live Ad vectors provides an excellent system for studying the regulation of SIV gene expression in cultured cells and evaluating the immunogenicity and protective efficacy of SIV proteins in macaques. Images PMID:1404612

  3. Host Range of a Population of Pratylenchus vulnus in Commercial Fruit, Nut, Citrus, and Grape Rootstocks in Spain.

    PubMed

    Pinochet, J; Verdejo, S; Soler, A; Canals, J

    1992-12-01

    In a host-range study carried out under greenhouse conditions, a total of 37 commercial fruit tree, grape, and citrus rootstocks were tested for their reaction to a population of the lesion nematode, Pratylenchus vulnus, in Spain. Twenty-five rootstocks had a Pf/Pi > 1.5. These included almond (Desmayo Rojo, 1143), apple (EM-9, EM-106), avocado (Hass), cherry (Santa Lucia 64, Camil, M x M 14, Masto de Montafiana), grape (41-B, Fercal, Ritcher 110), hazelnut (Pauetet), loquat (Nadal), peach (Montclar, GF-305), pear (OHF-333), pistachio (P. atlantica, P. vera, P. terebinthus), plum (San Julian 655-2, Montizo, Pixy, Myrobalan 605), and walnut (Serf). The peach rootstock Nemaguard and the grape 161-49 had Pf/Pi between 1.0 and 1.5 (slightly higher than inoculation level). All the tested citrus (Alemow, rough lemon, Carrizo citrange, sour orange, Troyer citrange, Citrumelo), plus three grape (SO4, Vitis rupestris, 1103-P), and the olive rootstock Arbequina had a Pf/Pi < 1.0.

  4. Host Range of a Population of Pratylenchus vulnus in Commercial Fruit, Nut, Citrus, and Grape Rootstocks in Spain

    PubMed Central

    Pinochet, J.; Verdejo, S.; Soler, A.; Canals, J.

    1992-01-01

    In a host-range study carried out under greenhouse conditions, a total of 37 commercial fruit tree, grape, and citrus rootstocks were tested for their reaction to a population of the lesion nematode, Pratylenchus vulnus, in Spain. Twenty-five rootstocks had a Pf/Pi > 1.5. These included almond (Desmayo Rojo, 1143), apple (EM-9, EM-106), avocado (Hass), cherry (Santa Lucia 64, Camil, M × M 14, Masto de Montafiana), grape (41-B, Fercal, Ritcher 110), hazelnut (Pauetet), loquat (Nadal), peach (Montclar, GF-305), pear (OHF-333), pistachio (P. atlantica, P. vera, P. terebinthus), plum (San Julian 655-2, Montizo, Pixy, Myrobalan 605), and walnut (Serf). The peach rootstock Nemaguard and the grape 161-49 had Pf/Pi between 1.0 and 1.5 (slightly higher than inoculation level). All the tested citrus (Alemow, rough lemon, Carrizo citrange, sour orange, Troyer citrange, Citrumelo), plus three grape (SO4, Vitis rupestris, 1103-P), and the olive rootstock Arbequina had a Pf/Pi < 1.0. PMID:19283047

  5. A correlation between macronutrient balancing and insect host-plant range: evidence from the specialist caterpillar Spodoptera exempta (Walker).

    PubMed

    Lee, Kwang Pum; Raubenheimer, David; Behmer, Spencer T; Simpson, Stephen J

    2003-12-01

    In an earlier study, we showed that the ingestive responses of the generalist caterpillar Spodoptera littoralis to foods imbalanced in their protein:carbohydrate content is similar to generalist locusts, but differs from that of specialist-feeding locusts. Here we further pursued the comparison by repeating the experiments using a closely related specialist caterpillar, Spodoptera exempta. First, caterpillars were allowed to self-compose a diet of preferred protein:carbohydrate balance by mixing between nutritionally complementary foods. Then, they were confined to one of five imbalanced foods, in which we measured the trade-off between over- and under-ingesting the two nutrients. On complementary foods, the caterpillars actively regulated their protein and carbohydrate intake. In the no-choice experiment, those fed excess-protein foods ingested small surpluses of protein compared with generalist feeders, thus showing a pattern of nutrient balancing similar to that observed in specialist locusts. Utilisation data indicated that ingested excesses and deficits were to some extent offset by differential utilisation. Evidence also showed that post-ingestive responses of the specialist S. exempta were less flexible than those observed in the generalist S. littoralis, a pattern which is again in accordance with comparisons of acridids differing in their host-plant range.

  6. Sensory basis of lepidopteran migration: focus on the monarch butterfly.

    PubMed

    Guerra, Patrick A; Reppert, Steven M

    2015-10-01

    In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compass and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources.

  7. Sensory basis of lepidopteran migration: Focus on the monarch butterfly

    PubMed Central

    Guerra, Patrick A.; Reppert, Steven M.

    2015-01-01

    In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compasses and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. PMID:25625216

  8. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador

    PubMed Central

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C. Miguel; Vallejo, Gustavo A.

    2015-01-01

    Abstract Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(−)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru. PMID:26645579

  9. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador.

    PubMed

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C Miguel; Vallejo, Gustavo A; Grijalva, Mario J

    2015-12-01

    Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(-)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru.

  10. Biology and management of economically important lepidopteran cereal stem borers in Africa.

    PubMed

    Kfir, Rami; Overholt, W A; Khan, Z R; Polaszek, A

    2002-01-01

    Cereals (maize, sorghum, millet, rice) are extremely important crops grown in Africa for human consumption. Of the various insect pests attacking cereal crops in Africa, lepidopteran stem borers are by far the most injurious. All 21 economically important stem borers of cultivated grasses in Africa are indigenous except Chilo partellus, which invaded the continent from India, and C. sacchariphagus, which has recently been found in sugarcane in Mozambique. C. partellus is competitively displacing indigenous stem borers in East and southern Africa. A parasitoid, Cotesia flavipes, was introduced from Pakistan for biological control of C. partellus and caused a 32-55% decrease in stem borer densities. This article is an attempt to summarize the status of knowledge about economically important cereal stem borers in Africa with emphasis on their distribution, pest status and yield losses, diapause, natural enemies, cultural control, host plant resistance, and biological control. Special attention is given to Busseola fusca and C. partellus, the most important pests of maize and grain sorghum.

  11. Engineered Repressible Lethality for Controlling the Pink Bollworm, a Lepidopteran Pest of Cotton

    PubMed Central

    Morrison, Neil I.; Simmons, Gregory S.; Fu, Guoliang; O’Connell, Sinead; Walker, Adam S.; Dafa’alla, Tarig; Walters, Michelle; Claus, John; Tang, Guolei; Jin, Li; Marubbi, Thea; Epton, Matthew J.; Harris, Claire L.; Staten, Robert T.; Miller, Ernest; Miller, Thomas A.; Alphey, Luke

    2012-01-01

    The sterile insect technique (SIT) is an environmentally friendly method of pest control in which insects are mass-produced, irradiated and released to mate with wild counterparts. SIT has been used to control major pest insects including the pink bollworm (Pectinophora gossypiella Saunders), a global pest of cotton. Transgenic technology has the potential to overcome disadvantages associated with the SIT, such as the damaging effects of radiation on released insects. A method called RIDL (Release of Insects carrying a Dominant Lethal) is designed to circumvent the need to irradiate insects before release. Premature death of insects’ progeny can be engineered to provide an equivalent to sterilisation. Moreover, this trait can be suppressed by the provision of a dietary antidote. In the pink bollworm, we generated transformed strains using different DNA constructs, which showed moderate-to-100% engineered mortality. In permissive conditions, this effect was largely suppressed. Survival data on cotton in field cages indicated that field conditions increase the lethal effect. One strain, called OX3402C, showed highly penetrant and highly repressible lethality, and was tested on host plants where its larvae caused minimal damage before death. These results highlight a potentially valuable insecticide-free tool against pink bollworm, and indicate its potential for development in other lepidopteran pests. PMID:23226548

  12. Survivorship of Z-Pheromone Race European Corn Borer (Lepidoptera: Crambidae) on a Range of Host Plants Varying in Defensive Chemistry.

    PubMed

    Fisher, Kelsey E; Mason, Charles E; Flexner, J Lindsey; Hough-Goldstein, Judith; McDonald, John H

    2017-03-03

    The European corn borer, Ostrinia nubilalis (Hübner), was introduced in North America in the early 1900s and became a major pest of corn. After its introduction, it was found on > 200 other plant hosts, but corn remained its primary host. Early life history studies indicated that European corn borer had the potential of a wide host range. For nearly 80 yr before the introduction of Bt corn, the European corn borer was a major pest of corn in North America. This study investigated the growth and survivorship of the Z-pheromone race European corn borer on a range of hosts that vary in defensive chemistries and historic degree of infestation to better understand the current host plant range of Z-pheromone race of O. nubilalis. The plants tested include sweet corn, cry1F Bt field corn, non-Bt corn, cucumber, tomato, and green bean. Experiments were conducted in the growth chamber, greenhouse, and field to determine survival under different conditions. In most cases, results supported the expected outcome, with significantly higher survival on non-Bt corn hosts than the other hosts tested. Neonate larvae fed exclusively on leaves of green bean exhibited intermediate survival, whereas third-instars fed on only leaves of cucumber survived intermediately. Larvae on Bt corn and tomato had comparable low survival rates, overall suggesting that the defensive features of tomato are about as effective as Cry1F Bt corn. Non-Bt corn was found to be the most suitable host plant, overall for European corn borer among those tested.

  13. A method for evaluating the host range of bacteriophages using phages fluorescently labeled with 5-ethynyl-2'-deoxyuridine (EdU).

    PubMed

    Ohno, Sayaka; Okano, Hironori; Tanji, Yasunori; Ohashi, Akiyoshi; Watanabe, Kazuya; Takai, Ken; Imachi, Hiroyuki

    2012-08-01

    The evaluation of bacteriophage (phage) host range is a significant issue in understanding phage and prokaryotic community interactions. However, in conventional methods, such as plaque assay, target host strains must be isolated, although almost all environmental prokaryotes are recalcitrant to cultivation. Here, we introduce a novel phage host range evaluation method using fluorescently labeled phages (the FLP method), which consists of the following four steps: (i) Fluorescently labeled phages are added to a microbial consortium, and host cells are infected and fluorescently labeled. (ii) Fluorescent cells are sorted by fluorescence-activated cell sorting. (iii) 16S rRNA gene sequences retrieved from sorted cells are analyzed, and specific oligonucleotide probes for fluorescence in situ hybridization (FISH) are designed. (iv) Cells labeled with both fluorescently labeled phage and FISH probe are identified as host cells. To verify the feasibility of this method, we used T4 phage and Escherichia coli as a model. We first used nucleic acid stain reagents for phage labeling; however, the reagents also stained non-host cells. Next, we employed the Click-iT EdU (5-ethynyl-2'-deoxyuridine) assay kit from Invitrogen for phage labeling. Using EdU-labeled T4 phage, we could specifically detect E. coli cells in a complex microbial consortium from municipal sewage. We also confirmed that FISH could be applied to the infected E. coli cells. These results suggest that this FLP method using the EdU assay kit is a useful method for evaluating phage host range and may have a potential application for various types of phages, even if their prokaryotic hosts are currently unculturable.

  14. The biology and preliminary host range of Megacopta cribraria (Heteroptera: Plataspidae) and its impact on kudzu growth.

    PubMed

    Zhang, Yanzhuo; Hanula, James L; Horn, Scott

    2012-02-01

    The bean plataspid, Megacopta cribraria (F.), recently was discovered in the United States feeding on kudzu, Pueraria montana Lour. (Merr.) variety lobata (Willd.), an economically important invasive vine. We studied its biology on kudzu and its impact on kudzu growth. We also tested its ability to use other common forest legumes for oviposition and development. Flight intercept traps operated from 17 May 2010 to 31 May 2011 in a kudzu field near Athens, GA showed three peaks of adult flight activity suggesting there are two generations per year on kudzu. Vine samples examined for eggs from April 2010 to April 2011 and June to October 2011 showed two periods of oviposition activity in 2010, which coincided with the peaks in adult activity. In 2011, the second period of oviposition began on or before 24 June and then egg abundance declined gradually thereafter until late August when we recovered <2 eggs/0.5 m of vine. Samples of the five nymphal instars and adults on vines did not show similar trends in abundance. Adults did not lay eggs on the various legume species tested in 2010 in a no-choice test possibly because the cages were too small. In the 2011 field host range experiments conducted in a kudzu field by using 12 legume species, M. cribraria preferentially oviposited on kudzu over soybean, Glycine max Merrill., but they still laid 320 eggs per plant on soybean. Lespedeza hirta (L.) Hornem. and Lespedeza cuneata (Dum. Cours.) G. Don had 122.2 and 108.4 eggs per plant, respectively. Kudzu and soybean were the only species M. cribraria completed development on. Plots protected from M. cribraria feeding by biweekly insecticide applications had 32.8% more kudzu biomass than unprotected plots. Our results show that M. cribraria has a significant impact on kudzu growth and could help suppress this pest weed.

  15. Recent host range expansion of canine distemper virus and variation in its receptor, the signaling lymphocyte activation molecule, in carnivores.

    PubMed

    Ohishi, Kazue; Suzuki, Rintaro; Maeda, Taro; Tsuda, Miwako; Abe, Erika; Yoshida, Takao; Endo, Yasuyuki; Okamura, Maki; Nagamine, Takashi; Yamamoto, Hanae; Ueda, Miya; Maruyama, Tadashi

    2014-07-01

    The signaling lymphocyte activation molecule (SLAM) is a receptor for morbilliviruses. To understand the recent host range expansion of canine distemper virus (CDV) in carnivores, we determined the nucleotide sequences of SLAMs of various carnivores and generated three-dimensional homology SLAM models. Thirty-four amino acid residues were found for the candidates binding to CDV on the interface of the carnivore SLAMs. SLAM of the domestic dog (Canis lupus familiaris) were similar to those of other members of the suborder Caniformia, indicating that the animals in this group have similar sensitivity to dog CDV. However, they were different at nine positions from those of felids. Among the nine residues, four of domestic cat (Felis catus) SLAM (72, 76, 82, and 129) and three of lion (Panthera leo persica) SLAM (72, 82, and 129) were associated with charge alterations, suggesting that the felid interfaces have lower affinities to dog CDV. Only the residue at 76 was different between domestic cat and lion SLAM interfaces. The domestic cat SLAM had threonine at 76, whereas the lion SLAM had arginine, a positively charged residue like that of the dog SLAM. The cat SLAM with threonine is likely to have lower affinity to CDV-H and to confer higher resistance against dog CDV. Thus, the four residues (72, 76, 82, and 129) on carnivore SLAMs are important for the determination of affinity and sensitivity with CDV. Additionally, the CDV-H protein of felid strains had a substitution of histidine for tyrosine at 549 of dog CDV-H and may have higher affinity to lion SLAM. Three-dimensional model construction is a new risk assessment method of morbillivirus infectivity. Because the method is applicable to animals that have no information about virus infection, it is especially useful for morbillivirus risk assessment and wildlife conservation.

  16. In-Silico Determination of Insecticidal Potential of Vip3Aa-Cry1Ac Fusion Protein Against Lepidopteran Targets Using Molecular Docking.

    PubMed

    Ahmad, Aftab; Javed, Muhammad R; Rao, Abdul Q; Khan, Muhammad A U; Ahad, Ammara; Din, Salah Ud; Shahid, Ahmad A; Husnain, Tayyab

    2015-01-01

    Study and research of Bt (Bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac) insecticidal protein and vegetative insecticidal protein (Vip3Aa) have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein. Cry1Ac and Vip3Aa are non-homologous insecticidal proteins possessing receptors against different targets within the midgut of insects. The insecticidal proteins were fused to broaden the insecticidal activity. Molecular docking analysis of the fusion protein against aminopeptidase-N (APN) and cadherin receptors of five Lepidopteran insects (Agrotis ipsilon, Helicoverpa armigera, Pectinophora gossypiella, Spodoptera exigua, and Spodoptera litura) revealed that the Ser290, Ser293, Leu337, Thr340, and Arg437 residues of the fusion protein are involved in the interaction with insect receptors. The Helicoverpa armigera cadherin receptor, however, showed no interaction, which might be due to either loss or burial of interactive residues inside the fusion protein. These findings revealed that the Vip3Aa-Cry1Ac fusion protein has a strong affinity against Lepidopteran insect receptors and hence has a potential to be an efficient broad-range insecticidal protein.

  17. In-Silico Determination of Insecticidal Potential of Vip3Aa-Cry1Ac Fusion Protein Against Lepidopteran Targets Using Molecular Docking

    PubMed Central

    Ahmad, Aftab; Javed, Muhammad R.; Rao, Abdul Q.; Khan, Muhammad A. U.; Ahad, Ammara; Din, Salah ud; Shahid, Ahmad A.; Husnain, Tayyab

    2015-01-01

    Study and research of Bt (Bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac) insecticidal protein and vegetative insecticidal protein (Vip3Aa) have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein. Cry1Ac and Vip3Aa are non-homologous insecticidal proteins possessing receptors against different targets within the midgut of insects. The insecticidal proteins were fused to broaden the insecticidal activity. Molecular docking analysis of the fusion protein against aminopeptidase-N (APN) and cadherin receptors of five Lepidopteran insects (Agrotis ipsilon, Helicoverpa armigera, Pectinophora gossypiella, Spodoptera exigua, and Spodoptera litura) revealed that the Ser290, Ser293, Leu337, Thr340, and Arg437 residues of the fusion protein are involved in the interaction with insect receptors. The Helicoverpa armigera cadherin receptor, however, showed no interaction, which might be due to either loss or burial of interactive residues inside the fusion protein. These findings revealed that the Vip3Aa-Cry1Ac fusion protein has a strong affinity against Lepidopteran insect receptors and hence has a potential to be an efficient broad-range insecticidal protein. PMID:26697037

  18. Bacteriophage module reshuffling results in adaptive host range as exemplified by the baseplate model of listerial phage A118.

    PubMed

    Cambillau, Christian

    2015-10-01

    Each phage infects its specific bacterial host strain through highly specific interactions between the baseplate-associated receptor binding protein (RBP) at the tip of the phage tail and the receptor at the host surface. Baseplates incorporate structural core modules, Dit and Tal, largely conserved among phages, and peripheral modules anchoring the RBPs. Exploiting structural information from the HHpred program and EM data from the Bielmann et al. (2015) paper, a molecular model of the A118 phage baseplate was generated from different building blocks. This model implies the occurrence of baseplate module reshuffling and suggests that listerial phage A118 may have been derived from lactococcal phage TP901-1 through host species exchange. With the increase of available viral module structures, modelling phage baseplates will become easier and more reliant, and will provide insightful information on the nature of the phage host receptor and its mode of recognition.

  19. Myxoma Virus M064 Is a Novel Member of the Poxvirus C7L Superfamily of Host Range Factors That Controls the Kinetics of Myxomatosis in European Rabbits

    PubMed Central

    Liu, Jia; Wennier, Sonia; Moussatche, Nissin; Reinhard, Mary; Condit, Richard

    2012-01-01

    The myxoma virus (MYXV) carries three tandem C7L-like host range genes (M062R, M063R, and M064R). However, despite the fact that the sequences of these three genes are similar, they possess very distinctive functions in vivo. The role of M064 in MYXV pathogenesis was investigated and compared to the roles of M062 and M063. We report that M064 is a virulence factor that contributes to MYXV pathogenesis but lacks the host range properties associated with M062 and M063. PMID:22379095

  20. Myxoma virus M064 is a novel member of the poxvirus C7L superfamily of host range factors that controls the kinetics of myxomatosis in European rabbits.

    PubMed

    Liu, Jia; Wennier, Sonia; Moussatche, Nissin; Reinhard, Mary; Condit, Richard; McFadden, Grant

    2012-05-01

    The myxoma virus (MYXV) carries three tandem C7L-like host range genes (M062R, M063R, and M064R). However, despite the fact that the sequences of these three genes are similar, they possess very distinctive functions in vivo. The role of M064 in MYXV pathogenesis was investigated and compared to the roles of M062 and M063. We report that M064 is a virulence factor that contributes to MYXV pathogenesis but lacks the host range properties associated with M062 and M063.

  1. Tick infestation patterns in free ranging African buffalo (Syncercus caffer): Effects of host innate immunity and niche segregation among tick species☆

    PubMed Central

    Anderson, Kadie; Ezenwa, Vanessa O.; Jolles, Anna E.

    2012-01-01

    Ticks are of vast importance to livestock health, and contribute to conflicts between wildlife conservation and agricultural interests; but factors driving tick infestation patterns on wild hosts are not well understood. We studied tick infestation patterns on free-ranging African buffalo (Syncercus caffer), asking (i) is there evidence for niche segregation among tick species?; and (ii) how do host characteristics affect variation in tick abundance among hosts? We identified ticks and estimated tick burdens on 134 adult female buffalo from two herds at Kruger National Park, South Africa. To assess niche segregation, we evaluated attachment site preferences and tested for correlations between abundances of different tick species. To investigate which host factors may drive variability in tick abundance, we measured age, body condition, reproductive and immune status in all hosts, and examined their effects on tick burdens. Two tick species were abundant on buffalo, Amblyomma hebraeum and Rhipicephalus evertsi evertsi. A. hebraeum were found primarily in the inguinal and axillary regions; R. e. evertsi attached exclusively in the perianal area. Abundances of A. hebraeum and R. e. evertsi on the host were unrelated. These results suggest spatial niche segregation between A. hebraeum and R. e. evertsi on the buffalo. Buffalo with stronger innate immunity, and younger buffalo, had fewer ticks. Buffalo with low body condition scores, and pregnant buffalo, had higher tick burdens, but these effects varied between the two herds we sampled. This study is one of the first to link ectoparasite abundance patterns and immunity in a free-ranging mammalian host population. Based on independent abundances of A. hebraeum and R. e. evertsi on individual buffalo, we would expect no association between the diseases these ticks transmit. Longitudinal studies linking environmental variability with host immunity are needed to understand tick infestation patterns and the dynamics of tick

  2. Baculovirus-encoded protein BV/ODV-E26 determines tissue tropism and virulence in lepidopteran insects.

    PubMed

    Katsuma, Susumu; Kobayashi, Jun; Koyano, Yasue; Matsuda-Imai, Noriko; Kang, WonKyung; Shimada, Toru

    2012-03-01

    Lepidopteran nucleopolyhedroviruses (NPVs) show distinct tissue tropism in host insect larvae. However, the molecular mechanism of this tropism is largely unknown. We quantitatively investigated NPV tissue tropism by measuring mRNA levels of viral genes in 16 tissues from Bombyx mori NPV (BmNPV)-infected B. mori larvae and found clear tissue tropism, i.e., BmNPV replicates poorly in the silk glands, midgut, and Malpighian tubule compared with other larval tissues. We next identified the viral genes determining tissue tropism in NPV infection by investigating the phenotypes of larvae infected with 44 BmNPV mutants in which one gene was functionally disrupted by a LacZ cassette insertion. We found that occlusion body (OB) production was markedly enhanced compared with that of the wild type in the middle silk glands (MSGs) of larvae infected with three mutants in which one of three tandemly arrayed genes (Bm7, Bm8, and Bm9) was disrupted. We generated additional mutants in which one or two genes of this gene cluster were partially deleted and showed that Bm8, also known as BV/ODV-E26, was solely required for the suppression of OB production in the MSGs of BmNPV-infected B. mori larvae. Western blotting showed that a LacZ cassette insertion in Bm7 or Bm9 resulted in aberrant expression of Bm8, presumably leading to abnormal OB production in the MSGs. Larval bioassays also revealed that disruption of Bm8 accelerated the death of B. mori larvae. These results suggest that the group I NPV-specific protein BV/ODV-E26 determines tissue tropism and virulence in host lepidopteran insects.

  3. Bacteria influence mountain pine beetle brood development through interactions with symbiotic and antagonistic fungi: implications for climate-driven host range expansion.

    PubMed

    Therrien, Janet; Mason, Charles J; Cale, Jonathan A; Adams, Aaron; Aukema, Brian H; Currie, Cameron R; Raffa, Kenneth F; Erbilgin, Nadir

    2015-10-01

    Bark beetles are associated with diverse communities of symbionts. Although fungi have received significant attention, we know little about how bacteria, and in particular their interactions with fungi, affect bark beetle reproduction. We tested how interactions between four bacterial associates, two symbiotic fungi, and two opportunistic fungi affect performance of mountain pine beetles (Dendroctonus ponderosae) in host tissue. We compared beetle performance in phloem of its historical host, lodgepole pine (Pinus contorta), and its novel host recently accessed through warming climate, jack pine (Pinus banksiana). Overall, beetles produced more larvae, and established longer ovipositional and larval galleries in host tissue predominantly colonized by the symbiotic fungi, Grosmannia clavigera, or Ophiostoma montium than by the opportunistic colonizer Aspergillus and to a lesser extent, Trichoderma. This occurred in both historical and naïve hosts. Impacts of bacteria on beetle reproduction depended on particular fungus-bacterium combinations and host species. Some bacteria, e.g., Pseudomonas sp. D4-22 and Hy4T4 in P. contorta and Pseudomonas sp. Hy4T4 and Stenotrophomonas in P. banksiana, reduced antagonistic effects by Aspergillus and Trichoderma resulting in more larvae and longer ovipositional and larval galleries. These effects were not selective, as bacteria also reduced beneficial effects by symbionts in both host species. Interestingly, Bacillus enhanced antagonistic effects by Aspergillus in both hosts. These results demonstrate that bacteria influence brood development of bark beetles in host tissue. They also suggest that climate-driven range expansion of D. ponderosae through the boreal forest will not be significantly constrained by requirements of, or interactions among, its microbial associates.

  4. Host range and genetic relatedness of Colletotrichum acutatum isolates from fruit crops and leatherleaf fern in Florida.

    PubMed

    MacKenzie, S J; Peres, N A; Barquero, M P; Arauz, L F; Timmer, L W

    2009-05-01

    Isolates of Colletotrichum acutatum were collected from anthracnose-affected strawberry, leatherleaf fern, and Key lime; ripe-rot-affected blueberry; and postbloom fruit drop (PFD)-affected sweet orange in Florida. Additional isolates from ripe-rot-affected blueberry were collected from Georgia and North Carolina and from anthracnose-affected leatherleaf fern in Costa Rica. Pathogenicity tests on blueberry and strawberry fruit; foliage of Key lime, leatherleaf fern, and strawberry; and citrus flowers showed that isolates were highly pathogenic to their host of origin. Isolates were not pathogenic on foliage of heterologous hosts; however, several nonhomologous isolates were mildly or moderately pathogenic to citrus flowers and blueberry isolates were pathogenic to strawberry fruit. Based on sequence data from the internal transcribed spacer (ITS)1-5.8S rRNA-ITS2 region of the rDNA repeat, the glutaraldehyde-3-phosphate dehydrogenase intron 2 (G3PD), and the glutamine synthase intron 2 (GS), isolates from the same host were identical or very similar to each other and distinct from those isolated from other hosts. Isolates from leatherleaf fern in Florida were the only exception. Among these isolates, there were two distinct G3PD and GS sequences that occurred in three of four possible combinations. Only one of these combinations occurred in Costa Rica. Although maximum parsimony trees constructed from genomic regions individually displayed little or no homoplasy, there was a lack of concordance among genealogies that was consistent with a history of recombination. This lack of concordance was particularly evident within a clade containing PFD, Key lime, and leatherleaf fern isolates. Overall, the data indicated that it is unlikely that a pathogenic strain from one of the hosts examined would move to another of these hosts and produce an epidemic.

  5. Host range of Tetramesa romana Walker (Hymenoptera: Eurytomidae), a potential biological control of giant reed, Arundo donax L. in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The eurytomid wasp, Tetramesa romana Walker, was evaluated as a potential biological control agent of the invasive reed grass, Arundo donax in North America. No-choice tests and timed behavioral studies were used to determine the fundamental host range of two genotypes of the wasp collected from Gr...

  6. Host range testing and biology of Abia sericea (Cimbicidae), a candidate for biological control of invasive teasels (Dipsacus spp.) in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive teasels (Dipsacus spp., Dipsacaceae) are widespread in the USA, being present in 43 states and listed as noxious in five. The cimbicid sawfly Abia sericea (L.) is under evaluation as a potential agent for biological control of teasels. The host range, biology, and life history of this ins...

  7. Slow cell infection, inefficient primary infection and inability to replicate in fat body determine host-range of Thysanoplusia orichalcea M Nucleopolyhedrovirus (ThorMNPV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An enhanced green fluorescence protein (EGFP) gene expression cassette was inserted at the gp37 locus of Thysanoplusia orichacea M nucleopolyhedrovirus (ThorMNPV) to produce vThGFP to study host-range mechanisms. Using EGFP to monitor infection in vitro, many cell lines showed EGFP expression sugges...

  8. ‘Candidatus Megaira polyxenophila’ gen. nov., sp. nov.: Considerations on Evolutionary History, Host Range and Shift of Early Divergent Rickettsiae

    PubMed Central

    Vannini, Claudia; Galati, Stefano; Schweikert, Michael; Görtz, Hans-Dieter; Verni, Franco; Petroni, Giulio

    2013-01-01

    “Neglected Rickettsiaceae” (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria. PMID:23977321

  9. Lepidopteran cells, an alternative for the production of recombinant antibodies?

    PubMed Central

    Cérutti, Martine; Golay, Josée

    2012-01-01

    Monoclonal antibodies are used with great success in many different therapeutic domains. In order to satisfy the growing demand and to lower the production cost of these molecules, many alternative systems have been explored. Among them, the baculovirus/insect cells system is a good candidate. This system is very safe, given that the baculoviruses have a highly restricted host range and they are not pathogenic to vertebrates or plants. But the major asset is the speed with which it is possible to obtain very stable recombinant viruses capable of producing fully active proteins whose glycosylation pattern can be modulated to make it similar to the human one. These features could ultimately make the difference by enabling the production of antibodies with very low costs. However, efforts are still needed, in particular to increase production rates and thus make this system commercially viable for the production of these therapeutic agents. PMID:22531440

  10. Characterization and host range of the symbiotic fungus Fusarium euwallaceae sp. nov., vectored by the invasive ambrosia beetle Euwallacea sp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel symbiotic Fusarium euwallaceae fungus that serves as a specific nutritional source for the invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) is farmed in the galleries of host plants. This beetle-fungus complex, which has invaded Israel and California, is clo...

  11. Extended geographical distribution and host range of the cactus moth Cactoblastis cactorum (Lepidoptera Pyralidae)in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field exploration was conducted to confirm the southernmost distribution of Cactoblastis cactorum in Argentina. The distribution of the moth was extended to the south (40° 10´S) and west (66° 56´W). The native Opuntia penicilligera was recorded as a host for the first time. These findings should ...

  12. Computational and Functional Analysis of the Virus-Receptor Interface Reveals Host Range Trade-Offs in New World Arenaviruses

    PubMed Central

    Kerr, Scott A.; Jackson, Eleisha L.; Lungu, Oana I.; Meyer, Austin G.; Demogines, Ann; Ellington, Andrew D.; Georgiou, George

    2015-01-01

    ABSTRACT Animal viruses frequently cause zoonotic disease in humans. As these viruses are highly diverse, evaluating the threat that they pose remains a major challenge, and efficient approaches are needed to rapidly predict virus-host compatibility. Here, we develop a combined computational and experimental approach to assess the compatibility of New World arenaviruses, endemic in rodents, with the host TfR1 entry receptors of different potential new host species. Using signatures of positive selection, we identify a small motif on rodent TfR1 that conveys species specificity to the entry of viruses into cells. However, we show that mutations in this region affect the entry of each arenavirus differently. For example, a human single nucleotide polymorphism (SNP) in this region, L212V, makes human TfR1 a weaker receptor for one arenavirus, Machupo virus, but a stronger receptor for two other arenaviruses, Junin and Sabia viruses. Collectively, these findings set the stage for potential evolutionary trade-offs, where natural selection for resistance to one virus may make humans or rodents susceptible to other arenavirus species. Given the complexity of this host-virus interplay, we propose a computational method to predict these interactions, based on homology modeling and computational docking of the virus-receptor protein-protein interaction. We demonstrate the utility of this model for Machupo virus, for which a suitable cocrystal structural template exists. Our model effectively predicts whether the TfR1 receptors of different species will be functional receptors for Machupo virus entry. Approaches such at this could provide a first step toward computationally predicting the “host jumping” potential of a virus into a new host species. IMPORTANCE We demonstrate how evolutionary trade-offs may exist in the dynamic evolutionary interplay between viruses and their hosts, where natural selection for resistance to one virus could make humans or rodents susceptible

  13. Baculovirus studies in new, indigenous lepidopteran cell lines.

    PubMed

    Pant, U; Sudeep, A B; Athawale, S S; Vipat, V C

    2002-01-01

    Eight lepidopteran cell lines were established recently and their susceptibility to different insect viruses was studied. Two Spodoptera litura cell lines from the larval and pupal ovaries, were found highly susceptible to S. litura nuclear polyhedrosis virus (SLNPV, 5-6 x 10(6) NPV/ml). The Helicoverpa armigera cell line from the embryonic tissue was highly susceptible to H. armigera NPV (HaNPV, 6.3 x 10(6) NPV/ml). These in vitro grown SLNPV and HaNPV caused 100% mortality to respective 2nd instar larvae. The susceptibility of the cryo-preserved cell lines to respective baculoviruses (SLNPV/HaNPV) was studied and no significant difference in their susceptibility status was observed. The cultures could grow as suspension culture on shakers and may find application for in vitro production of wild type/recombinant baculoviruses as bio-insecticides. S. litura and Bombyx mori cell lines from larval ovaries, were highly susceptible to Autographa californica NPV (5.5 x 10(6) NPV/ml) and Bombyx mori NPV (BmNPV, 6.1 x 10(6) NPV/ml) respectively. These cell lines may find application in baculovirus expression vector studies for the production of recombinant proteins, useful in the development of diagnostic kits or as vaccines.

  14. Structure of the lepidopteran proboscis in relation to feeding guild.

    PubMed

    Lehnert, Matthew S; Beard, Charles E; Gerard, Patrick D; Kornev, Konstantin G; Adler, Peter H

    2016-02-01

    Most butterflies and moths (Lepidoptera) use modified mouthparts, the proboscis, to acquire fluids. We quantified the proboscis architecture of five butterfly species in three families to test the hypothesis that proboscis structure relates to feeding guild. We used scanning electron microscopy to elucidate the fine structure of the proboscis of both sexes and to quantify dimensions, cuticular patterns, and the shapes and sizes of sensilla and dorsal legulae. Sexual dimorphism was not detected in the proboscis structure of any species. A hierarchical clustering analysis of overall proboscis architecture reflected lepidopteran phylogeny, but did not produce a distinct group of flower visitors or of puddle visitors within the flower visitors. Specific characters of the proboscis, nonetheless, can indicate flower and nonflower visitors, such as the configuration of sensilla styloconica, width of the lower branches of dorsal legulae, presence or absence of dorsal legulae at the extreme apex, and degree of proboscis tapering. We suggest that the overall proboscis architecture of Lepidoptera reflects a universal structural organization that promotes fluid uptake from droplets and films. On top of this fundamental structural organization, we suggest that the diversity of floral structure has selected for structural adaptations that facilitate entry of the proboscis into floral tubes.

  15. The origins of new pandemic viruses: the acquisition of new host ranges by canine parvovirus and influenza A viruses.

    PubMed

    Parrish, Colin R; Kawaoka, Yoshihiro

    2005-01-01

    Transfer of viruses between hosts to create a new self-sustaining epidemic is rare; however, those new viruses can cause severe outbreaks. Examples of such viruses include three pandemic human influenza A viruses and canine parvovirus in dogs. In each case one virus made the original transfer and spread worldwide, and then further adaptation resulted in the emergence of variants worldwide. For the influenza viruses several changes were required for growth and spread between humans, and the emergence of human H2N2 and H3N2 strains in 1957 and 1968 involved the acquisition of three or two new genomic segments, respectively. Adaptation to humans involved several viral genes including the hemagglutinin, the neuraminidase, and the replication proteins. The canine adaptation of the parvoviruses involved capsid protein changes altering the recognition of the host transferrin receptors, allowing canine transferrin receptor binding and its use as a receptor for cell infection.

  16. Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range.

    PubMed

    Henderson, Gemma; Cox, Faith; Ganesh, Siva; Jonker, Arjan; Young, Wayne; Janssen, Peter H

    2015-10-09

    Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific.

  17. Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range

    PubMed Central

    Henderson, Gemma; Cox, Faith; Ganesh, Siva; Jonker, Arjan; Young, Wayne; Abecia, Leticia; Angarita, Erika; Aravena, Paula; Nora Arenas, Graciela; Ariza, Claudia; Attwood, Graeme T.; Mauricio Avila, Jose; Avila-Stagno, Jorge; Bannink, André; Barahona, Rolando; Batistotti, Mariano; Bertelsen, Mads F.; Brown-Kav, Aya; Carvajal, Andres M.; Cersosimo, Laura; Vieira Chaves, Alexandre; Church, John; Clipson, Nicholas; Cobos-Peralta, Mario A.; Cookson, Adrian L.; Cravero, Silvio; Cristobal Carballo, Omar; Crosley, Katie; Cruz, Gustavo; Cerón Cucchi, María; de la Barra, Rodrigo; De Menezes, Alexandre B.; Detmann, Edenio; Dieho, Kasper; Dijkstra, Jan; dos Reis, William L. S.; Dugan, Mike E. R.; Hadi Ebrahimi, Seyed; Eythórsdóttir, Emma; Nde Fon, Fabian; Fraga, Martín; Franco, Francisco; Friedeman, Chris; Fukuma, Naoki; Gagić, Dragana; Gangnat, Isabelle; Javier Grilli, Diego; Guan, Le Luo; Heidarian Miri, Vahideh; Hernandez-Sanabria, Emma; Gomez, Alma Ximena Ibarra; Isah, Olubukola A.; Ishaq, Suzanne; Jami, Elie; Jelincic, Juan; Kantanen, Juha; Kelly, William J.; Kim, Seon-Ho; Klieve, Athol; Kobayashi, Yasuo; Koike, Satoshi; Kopecny, Jan; Nygaard Kristensen, Torsten; Julie Krizsan, Sophie; LaChance, Hannah; Lachman, Medora; Lamberson, William R.; Lambie, Suzanne; Lassen, Jan; Leahy, Sinead C.; Lee, Sang-Suk; Leiber, Florian; Lewis, Eva; Lin, Bo; Lira, Raúl; Lund, Peter; Macipe, Edgar; Mamuad, Lovelia L.; Cuquetto Mantovani, Hilário; Marcoppido, Gisela Ariana; Márquez, Cristian; Martin, Cécile; Martinez, Gonzalo; Eugenia Martinez, Maria; Lucía Mayorga, Olga; McAllister, Tim A.; McSweeney, Chris; Mestre, Lorena; Minnee, Elena; Mitsumori, Makoto; Mizrahi, Itzhak; Molina, Isabel; Muenger, Andreas; Munoz, Camila; Murovec, Bostjan; Newbold, John; Nsereko, Victor; O’Donovan, Michael; Okunade, Sunday; O’Neill, Brendan; Ospina, Sonia; Ouwerkerk, Diane; Parra, Diana; Pereira, Luiz Gustavo Ribeiro; Pinares-Patino, Cesar; Pope, Phil B.; Poulsen, Morten; Rodehutscord, Markus; Rodriguez, Tatiana; Saito, Kunihiko; Sales, Francisco; Sauer, Catherine; Shingfield, Kevin; Shoji, Noriaki; Simunek, Jiri; Stojanović-Radić, Zorica; Stres, Blaz; Sun, Xuezhao; Swartz, Jeffery; Liang Tan, Zhi; Tapio, Ilma; Taxis, Tasia M.; Tomkins, Nigel; Ungerfeld, Emilio; Valizadeh, Reza; van Adrichem, Peter; Van Hamme, Jonathan; Van Hoven, Woulter; Waghorn, Garry; John Wallace, R.; Wang, Min; Waters, Sinéad M.; Keogh, Kate; Witzig, Maren; Wright, Andre-Denis G.; Yamano, Hidehisa; Yan, Tianhai; Yanez-Ruiz, David R.; Yeoman, Carl J.; Zambrano, Ricardo; Zeitz, Johanna; Zhou, Mi; Wei Zhou, Hua; Xia Zou, Cai; Zunino, Pablo; Janssen, Peter H.

    2015-01-01

    Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific. PMID:26449758

  18. Genomic evidence that resource-based trade-offs limit host-range expansion in a seed beetle.

    PubMed

    Gompert, Zachariah; Messina, Frank J

    2016-06-01

    Trade-offs have often been invoked to explain the evolution of ecological specialization. Phytophagous insects have been especially well studied, but there has been little evidence that resource-based trade-offs contribute to the evolution of host specialization in this group. Here, we combine experimental evolution and partial genome resequencing of replicate seed beetle selection lines to test the trade-off hypothesis and measure the repeatability of evolution. Bayesian estimates of selection coefficients suggest that rapid adaptation to a poor host (lentil) was mediated by standing genetic variation at multiple genetic loci and involved many of the same variants in replicate lines. Sublines that were then switched back to the ancestral host (mung bean) showed a more gradual and variable (less repeatable) loss of adaptation to lentil. We were able to obtain estimates of variance effective population sizes from genome-wide differences in allele frequencies within and between lines. These estimates were relatively large, which suggests that the contribution of genetic drift to the loss of adaptation following reversion was small. Instead, we find that some alleles that were favored on lentil were selected against during reversion on mung bean, consistent with the genetic trade-off hypothesis.

  19. Discovery of Novel dsRNA Viral Sequences by In Silico Cloning and Implications for Viral Diversity, Host Range and Evolution

    PubMed Central

    Liu, Huiquan; Fu, Yanping; Xie, Jiatao; Cheng, Jiasen; Ghabrial, Said A.; Li, Guoqing; Yi, Xianhong; Jiang, Daohong

    2012-01-01

    Genome sequence of viruses can contribute greatly to the study of viral evolution, diversity and the interaction between viruses and hosts. Traditional molecular cloning methods for obtaining RNA viral genomes are time-consuming and often difficult because many viruses occur in extremely low titers. DsRNA viruses in the families, Partitiviridae, Totiviridae, Endornaviridae, Chrysoviridae, and other related unclassified dsRNA viruses are generally associated with symptomless or persistent infections of their hosts. These characteristics indicate that samples or materials derived from eukaryotic organisms used to construct cDNA libraries and EST sequencing might carry these viruses, which were not easily detected by the researchers. Therefore, the EST databases may include numerous unknown viral sequences. In this study, we performed in silico cloning, a procedure for obtaining full or partial cDNA sequence of a gene by bioinformatics analysis, using known dsRNA viral sequences as queries to search against NCBI Expressed Sequence Tag (EST) database. From this analysis, we obtained 119 novel virus-like sequences related to members of the families, Endornaviridae, Chrysoviridae, Partitiviridae, and Totiviridae. Many of them were identified in cDNA libraries of eukaryotic lineages, which were not known to be hosts for these viruses. Furthermore, comprehensive phylogenetic analysis of these newly discovered virus-like sequences with known dsRNA viruses revealed that these dsRNA viruses may have co-evolved with respective host supergroups over a long evolutionary time while potential horizontal transmissions of viruses between different host supergroups also is possible. We also found that some of the plant partitiviruses may have originated from fungal viruses by horizontal transmissions. These findings extend our knowledge of the diversity and possible host range of dsRNA viruses and offer insight into the origin and evolution of relevant viruses with their hosts. PMID

  20. Host Range Testing of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) for Use in Classical Biological Control of Diaphorina citri (Hemiptera: Liviidae) in California.

    PubMed

    Bistline-East, Allison; Pandey, Raju; Kececi, Mehmet; Hoddle, Mark S

    2015-06-01

    Host range tests for Diaphorencyrtus aligarhensis (Shafee, Alam, & Agarwal) (Hymenoptera: Encyrtidae), an endoparasitoid of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), sourced from Punjab Pakistan, were conducted in quarantine at the University of California, Riverside, CA. Seven nontarget psyllid species representing four psyllid families were exposed to mated D. aligarhensis females in four different treatment types: 1) short sequential no-choice treatments, 2) prolonged sequential no-choice treatments, 3) prolonged no-choice static treatments, and 4) choice treatments. Selection of nontarget psyllid species was based on phylogenetic proximity to D. citri, likelihood of being encountered by D. aligarhensis in the prospective release areas in California, and psyllid species in biological control of invasive weeds. D. aligarhensis exhibited high host affinity to D. citri, and only parasitized one nontarget species, the pestiferous potato psyllid, Bactericera cockerelli (Sulc), at low levels (<14%). Based on the results of this study, we conclude that D. aligarhensis has a narrow host range and exhibits a high level of host specificity, as it shows a significant attack preference for the target pest, D. citri. Results presented here suggest D. aligarhensis poses minimal risk to nontarget psyllid species in California.

  1. Evaluation of host range and larval feeding impact of Chrysolina aurichalcea asclepiadis (Villa): considerations for biological control of Vincetoxicum in North America.

    PubMed

    Weed, Aaron S; Casagrande, Richard A

    2011-12-01

    A biological control program has been initiated against European swallow-worts Vincetoxicum nigrum (L.) Moench. and V. rossicum (Kleopow) Barbar., which are invasive in North America. A population of the leaf beetle Chrysolina aurichalcea asclepiadis (Villa) originating from the western Alps has been under evaluation as a part of this program. The preliminary host range of C. a. asclepiadis was determined among 37 potential host plants. In addition, a prerelease impact study was conducted to determine the effect of larval feeding on the performance of V. nigrum. Under no-choice conditions beetle larvae completed development on nine plant species within the genera Artemisia and Tanacetum (Asteraceae) and Asclepias and Vincetoxicum (Apocynaceae). The host range of adults is broader than larvae (13 plant species within five genera received sustained feeding). Three of the six nontarget species supporting larval development are native to North America, however in separate oviposition tests, female beetles failed to produce eggs when confined to these hosts. In multiple-choice tests, neither larvae nor adults preferred Vincetoxicum spp. to nontarget species. Larval damage by C. a. asclepiadis at densities at and above five larvae per plant substantially reduced growth, biomass, and delayed reproduction of V. nigrum. However, this population of C. a. asclepiadis is polyphagous and unsuitable for biological control of Vincetoxicum because of potential risk of attack to Asclepias tuberosa L. and native North American Asteraceae, particularly Artemisia.

  2. The Role of Female Search Behaviour in Determining Host Plant Range in Plant Feeding Insects: A Test of the Information Processing Hypothesis

    NASA Astrophysics Data System (ADS)

    Janz, Niklas; Nylin, Soren

    1997-05-01

    Recent theoretical studies have suggested that host range in herbivorous insects may be more restricted by constraints on information processing on the ovipositing females than by trade-offs in larval feeding efficiency. We have investigated if females from polyphagous species have to pay for their ability to localize and evaluate plants from different species with a lower ability to discriminate between conspecific host plants with differences in quality. Females of the monophagous butterflies Polygonia satyrus, Vanessa indica and Inachis io and the polyphagous P. c-album and Cynthia cardui (all in Lepidoptera, Nymphalidae) were given a simultaneous choice of stinging nettles (Urtica dioica) of different quality. In addition, the same choice trial was given to females from two populations of P. c-album with different degrees of specificity. As predicted from the information processing hypothesis, all specialists discriminated significantly against the bad quality nettle, whereas the generalists laid an equal amount of eggs on both types of nettle. There were no corresponding differences between specialist and generalist larvae in their ability to utilize poor quality leaves. Our study therefore suggests that female host-searching behaviour plays an important role in determining host plant range.

  3. Distribution, host range, and climatic constraints on Centistes gasseni (Hymenoptera: Braconidae), a South American parasitoid of cucumber beetles, Diabrotica spp. (Coleoptera: Chrysomelidae).

    PubMed

    Cabrera Walsh, G; Athanas, M M; Salles, L A B; Schroder, R F W

    2003-12-01

    The genus Diabrotica includes a large number of pest species, including some of the most important crop pests of the Americas. The parasitoid Centistes gasseni Shaw is the first braconid to be described parasitizing Diabrotica in South America, and high natural infestations are reported. Field and experimental observations on the host range, distribution and biology of this parasitoid are described. Centistes gasseniwas collected in southern Brazil, eastern Paraguay and northeastern Argentina, in a region comprising humid lowlands and highlands, and cool temperate to warm subtropical climates, with regular rainfall in excess of 1300 mm. Three Diabroticaspecies, D. limitata (Sahlberg), D. speciosa (Germar) and D. viridula (Fabricius) were found to host the parasitoid, with mean percent parasitism of 5.4, 2.0 and 1.0%, respectively. Diabrotica speciosa and D. viridula are the two most important pest Diabroticaspecies in South America. Laboratory experiments with field-collected beetles and parasitoid cocoons indicated that C. gasseni overwinters in adult host beetles, remaining dormant in its live host below developmental temperatures. A potential distribution of C. gasseni in North America is proposed based on its known climatic range and the distribution of the main pest species of adult overwintering North American Diabrotica.

  4. No excess gene movement is detected off the avian or lepidopteran Z chromosome.

    PubMed

    Toups, Melissa A; Pease, James B; Hahn, Matthew W

    2011-01-01

    Most of our knowledge of sex-chromosome evolution comes from male heterogametic (XX/XY) taxa. With the genome sequencing of multiple female heterogametic (ZZ/ZW) taxa, we can now ask whether there are patterns of evolution common to both sex chromosome systems. In all XX/XY systems examined to date, there is an excess of testis-biased retrogenes moving from the X chromosome to the autosomes, which is hypothesized to result from either sexually antagonistic selection or escape from meiotic sex chromosome inactivation (MSCI). We examined RNA-mediated (retrotransposed) and DNA-mediated gene movement in two independently evolved ZZ/ZW systems, birds (chicken and zebra finch) and lepidopterans (silkworm). Even with sexually antagonistic selection likely operating in both taxa and MSCI having been identified in the chicken, we find no evidence for an excess of genes moving from the Z chromosome to the autosomes in either lineage. We detected no excess for either RNA- or DNA-mediated duplicates, across a range of approaches and methods. We offer some potential explanations for this difference between XX/XY and ZZ/ZW sex chromosome systems, but further work is needed to distinguish among these hypotheses. Regardless of the root causes, we have identified an additional, potentially inherent, difference between XX/XY and ZZ/ZW systems.

  5. Host and Environmental Factors Modulate the Exposure of Free-Ranging and Farmed Red Deer (Cervus elaphus) to Coxiella burnetii

    PubMed Central

    Velasco Ávila, Ana Luisa; Boadella, Mariana; Beltrán-Beck, Beatriz; Barasona, José Ángel; Santos, João P. V.; Queirós, João; García-Pérez, Ana L.; Barral, Marta; Ruiz-Fons, Francisco

    2015-01-01

    The control of multihost pathogens, such as Coxiella burnetii, should rely on accurate information about the roles played by the main hosts. We aimed to determine the involvement of the red deer (Cervus elaphus) in the ecology of C. burnetii. We predicted that red deer populations from broad geographic areas within a European context would be exposed to C. burnetii, and therefore, we hypothesized that a series of factors would modulate the exposure of red deer to C. burnetii. To test this hypothesis, we designed a retrospective survey of 47 Iberian red deer populations from which 1,751 serum samples and 489 spleen samples were collected. Sera were analyzed by enzyme-linked immunosorbent assays (ELISA) in order to estimate exposure to C. burnetii, and spleen samples were analyzed by PCR in order to estimate the prevalence of systemic infections. Thereafter, we gathered 23 variables—within environmental, host, and management factors—potentially modulating the risk of exposure of deer to C. burnetii, and we performed multivariate statistical analyses to identify the main risk factors. Twenty-three populations were seropositive (48.9%), and C. burnetii DNA in the spleen was detected in 50% of the populations analyzed. The statistical analyses reflect the complexity of C. burnetii ecology and suggest that although red deer may maintain the circulation of C. burnetii without third species, the most frequent scenario probably includes other wild and domestic host species. These findings, taken together with previous evidence of C. burnetii shedding by naturally infected red deer, point at this wild ungulate as a true reservoir for C. burnetii and an important node in the life cycle of C. burnetii, at least in the Iberian Peninsula. PMID:26150466

  6. Host and Environmental Factors Modulate the Exposure of Free-Ranging and Farmed Red Deer (Cervus elaphus) to Coxiella burnetii.

    PubMed

    González-Barrio, David; Velasco Ávila, Ana Luisa; Boadella, Mariana; Beltrán-Beck, Beatriz; Barasona, José Ángel; Santos, João P V; Queirós, João; García-Pérez, Ana L; Barral, Marta; Ruiz-Fons, Francisco

    2015-09-01

    The control of multihost pathogens, such as Coxiella burnetii, should rely on accurate information about the roles played by the main hosts. We aimed to determine the involvement of the red deer (Cervus elaphus) in the ecology of C. burnetii. We predicted that red deer populations from broad geographic areas within a European context would be exposed to C. burnetii, and therefore, we hypothesized that a series of factors would modulate the exposure of red deer to C. burnetii. To test this hypothesis, we designed a retrospective survey of 47 Iberian red deer populations from which 1,751 serum samples and 489 spleen samples were collected. Sera were analyzed by enzyme-linked immunosorbent assays (ELISA) in order to estimate exposure to C. burnetii, and spleen samples were analyzed by PCR in order to estimate the prevalence of systemic infections. Thereafter, we gathered 23 variables-within environmental, host, and management factors-potentially modulating the risk of exposure of deer to C. burnetii, and we performed multivariate statistical analyses to identify the main risk factors. Twenty-three populations were seropositive (48.9%), and C. burnetii DNA in the spleen was detected in 50% of the populations analyzed. The statistical analyses reflect the complexity of C. burnetii ecology and suggest that although red deer may maintain the circulation of C. burnetii without third species, the most frequent scenario probably includes other wild and domestic host species. These findings, taken together with previous evidence of C. burnetii shedding by naturally infected red deer, point at this wild ungulate as a true reservoir for C. burnetii and an important node in the life cycle of C. burnetii, at least in the Iberian Peninsula.

  7. Description of Meloidogyne christiei n. sp. (Nematoda: Meloidogynidae) from Oak with SEM and Host-Range Observations

    PubMed Central

    Golden, A. Morgan; Kaplan, David T.

    1986-01-01

    Meloidogyne christiei n. sp. is described and illustrated from turkey oak (Quercus laevis) in Sanlando Park, Altamonte Springs, Florida. This new nematode species has a distinctive perineal pattern commonly with a high, squarish arch and coarse broken striae which tend to diverge at various angles, especially in and above the anal area. Female labial disc is indented, forming four points or prongs, unlike other species. Eggs are deposited inside the gall in a tubular, coiled manner. Vaginal muscles are exceptionally prominent and dense. SEM observations provided further detail of the perineal pattern and details of the head of females, males, and second-stage juveniles. Galls on the root commonly occur singly, but sometimes in small clusters, and appear as discrete nodules on the side of the root and without adjacent swelling. In general, only one female is found in each gall but occasionally two are present. In greenhouse tests, citrus, tobacco, cotton, pepper, watermelon, peanut, and tomato were not hosts. This nematode occurs throughout central Florida commonly on Q. laevis, the only known host. PMID:19294223

  8. Role of the B Allele of Influenza A Virus Segment 8 in Setting Mammalian Host Range and Pathogenicity

    PubMed Central

    Turnbull, Matthew L.; Wise, Helen M.; Nicol, Marlynne Q.; Smith, Nikki; Dunfee, Rebecca L.; Beard, Philippa M.; Jagger, Brett W.; Ligertwood, Yvonne; Hardisty, Gareth R.; Xiao, Haixia; Benton, Donald J.; Coburn, Alice M.; Paulo, Joao A.; Gygi, Steven P.; McCauley, John W.; Taubenberger, Jeffery K.; Lycett, Samantha J.; Weekes, Michael P.; Dutia, Bernadette M.

    2016-01-01

    ABSTRACT Two alleles of segment 8 (NS) circulate in nonchiropteran influenza A viruses. The A allele is found in avian and mammalian viruses, but the B allele is viewed as being almost exclusively found in avian viruses. This might reflect the fact that one or both of its encoded proteins (NS1 and NEP) are maladapted for replication in mammalian hosts. To test this, a number of clade A and B avian virus-derived NS segments were introduced into human H1N1 and H3N2 viruses. In no case was the peak virus titer substantially reduced following infection of various mammalian cell types. Exemplar reassortant viruses also replicated to similar titers in mice, although mice infected with viruses with the avian virus-derived segment 8s had reduced weight loss compared to that achieved in mice infected with the A/Puerto Rico/8/1934 (H1N1) parent. In vitro, the viruses coped similarly with type I interferons. Temporal proteomics analysis of cellular responses to infection showed that the avian virus-derived NS segments provoked lower levels of expression of interferon-stimulated genes in cells than wild type-derived NS segments. Thus, neither the A nor the B allele of avian virus-derived NS segments necessarily attenuates virus replication in a mammalian host, although the alleles can attenuate disease. Phylogenetic analyses identified 32 independent incursions of an avian virus-derived A allele into mammals, whereas 6 introductions of a B allele were identified. However, A-allele isolates from birds outnumbered B-allele isolates, and the relative rates of Aves-to-Mammalia transmission were not significantly different. We conclude that while the introduction of an avian virus segment 8 into mammals is a relatively rare event, the dogma of the B allele being especially restricted is misleading, with implications in the assessment of the pandemic potential of avian influenza viruses. IMPORTANCE Influenza A virus (IAV) can adapt to poultry and mammalian species, inflicting a

  9. Multiple amino acids in the capsid structure of canine parvovirus coordinately determine the canine host range and specific antigenic and hemagglutination properties.

    PubMed Central

    Chang, S F; Sgro, J Y; Parrish, C R

    1992-01-01

    Canine parvovirus (CPV) and feline panleukopenia virus (FPV) are over 98% similar in DNA sequence but have specific host range, antigenic, and hemagglutination (HA) properties which were located within the capsid protein gene. In vitro mutagenesis and recombination were used to prepare 16 different recombinant genomic clones, and viruses derived from those clones were analyzed for their in vitro host range, antigenic, and HA properties. The region of CPV from 59 to 91 map units determined the ability to replicate in canine cells. A complex series of interactions was observed among the individual sequence differences between 59 and 73 map units. The canine host range required that VP2 amino acids (aa) 93 and 323 both be the CPV sequence, and those two CPV sequences introduced alone into FPV greatly increased viral replication in canine cells. Changing any one of aa 93, 103, or 323 of CPV to the FPV sequence either greatly decreased replication in canine cells or resulted in an inviable plasmid. The Asn-Lys difference of aa 93 alone was responsible for the CPV-specific epitope recognized by monoclonal antibodies. An FPV-specific epitope was affected by aa 323. Amino acids 323 and 375 together determined the pH dependence of HA. Amino acids involved in the various specific properties were all around the threefold spikes of the viral particle. Images PMID:1331498

  10. Envelope-binding domain in the cationic amino acid transporter determines the host range of ecotropic murine retroviruses.

    PubMed Central

    Albritton, L M; Kim, J W; Tseng, L; Cunningham, J M

    1993-01-01

    Infection of rodent cells by ecotropic type C retroviruses requires the expression of a cationic amino acid transporter composed of multiple membrane-spanning domains. By exchanging portions of cDNAs encoding the permissive mouse and nonpermissive human transporters and examining their abilities to specify virus infection upon expression in human 293 cells, we have identified the amino acid residues in the extracellular loop connecting the fifth and sixth membrane-spanning segments of the mouse transporter that are required for both envelope gp70 binding and infection. These findings strongly suggest that the role of the mouse transporter in determining infection is to provide an envelope-binding site. This role is analogous to those of host membrane proteins composed of a single membrane-spanning domain that serve as binding proteins or receptors for other enveloped viruses such as human immunodeficiency virus, Epstein-Barr virus, and murine and human coronaviruses. PMID:8445722

  11. Host range and diversity of the genus Geosmithia (Ascomycota: Hypocreales) living in association with bark beetles in the Mediterranean area.

    PubMed

    Kolarík, Miroslav; Kostovcík, Martin; Pazoutová, Sylvie

    2007-11-01

    Geosmithia spp. (Ascomycota: Hypocreales) are dry-spored fungi that occur in galleries built by many phloeophagous bark beetles. This study mapped the diversity, host spectrum and area of distribution of Geosmithia spp. occurring in galleries of bark beetle species with a Mediterranean distribution. Eighty-six wood samples of 19 tree species infested by 18 subcortical insect species were collected from across the Mediterranean Basin during the years 2003-2006. Geosmithia spp. were found in 82 samples of angiosperms and two host trees from the family Juniperaceae infested by 14 bark beetles and the bostrichid Scobicia pustulata, suggesting that the association of Geosmithia and phloeophagous bark beetles is very widespread in the Mediterranean. Geosmithia isolates were sorted into 13 operational taxonomic units (OTUs) based on their phenotype similarity and phylogeny of their ITS regions of rDNA (ITS1-5.8S-ITS2). The OTUs represent five known species (G. flava, G. langdonii, G. lavendula, G. pallida, G. putterillii) and seven undescribed taxa. Most of the bark beetles were associated with on average 1-2.5 OTUs per sample. G. lavendula, considered very uncommon in nature, was found as a common associate of bark beetles. Six out of 13 OTUs were found to be distributed in the Mediterranean but not in neighbouring areas of temperate Europe suggesting that Geosmithia spp. have a geographically limited distribution, probably due to their dependency on the geographically limited area of their vectors. The proportion of generalists and specialists among Geosmithia spp. was smaller compared with data from temperate Europe. A possible explanation is the effective dispersal of Geosmithia by polyphagous bostrichids across the niches defined by mutually exclusive bark beetles.

  12. Evidence for suppression of immunity as a driver for genomic introgressions and host range expansion in races of Albugo candida, a generalist parasite

    PubMed Central

    McMullan, Mark; Gardiner, Anastasia; Bailey, Kate; Kemen, Eric; Ward, Ben J; Cevik, Volkan; Robert-Seilaniantz, Alexandre; Schultz-Larsen, Torsten; Balmuth, Alexi; Holub, Eric; van Oosterhout, Cock; Jones, Jonathan DG

    2015-01-01

    How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies of five isolates, we show they represent three races that are genetically diverged by ∼1%. Despite this divergence, their genomes are mosaic-like, with ∼25% being introgressed from other races. Sequential infection experiments show that infection by adapted races enables subsequent infection of hosts by normally non-infecting races. This facilitates introgression and the exchange of effector repertoires, and may enable the evolution of novel races that can undergo clonal population expansion on new hosts. We discuss recent studies on hybridization in other eukaryotes such as yeast, Heliconius butterflies, Darwin's finches, sunflowers and cichlid fishes, and the implications of introgression for pathogen evolution in an agro-ecological environment. DOI: http://dx.doi.org/10.7554/eLife.04550.001 PMID:25723966

  13. Comparative genomic and transcriptome analyses of pathotypes of Xanthomonas citri subsp. citri provide insights into mechanisms of bacterial virulence and host range

    PubMed Central

    2013-01-01

    Background Citrus bacterial canker is a disease that has severe economic impact on citrus industries worldwide and is caused by a few species and pathotypes of Xanthomonas. X. citri subsp. citri strain 306 (XccA306) is a type A (Asiatic) strain with a wide host range, whereas its variant X. citri subsp. citri strain Aw12879 (Xcaw12879, Wellington strain) is restricted to Mexican lime. Results To characterize the mechanism for the differences in host range of XccA and Xcaw, the genome of Xcaw12879 that was completed recently was compared with XccA306 genome. Effectors xopAF and avrGf1 are present in Xcaw12879, but were absent in XccA306. AvrGf1 was shown previously for Xcaw to cause hypersensitive response in Duncan grapefruit. Mutation analysis of xopAF indicates that the gene contributes to Xcaw growth in Mexican lime but does not contribute to the limited host range of Xcaw. RNA-Seq analysis was conducted to compare the expression profiles of Xcaw12879 and XccA306 in Nutrient Broth (NB) medium and XVM2 medium, which induces hrp gene expression. Two hundred ninety two and 281 genes showed differential expression in XVM2 compared to in NB for XccA306 and Xcaw12879, respectively. Twenty-five type 3 secretion system genes were up-regulated in XVM2 for both XccA and Xcaw. Among the 4,370 common genes of Xcaw12879 compared to XccA306, 603 genes in NB and 450 genes in XVM2 conditions were differentially regulated. Xcaw12879 showed higher protease activity than XccA306 whereas Xcaw12879 showed lower pectate lyase activity in comparison to XccA306. Conclusions Comparative genomic analysis of XccA306 and Xcaw12879 identified strain specific genes. Our study indicated that AvrGf1 contributes to the host range limitation of Xcaw12879 whereas XopAF contributes to virulence. Transcriptome analyses of XccA306 and Xcaw12879 presented insights into the expression of the two closely related strains of X. citri subsp. citri. Virulence genes including genes encoding T3SS components

  14. Rapidly expanding genetic diversity and host range of the Circoviridae viral family and other Rep encoding small circular ssDNA genomes

    PubMed Central

    Delwart, Eric; Li, Linlin

    2011-01-01

    The genomes of numerous circoviruses and distantly related circular DNA viruses encoding a rolling circle replication initiator protein (Rep) have been characterized from the tissues of mammals, fish, insects, and plants (geminivirus and nanovirus), human and animal feces, in an algae cell, and in diverse environmental samples. We review the genome organization, phylogenetic relationships and initial prevalence studies of cycloviruses, a proposed new genus in the Circoviridae family. Viral fossil rep sequences were also identified integrated on the chromosomes of mammals, frogs, lancelets, crustaceans, mites, gastropods, roundworms, placozoans, hydrozoans, protozoans, land plants, fungi, algae, and phytoplasma bacterias and their plasmids, reflecting their past host range. An ancient origin for viruses with rep-encoding single stranded small circular genomes, predating the diversification of eukaryotes, is discussed. The cellular hosts and pathogenicity of many recently described rep-containing circular genomes remain to be determined. Future studies of the virome of single cell and multi-cellular eukaryotes are likely to further extend the known diversity and host-range of small rep-containing circular viral genomes. PMID:22155583

  15. Mutational Analysis of the tra Locus of the Broad-Host-Range Streptomyces Plasmid pIJ101

    PubMed Central

    Pettis, Gregg S.; Cohen, Stanley N.

    2000-01-01

    The tra gene of Streptomyces lividans plasmid pIJ101 encodes a 621-amino-acid protein that can mediate both plasmid transfer and the interbacterial transfer of chromosomal genes (i.e., chromosome-mobilizing ability [Cma]) during mating. Here we report the results of in-frame insertional mutagenesis studies aimed at defining regions of Tra required for these functions. While hexameric linker insertions throughout the tra gene affected plasmid and chromosomal gene transfer, insertions in a 200-amino-acid region of the Tra protein that contains presumed nucleotide-binding motifs and that is widely conserved among a functionally diverse family of bacterial and plasmid proteins (K. J. Begg, S. J. Dewar, and W. D. Donachie, J. Bacteriol. 177:6211–6222, 1995) had especially prominent effects on both functions. Insertions near the N terminus of Tra reduced Cma for either circular or linear host chromosomes to a much greater extent than pIJ101 plasmid transfer. Our results suggest that Cma involves Tra functions incremental to those needed for plasmid DNA transfer. PMID:10913083

  16. Presence of Extracellular DNA during Biofilm Formation by Xanthomonas citri subsp. citri Strains with Different Host Range

    PubMed Central

    Sena-Vélez, Marta; Redondo, Cristina; Graham, James H.; Cubero, Jaime

    2016-01-01

    Xanthomonas citri subsp. citri (Xcc) A strain causes citrus bacterial canker, a serious leaf, fruit and stem spotting disease of several Citrus species. X. alfalfae subsp. citrumelonis (Xac) is the cause of citrus bacterial spot, a minor disease of citrus nursery plants and X. campestris pv. campestris (Xc) is a systemic pathogen that causes black rot of cabbage. Xanthomonas spp. form biofilms in planta that facilitate the host infection process. Herein, the role of extracellular DNA (eDNA) was evaluated in the formation and stabilization of the biofilm matrix at different stages of biofilm development. Fluorescence and light microscopy, as well as DNAse treatments, were used to determine the presence of eDNA in biofilms and bacterial cultures. DNAse treatments of Xcc strains and Xac reduced biofilm formation at the initial stage of development, as well as disrupted preformed biofilm. By comparison, no significant effect of the DNAse was detected for biofilm formation by Xc. DNAse effects on biofilm formation or disruption varied among Xcc strains and Xanthomonas species which suggest different roles for eDNA. Variation in the structure of fibers containing eDNA in biofilms, bacterial cultures, and in twitching motility was also visualized by microscopy. The proposed roles for eDNA are as an adhesin in the early stages of biofilm formation, as an structural component of mature bacterial aggregates, and twitching motility structures. PMID:27248687

  17. Characterization of California sea lion polyomavirus 1: expansion of the known host range of the Polyomaviridae to Carnivora.

    PubMed

    Wellehan, James F X; Rivera, Rebecca; Archer, Linda L; Benham, Celeste; Muller, Jennifer K; Colegrove, Kathleen M; Gulland, Frances M D; St Leger, Judy A; Venn-Watson, Stephanie K; Nollens, Hendrik H

    2011-07-01

    The genome of a novel polyomavirus first identified in a proliferative tongue lesion of a California sea lion (Zalophus californianus) is reported. This is only the third described polyomavirus of laurasiatherian mammals, is the first of the three associated with a lesion, and is the first known polyomavirus of a host in the order Carnivora. Predicted large T, small t, VP1, VP2, and VP3 genes were identified based on homology to proteins of known polyomaviruses, and a putative agnoprotein was identified based upon its location in the genome. Phylogenetic analysis of the predicted late region proteins found that the laurasiatherian polyomaviruses, together with Squirrel monkey polyomavirus and Murine pneumotropic virus, form a monophyletic clade. Phylogenetic analysis of the early region was more ambiguous. The noncoding control region of California sea lion polyomavirus 1 is unusual in that only two apparent large T binding sites are present; this is less than any other known polyomavirus. The VP1 of this virus has an unusually long carboxy-terminal region. A quantitative polymerase chain reaction was developed and utilized on various samples from 79 additional animals from either managed or wild stranded California sea lion populations, and California sea lion polyomavirus 1 infection was found in 24% of stranded animals. Sequence of additional samples identified four sites of variation in the t antigens, three of which resulted in predicted coding changes.

  18. Parasite species richness and intensity of interspecific interactions increase with latitude in two wide-ranging hosts.

    PubMed

    Torchin, Mark E; Miura, Osamu; Hechinger, Ryan F

    2015-11-01

    Although the latitudinal diversity gradient is a well-known and general pattern, the mechanisms structuring it remain elusive. Two key issues limit differentiating these. First, habitat type usually varies with latitude, precluding a standardized evaluation of species richness. Second, broad-scale and local factors hypothesized to shape diversity patterns covary with one another, making it difficult to tease apart independent effects. Examining communities of parasites in widely distributed hosts can eliminate some of these confounding factors. We quantified diversity and interspecific interactions for trematode parasites infecting two similar snail species across 27 degrees of latitude from 43 locations in tropical and temperate oceans. Counter to typical patterns, we found that species richness, levels of parasitism, and intensity of intraguild predation increased with latitude. Because speciation rates are precluded from driving diversity gradients in this particular system, the reversed gradients are likely due to local ecological factors, specifically, increased productivity and stability. We highlight how this system may serve as a useful tool to provide insight into what processes drive diversity gradients in general.

  19. Fine structure and cellular responses at the host-parasite interface in a range of fish-helminth systems.

    PubMed

    Dezfuli, B S; Bo, T; Lorenzoni, M; Shinn, A P; Giari, L

    2015-03-15

    A series of ultrastructural-based studies were conducted on the interface region in different fish-helminth systems: (a) an intestinal infection of the cestode Monobothrium wageneri in tench, Tinca tinca; (b) an extensive intestinal submucosa and mucosal infection in tench by metacercariae of an unidentified digenean trematode; (c) an intestinal infection in brown trout, Salmo trutta, by the acanthocephalan Dentitruncus truttae; (d) an extraintestinal infection by larvae of the acanthocephalan, Pomphorhynchus laevis in three-spined sticklebacks, Gasterosteus aculeatus; and (e) an infection in the livers of Eurasian minnow, Phoxinus phoxinus, by larvae of the nematode Raphidascaris acus. Endoparasitic helminths frequently cause inflammation of the digestive tract and associated organs, inducing the recruitment of various immune cells to the site of infection. In each of the fish-helminth systems that were studied, a massive hyperplastic granulocyte response involving mast cells (MCs) and neutrophils in close proximity to the helminths was documented. The current study presents data on the interface region in each fish-helminth system and documents the penetration of mast cells granules within the tegument of P. laevis larvae. No extracellular vesicles containing tegumental secretions from any of the four different taxa of endoparasitic helminths species at the host-parasite interface region were seen.

  20. Variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle

    PubMed Central

    Taft, Spencer; Najar, Ahmed; Godbout, Julie; Bousquet, Jean; Erbilgin, Nadir

    2015-01-01

    The secondary compounds of pines (Pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae) that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana) has a wide natural distribution range in North America (Canada and USA) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (Dendroctonus ponderosae), which has recently expanded its range into the novel jack pine boreal forest. We investigated monoterpene composition of 601 jack pine trees from natural and provenance forest stands representing 63 populations from Alberta to the Atlantic coast. Throughout its range, jack pine exhibited three chemotypes characterized by high proportions of α-pinene, β-pinene, or limonene. The frequency with which the α-pinene and β-pinene chemotypes occurred at individual sites was correlated to climatic variables, such as continentality and mean annual precipitation, as were the individual α-pinene and β-pinene concentrations. However, other monoterpenes were generally not correlated to climatic variables or geographic distribution. Finally, while the enantiomeric ratios of β-pinene and limonene remained constant across jack pine's distribution, (−):(+)-α-pinene exhibited two separate trends, thereby delineating two α-pinene phenotypes, both of which occurred across jack pine's range. These significant variations in jack pine monoterpene composition may have cascading effects on the continued eastward spread and success of D. ponderosae in the Canadian boreal forest. PMID:26042134

  1. Establishment, population increase, spread, and ecological host range of Lophodiplosis trifida (Diptera: Cecidomyiidae), a biological control agent of the invasive tree Melaleuca quinquenervia (Myrtales: Myrtaceae).

    PubMed

    Pratt, P D; Rayamajhi, M B; Tipping, P W; Center, T D; Wright, S A; Purcell, M

    2013-10-01

    The Australian tree Melaleuca quinquenervia (Cavanilles) Blake is an invasive weed in wetland systems of Florida. A biological control program targeting M. quinquenervia has resulted in the release of the gall forming midge Lophodiplosis trifida Gagné (Diptera: Cecidomyiidae). Populations of the introduced herbivore readily established at all 24 release sites across the weed's range in Florida, and there was no evidence that founding colony size (100, 2,000, or 6,000 adults) influenced herbivore establishment or local population growth rates. Landscape level spread of L. trifida from release sites averaged nearly 6 km/yr, ranging as high as 14.4 km/yr. Prerelease host range testing predicted that L. trifida oviposits indiscriminately on test plant species but does not complete development on any of the test species, including congeners present in Florida. To test the predictability of these host range tests, L. trifida was released in a common garden consisting of 18 test plant species that were interplanted with M. quinquenervia. Plant species postulated to be at risk experienced no gall development by L. trifida while intermingled M. quinquenervia trees supported 704.8 (± 158.5) galls per plant. Historically, many introduced Cecidomyiidae have limited effect on plant performance of target weeds because of recruitment of native parasitoids that disrupt biological control efficacy. In contrast to this trend, there has been no evidence to date that parasitoids are exploiting L. trifida in Florida.

  2. Variations in foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle.

    PubMed

    Taft, Spencer; Najar, Ahmed; Godbout, Julie; Bousquet, Jean; Erbilgin, Nadir

    2015-01-01

    The secondary compounds of pines (Pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae) that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana) has a wide natural distribution range in North America (Canada and USA) and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (Dendroctonus ponderosae), which has recently expanded its range into the novel jack pine boreal forest. We investigated monoterpene composition of 601 jack pine trees from natural and provenance forest stands representing 63 populations from Alberta to the Atlantic coast. Throughout its range, jack pine exhibited three chemotypes characterized by high proportions of α-pinene, β-pinene, or limonene. The frequency with which the α-pinene and β-pinene chemotypes occurred at individual sites was correlated to climatic variables, such as continentality and mean annual precipitation, as were the individual α-pinene and β-pinene concentrations. However, other monoterpenes were generally not correlated to climatic variables or geographic distribution. Finally, while the enantiomeric ratios of β-pinene and limonene remained constant across jack pine's distribution, (-):(+)-α-pinene exhibited two separate trends, thereby delineating two α-pinene phenotypes, both of which occurred across jack pine's range. These significant variations in jack pine monoterpene composition may have cascading effects on the continued eastward spread and success of D. ponderosae in the Canadian boreal forest.

  3. Life history and host range of Oxydia vesulia transpeneus, an unsuitable biological control agent of Brazilian peppertree

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The suitability of Oxydia vesulia (Cramer) (Lepidoptera: Geometridae) was assessed as a potential biological control agent of the invasive weed Brazilian Peppertree Schinus terebinthifolia. Larvae were collected in Brazil feeding on the plant in its native range and colonized in quarantine where lif...

  4. Salivary gland hypertrophy virus of house flies in Denmark: Prevalence, host range, and comparison with a Florida isolate.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    House flies (Musca domestica) infected with Musca domestica salivary gland hypertrophy virus (MdSGHV) were found in fly populations collected from 12 out of 18 Danish livestock farms that were surveyed in 2007 and 2008. Infection rates ranged from 0.5% to 5% and averaged 1.2% overall. None of the ...

  5. Pathogen-Host Associations and Predicted Range Shifts of Human Monkeypox in Response to Climate Change in Central Africa

    PubMed Central

    Thomassen, Henri A.; Fuller, Trevon; Asefi-Najafabady, Salvi; Shiplacoff, Julia A. G.; Mulembakani, Prime M.; Blumberg, Seth; Johnston, Sara C.; Kisalu, Neville K.; Kinkela, Timothée L.; Fair, Joseph N.; Wolfe, Nathan D.; Shongo, Robert L.; LeBreton, Matthew; Meyer, Hermann; Wright, Linda L.; Muyembe, Jean-Jacques; Buermann, Wolfgang; Okitolonda, Emile; Hensley, Lisa E.; Lloyd-Smith, James O.; Smith, Thomas B.; Rimoin, Anne W.

    2013-01-01

    Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV), an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first created spatially explicit probability distributions of its candidate reservoir species in Africa's Congo Basin. Reservoir species distributions were subsequently used to model current and projected future distributions of human monkeypox (MPX). Results indicate that forest clearing and climate are significant driving factors of the transmission of MPX from wildlife to humans under current climate conditions. Models under contemporary climate conditions performed well, as indicated by high values for the area under the receiver operator curve (AUC), and tests on spatially randomly and non-randomly omitted test data. Future projections were made on IPCC 4th Assessment climate change scenarios for 2050 and 2080, ranging from more conservative to more aggressive, and representing the potential variation within which range shifts can be expected to occur. Future projections showed range shifts into regions where MPX has not been recorded previously. Increased suitability for MPX was predicted in eastern Democratic Republic of Congo. Models developed here are useful for identifying areas where environmental conditions may become more suitable for human MPX; targeting candidate reservoir species for future screening efforts; and prioritizing regions for future MPX surveillance efforts. PMID:23935820

  6. Genomics of adaptation to host-plants in herbivorous insects.

    PubMed

    Simon, Jean-Christophe; d'Alençon, Emmanuelle; Guy, Endrick; Jacquin-Joly, Emmanuelle; Jaquiéry, Julie; Nouhaud, Pierre; Peccoud, Jean; Sugio, Akiko; Streiff, Réjane

    2015-11-01

    Herbivorous insects represent the most species-rich lineages of metazoans. The high rate of diversification in herbivorous insects is thought to result from their specialization to distinct host-plants, which creates conditions favorable for the build-up of reproductive isolation and speciation. These conditions rely on constraints against the optimal use of a wide range of plant species, as each must constitute a viable food resource, oviposition site and mating site for an insect. Utilization of plants involves many essential traits of herbivorous insects, as they locate and select their hosts, overcome their defenses and acquire nutrients while avoiding intoxication. Although advances in understanding insect-plant molecular interactions have been limited by the complexity of insect traits involved in host use and the lack of genomic resources and functional tools, recent studies at the molecular level, combined with large-scale genomics studies at population and species levels, are revealing the genetic underpinning of plant specialization and adaptive divergence in non-model insect herbivores. Here, we review the recent advances in the genomics of plant adaptation in hemipterans and lepidopterans, two major insect orders, each of which includes a large number of crop pests. We focus on how genomics and post-genomics have improved our understanding of the mechanisms involved in insect-plant interactions by reviewing recent molecular discoveries in sensing, feeding, digesting and detoxifying strategies. We also present the outcomes of large-scale genomics approaches aimed at identifying loci potentially involved in plant adaptation in these insects.

  7. Complete nucleotide sequence and analysis of two conjugative broad host range plasmids from a marine microbial biofilm.

    PubMed

    Norberg, Peter; Bergström, Maria; Hermansson, Malte

    2014-01-01

    The complete nucleotide sequence of plasmids pMCBF1 and pMCBF6 was determined and analyzed. pMCBF1 and pMCBF6 form a novel clade within the IncP-1 plasmid family designated IncP-1 ς. The plasmids were exogenously isolated earlier from a marine biofilm. pMCBF1 (62 689 base pairs; bp) and pMCBF6 (66 729 bp) have identical backbones, but differ in their mercury resistance transposons. pMCBF1 carries Tn5053 and pMCBF6 carries Tn5058. Both are flanked by 5 bp direct repeats, typical of replicative transposition. Both insertions are in the vicinity of a resolvase gene in the backbone, supporting the idea that both transposons are "res-site hunters" that preferably insert close to and use external resolvase functions. The similarity of the backbones indicates recent insertion of the two transposons and the ongoing dynamics of plasmid evolution in marine biofilms. Both plasmids also carry the insertion sequence ISPst1, albeit without flanking repeats. ISPs1is located in an unusual site within the control region of the plasmid. In contrast to most known IncP-1 plasmids the pMCBF1/pMCBF6 backbone has no insert between the replication initiation gene (trfA) and the vegetative replication origin (oriV). One pMCBF1/pMCBF6 block of about 2.5 kilo bases (kb) has no similarity with known sequences in the databases. Furthermore, insertion of three genes with similarity to the multidrug efflux pump operon mexEF and a gene from the NodT family of the tripartite multi-drug resistance-nodulation-division (RND) system in Pseudomonas aeruginosa was found. They do not seem to confer antibiotic resistance to the hosts of pMCBF1/pMCBF6, but the presence of RND on promiscuous plasmids may have serious implications for the spread of antibiotic multi-resistance.

  8. Genomic and functional characterization of the modular broad-host-range RA3 plasmid, the archetype of the IncU group.

    PubMed

    Kulinska, Anna; Czeredys, Magdalena; Hayes, Finbarr; Jagura-Burdzy, Grazyna

    2008-07-01

    IncU plasmids are a distinctive group of mobile elements with highly conserved backbone functions and variable antibiotic resistance gene cassettes. The IncU archetype is conjugative plasmid RA3, whose sequence (45,909 bp) shows it to be a mosaic, modular replicon with a class I integron different from that of other IncU replicons. Functional analysis demonstrated that RA3 possesses a broad host range and can efficiently self-transfer, replicate, and be maintained stably in alpha-, beta-, and gammaproteobacteria. RA3 contains 50 open reading frames clustered in distinct functional modules. The replication module encompasses the repA and repB genes embedded in long repetitive sequences. RepA, which is homologous to antitoxin proteins from alpha- and gammaproteobacteria, contains a Cro/cI-type DNA-binding domain present in the XRE family of transcriptional regulators. The repA promoter is repressed by RepA and RepB. The minireplicon encompasses repB and the downstream repetitive sequence r1/r2. RepB shows up to 80% similarity to putative replication initiation proteins from environmental plasmids of beta- and gammaproteobacteria, as well as similarity to replication proteins from alphaproteobacteria and Firmicutes. Stable maintenance functions of RA3 are most like those of IncP-1 broad-host-range plasmids and comprise the active partitioning apparatus formed by IncC (ParA) and KorB (ParB), the antirestriction protein KlcA, and accessory stability components KfrA and KfrC. The RA3 origin of transfer was localized experimentally between the maintenance and conjugative-transfer operons. The putative conjugative-transfer module is highly similar in organization and in its products to transfer regions of certain broad-host-range environmental plasmids.

  9. Broad-Host-Range ProUSER Vectors Enable Fast Characterization of Inducible Promoters and Optimization of p-Coumaric Acid Production in Pseudomonas putida KT2440.

    PubMed

    Calero, Patricia; Jensen, Sheila I; Nielsen, Alex T

    2016-07-15

    Pseudomonas putida KT2440 has gained increasing interest as a host for the production of biochemicals. Because of the lack of a systematic characterization of inducible promoters in this strain, we generated ProUSER broad-host-expression plasmids that facilitate fast uracil-based cloning. A set of ProUSER-reporter vectors was further created to characterize different inducible promoters. The PrhaB and Pm promoters were orthogonal and showed titratable, high, and homogeneous expression. To optimize the production of p-coumaric acid, P. putida was engineered to prevent degradation of tyrosine and p-coumaric acid. Pm and PrhaB were used to control the expression of a tyrosine ammonia lyase or AroG* and TyrA* involved in tyrosine production, respectively. Pathway expression was optimized by modulating inductions, resulting in small-scale p-coumaric acid production of 1.2 mM, the highest achieved in Pseudomonads under comparable conditions. With broad-host-range compatibility, the ProUSER vectors will serve as useful tools for optimizing gene expression in a variety of bacteria.

  10. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a... similar synthetic compounds, designated by an unbranched aliphatic chain (between 9 and 18 carbons) ending...; and applied as a post-harvest treatment to stored food commodities at a rate not to exceed 3.5...

  11. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a... similar synthetic compounds, designated by an unbranched aliphatic chain (between 9 and 18 carbons) ending...; and applied as a post-harvest treatment to stored food commodities at a rate not to exceed 3.5...

  12. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a... similar synthetic compounds, designated by an unbranched aliphatic chain (between 9 and 18 carbons) ending...; and applied as a post-harvest treatment to stored food commodities at a rate not to exceed 3.5...

  13. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a... similar synthetic compounds, designated by an unbranched aliphatic chain (between 9 and 18 carbons) ending...; and applied as a post-harvest treatment to stored food commodities at a rate not to exceed 3.5...

  14. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a... similar synthetic compounds, designated by an unbranched aliphatic chain (between 9 and 18 carbons) ending...; and applied as a post-harvest treatment to stored food commodities at a rate not to exceed 3.5...

  15. Efficacy of silk channel injections with insecticides for management of Lepidopteran pests of sweet corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary Lepidopteran pests of sweet corn in Georgia are the corn earworm, Helicoverpa zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J.E. Smith). Control of these pests typically requires multiple insecticide applications from first silking until harvest, with commercial growers fre...

  16. Belowground resistance to western corn rootworm in Lepidopteran-resistant maize genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several maize inbred lines developed from an Antiguan maize population have been shown to exhibit resistance to numerous aboveground lepidopteran pests. This study shows that these genotypes are able to significantly reduce the survival of two root feeding pests, western corn rootworm (Diabrotica v...

  17. Chapter 9. routine maintenance and storage of lepidopteran insect cell lines and baculoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The various methods for maintaining (a.k.a., subculturing, splitting, or passaging) established lepidopteran cell lines are described. Three procedures are presented that are appropriate for different cell lines dependent upon the growth characteristics (in particular, cell attachment properties) o...

  18. Diversity and geographical distribution of Flavobacterium psychrophilum isolates and their phages: patterns of susceptibility to phage infection and phage host range.

    PubMed

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio; Middelboe, Mathias

    2014-05-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in disease control requires detailed knowledge about the diversity and dynamics of host susceptibility to phage infection. For this reason, we examined the genetic diversity of 49 F. psychrophilum strains isolated in three different areas (Chile, Denmark, and USA) through direct genome restriction enzyme analysis (DGREA) and their susceptibility to 33 bacteriophages isolated in Chile and Denmark, thus covering large geographical (>12,000 km) and temporal (>60 years) scales of isolation. An additional 40 phage-resistant isolates obtained from culture experiments after exposure to specific phages were examined for changes in phage susceptibility against the 33 phages. The F. psychrophilum and phage populations isolated from Chile and Denmark clustered into geographically distinct groups with respect to DGREA profile and host range, respectively. However, cross infection between Chilean phage isolates and Danish host isolates and vice versa was observed. Development of resistance to certain bacteriophages led to susceptibility to other phages suggesting that "enhanced infection" is potentially an important cost of resistance in F. psychrophilum, possibly contributing to the observed co-existence of phage-sensitive F. psychrophilum strains and lytic phages across local and global scales. Overall, our results showed that despite the identification of local communities of phages and hosts, some key properties determining phage infection patterns seem to be globally distributed.

  19. Mitochondrial genome of the cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) and comparison with other Lepidopterans.

    PubMed

    Yin, Jiao; Hong, Gui-Yun; Wang, Ai-Min; Cao, Ya-Zhong; Wei, Zhao-Jun

    2010-10-01

    We present the complete sequence of the mitochondrial genome (mitogenome) of the cotton bollworm Helicoverpa armigera. The 15,347-bp mitogenome of H. armigera was arranged in the same order described for all other sequenced lepidopterans, which differs from the most common type found in insects, due to the movement of trnM to a position 5'-upstream of trnI. The gene overlap in the H. armigera mitogenome is totally 23 bp in six locations. The H. armigera mitogenome has a total of 175 bp of intergenic spacer sequences spread over 14 regions ranging in size from 1 to 45 bp. The nucleotide composition of the whole mitogenome of H. armigera is highly A+T biased, accounting for 80.97%, with a slightly positive AT skewness and negative GC skewness, indicating the occurrence of more A than T, C more than G. The protein-encoding genes have typical mitochondrial start codons, except for cox1, which contains the unusual CGA. The cox1, cox2, and nad4 genes have incomplete stop codons (T). The lrRNA and srRNA genes are 1395 and 794-bp long, respectively. All tRNAs have a typical cloverleaf structure of mitochondrial tRNAs, except for trnS1(AGN), the dihydrouridine arm of which could not form a stable stem-loop structure. The H. armigera A+T-rich region contains a conserved structure combining the motif ATAGA and a 19-bp poly-T stretch, but absence of the 9-bp poly-A element upstream of trnM.

  20. Effects of transgenic cry1Ie maize on non-lepidopteran pest abundance, diversity and community composition.

    PubMed

    Guo, Jingfei; He, Kanglai; Bai, Shuxiong; Zhang, Tiantao; Liu, Yunjun; Wang, Fuxin; Wang, Zhenying

    2016-12-01

    Non-lepidopteran pests are exposed to, and may be influenced by, Bt toxins when feeding on Bt maize that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt). In order to assess the potential effects of transgenic cry1Ie maize on non-lepidopteran pest species and ecological communities, a 2-year field study was conducted to compare the non-lepidopteran pest abundance, diversity and community composition between transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) by whole plant inspections. Results showed that Bt maize had no effects on non-lepidopteran pest abundance and diversity (Shannon-Wiener diversity index, Simpson's diversity index, species richness, and Pielou's index). There was a significant effect of year and sampling time on those indices analyzed. Redundancy analysis indicated maize type, sampling time and year totally explained 20.43 % of the variance in the non-lepidopteran pest community composition, but no association was presented between maize type (Bt maize and non-Bt maize) and the variance. Nonmetric multidimensional scaling analysis showed that sampling time and year, rather than maize type had close relationship with the non-lepidopteran pest community composition. These results corroborated the hypothesis that, at least in the short-term, the transgenic cry1Ie maize had negligible effects on the non-lepidopteran pest abundance, diversity and community composition.

  1. Broad host range vectors for expression of proteins with (Twin-) Strep-tag, His-tag and engineered, export optimized yellow fluorescent protein

    PubMed Central

    2013-01-01

    Background In current protein research, a limitation still is the production of active recombinant proteins or native protein associations to assess their function. Especially the localization and analysis of protein-complexes or the identification of modifications and small molecule interaction partners by co-purification experiments requires a controllable expression of affinity- and/or fluorescence tagged variants of a protein of interest in its native cellular background. Advantages of periplasmic and/or homologous expressions can frequently not be realized due to a lack of suitable tools. Instead, experiments are often limited to the heterologous production in one of the few well established expression strains. Results Here, we introduce a series of new RK2 based broad host range expression plasmids for inducible production of affinity- and fluorescence tagged proteins in the cytoplasm and periplasm of a wide range of Gram negative hosts which are designed to match the recently suggested modular Standard European Vector Architecture and database. The vectors are equipped with a yellow fluorescent protein variant which is engineered to fold and brightly fluoresce in the bacterial periplasm following Sec-mediated export, as shown from fractionation and imaging studies. Expression of Strep-tag®II and Twin-Strep-tag® fusion proteins in Pseudomonas putida KT2440 is demonstrated for various ORFs. Conclusion The broad host range constructs we have produced enable good and controlled expression of affinity tagged protein variants for single-step purification and qualify for complex co-purification experiments. Periplasmic export variants enable production of affinity tagged proteins and generation of fusion proteins with a novel engineered Aequorea-based yellow fluorescent reporter protein variant with activity in the periplasm of the tested Gram-negative model bacteria Pseudomonas putida KT2440 and Escherichia coli K12 for production, localization or co

  2. Isolation of phages for phage therapy: a comparison of spot tests and efficiency of plating analyses for determination of host range and efficacy.

    PubMed

    Khan Mirzaei, Mohammadali; Nilsson, Anders S

    2015-01-01

    Phage therapy, treating bacterial infections with bacteriophages, could be a future alternative to antibiotic treatment of bacterial infections. There are, however, several problems to be solved, mainly associated to the biology of phages, the interaction between phages and their bacterial hosts, but also to the vast variation of pathogenic bacteria which implies that large numbers of different phages are going to be needed. All of these phages must under present regulation of medical products undergo extensive clinical testing before they can be applied. It will consequently be of great economic importance that effective and versatile phages are selected and collected into phage libraries, i.e., the selection must be carried out in a way that it results in highly virulent phages with broad host ranges. We have isolated phages using the Escherichia coli reference (ECOR) collection and compared two methods, spot testing and efficiency of plating (EOP), which are frequently used to identify phages suitable for phage therapy. The analyses of the differences between the two methods show that spot tests often overestimate both the overall virulence and the host range and that the results are not correlated to the results of EOP assays. The conclusion is that single dilution spot tests cannot be used for identification and selection of phages to a phage library and should be replaced by EOP assays. The difference between the two methods can be caused by many factors. We have analysed if the differences and lack of correlation could be caused by lysis from without, bacteriocins in the phage lysate, or by the presence of prophages harbouring genes coding for phage resistance systems in the genomes of the bacteria in the ECOR collection.

  3. Novel Virulent and Broad-Host-Range Erwinia amylovora Bacteriophages Reveal a High Degree of Mosaicism and a Relationship to Enterobacteriaceae Phages ▿†

    PubMed Central

    Born, Yannick; Fieseler, Lars; Marazzi, Janine; Lurz, Rudi; Duffy, Brion; Loessner, Martin J.

    2011-01-01

    A diverse set of 24 novel phages infecting the fire blight pathogen Erwinia amylovora was isolated from fruit production environments in Switzerland. Based on initial screening, four phages (L1, M7, S6, and Y2) with broad host ranges were selected for detailed characterization and genome sequencing. Phage L1 is a member of the Podoviridae, with a 39.3-kbp genome featuring invariable genome ends with direct terminal repeats. Phage S6, another podovirus, was also found to possess direct terminal repeats but has a larger genome (74.7 kbp), and the virus particle exhibits a complex tail fiber structure. Phages M7 and Y2 both belong to the Myoviridae family and feature long, contractile tails and genomes of 84.7 kbp (M7) and 56.6 kbp (Y2), respectively, with direct terminal repeats. The architecture of all four phage genomes is typical for tailed phages, i.e., organized into function-specific gene clusters. All four phages completely lack genes or functions associated with lysogeny control, which correlates well with their broad host ranges and indicates strictly lytic (virulent) lifestyles without the possibility for host lysogenization. Comparative genomics revealed that M7 is similar to E. amylovora virus ΦEa21-4, whereas L1, S6, and Y2 are unrelated to any other E. amylovora phage. Instead, they feature similarities to enterobacterial viruses T7, N4, and ΦEcoM-GJ1. In a series of laboratory experiments, we provide proof of concept that specific two-phage cocktails offer the potential for biocontrol of the pathogen. PMID:21764969

  4. Vaccinia virus K1L protein mediates host-range function in RK-13 cells via ankyrin repeat and may interact with a cellular GTPase-activating protein.

    PubMed

    Bradley, Ritu R; Terajima, Masanori

    2005-12-01

    The K1L protein of vaccinia virus is required for its growth in certain cell lines (RK-13 and human). The cowpox host-range protein CP77 has been shown to complement K1L function in RK-13 cells, despite a lack of homology between the two proteins except for ankyrin repeats. We investigated the role of ankyrin repeats of K1L protein in RK-13 cells. The growth of a recombinant vaccinia virus, with K1L gene mutated in the most conserved ankyrin repeat, was severely impaired. Infection with the mutant virus caused shutdown of cellular and viral protein synthesis early in infection. We also investigated the interaction of K1L protein with cellular proteins and found that K1L interacts with the rabbit homologue of human ACAP2, a GTPase-activating protein with ankyrin repeats. Our result suggests the importance of ankyrin repeat for host-range function of K1L in RK-13 cells and identifies ACAP2 as a cellular protein, which may be interacting with K1L.

  5. Divergence of host range and biological properties between natural isolate and full-length infectious cDNA clone of the Beet mild yellowing virus 2ITB.

    PubMed

    Klein, Elodie; Brault, Véronique; Klein, Delphine; Weyens, Guy; Lefèbvre, Marc; Ziegler-Graff, Véronique; Gilmer, David

    2014-01-01

    Plant infection by poleroviruses is restricted to phloem tissues, preventing any classical leaf rub inoculation with viral RNA or virions. Efficient virus inoculation to plants is achieved by viruliferous aphids that acquire the virus by feeding on infected plants. The use of promoter-driven infectious cDNA is an alternative means to infect plants and allows reverse genetic studies to be performed. Using Beet mild yellowing virus isolate 2ITB (BMYV-2ITB), we produced a full-length infectious cDNA clone of the virus (named BMYV-EK) placed under the control of the T7 RNA polymerase and the Cauliflower mosaic virus 35S promoters. Infectivity of the engineered BMYV-EK virus was assayed in different plant species and compared with that of the original virus. We showed that in vitro- or in planta-derived transcripts were infectious in protoplasts and in whole plants. Importantly, the natural aphid vector Myzus persicae efficiently transmitted the viral progeny produced in infected plants. By comparing agroinoculation and aphid infection in a host range assay, we showed that the engineered BMYV-EK virus displayed a similar host range to BMYV-2ITB, except for Nicotiana benthamiana, which proved to be resistant to systemic infection with BMYV-EK. Finally, both the BMYV-EK P0 and the full-length clone were able to strongly interfere with post-transcriptional gene silencing.

  6. Complete Genome Sequence of the N2-Fixing Broad Host Range Endophyte Klebsiella pneumoniae 342 and Virulence Predictions Verified in Mice

    PubMed Central

    Fouts, Derrick E.; Tyler, Heather L.; DeBoy, Robert T.; Daugherty, Sean; Ren, Qinghu; Badger, Jonathan H.; Durkin, Anthony S.; Huot, Heather; Shrivastava, Susmita; Kothari, Sagar; Dodson, Robert J.; Mohamoud, Yasmin; Khouri, Hoda; Roesch, Luiz F. W.; Krogfelt, Karen A.; Struve, Carsten; Triplett, Eric W.; Methé, Barbara A.

    2008-01-01

    We report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, Klebsiella pneumoniae 342. Although K. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world), while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. Genomic analysis examined K. pneumoniae 342 for the presence of previously identified genes from other bacteria involved in colonization of, or growth in, plants. From this set, approximately one-third were identified in K. pneumoniae 342, suggesting additional factors most likely contribute to its endophytic lifestyle. Comparative genome analyses were used to provide new insights into this question. Results included the identification of metabolic pathways and other features devoted to processing plant-derived cellulosic and aromatic compounds, and a robust complement of transport genes (15.4%), one of the highest percentages in bacterial genomes sequenced. Although virulence and antibiotic resistance genes were predicted, experiments conducted using mouse models showed pathogenicity to be attenuated in this strain. Comparative genomic analyses with the presumed human pathogen K. pneumoniae MGH78578 revealed that MGH78578 apparently cannot fix nitrogen, and the distribution of genes essential to surface attachment, secretion, transport, and regulation and signaling varied between each genome, which may indicate critical divergences between the strains that influence their preferred host ranges and lifestyles (endophytic plant associations for K. pneumoniae 342 and presumably human pathogenesis for MGH78578). Little genome information is available concerning endophytic bacteria. The K. pneumoniae 342 genome will drive new research into this less-understood, but important category

  7. Broad-host-range expression vectors that carry the L-arabinose-inducible Escherichia coli araBAD promoter and the araC regulator.

    PubMed

    Newman, J R; Fuqua, C

    1999-02-18

    We describe the development and analysis of broad-host-range (BHR) cloning vectors that carry the araC-PBAD controlled expression cassette from Escherichia coli. These plasmids are designed to facilitate l-arabinose-responsive control of target genes in a variety of Gram-negative bacterial hosts. BHR PBAD::lacZ fusions were used to analyze the utility of this controlled expression system in the plant pathogen Agrobacterium tumefaciens. In A. tumefaciens, the level of control afforded is significant, although less stringent than that observed in E. coli. The BHR PBAD vectors offer a useful alternative to currently used controlled expression systems, and can be employed in conjunction with other regulated promoters to simultaneously regulate expression of multiple genes. Addition of a variety of carbon sources, namely C4 acids and the anti-inducer d-fucose, allows modulation of l-arabinose induction. Activation of PBAD expression in A. tumefaciens requires a plasmid-borne copy of araC, and is not affected by endogenous regulators.

  8. Ensifer meliloti bv. lancerottense establishes nitrogen-fixing symbiosis with Lotus endemic to the Canary Islands and shows distinctive symbiotic genotypes and host range.

    PubMed

    León-Barrios, Milagros; Lorite, María José; Donate-Correa, Javier; Sanjuán, Juan

    2009-09-01

    Eleven strains were isolated from root nodules of Lotus endemic to the Canary Islands and they belonged to the genus Ensifer, a genus never previously described as a symbiont of Lotus. According to their 16S rRNA and atpD gene sequences, two isolates represented minority genotypes that could belong to previously undescribed Ensifer species, but most of the isolates were classified within the species Ensifer meliloti. These isolates nodulated Lotus lancerottensis, Lotus corniculatus and Lotus japonicus, whereas Lotus tenuis and Lotus uliginosus were more restrictive hosts. However, effective nitrogen fixation only occurred with the endemic L. lancerottensis. The E. meliloti strains did not nodulate Medicago sativa, Medicago laciniata Glycine max or Glycine soja, but induced non-fixing nodules on Phaseolus vulgaris roots. nodC and nifH symbiotic gene phylogenies showed that the E. meliloti symbionts of Lotus markedly diverged from strains of Mesorhizobium loti, the usual symbionts of Lotus, as well as from the three biovars (bv. meliloti, bv. medicaginis, and bv. mediterranense) so far described within E. meliloti. Indeed, the nodC and nifH genes from the E. meliloti isolates from Lotus represented unique symbiotic genotypes. According to their symbiotic gene sequences and host range, the Lotus symbionts would represent a new biovar of E. meliloti for which bv. lancerottense is proposed.

  9. Disentangling Peronospora on Papaver: phylogenetics, taxonomy, nomenclature and host range of downy mildew of opium poppy (Papaver somniferum) and related species.

    PubMed

    Voglmayr, Hermann; Montes-Borrego, Miguel; Landa, Blanca B

    2014-01-01

    Based on sequence data from ITS rDNA, cox1 and cox2, six Peronospora species are recognised as phylogenetically distinct on various Papaver species. The host ranges of the four already described species P. arborescens, P. argemones, P. cristata and P. meconopsidis are clarified. Based on sequence data and morphology, two new species, P. apula and P. somniferi, are described from Papaver apulum and P. somniferum, respectively. The second Peronospora species parasitizing Papaver somniferum, that was only recently recorded as Peronospora cristata from Tasmania, is shown to represent a distinct taxon, P. meconopsidis, originally described from Meconopsis cambrica. It is shown that P. meconopsidis on Papaver somniferum is also present and widespread in Europe and Asia, but has been overlooked due to confusion with P. somniferi and due to less prominent, localized disease symptoms. Oospores are reported for the first time for P. meconopsidis from Asian collections on Papaver somniferum. Morphological descriptions, illustrations and a key are provided for all described Peronospora species on Papaver. cox1 and cox2 sequence data are confirmed as equally good barcoding loci for reliable Peronospora species identification, whereas ITS rDNA does sometimes not resolve species boundaries. Molecular phylogenetic data reveal high host specificity of Peronospora on Papaver, which has the important phytopathological implication that wild Papaver spp. cannot play any role as primary inoculum source for downy mildew epidemics in cultivated opium poppy crops.

  10. Disentangling Peronospora on Papaver: Phylogenetics, Taxonomy, Nomenclature and Host Range of Downy Mildew of Opium Poppy (Papaver somniferum) and Related Species

    PubMed Central

    Voglmayr, Hermann; Montes-Borrego, Miguel; Landa, Blanca B.

    2014-01-01

    Based on sequence data from ITS rDNA, cox1 and cox2, six Peronospora species are recognised as phylogenetically distinct on various Papaver species. The host ranges of the four already described species P. arborescens, P. argemones, P. cristata and P. meconopsidis are clarified. Based on sequence data and morphology, two new species, P. apula and P. somniferi, are described from Papaver apulum and P. somniferum, respectively. The second Peronospora species parasitizing Papaver somniferum, that was only recently recorded as Peronospora cristata from Tasmania, is shown to represent a distinct taxon, P. meconopsidis, originally described from Meconopsis cambrica. It is shown that P. meconopsidis on Papaver somniferum is also present and widespread in Europe and Asia, but has been overlooked due to confusion with P. somniferi and due to less prominent, localized disease symptoms. Oospores are reported for the first time for P. meconopsidis from Asian collections on Papaver somniferum. Morphological descriptions, illustrations and a key are provided for all described Peronospora species on Papaver. cox1 and cox2 sequence data are confirmed as equally good barcoding loci for reliable Peronospora species identification, whereas ITS rDNA does sometimes not resolve species boundaries. Molecular phylogenetic data reveal high host specificity of Peronospora on Papaver, which has the important phytopathological implication that wild Papaver spp. cannot play any role as primary inoculum source for downy mildew epidemics in cultivated opium poppy crops. PMID:24806292

  11. Steinernema carpocapsae DD136: metabolites limit the non-self adhesion responses of haemocytes of two lepidopteran larvae, Galleria mellonella (F. Pyralidae) and Malacosoma disstria (F. Lasiocampidae).

    PubMed

    Walter, Tita N; Dunphy, Gary B; Mandato, Craig A

    2008-10-01

    Live adult and juvenile entomopathogenic Steinernema carpocapsae DD136 (P. Nematoda) were not subjected to adhesion by haemocytes of lepidopteran insect larvae of Galleria mellonella or Malacosoma disstriain vitro or in vivo. In vitro freeze-killed nematodes exhibited haemocyte attachment, the intensity increasing with time. Accumulation of haemocytes on the dead nematodes was associated with host phenoloxidase activity; live nematodes and their exudates did not activate the enzyme whereas dead nematodes but not their exudate did activate phenoloxidase. Live-nematode exudate inhibited granular cell and some plasmatocyte adhesion to slides, increased granular cell but not plasmatocyte dissociation from preformed haemocyte monolayers and in vivo elevated total haemocyte counts and changed the floating haemocyte types while impairing bacterial removal from the haemolymph. Dead-nematode exudate did not affect these parameters thus immunosuppressant activity by live nematodes may represent the release of inhibitors not associated with their cuticle. The third stage juveniles released the inhibitors.

  12. Comparative evaluation of phenoloxidase in different larval stages of four lepidopteran pests after exposure to Bacillus thuringiensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some lepidopteran insects are important agricultural pests, causing serious crop damage. Microbial entomopathogen-based bioinsecticides are considered effective pest control alternatives to synthetic chemicals. However, insects can defend against pathogens by innate mechanisms, including phenoloxi...

  13. Complete Genome sequence of Burkholderia phymatum STM815T, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    PubMed Central

    Moulin, Lionel; Klonowska, Agnieszka; Caroline, Bournaud; Booth, Kristina; Vriezen, Jan A.C.; Melkonian, Rémy; James, Euan K.; Young, J. Peter W.; Bena, Gilles; Hauser, Loren; Land, Miriam; Kyrpides, Nikos; Bruce, David; Chain, Patrick; Copeland, Alex; Pitluck, Sam; Woyke, Tanja; Lizotte-Waniewski, Michelle; Bristow, Jim; Riley, Margaret

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp). PMID:25197461

  14. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    SciTech Connect

    Moulin, Lionel; Klonowska, Agnieszka; Caroline, Bournaud; Booth, Kristina; Vriezen, Jan A.C.; Melkonian, Remy; James, Euan; Young, Peter W.; Bena, Gilles; Hauser, Loren John; Land, Miriam L; Kyrpides, Nikos C; Bruce, David; Chain, Patrick S. G.; Copeland, A; Pitluck, Sam; Woyke, Tanja; Lizotte-Waniewski, Michelle; Bristow, James; Riley, Monica

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  15. The newly described mecA homologue, mecALGA251, is present in methicillin-resistant Staphylococcus aureus isolates from a diverse range of host species

    PubMed Central

    Paterson, G. K.; Larsen, A. R.; Robb, A.; Edwards, G. E.; Pennycott, T. W.; Foster, G.; Mot, D.; Hermans, K.; Baert, K.; Peacock, S. J.; Parkhill, J.; Zadoks, R. N.; Holmes, M. A.

    2012-01-01

    Objectives A previously unidentified mecA homologue, mecALGA251, has recently been described in methicillin-resistant Staphylococcus aureus (MRSA) from humans and dairy cattle. The origin and epidemiology of this novel homologue are unclear. The objective of this study was to provide basic descriptive information of MRSA isolates harbouring mecALGA251 from a range of host animal species. Methods A number of S. aureus isolates from historical animal isolate collections were chosen for investigation based on their similarity to known mecALGA251 MRSA isolates. The presence of mecALGA251 was determined using a multiplex PCR and antimicrobial susceptibility testing performed by disc diffusion. Results MRSA harbouring mecALGA251 were found in isolates from a domestic dog, brown rats, a rabbit, a common seal, sheep and a chaffinch. All of the isolates were phenotypically MRSA, although this depended on which test was used; some isolates would be considered susceptible with certain assays. All isolates were susceptible to linezolid, rifampicin, kanamycin, norfloxacin, erythromycin, clindamycin, fusidic acid, tetracycline, trimethoprim/sulfamethoxazole and mupirocin. Five multilocus sequence types were represented (2273, 130, 425, 1764 and 1245) and six spa types (t208, t6293, t742, t6594, t7914 and t843). Conclusions The discovery of MRSA isolates possessing mecALGA251 from a diverse range of host species, including different taxonomic classes, has important implications for the diagnosis of MRSA in these species and our understanding of the epidemiology of this novel mecA homologue. PMID:22941897

  16. The Detection and Sequencing of a Broad-Host-Range Conjugative IncP-1β Plasmid in an Epidemic Strain of Mycobacterium abscessus subsp. bolletii

    PubMed Central

    Leão, Sylvia Cardoso; Matsumoto, Cristianne Kayoko; Carneiro, Adriana; Ramos, Rommel Thiago; Nogueira, Christiane Lourenço; Junior, James Daltro Lima; Lima, Karla Valéria; Lopes, Maria Luiza; Schneider, Horacio; Azevedo, Vasco Ariston; da Costa da Silva, Artur

    2013-01-01

    Background An extended outbreak of mycobacterial surgical infections occurred in Brazil during 2004–2008. Most infections were caused by a single strain of Mycobacterium abscessus subsp. bolletii, which was characterized by a specific rpoB sequevar and two highly similar pulsed-field gel electrophoresis (PFGE) patterns differentiated by the presence of a ∼50 kb band. The nature of this band was investigated. Methodology/Principal Findings Genomic sequencing of the prototype outbreak isolate INCQS 00594 using the SOLiD platform demonstrated the presence of a 56,264-bp circular plasmid, designated pMAB01. Identity matrices, genetic distances and phylogeny analyses indicated that pMAB01 belongs to the broad-host-range plasmid subgroup IncP-1β and is highly related to BRA100, pJP4, pAKD33 and pB10. The presence of pMAB01-derived sequences in 41 M. abscessus subsp. bolletii isolates was evaluated using PCR, PFGE and Southern blot hybridization. Sixteen of the 41 isolates showed the presence of the plasmid. The plasmid was visualized as a ∼50-kb band using PFGE and Southern blot hybridization in 12 isolates. The remaining 25 isolates did not exhibit any evidence of this plasmid. The plasmid was successfully transferred to Escherichia coli by conjugation and transformation. Lateral transfer of pMAB01 to the high efficient plasmid transformation strain Mycobacterium smegmatis mc2155 could not be demonstrated. Conclusions/Significance The occurrence of a broad-host-range IncP-1β plasmid in mycobacteria is reported for the first time. Thus, genetic exchange could result in the emergence of specific strains that might be better adapted to cause human disease. PMID:23565273

  17. Suppressors of a Host Range Mutation in the Rabbitpox Virus Serpin SPI-1 Map to Proteins Essential for Viral DNA Replication

    PubMed Central

    Luttge, Benjamin G.; Moyer, Richard W.

    2005-01-01

    The orthopoxvirus serpin SPI-1 is an intracellular serine protease inhibitor that is active against cathepsin G in vitro. Rabbitpox virus (RPV) mutants with deletions of the SPI-1 gene grow on monkey kidney cells (CV-1) but do not plaque on normally permissive human lung carcinoma cells (A549). This reduced-host-range (hr) phenotype suggests that SPI-1 may interact with cellular and/or other viral proteins. We devised a genetic screen for suppressors of SPI-1 hr mutations by first introducing a mutation into SPI-1 (T309R) at residue P14 of the serpin reactive center loop. The SPI-1 T309R serpin is inactive as a protease inhibitor in vitro. Introduction of the mutation into RPV leads to the same restricted hr phenotype as deletion of the SPI-1 gene. Second-site suppressors were selected by restoration of growth of the RPV SPI-1 T309R hr mutant on A549 cells. Both intragenic and extragenic suppressors of the T309R mutation were identified. One novel intragenic suppressor mutation, T309C, restored protease inhibition by SPI-1 in vitro. Extragenic suppressor mutations were mapped by a new procedure utilizing overlapping PCR products encompassing the entire genome in conjunction with marker rescue. One suppressor mutation, which also rendered the virus temperature sensitive for growth, mapped to the DNA polymerase gene (E9L). Several other suppressors mapped to gene D5R, an NTPase required for DNA replication. These results unexpectedly suggest that the host range function of SPI-1 may be associated with viral DNA replication by an as yet unknown mechanism. PMID:15994811

  18. Suppressors of a host range mutation in the rabbitpox virus serpin SPI-1 map to proteins essential for viral DNA replication.

    PubMed

    Luttge, Benjamin G; Moyer, Richard W

    2005-07-01

    The orthopoxvirus serpin SPI-1 is an intracellular serine protease inhibitor that is active against cathepsin G in vitro. Rabbitpox virus (RPV) mutants with deletions of the SPI-1 gene grow on monkey kidney cells (CV-1) but do not plaque on normally permissive human lung carcinoma cells (A549). This reduced-host-range (hr) phenotype suggests that SPI-1 may interact with cellular and/or other viral proteins. We devised a genetic screen for suppressors of SPI-1 hr mutations by first introducing a mutation into SPI-1 (T309R) at residue P14 of the serpin reactive center loop. The SPI-1 T309R serpin is inactive as a protease inhibitor in vitro. Introduction of the mutation into RPV leads to the same restricted hr phenotype as deletion of the SPI-1 gene. Second-site suppressors were selected by restoration of growth of the RPV SPI-1 T309R hr mutant on A549 cells. Both intragenic and extragenic suppressors of the T309R mutation were identified. One novel intragenic suppressor mutation, T309C, restored protease inhibition by SPI-1 in vitro. Extragenic suppressor mutations were mapped by a new procedure utilizing overlapping PCR products encompassing the entire genome in conjunction with marker rescue. One suppressor mutation, which also rendered the virus temperature sensitive for growth, mapped to the DNA polymerase gene (E9L). Several other suppressors mapped to gene D5R, an NTPase required for DNA replication. These results unexpectedly suggest that the host range function of SPI-1 may be associated with viral DNA replication by an as yet unknown mechanism.

  19. Rhodomyrtus tomentosa: New Host Records for Metanastria gemella and Arna bipunctapex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surveys for host specific natural enemies of R. tomentosa in China (mainland and Hong Kong) resulted in the discovery of two lepidopteran species that have not been previously reported as herbivores of the plant: M. gemella and A. bipunctapex. Multiple generations of both species were reared on R. t...

  20. A Standardized Lepidopteran Bioassay to Investigate the Bioactivity of Insecticidal Proteins Produced in Transgenic Crops.

    PubMed

    Graser, Gerson; Walters, Frederick S

    2016-01-01

    Insecticidal bioassays are the only reliable method to investigate the biological activity of an insecticidal protein and therefore provide an essential toolkit for the characterization and potency determination of these proteins. Here we present a standardized method for a lepidopteran larval bioassay, which is optimized to specifically estimate activity of insecticidal proteins produced in transgenic plants. The treatment can be either applied to the surface of the artificial diet, or blended into the diet.

  1. Lepidopteran HMG-CoA reductase is a potential selective target for pest control

    PubMed Central

    Li, Yuan-mei; Huang, Juan; Tobe, Stephen S.

    2017-01-01

    As a consequence of the negative impacts on the environment of some insecticides, discovery of eco-friendly insecticides and target has received global attention in recent years. Sequence alignment and structural comparison of the rate-limiting enzyme HMG-CoA reductase (HMGR) revealed differences between lepidopteran pests and other organisms, which suggested insect HMGR could be a selective insecticide target candidate. Inhibition of JH biosynthesis in vitro confirmed that HMGR inhibitors showed a potent lethal effect on the lepidopteran pest Manduca sexta, whereas there was little effect on JH biosynthesis in Apis mellifera and Diploptera punctata. The pest control application of these inhibitors demonstrated that they can be insecticide candidates with potent ovicidal activity, larvicidal activity and insect growth regulatory effects. The present study has validated that Lepidopteran HMGR can be a potent selective insecticide target, and the HMGR inhibitors (especially type II statins) could be selective insecticide candidates and lead compounds. Furthermore, we demonstrated that sequence alignment, homology modeling and structural comparison may be useful for determining potential enzymes or receptors which can be eco-friendly pesticide  targets. PMID:28133568

  2. Characterization of protein phosphatase 5 from three lepidopteran insects: Helicoverpa armigera, Mythimna separata and Plutella xylostella.

    PubMed

    Chen, Xi'en; Lü, Shumin; Zhang, Yalin

    2014-01-01

    Protein phosphatase 5 (PP5), a unique member of serine/threonine phosphatases, regulates a variety of biological processes. We obtained full-length PP5 cDNAs from three lepidopteran insects, Helicoverpa armigera, Mythimna separata and Plutella xylostella, encoding predicted proteins of 490 (55.98 kDa), 490 (55.82 kDa) and 491 (56.07 kDa) amino acids, respectively. These sequences shared a high identity with other insect PP5s and contained the TPR (tetratricopeptide repeat) domains at N-terminal regions and highly conserved C-terminal catalytic domains. Tissue- and stage-specific expression pattern analyses revealed these three PP5 genes were constitutively expressed in all stages and in tested tissues with predominant transcription occurring at the egg and adult stages. Activities of Escherichia coli-produced recombinant PP5 proteins could be enhanced by almost 2-fold by a known PP5 activator: arachidonic acid. Kinetic parameters of three recombinant proteins against substrate pNPP were similar both in the absence or presence of arachidonic acid. Protein phosphatases inhibitors, okadaic acid, cantharidin, and endothall strongly impeded the activities of the three recombinant PP5 proteins, as well as exerted an inhibitory effect on crude protein phosphatases extractions from these three insects. In summary, lepidopteran PP5s share similar characteristics and are all sensitive to the protein phosphatases inhibitors. Our results also imply protein phosphatase inhibitors might be used in the management of lepidopteran pests.

  3. A baseline analysis of the distribution, host-range, and severity of the rust Puccinia Psidii in the Hawaiian islands, 2005-2010

    USGS Publications Warehouse

    Anderson, Robert C.

    2012-01-01

    Puccinia psidii was first described by Winter (1884) on guava (Psidium guajava L.) in Brazil. The rust is still a major pest of native guava in Brazil and is often referred to as “guava rust” internationally. It is unusual among rust fungi because of its broad and ever-expanding host-range within the Myrtaceae plant family (Simpson et al. 2006). The pathogen is regarded as a major threat to Eucalyptus plantations and other Myrtaceae worldwide (Coutinho et al. 1998, Grgurinovic et al. 2006, Glen et al. 2007). Infections of leaves and meristems are particularly severe on susceptible seedlings, cuttings, young trees, and coppice, causing plants to be stunted and multi-branched, inhibiting normal growth and development, and sometimes causing death to young seedlings (Booth et al. 2000, Rayachhetry et al. 2001). The fungus has expanded its host-range in Brazil, affecting both native and introduced Myrtaceae (Coutinho et al. 1998).


    Since its discovery in 1884, P. psidii has continually been discovered to have an expanding host-range within the Myrtaceae, affecting hosts throughout much of South and Central America and the Caribbean. Spreading out originally from Brazil in 1884, the fungus has been reported on hosts in the following countries (first record in parentheses): Paraguay (1884), Uruguay (1889), Ecuador (1891), Colombia (1913), Puerto Rico (1913), Cuba (1926), Dominican Republic (1933), Venezuela (1934), Jamaica (1936), Argentina (1946), Dominica (1948), Trinidad and Tobago (1951), Guatemala (1968), United States (Florida; 1977), Mexico (1981), El Salvador (1987), and Costa Rica (1998) (Simpson et al. 2006). It is possible that P. psidii was present in El Salvador and Costa Rica prior to 1980, but was not reported until 1987 and 1998, respectively.


    Until recently, Puccinia psidii was restricted to the Neotropics, Mexico, and the

  4. Different Phenotypes of Walker-Like A Box Mutants of ParA Homolog IncC of Broad-Host-Range IncP Plasmids

    PubMed Central

    Siddique, Azeem; Figurski, David H.

    2012-01-01

    The promiscuous IncPα plasmids RK2 and R995 encode a broad-host-range partition system, whose essential components include the incC and korB genes and a DNA site (OB) to which the korB product binds. IncC2, the smaller of the two incC products, is sufficient for stabilization of R995ΔincC. It is a member of the type Ia ParA family of partition ATPases. To better understand the role of ATP in partition, we constructed three alanine-substitution mutants of IncC2. Each mutation changed a different residue of the Walker-like ATP-binding and hydrolysis motif, including a lysine (K10) conserved solely among members of the ParA and MinD families. All three IncC2 mutants were defective in plasmid partition, but they differed from one another in other respects. The IncC2 T16A mutant, predicted to be defective in Mg2+ coordination, was severely impaired in all activities tested. IncC2 K10A, predicted to be defective in ATP hydrolysis, mediated enhanced incompatibility with R995 derivatives. IncC2 K15A, predicted to be defective in ATP binding, exhibited two distinct incompatibility properties depending on the genotype of the target plasmid. When in trans to plasmids carrying a complementable incC deletion, IncC2 K15A caused dramatic plasmid loss, even at low levels of expression. In trans to wild-type R995 or to R995ΔincC carrying a functional P1 partition system, IncC2 K15A-mediated incompatibility was significantly less than that caused by wild-type IncC2. All three Walker-like A box mutants were also defective for the host toxicity that normally results from co-overexpression of incC and korB. The phenotypes of the mutants support a model in which nucleotide hydrolysis is required for separation of paired plasmid complexes and possible interaction with a host factor. PMID:22579980

  5. C7L Family of Poxvirus Host Range Genes Inhibits Antiviral Activities Induced by Type I Interferons and Interferon Regulatory Factor 1

    PubMed Central

    Meng, Xiangzhi; Schoggins, John; Rose, Lloyd; Cao, Jingxin; Ploss, Alexander; Rice, Charles M.

    2012-01-01

    Vaccinia virus (VACV) K1L and C7L function equivalently in many mammalian cells to support VACV replication and antagonize antiviral activities induced by type I interferons (IFNs). While K1L is limited to orthopoxviruses, genes that are homologous to C7L are found in diverse mammalian poxviruses. In this study, we showed that the C7L homologues from sheeppox virus and swinepox virus could rescue the replication defect of a VACV mutant deleted of both K1L and C7L (vK1L−C7L−). Interestingly, the sheeppox virus C7L homologue could rescue the replication of vK1L−C7L− in human HeLa cells but not in murine 3T3 and LA-4 cells, in contrast to all other C7L homologues. Replacing amino acids 134 and 135 of the sheeppox virus C7L homologue, however, made it functional in the two murine cell lines, suggesting that these two residues are critical for antagonizing a putative host restriction factor which has some subtle sequence variation in human and murine cells. Furthermore, the C7L family of host range genes from diverse mammalian poxviruses were all capable of antagonizing type I IFN-induced antiviral activities against VACV. Screening of a library of more than 350 IFN-stimulated genes (ISGs) identified interferon-regulated factor 1 (IRF1) as an inhibitor of vK1L−C7L− but not wild-type VACV. Expression of either K1L or C7L, however, rendered vK1L−C7L− resistant to IRF1-induced antiviral activities. Altogether, our data show that K1L and C7L antagonize IRF1-induced antiviral activities and that the host modulation function of C7L is evolutionally conserved in all poxviruses that can readily replicate in tissue-cultured mammalian cells. PMID:22345458

  6. Fundamental host range of Pseudophilothrips ichini s.l. (Thysanoptera: Phlaeothripidae): a candidate biological control agent of Schinus terebinthifolius (Sapindales: Anacardiaceae) in the United States.

    PubMed

    Cuda, J P; Medal, J C; Gillmore, J L; Habeck, D H; Pedrosa-Macedo, J H

    2009-12-01

    Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) is a non-native perennial woody plant that is one of the most invasive weeds in Florida, Hawaii, and more recently California and Texas. This plant was introduced into Florida from South America as a landscape ornamental in the late 19th century, eventually escaped cultivation, and now dominates entire ecosystems in south-central Florida. Recent DNA studies have confirmed two separate introductions of S. terebinthifolius in Florida, and there is evidence of hybridization. A thrips, Pseudophilothrips ichini s.l. (Hood) (Thysanoptera: Phlaeothripidae), is commonly found attacking shoots and flowers of S. terebinthifolius in Brazil. Immatures and occasionally adults form large aggregations on young terminal growth (stems and leaves) of the plant. Feeding damage by P. ichini s.l. frequently kills new shoots, which reduces vigor and restricts growth of S. terebinthifolius. Greenhouse and laboratory host range tests with 46 plant species in 18 families and 10 orders were conducted in Paraná, Brazil, and Florida. Results of no-choice, paired-choice, and multiple-choice tests indicated that P. ichini s.l. is capable of reproducing only on S. terebinthifolius and possibly Schinus molle L., an ornamental introduced into California from Peru that has escaped cultivation and is considered invasive. Our results showed that P. ichini s.l. posed minimal risk to mature S. molle plants or the Florida native Metopium toxiferum L. Krug and Urb. In May 2007, the federal interagency Technical Advisory Group for Biological Control Agents of Weeds (TAG) concluded P. ichini s.l. was sufficiently host specific to recommend its release from quarantine.

  7. Geochemistry and geochronology of carbonate-hosted base metal deposits in the southern Brooks Range, Alaska: temporal association with VMS deposits and metallogenic implications

    USGS Publications Warehouse

    Kelly, Karen; Slack, John; Selby, David

    2009-01-01

    The Brooks Range contains enormous accumulations of zinc and copper, either as VMS or sediment-hosted deposits. The Ruby Creek and Omar deposits are Cu-Co stratabound deposits associated with dolomitic breccias. Numerous volcanogenic Cu-Zn (+/-Ag, Au) deposits are situated ~20 km north of the Ruby Creek deposit. The carbonate-hosted deposits consist of chalcopyrite and bornite that fill open spaces, replace the matrix of the breccias, and occur in later cross-cutting veins. Cobaltiferous pyrite, chalcocite, minor tennantite-tetrahedrite, galena, and sphalerite are also present. At Ruby Creek, phases such as carrollite, renierite, and germanite occur rarely. The deposits have undergone post-depositional metamorphism (Ruby Creek, low greenschist facies; Omar, blueschist facies). The unusual geochemical signature includes Cu-Co +/- Ag, As, Au, Bi, Ge, Hg, Sb, and U with sporadic high Re concentrations (up to 2.7 ppm). New Re-Os data were obtained for chalcopyrite, bornite, and pyrite from the Ruby Creek deposit (analyses of sulfides from Omar are in progress). The data show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the Ruby Creek deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization occurred at 384 +/-4.2 Ma, which coincides with zircon U-Pb ages from igneous rocks that are spatially and genetically associated with VMS deposits. This suggests a temporal link between regional magmatism and hydrothermal mineralization.

  8. Sarcocystis calchasi has an expanded host range and induces neurological disease in cockatiels (Nymphicus hollandicus) and North American rock pigeons (Columbia livia f. dom.).

    PubMed

    Olias, Philipp; Maier, Kristina; Wuenschmann, Arno; Reed, Leslie; Armién, Aníbal G; Shaw, Daniel P; Gruber, Achim D; Lierz, Michael

    2014-02-24

    Pigeon protozoal encephalitis (PPE) is an emerging central nervous system disease of pigeons (Columba livia f. domestica) caused by the apicomplexan parasite Sarcocystis calchasi. The intermediate host specificity of S. calchasi had been considered high, as domestic chickens were resistant to experimental infection. Here, we have re-evaluated this concept and expanded the known host range of S. calchasi by experimental infection of cockatiels (Nymphicus hollandicus), a species distantly related to pigeons. In this work, a group of eight cockatiels were experimentally infected with S. calchasi, which resulted in a biphasic central nervous system disease that paralleled PPE in many aspects, albeit with a more diverse pathology. All cockatiels became lethargic and polyuric between days 7 and 13 pi and during that time schizonts of S. calchasi were found primarily in the liver and spleen accompanied by necrosis and inflammation. As with pigeons, neurological signs occurred during a chronic phase of the disease in three cockatiels between 57 and 63 dpi. However, all five cockatiels necropsied in that period, or at the end of the trial at 76 dpi, had a severe lymphohistiocytic and necrotizing encephalitis. No tissue cysts were found in the heart, and cockatiels infected with 10(5) sporocysts only had a negligible parasite load in skeletal muscles despite the presence of severe central nervous system lesions. Notably, intralesional schizonts were identified in the brain of one cockatiel. In contrast to previous results, intralesional schizonts were also identified in the brains of three of six naturally infected pigeons from Minnesota and Missouri examined as part of an epidemiological investigation. In both the cockatiel and the pigeons, tissue cysts were found concurrently with schizonts suggesting an uncommon phenomenon in the Sarcocystis life cycle. Based on the results of this study, transmission of S. calchasi to avian species other than the domestic pigeon is

  9. Understanding phyolgenetic relationships among species in the Nosema/Vairimorpha clade: what does genetic similarity say about host switching in the microsporidia?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microsporidian species with high genetic identity based on rDNA phylogenies have been isolated from different insect species and even higher level host taxa across the globe. Complicating the picture, for genera such as the lepidopteran Nosema and Vairimorpha, isolates from different hosts may be mo...

  10. A Lepidopteran-Specific Gene Family Encoding Valine-Rich Midgut Proteins

    PubMed Central

    Odman-Naresh, Jothini; Duevel, Margret; Muthukrishnan, Subbaratnam; Merzendorfer, Hans

    2013-01-01

    Many lepidopteran larvae are serious agricultural pests due to their feeding activity. Digestion of the plant diet occurs mainly in the midgut and is facilitated by the peritrophic matrix (PM), an extracellular sac-like structure, which lines the midgut epithelium and creates different digestive compartments. The PM is attracting increasing attention to control lepidopteran pests by interfering with this vital function. To identify novel PM components and thus potential targets for insecticides, we performed an immunoscreening with anti-PM antibodies using an expression library representing the larval midgut transcriptome of the tobacco hornworm, Manduca sexta. We identified three cDNAs encoding valine-rich midgut proteins of M. sexta (MsVmps), which appear to be loosely associated with the PM. They are members of a lepidopteran-specific family of nine VMP genes, which are exclusively expressed in larval stages in M. sexta. Most of the MsVMP transcripts are detected in the posterior midgut, with the highest levels observed for MsVMP1. To obtain further insight into Vmp function, we expressed MsVMP1 in insect cells and purified the recombinant protein. Lectin staining and glycosidase treatment indicated that MsVmp1 is highly O-glycosylated. In line with results from qPCR, immunoblots revealed that MsVmp1 amounts are highest in feeding larvae, while MsVmp1 is undetectable in starving and molting larvae. Finally using immunocytochemistry, we demonstrated that MsVmp1 localizes to the cytosol of columnar cells, which secrete MsVmp1 into the ectoperitrophic space in feeding larvae. In starving and molting larvae, MsVmp1 is found in the gut lumen, suggesting that the PM has increased its permeability. The present study demonstrates that lepidopteran species including many agricultural pests have evolved a set of unique proteins that are not found in any other taxon and thus may reflect an important adaptation in the highly specialized lepidopteran digestive tract facing

  11. Conserved RNA cis-elements regulate alternative splicing of Lepidopteran doublesex.

    PubMed

    Wang, Xiu-Ye; Zheng, Zeng-Zhang; Song, Hong-Sheng; Xu, Yong-Zhen

    2014-01-01

    Doublesex (dsx) is a downstream key regulator in insect sex determination pathway. In Drosophila, alternative splicing of Dm-dsx gene is sex-specifically regulated by transformer (tra), in which the functional TRA promotes female-specific Dm-dsx. However, the sex determination pathway in Lepidoptera is not well understood; here we focused on alternative splicing of doublesex (dsx) in two agricultural pests, Asian corn borer (Ostrinia furnacalis) and cotton bollworm (Helicoverpa armigera), as well as the silkworm (Bombyx mori). More than a dozen new alternative splicing isoforms of dsx were found in the Lepidopteran females, which exist in all tested developmental stages and differentiated tissues. Alignment of mRNA and protein sequences of doublesex revealed high conservation of this gene in Lepidoptera. Strength analysis of splice sites revealed a weak 5' splice site at intron 3 in Lepidopteran dsx, which was experimentally confirmed. Furthermore, we identified highly conserved RNA sequences in the Lepidopteran dsx, including RNA elements I (14 nt), II (11 nt), III (26 nt), IV (17 nt), 3E-1 (8 nt) and 3E-2 (8 nt). The RNA elements III and IV were previously found in exon 4 of B. mori dsx and bound with Bm-PSI, which suppressed the inclusion of exons 3 & 4 into the male-specific Bm-dsx. Then we identified and analyzed the homologous genes of Bm-psi in the two Lepidopteran pests, which expressed at similar levels and exhibited a unique isoform in the males and females from each Lepidoptera. Importantly, mutagenesis of Bm-dsx mini-genes and their expression in BmN cell line demonstrated that three RNA elements are involved in the female-specific alternative splicing of Bm-dsx. Mutations in the RNA cis-elements 3E-1 and 3E-2 resulted in decreased inclusion of exon 3 into the female-specific dsx mRNA, suggesting that these two elements would be exonic splicing enhancers that facilitate the recognition of the weak 5' splice site at intron 3 of Lepidopteran dsx. We

  12. A characterization of non-biotic environmental features of prairies hosting the Dakota Skipper (Hesperia dacotae, Hesperiidae) across its remaining U.S. range

    USGS Publications Warehouse

    Royer, R.A.; McKenney, R.A.; Newton, W.E.

    2008-01-01

    Within the United States, the Dakota Skipper now occurs only in Minnesota, North Dakota, and South Dakota. In these states it has been associated with margins of glacial lakes and calcareous mesic prairies that host warm-season native grasses. Preliminary geographic information system (GIS) analysis in North Dakota has indicated a close congruency between historic distribution of the Dakota Skipper and that of specific near-shore glacial lake features and related soil associations. This study analyzed humidity-related non-biotic microhabitat characteristics within three remaining occupied Dakota Skipper sites in each state during the larval growth period in 2000. Measured parameters included topographic relief, soil compaction, soil pH, moisture, and temperature at various depths, soil bulk density, soil texture, and temperature and humidity within the larval nest zone. Results of these efforts reveal two distinctive habitat substrates, one of relatively low surface relief with dense but relatively less compact soils, and another of relatively high relief with less dense but more compact soils. In the low-relief habitat, grazing appears to compact soils unfavorably in otherwise similar prairies in the more xeric western portion of the range, potentially by affecting ground-water buffering of larval nest zone humidity.

  13. Characterization of the basic replicon of pCM1, a narrow-host-range plasmid from the moderate halophile Chromohalobacter marismortui.

    PubMed Central

    Mellado, E; Asturias, J A; Nieto, J J; Timmis, K N; Ventosa, A

    1995-01-01

    The moderately halophilic bacterium Chromohalobacter marismortui contains a 17.5-kb narrow-host-range plasmid, pCM1, which shows interesting properties for the development of cloning vectors for the genetic manipulation of this important group of extremophiles. Plasmid pCM1 can stably replicate and is maintained in most gram-negative moderate halophiles tested. The replication origin has been identified and sequenced, and the minimal pCM1 replicon has been localized to a 1,600-bp region which includes two functionally discrete regions, the oriV region and the repA gene. oriV, located on a 700-bp fragment, contains four iterons 20 bp in length adjacent to a DnaA box that is dispensable but required for efficient replication of pCM1, and it requires trans-acting functions. The repA gene, which encodes a replication protein of 289 residues, is similar to the replication proteins of other gram-negative bacteria. PMID:7768853

  14. Isolation and characterization of insertion sequence elements from gram-negative bacteria by using new broad-host-range, positive selection vectors.

    PubMed Central

    Simon, R; Hötte, B; Klauke, B; Kosier, B

    1991-01-01

    On the basis of an RSF1010-derived broad-host-range vector, three different systems which enable positive detection and isolation of insertion sequence (IS) elements from gram-negative bacteria were constructed. Vectors pSUP104-pheS, pSUP104-rpsL, and pSUP104-sac were used successfully in a number of Rhizobium strains and in Xanthomonas campestris. More than 20 different IS elements were isolated and characterized. The 16 IS elements from Rhizobium meliloti were further used to characterize various R. meliloti strains by hybridization. The resulting hybridization patterns were different for every strain and gave a clear and definite IS fingerprint of each strain. These IS fingerprints can be used to identify and characterize R. meliloti strains rapidly and unequivocally, as they proved to be relatively stable. Some of the IS elements were found to be identical when the IS fingerprints from a given strain were compared. This method of IS fingerprinting can also establish whether IS elements are the same, related, or different. Images PMID:1847366

  15. Novel trypanosome Trypanosoma gilletti sp. (Euglenozoa: Trypanosomatidae) and the extension of the host range of Trypanosoma copemani to include the koala ( Phascolarctos cinereus).

    PubMed

    McInnes, L M; Hanger, J; Simmons, G; Reid, S A; Ryan, U M

    2011-01-01

    Trypanosoma irwini was previously described from koalas and we now report the finding of a second novel species, T. gilletti, as well as the extension of the host range of Trypanosoma copemani to include koalas. Phylogenetic analysis at the 18S rDNA and gGAPDH loci demonstrated that T. gilletti was genetically distinct with a genetic distance (± s.e.) at the 18S rDNA locus of 2.7 ± 0.5% from T. copemani (wombat). At the gGAPDH locus, the genetic distance (± s.e.) of T. gilletti was 8.7 ± 1.1% from T. copemani (wombat). Trypanosoma gilletti was detected using a nested trypanosome 18S rDNA PCR in 3/139 (∼2%) blood samples and in 2/29 (∼7%) spleen tissue samples from koalas whilst T. irwini was detected in 72/139 (∼52%) blood samples and T. copemani in 4/139 (∼3%) blood samples from koalas. In addition, naturally occurring mixed infections were noted in 2/139 (∼1.5%) of the koalas tested.

  16. Construction and use of a broad-host-range plasmid expressing the lamB gene for utilization of bacteriophage lambda vectors in the marine bacterium Vibrio harveyi.

    PubMed

    Jasiecki, J; Czy, A; Gabig, M; Wegrzyn, G

    2001-07-01

    The remarkable success of Escherichia coli as a model organism in molecular genetics was dependent, among other things, on its susceptibility to genetic manipulation. Many versatile and sophisticated genetic tools for molecular biology studies are derived from bacteriophage lambda. However, this bacteriophage is specific for E. coli, and thus lambda-based techniques have been restricted to this bacterium. Plasmids expressing the E. coli gene coding for bacteriophage lambda receptor were reported previously, and introduction of such plasmids into cells of some other bacteria made them sensitive to phage lambda infection. However, we found that these systems were not efficient for Vibrio harveyi, one of the most frequently investigated species of marine bacteria. Here we describe construction of a broad-host-range plasmid expressing the lamB gene. Introduction of this plasmid to V. harveyi cells and expression of lamB made this strain susceptible to bacteriophage lambda adsorption and lambda DNA injection. Foreign genetic material could be introduced into cells of this strain using a cosmid vector.

  17. Bactrocera invadens (Diptera: Tephritidae), a new invasive fruit fly pest for the Afrotropical region: host plant range and distribution in West and Central Africa.

    PubMed

    Goergen, Georg; Vayssières, Jean-François; Gnanvossou, Désiré; Tindo, Maurice

    2011-08-01

    In 2003, the invasive fruit fly Bactrocera invadens Drew, Tsuruta & White (Diptera: Tephritidae) (Drew et al. 2005), of possible Sri Lankan origin, has been detected in the East and about 1 yr later in West Africa. In regular surveys in Benin and Cameroon covering 4 yr, samples from 117 plant species across 43 families have been obtained. Incubation of field-collected fruits demonstrate that in West and Central Africa (WCA) B. invadens is highly polyphagous, infesting wild and cultivated fruits of at least 46 species from 23 plant families with guava (Psidium spp.), mango (Mangifera spp.), and citrus (spp.), and the wild hosts tropical almond (Terminalia catappa L.), African wild mango (Irvingia gabonensis (Aubry-Lecomte) Baill.), and sheanut (Vitellaria paradoxa C.F.Gaertn.) showing the highest infestation index. B. invadens occurs in 22 countries of WCA with new records for Angola, Central African Republic, the Congo, DR Congo, Equatorial Guinea, Gabon, Gambia, Guinea Bissau, Mali, Mauritania, Niger, and Sierra Leone. Overall, the pest has spread across a North-South distance of ≍5,000 km representing a contiguous area of >8.3 million km(2) within WCA. B. invadens has adapted to a wide range of ecological and climatic conditions extending from low land rainforest to dry savanna. Because of its highly destructive and invasive potential, B. invadens poses a serious threat to horticulture in Africa if left uncontrolled. Moreover, the presence of this quarantine pest causes considerable restrictions on international trade of affected crops.

  18. A mitochondrial genome phylogeny of owlet moths (Lepidoptera: Noctuoidea), and examination of the utility of mitochondrial genomes for lepidopteran phylogenetics.

    PubMed

    Yang, Xiushuai; Cameron, Stephen L; Lees, David C; Xue, Dayong; Han, Hongxiang

    2015-04-01

    A phylogenetic hypothesis for the lepidopteran superfamily Noctuoidea was inferred based on the complete mitochondrial (mt) genomes of 12 species (six newly sequenced). The monophyly of each noctuoid family in the latest classification was well supported. Novel and robust relationships were recovered at the family level, in contrast to previous analyses using nuclear genes. Erebidae was recovered as sister to (Nolidae+(Euteliidae+Noctuidae)), while Notodontidae was sister to all these taxa (the putatively basalmost lineage Oenosandridae was not included). In order to improve phylogenetic resolution using mt genomes, various analytical approaches were tested: Bayesian inference (BI) vs. maximum likelihood (ML), excluding vs. including RNA genes (rRNA or tRNA), and Gblocks treatment. The evolutionary signal within mt genomes had low sensitivity to analytical changes. Inference methods had the most significant influence. Inclusion of tRNAs positively increased the congruence of topologies, while inclusion of rRNAs resulted in a range of phylogenetic relationships varying depending on other analytical factors. The two Gblocks parameter settings had opposite effects on nodal support between the two inference methods. The relaxed parameter (GBRA) resulted in higher support values in BI analyses, while the strict parameter (GBDH) resulted in higher support values in ML analyses.

  19. Wheat curl mite (Aceria tosichella s.l.) cryptic biotypes with divergent host ranges: Implications for using Eriophyidae for biological control of invasive grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-specificity is the most important criterion for biological control agents (BCAs) and is particularly important for BCAs of invasive grasses that are close relatives of grass crop species. Plant-feeding mites in the family Eriophyidae are often highly host-specific. A study was conducted on th...

  20. Mitochondrial genome characterization of Tecia solanivora (Lepidoptera: Gelechiidae) and its phylogenetic relationship with other lepidopteran insects.

    PubMed

    Ramírez-Ríos, Viviana; Franco-Sierra, Nicolás D; Alvarez, Javier Correa; Saldamando-Benjumea, Clara I; Villanueva-Mejía, Diego F

    2016-05-01

    The complete mitogenome of the potato tuber moth Tecia solanivora (Lepidoptera: Gelechiidae) was sequenced, annotated, characterized and compared with 140 species of the order Lepidoptera. The circular genome is 15,251 bp, containing 37 genes (13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and an A+T-rich region). The gene arrangement was identical to other lepidopteran mitogenomes but different from the ancestral arrangement found in most insects for the tRNA-Met gene (A+T-region, tRNA-I, tRNA-Q, tRNA-M). The mitogenome of T. solanivora is highly A+T-biased (78.2%) and exhibits negative AT- and GC-skews. All PCGs are initiated by canonical ATN start codons, except for Cytochrome Oxidase subunit 1 (COI), which is initiated by CGA. Most PCGs have a complete typical stop codon (TAA). Only NAD1 has a TAG stop codon and the COII and NAD5 genes have an incomplete stop codon consisting of just a T. The A+T-rich region is 332 bp long and contains common features found in lepidopteran mitogenomes, including the 'ATAGA' motif, a 17 bp poly (T) stretch and a (AT)8 element preceded by the 'ATTTA' motif. Other tandem repeats like (TAA)4 and (TAT)7 were found, as well as (T)6 and (A)10 mononucleotide repeat elements. Finally, this mitogenome has 20 intergenic spacer regions. The phylogenetic relationship of T. solanivora with 28 other lepidopteran families (12 superfamilies) showed that taxonomic classification by morphological features coincides with the inferred phylogeny. Thus, the Gelechiidae family represents a monophyletic group, suggesting that T. solanivora and Pectinophora gossypiella have a recent common ancestor.

  1. Persistent RNA virus infection of lepidopteran cell lines: Interactions with the RNAi machinery.

    PubMed

    Swevers, Luc; Ioannidis, Konstantinos; Kolovou, Marianna; Zografidis, Aris; Labropoulou, Vassiliki; Santos, Dulce; Wynant, Niels; Broeck, Jozef Vanden; Wang, Luoluo; Cappelle, Kaat; Smagghe, Guy

    RNAi is broadly used as a technique for specific gene silencing in insects but few studies have investigated the factors that can affect its efficiency. Viral infections have the potential to interfere with RNAi through their production of viral suppressors of RNAi (VSRs) and the production of viral small RNAs that can saturate and inactivate the RNAi machinery. In this study, the impact of persistent infection of the RNA viruses Flock house virus (FHV) and Macula-like virus (MLV) on RNAi efficiency was investigated in selected lepidopteran cell lines. Lepidopteran cell lines were found to be readily infected by both viruses without any apparent pathogenic effects, with the exception of Bombyx-derived Bm5 and BmN4 cells, which could not be infected by FHV. Because Sf21 cells were free from both FHV and MLV and Hi5-SF were free from FHV and only contained low levels of MLV, they were tested to evaluate the impact of the presence of the virus. Two types of RNAi reporter assays however did not detect a significant interference with gene silencing in infected Sf21 and Hi5-SF cells when compared to virus-free cells. In Hi5 cells, the presence of FHV could be easily cleared through the expression of an RNA hairpin that targets its VSR gene, confirming that the RNAi mechanism was not inhibited. Sequencing indicated that the B2 RNAi inhibitor gene of FHV and a putative VSR gene from MLV were intact in persistently infected cell lines, indicating that protection against RNAi remains essential for virus survival. It is proposed that infection levels of persistent viruses in the cell lines are too low to have an impact on RNAi efficiency in the lepidopteran cell lines and that encoded VSRs act locally at the sites of viral replication (mitochondrial membranes) without affecting the rest of the cytoplasm.

  2. In vivo expression of genes in the entomopathogenic fungus Beauveria bassiana during infection of lepidopteran larvae.

    PubMed

    Galidevara, Sandhya; Reineke, Annette; Koduru, Uma Devi

    2016-05-01

    The entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin is commercially available as a bio insecticide. The expression of three genes previously identified to have a role in pathogenicity in in vitro studies was validated in vivo in three lepidopteran insects infected with B. bassiana. Expression of all three genes was observed in all the tested insects starting from 48 or 72h to 10d post infection corroborating their role in pathogenicity. We suggest that it is essential to test the expression of putative pathogenicity genes both in vitro and in vivo to understand their role in different insect species.

  3. Transcriptome mapping of pAR060302, a blaCMY-2-positive broad-host-range IncA/C plasmid.

    PubMed

    Lang, Kevin S; Danzeisen, Jessica L; Xu, Wayne; Johnson, Timothy J

    2012-05-01

    The multidrug resistance-encoding plasmids belonging to the IncA/C incompatibility group have recently emerged among Escherichia coli and Salmonella enterica strains in the United States. These plasmids have a unique genetic structure compared to other enterobacterial plasmid types, a broad host range, and a propensity to acquire large numbers of antimicrobial resistance genes via their accessory regions. Using E. coli strain DH5α harboring the prototype IncA/C plasmid pAR060302, we sought to define the baseline transcriptome of IncA/C plasmids under laboratory growth and in the face of selective pressure. The effects of ampicillin, florfenicol, or streptomycin exposure were compared to those on cells left untreated at logarithmic phase using Illumina platform-based RNA sequencing (RNA-Seq). Under growth in Luria-Bertani broth lacking antibiotics, much of the backbone of pAR060302 was transcriptionally inactive, including its putative transfer regions. A few plasmid backbone genes of interest were highly transcribed, including genes of a putative toxin-antitoxin system and an H-NS-like transcriptional regulator. In contrast, numerous genes within the accessory regions of pAR060302 were highly transcribed, including the resistance genes floR, bla(CMY-2), aadA, and aacA. Treatment with ampicillin or streptomycin resulted in no genes being differentially expressed compared to controls lacking antibiotics, suggesting that many of the resistance-associated genes are not differentially expressed due to exposure to these antibiotics. In contrast, florfenicol treatment resulted in the upregulation of floR and numerous chromosomal genes. Overall, the transcriptome mapping of pAR060302 suggests that it mitigates the fitness costs of carrying resistance-associated genes through global regulation with its transcriptional regulators.

  4. Gene regulation on broad host range plasmid RK2: identification of three novel operons whose transcription is repressed by both KorA and KorC.

    PubMed Central

    Thomas, C M; Ibbotson, J P; Wang, N Y; Smith, C A; Tipping, R; Loader, N M

    1988-01-01

    The product of the korA gene of broad host range plasmid RK2 is a key transcriptional repressor which regulates not only the expression of the essential replication gene trfA but also its own expression and that of the kilA operon. It has previously been proposed that korA also encodes a positive activator of transcription of the korC gene, which may act as a transcriptional antiterminator. Here we show that the action of korA in relation to korC can be explained entirely through the korA protein's property as a transcriptional repressor. The limited ability of the previously cloned korC gene to suppress kilC on its own is shown to be due to the fact that korC in RK2 is transcribed from the bla promoter of Tn1 which was deleted in the original korC clones. We demonstrate that korA is a second repressor along with korC of three operons, one of which encodes kilC, the other two not having been described previously and serving an as yet unknown function. We have designated these operons kcrA, B and C for KorC-regulated. Putative kilC is designated kcrC. The homology between the expression signals of these operons suggests that they have arisen by duplication. This is confirmed in the case of kcrA and B by the existence of considerable homology between the products of the first ORFs in each of these operons. Images PMID:2838814

  5. Seeing red; the development of pON.mCherry, a broad-host range constitutive expression plasmid for Gram-negative bacteria

    PubMed Central

    Jacobson, Rachael K.; Shuman, Howard A.

    2017-01-01

    The development of plasmid-mediated gene expression control in bacteria revolutionized the field of bacteriology. Many of these expression control systems rely on the addition of small molecules, generally metabolites or non-metabolized analogs thereof, to the growth medium to induce expression of the genes of interest. The paradigmatic example of an expression control system is the lac system from Escherichia coli, which typically relies on the Ptac promoter and the Lac repressor, LacI. In many cases, however, constitutive gene expression is desired, and other experimental approaches require the coordinated control of multiple genes. While multiple systems have been developed for use in E. coli and its close relatives, the utility and/or functionality of these tools does not always translate to other species. For example, for the Gram-negative pathogen, Legionella pneumophila, a causative agent of Legionnaires’ Disease, the aforementioned Ptac system represents the only well-established expression control system. In order to enhance the tools available to study bacterial gene expression in L. pneumophila, we developed a plasmid, pON.mCherry, which confers constitutive gene expression from a mutagenized LacI binding site. We demonstrate that pON.mCherry neither interferes with other plasmids harboring an intact LacI-Ptac expression system nor alters the growth of Legionella species during intracellular growth. Furthermore, the broad-host range plasmid backbone of pON.mCherry allows constitutive gene expression in a wide variety of Gram-negative bacterial species, making pON.mCherry a useful tool for the greater research community. PMID:28257493

  6. Insect-Specific Flaviviruses: A Systematic Review of Their Discovery, Host Range, Mode of Transmission, Superinfection Exclusion Potential and Genomic Organization

    PubMed Central

    Blitvich, Bradley J.; Firth, Andrew E.

    2015-01-01

    There has been a dramatic increase in the number of insect-specific flaviviruses (ISFs) discovered in the last decade. Historically, these viruses have generated limited interest due to their inability to infect vertebrate cells. This viewpoint has changed in recent years because some ISFs have been shown to enhance or suppress the replication of medically important flaviviruses in co-infected mosquito cells. Additionally, comparative studies between ISFs and medically important flaviviruses can provide a unique perspective as to why some flaviviruses possess the ability to infect and cause devastating disease in humans while others do not. ISFs have been isolated exclusively from mosquitoes in nature but the detection of ISF-like sequences in sandflies and chironomids indicates that they may also infect other dipterans. ISFs can be divided into two distinct phylogenetic groups. The first group currently consists of approximately 12 viruses and includes cell fusing agent virus, Kamiti River virus and Culex flavivirus. These viruses are phylogenetically distinct from all other known flaviviruses. The second group, which is apparently not monophyletic, currently consists of nine viruses and includes Chaoyang virus, Nounané virus and Lammi virus. These viruses phylogenetically affiliate with mosquito/vertebrate flaviviruses despite their apparent insect-restricted phenotype. This article provides a review of the discovery, host range, mode of transmission, superinfection exclusion ability and genomic organization of ISFs. This article also attempts to clarify the ISF nomenclature because some of these viruses have been assigned more than one name due to their simultaneous discoveries by independent research groups. PMID:25866904

  7. Seeing red; the development of pON.mCherry, a broad-host range constitutive expression plasmid for Gram-negative bacteria.

    PubMed

    Gebhardt, Michael J; Jacobson, Rachael K; Shuman, Howard A

    2017-01-01

    The development of plasmid-mediated gene expression control in bacteria revolutionized the field of bacteriology. Many of these expression control systems rely on the addition of small molecules, generally metabolites or non-metabolized analogs thereof, to the growth medium to induce expression of the genes of interest. The paradigmatic example of an expression control system is the lac system from Escherichia coli, which typically relies on the Ptac promoter and the Lac repressor, LacI. In many cases, however, constitutive gene expression is desired, and other experimental approaches require the coordinated control of multiple genes. While multiple systems have been developed for use in E. coli and its close relatives, the utility and/or functionality of these tools does not always translate to other species. For example, for the Gram-negative pathogen, Legionella pneumophila, a causative agent of Legionnaires' Disease, the aforementioned Ptac system represents the only well-established expression control system. In order to enhance the tools available to study bacterial gene expression in L. pneumophila, we developed a plasmid, pON.mCherry, which confers constitutive gene expression from a mutagenized LacI binding site. We demonstrate that pON.mCherry neither interferes with other plasmids harboring an intact LacI-Ptac expression system nor alters the growth of Legionella species during intracellular growth. Furthermore, the broad-host range plasmid backbone of pON.mCherry allows constitutive gene expression in a wide variety of Gram-negative bacterial species, making pON.mCherry a useful tool for the greater research community.

  8. The broad-host-range plasmid pSFA231 isolated from petroleum-contaminated sediment represents a new member of the PromA plasmid family

    PubMed Central

    Li, Xiaobin; Top, Eva M.; Wang, Yafei; Brown, Celeste J.; Yao, Fei; Yang, Shan; Jiang, Yong; Li, Hui

    2015-01-01

    A self-transmissible broad-host-range (BHR) plasmid pSFA231 was isolated from petroleum-contaminated sediment in Shen-fu wastewater irrigation zone, China, using the triparental mating exogenous plasmid capture method. Based on its complete sequence the plasmid has a size of 41.5 kb and codes for 50 putative open reading frames (orfs), 29 of which represent genes involved in replication, partitioning and transfer functions of the plasmid. Phylogenetic analysis grouped pSFA231 into the newly defined PromA plasmid family, which currently includes five members. Further comparative genomic analysis shows that pSFA231 shares the common backbone regions with the other PromA plasmids, i.e., genes involved in replication, maintenance and control, and conjugative transfer. Nevertheless, phylogenetic divergence was found in specific gene products. We propose to divide the PromA group into two subgroups, PromA-α (pMRAD02, pSB102) and PromA-β (pMOL98, pIPO2T, pSFA231, pTer331), based on the splits network analysis of the RepA protein. Interestingly, a cluster of hypothetical orfs located between parA and traA of pSFA231 shows high similarity with the corresponding regions on pMOL98, pIPO2T, and pTer331, suggesting these hypothetical orfs may represent “essential” plasmid backbone genes for the PromA-β subgroup. Alternatively, they may also be accessory genes that were first acquired and then stayed as the plasmid diverged. Our study increases the available collection of complete genome sequences of BHR plasmids, and since pSFA231 is the only characterized PromA plasmid from China, our findings also enhance our understanding of the genetic diversity of this plasmid group in different parts of the world. PMID:25628616

  9. Host ranges of gregarious muscoid fly parasitoids: Muscidifurax raptorellus (Kogan and Legner) (Hymenoptera:Pteromalidae), Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae), and Trichopria (Hymenoptera: Diapriidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Attack rates, progeny production, sex ratios and host utilization efficiency of Muscidifurax raptorellus (Kogan and Legner) (Hymenoptera: Pteromalidae), Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae), and Trichopria nigra (Nees) (Hymenoptera: Diapriidae) were evaluated in laboratory bi...

  10. Emergence and Dissemination of Enterobacteriaceae Isolates Producing CTX-M-1-Like Enzymes in Spain Are Associated with IncFII (CTX-M-15) and Broad-Host-Range (CTX-M-1, -3, and -32) Plasmids▿

    PubMed Central

    Novais, Ângela; Cantón, Rafael; Moreira, Raquel; Peixe, Luísa; Baquero, Fernando; Coque, Teresa M.

    2007-01-01

    The spread of CTX-M-1-like enzymes in Spain is associated with particular plasmids of broad-host-range IncN (blaCTX-M-32, blaCTX-M-1), IncL/M (blaCTX-M-1), and IncA/C2 (blaCTX-M-3) or narrow-host-range IncFII (blaCTX-M-15). The identical genetic surroundings of blaCTX-M-32 and blaCTX-M-1 and their locations on related 40-kb IncN plasmids indicate the in vivo evolution of this element. PMID:17145793

  11. Chromosomal characterisation of five lepidopteran cell lines of Malacosoma disstria (Lasiocampidae) and Christoneura fumiferana (Tortricidae).

    PubMed

    Ennis, T J; Sohi, S S

    1976-09-01

    Chromosome number and morphology have been examined in four established cell lines (Md63, Md66, Md108, and Md109) of the forest tent caterpillar, Malacosoma disstria Hübner, and one (Cf124) of the spruce budworm, Choristoneura fumiferana (Clemens). Chromosome number distributions of Md63 (mode = 112) Md108 (mode = 103), Md109 (mode= 103), and Cf124 (mode = 110) overlap sufficiently to prevent identification of individual lines by number alone. However, Md66 is exceptional in possessing a modal number of 157. One large chromosome occurs in cells of all lines. The presence of this chromosome, the lack of any distinct polyploid series among chromosome numbers encountered, and the general inverse relationship between number and size of chromosomes, suggest that the high level of heteroploidy characteristic of these and other lepidopteran cell lines reflects not only a possible polyploid origin but also extensive chromosomal rearrangement and fragmentation. Tolerance for such change is attributed to the holokinetic organisation of lepidopteran chromosomes. A distinct heteropycnotic body is present in about 10% of Cf124 cell nuclei, and can be used as a marker for this line. This body may represent the sex chromatin normally encountered in somatic cells of female C. fumiferana.

  12. Panning for sperm gold: Isolation and purification of apyrene and eupyrene sperm from lepidopterans.

    PubMed

    Karr, Timothy L; Walters, James R

    2015-08-01

    We describe a simple and straightforward procedure for the purification and separation of apyrene and eupyrene forms of lepidopteran sperm. The procedure is generally applicable to both butterfly and moth species with results varying according to the relative amounts of sperm produced and size of sperm storage organs. The technique relies upon inherent differences between eupyene sperm bundles and free apyrene sperm morphology. These differences allow for separation of the sperm morphs by repeated "panning" of sperm bundles into the center of a plastic dish. The purified eupyrene sperm bundles can then be removed and apyrene sperm collected from the supernatant by centrifugation. Efficacy of the purification process was confirmed by light microscopy and gel electrophoresis of the resulting fractions. Both one- and two-dimensional gel electrophoresis identified significant protein differences between the fractions further suggesting that the panning procedure effectively separated eurpyrene from apyrene sperm. The panning procedure should provide a convenient and accessible technique for further studies of sperm biology in lepidopterans.

  13. A host-range restricted parainfluenza virus type 3 (PIV3) expressing the human metapneumovirus (hMPV) fusion protein elicits protective immunity in African green monkeys.

    PubMed

    Tang, Roderick S; Mahmood, Kutubuddin; Macphail, Mia; Guzzetta, Jeanne M; Haller, Aurelia A; Liu, Hui; Kaur, Jasmine; Lawlor, Heather A; Stillman, Elizabeth A; Schickli, Jeanne H; Fouchier, Ron A M; Osterhaus, Albert D M E; Spaete, Richard R

    2005-02-25

    Human metapneumovirus (hMPV) infection causes respiratory tract disease similar to that observed during human respiratory syncytial virus infection (hRSV). hMPV infections have been reported across the entire age spectrum although the most severe disease occurs in young children. No vaccines, chemotherapeutics or antibodies are presently available for preventing or treating hMPV infections. In this study, a bovine/human chimeric parainfluenza virus type 3 (b/h PIV3) expressing the human parainfluenza type 3 (hPIV3) fusion (F) and hemagglutinin-neuraminidase (HN) proteins was engineered to express hMPV fusion (F) protein from the second genome position (b/h PIV3/hMPV F2) with the goal of generating a novel hMPV vaccine. b/h PIV3/hMPV F2 was previously shown to protect hamsters from challenge with wt hMPV (Tang RS, Schickli JH, Macphail M, Fernandes F, Bicha L, Spaete J, et al. Effects of human metapneumovirus and respiratory syncytial virus antigen insertion in two 3' proximal genome positions of bovine/human parainfluenza virus type 3 on virus replication and immunogenicity. J Virol 2003;77:10819-28) and is here further evaluated for efficacy and immunogenicity in African green monkeys (AGMs). AGMs immunized intranasally and intratracheally with b/h PIV3/hMPV F2 generated hMPV- and hPIV3-specific humoral and cellular immune responses and were protected from wt hMPV infection. In a separate study, the host-range restriction of b/h PIV3/hMPV F2 replication relative to wt hPIV3 was performed in rhesus monkeys to demonstrate attenuation. These studies showed that b/h PIV3/hMPV F2 was immunogenic, protective and attenuated in non-human primates and warrants further evaluation in humans as a vaccine candidate for prevention of hMPV-associated respiratory tract diseases.

  14. Clastic-hosted stratiform, vein/breccia and disseminated Zn-Pb-Ag deposits of the northwestern Brooks Range, AK: Are they different expressions of dewatering of the same source basin

    SciTech Connect

    Schmidt, J.M. ); Werdon, M.B. . Dept. of Geology)

    1993-04-01

    Sphalerite and galena, with significant silver occur in 3 distinct types of mineralization hosted in Upper Devonian and Carboniferous clastic rocks of the northwestern Brooks Range. The best known are Zn-Pb-Ag massive sulfide deposits with variable pyrite, barite, and hydrothermal silifica hosted in Mississippian (to Pennsylvanian ) black siliceous shale and chert, and similar to shale-hosted Pb-Zn massive sulfide deposits worldwide. Zn-Pb-Ag breccias and veins are hosted in Upper Devonian to Lower Mississippian fine-grained quartzites and siltstone which stratigraphically underlie the massive sulfide-hosting units. The breccia-vein and disseminated occurrences are co-extensive with the rocks that host massive sulfide deposits, and with the western part of the Endicott Group clastic basin. Pb isotopic ratios of galena from all the deposits are remarkably uniform, and suggest a single Pb source. The authors genetic model suggests that all types are the result of dewatering of a single clastic source basin. Different mineralization styles are probably due to variable depths of emplacement (at or below the seafloor), thermal variations related to extensional thinning of the crust, and hydrologic flow out of the basin controlled by extensional thinning of the crust, and hydrologic flow out of the basin controlled by extensional faulting and permeability variations in local stratigraphy. The most likely sources for Zn and Pb are clay minerals within the lowermost (Hunt Fork Shale) portions of the western Endicott Group.

  15. Identification of a Putative Salmonella enterica Serotype Typhimurium Host Range Factor with Homology to IpaH and YopM by Signature-Tagged Mutagenesis

    PubMed Central

    Tsolis, Renée M.; Townsend, Stacy M.; Miao, Edward A.; Miller, Samuel I.; Ficht, Thomas A.; Adams, L. Garry; Bäumler, Andreas J.

    1999-01-01

    The genetic basis for the host adaptation of Salmonella serotypes is currently unknown. We have explored a new strategy to identify Salmonella enterica serotype Typhimurium (S. typhimurium) genes involved in host adaptation, by comparing the virulence of 260 randomly generated signature-tagged mutants during the oral infection of mice and calves. This screen identified four mutants, which were defective for colonization of only one of the two host species tested. One mutant, which only displayed a colonization defect during the infection of mice, was further characterized. During competitive infection experiments performed with the S. typhimurium wild type, the mutant was defective for colonization of murine Peyer's patches but colonized bovine Peyer's patches at the wild-type level. No difference in virulence between wild type and mutant was observed when calves were infected orally with 1010 CFU/animal. In contrast, the mutant possessed a sixfold increase in 50% lethal morbidity dose when mice were infected orally. The transposon in this mutant was inserted in a 2.9-kb pathogenicity islet, which is located between uvrB and yphK on the S. typhimurium chromosome. This pathogenicity islet contained a single gene, termed slrP, with homology to ipaH of Shigella flexneri and yopM of Yersinia pestis. These data show that comparative screening of signature-tagged mutants in two animal species can be used for scanning the S. typhimurium genome for genes involved in host adaptation. PMID:10569754

  16. Impact of the Boll Weevil Eradication Program in south Texas on predation of Lepidopteran eggs, 2005-2006.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predation on eggs of the lepidopteran pests (Helicoverpa zea Boddie) and Spodoptera exigua (Hübner) in cotton was monitored before and during the first two seasons of the Boll Weevil Eradication Program in south Texas (2005-2006). Mortality of eggs was reduced after malathion sprays for boll weevil...

  17. Efficacy of Vip3A and Cry1Ab transgenic traits in cotton against various lepidopteran pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From 2004 through 2005, plots of experimental transgenic cotton lines containing the vegetative insecticidal protein, Vip3A; '-endotoxin, Cry1Ab; and both Vip3A and Cry1Ab were evaluated for efficacy against certain lepidopteran pests. Results showed that the cotton line containing Vip3A was more e...

  18. Revision of the world Monoctonia Starý, parasitoids of gall aphids: taxonomy, distribution, host range, and phylogeny (Hymenoptera, Braconidae: Aphidiinae).

    PubMed

    Rakhshani, Ehsan; Starý, Petr; Hidalgo, Nicolás Pérez; Čkrkić, Jelisaveta; Moghaddam, Mostafa Ghafouri; Tomanović, Snežana; Petrović, Andjeljko; Tomanović, Željko

    2015-01-14

    The present paper represents a contribution to the knowledge of the taxonomy of Monoctonia Starý aphid parasitoids obtained using the barcoding region of the mitochondrial COI gene. We discuss the phylogenetic position of the genus within the subtribe Monoctonina, redescribe known species, and describe Monoctonia japonica sp. n. from Japan in the association Pemphigus matsumurai Monzen/Populus maximowiczii. A key for species identification is provided. Also, we review and discuss the host records, origin, and geographical distribution of Monoctonia species. It is hypothesized that the genus Monoctonia evolved in Paleogene forests of the temperate (and subtropical) belt, most probably in the European part of the Mediterranean region, which is also the center of origin of their host plants. 

  19. The RepA_N replicons of Gram-positive bacteria: a family of broadly distributed but narrow host range plasmids.

    PubMed

    Weaver, Keith E; Kwong, Stephen M; Firth, Neville; Francia, Maria Victoria

    2009-03-01

    The pheromone-responsive conjugative plasmids of Enterococcus faecalis and the multiresistance plasmids pSK1 and pSK41 of Staphylococcus aureus are among the best studied plasmids native to Gram-positive bacteria. Although these plasmids seem largely restricted to their native hosts, protein sequence comparison of their replication initiator proteins indicates that they are clearly related. Homology searches indicate that these replicons are representatives of a large family of plasmids and a few phage that are widespread among the low G+C Gram-positive bacteria. We propose to name this family the RepA_N family of replicons after the annotated conserved domain that the initiator protein contains. Detailed sequence comparisons indicate that the initiator protein phylogeny is largely congruent with that of the host, suggesting that the replicons have evolved along with their current hosts and that intergeneric transfer has been rare. However, related proteins were identified on chromosomal regions bearing characteristics indicative of ICE elements, and the phylogeny of these proteins displayed evidence of more frequent intergeneric transfer. Comparison of stability determinants associated with the RepA_N replicons suggests that they have a modular evolution as has been observed in other plasmid families.

  20. Response of brown-headed cowbirds and three host species to thinning treatments in low-elevation ponderosa pine forests along the northern Colorado Front Range

    USGS Publications Warehouse

    Keeley, W.H.; Germaine, Stephen S.; Stanley, Thomas R.; Spaulding, Sarah A.; Wanner, C.E.

    2013-01-01

    Thinning ponderosa pine (Pinus ponderosa) forests to achieve desired ecological conditions remains a priority in the North American west. In addition to reducing the risk of high-severity wildfires in unwanted areas, stand thinning may increase wildlife and plant diversity and provide increased opportunity for seedling recruitment. We initiated conservative (i.e. minimal removal of trees) ponderosa stand thinning treatments with the goals of reducing fire risk and improving habitat conditions for native wildlife and flora. We then compared site occupancy of brown-headed cowbirds (Molothrus ater), chipping sparrows (Spizella passerina), plumbeous vireos (Vireo plumbeus), and western wood-pewees (Contopus sordidulus) in thinned and unthinned (i.e., control) forest stands from 2007 to 2009. Survey stations located in thinned stands had 64% fewer trees/ha, 25% less canopy cover, and 23% less basal area than stations in control stands. Occupancy by all three host species was negatively associated with tree density, suggesting that these species respond favorably to forest thinning treatments in ponderosa pine forests. We also encountered plumbeous vireos more frequently in plots closer to an ecotonal (forest/grassland) edge, an association that may increase their susceptibility to edge-specialist, brood parasites like brown-headed cowbirds. Occupancy of brown-headed cowbirds was not related to forest metrics but was related to occupancy by plumbeous vireos and the other host species in aggregate, supporting previous reports on the affiliation between these species. Forest management practices that promote heterogeneity in forest stand structure may benefit songbird populations in our area, but these treatments may also confer costs associated with increased cowbird occupancy. Further research is required to understand more on the complex relationships between occupancy of cowbirds and host species, and between cowbird occupancy and realized rates of nest parasitism.

  1. Host range and genetic diversity of croton yellow vein mosaic virus, a weed-infecting monopartite begomovirus causing leaf curl disease in tomato.

    PubMed

    Pramesh, D; Mandal, Bikash; Phaneendra, Chigurupati; Muniyappa, V

    2013-03-01

    Croton yellow vein mosaic virus (CYVMV) is a widely occurring begomovirus in Croton bonplandianum, a common weed in the Indian subcontinent. In this study, CYVMV (genus Begomovirus, family Geminiviridae) was transmitted by whiteflies (Bemisia tabaci) to as many as 35 plant species belonging to 11 families, including many vegetables, tobacco varieties, ornamentals and weeds. CYVMV produced bright yellow vein symptoms in croton, whereas in all the other host species, the virus produced leaf curl symptoms. CYVMV produced leaf curl in 13 tobacco species and 22 cultivars of Nicotiana tabacum and resembled tobacco leaf curl virus (TobLCV) in host reactions. However, CYVMV was distinguished from TobLCV in four differential hosts, Ageratum conyzoides, C. bonplandianum, Euphorbia geniculata and Sonchus bracyotis. The complete genome sequences of four isolates originating from northern, eastern and southern India revealed that a single species of DNA-A and a betasatellite, croton yellow vein mosaic betasatellite (CroYVMB) were associated with the yellow vein mosaic disease of croton. The sequence identity among the isolates of CYVMV DNA-A and CroYVMB occurring in diverse plant species was 91.8-97.9 % and 83.3-100 %, respectively. The CYVMV DNA-A and CroYVMB generated through rolling-circle amplification of the cloned DNAs produced typical symptoms of yellow vein mosaic and leaf curling in croton and tomato, respectively. The progeny virus from both the croton and tomato plants was transmitted successfully by B. tabaci. The present study establishes the etiology of yellow vein mosaic disease of C. bonplandianum and provides molecular evidence that a weed-infecting monopartite begomovirus causes leaf curl in tomato.

  2. Interspecific transfer of Wolbachia between two lepidopteran insects expressing cytoplasmic incompatibility: a Wolbachia variant naturally infecting Cadra cautella causes male killing in Ephestia kuehniella.

    PubMed Central

    Sasaki, Tetsuhiko; Kubo, Takeo; Ishikawa, Hajime

    2002-01-01

    Wolbachia is known as the causative agent of various reproductive alterations in arthropods. The almond moth Cadra cautella is doubly infected with A- and B-group Wolbachia and expresses complete cytoplasmic incompatibility (CI). The Mediterranean flour moth Ephestia kuehniella carries A-group Wolbachia and expresses partial CI. In the present study, the Wolbachia in C. cautella was transferred to E. kuehniella from which the original Wolbachia had been removed. We obtained transfected lines of three different infection states: single infection with A, single infection with B, and double infection with A and B. The doubly transfected lines and those transfected with only A produced exclusively female progeny. Two lines of evidence suggested that the sex ratio distortion was due to male killing. First, reduced egg hatch rate was observed. Second, removal of the Wolbachia from the transfected lines resulted in the recovery of a normal sex ratio of approximately 1:1. The occurrence of male killing following transfection showed that host factors influence the determination of the reproductive phenotype caused by Wolbachia. The transfected E. kuehniella males carrying exclusively B-group Wolbachia expressed partial incompatibility when crossed with the uninfected females. In addition, the transfected lines were bidirectionally incompatible with the naturally infected strain, which was the first demonstration of bidirectional CI in a lepidopteran. PMID:12454075

  3. Scientific communications: Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the carbonate-hosted copper deposits at ruby creek, southern brooks range, Alaska

    USGS Publications Warehouse

    Selby, D.; Kelley, K.D.; Hitzman, M.W.; Zieg, J.

    2009-01-01

    New Re-Os data for chalcopyrite, bornite, and pyrite from the carbonate-hosted Cu deposit at Ruby Creek (Bornite), Alaska, show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the carbonate-hosted Ruby Creek Cu-(Co) deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization pre dominantly occurred at 384 ?? 4.2 Ma, with an earlier phase possibly at ???400 Ma. The Re-Os data are consistent with the observed paragenetic sequence and coincide with zircon U-Pb ages from igneous rocks within the Ambler metallogenic belt, some of which are spatially and genetically associated with regional volcanogenic massive sulfide deposits. The latter may suggest a temporal link between regional magmatism and hydrothermal mineralization in the Ambler district. The utility of bornite and chalcopyrite, in addition to pyrite, contributes to a new understanding of Re-Os geochronology and permits a refinement of the genetic model for the Ruby Creek deposit. ?? 2009 Society of Economices Geologists, Inc.

  4. The Complete Genome Sequence of the Phytopathogenic Fungus Sclerotinia sclerotiorum Reveals Insights into the Genome Architecture of Broad Host Range Pathogens

    PubMed Central

    Denton-Giles, Matthew; Hegedus, Dwayne; Seifbarghy, Shirin; Rollins, Jeffrey; van Kan, Jan; Seidl, Michael F.; Faino, Luigi; Mbengue, Malick; Navaud, Olivier; Raffaele, Sylvain; Hammond-Kosack, Kim; Heard, Stephanie; Oliver, Richard

    2017-01-01

    Sclerotinia sclerotiorum is a phytopathogenic fungus with over 400 hosts including numerous economically important cultivated species. This contrasts many economically destructive pathogens that only exhibit a single or very few hosts. Many plant pathogens exhibit a “two-speed” genome. So described because their genomes contain alternating gene rich, repeat sparse and gene poor, repeat-rich regions. In fungi, the repeat-rich regions may be subjected to a process termed repeat-induced point mutation (RIP). Both repeat activity and RIP are thought to play a significant role in evolution of secreted virulence proteins, termed effectors. We present a complete genome sequence of S. sclerotiorum generated using Single Molecule Real-Time Sequencing technology with highly accurate annotations produced using an extensive RNA sequencing data set. We identified 70 effector candidates and have highlighted their in planta expression profiles. Furthermore, we characterized the genome architecture of S. sclerotiorum in comparison to plant pathogens that exhibit “two-speed” genomes. We show that there is a significant association between positions of secreted proteins and regions with a high RIP index in S. sclerotiorum but we did not detect a correlation between secreted protein proportion and GC content. Neither did we detect a negative correlation between CDS content and secreted protein proportion across the S. sclerotiorum genome. We conclude that S. sclerotiorum exhibits subtle signatures of enhanced mutation of secreted proteins in specific genomic compartments as a result of transposition and RIP activity. However, these signatures are not observable at the whole-genome scale. PMID:28204478

  5. Influenza HA Subtypes Demonstrate Divergent Phenotypes for Cleavage Activation and pH of Fusion: Implications for Host Range and Adaptation

    PubMed Central

    Galloway, Summer E.; Reed, Mark L.; Russell, Charles J.; Steinhauer, David A.

    2013-01-01

    The influenza A virus (IAV) HA protein must be activated by host cells proteases in order to prime the molecule for fusion. Consequently, the availability of activating proteases and the susceptibility of HA to protease activity represents key factors in facilitating virus infection. As such, understanding the intricacies of HA cleavage by various proteases is necessary to derive insights into the emergence of pandemic viruses. To examine these properties, we generated a panel of HAs that are representative of the 16 HA subtypes that circulate in aquatic birds, as well as HAs representative of the subtypes that have infected the human population over the last century. We examined the susceptibility of the panel of HA proteins to trypsin, as well as human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2). Additionally, we examined the pH at which these HAs mediated membrane fusion, as this property is related to the stability of the HA molecule and influences the capacity of influenza viruses to remain infectious in natural environments. Our results show that cleavage efficiency can vary significantly for individual HAs, depending on the protease, and that some HA subtypes display stringent selectivity for specific proteases as activators of fusion function. Additionally, we found that the pH of fusion varies by 0.7 pH units among the subtypes, and notably, we observed that the pH of fusion for most HAs from human isolates was lower than that observed from avian isolates of the same subtype. Overall, these data provide the first broad-spectrum analysis of cleavage-activation and membrane fusion characteristics for all of the IAV HA subtypes, and also show that there are substantial differences between the subtypes that may influence transmission among hosts and establishment in new species. PMID:23459660

  6. A poxvirus host range protein, CP77, binds to a cellular protein, HMG20A, and regulates its dissociation from the vaccinia virus genome in CHO-K1 cells.

    PubMed

    Hsiao, Jye-Chian; Chao, Chien-Chiang; Young, Ming-Jer; Chang, Yu-Tai; Cho, Er-Chieh; Chang, Wen

    2006-08-01

    Vaccinia virus does not grow in Chinese hamster ovary (CHO-K1) cells in the absence of a viral host range factor, cowpox protein CP77. In this study, CP77 was fused to the C terminus of green fluorescence protein (GFP-CP77) and a series of nested deletion mutants of GFP-CP77 was constructed for insertion into a vaccinia virus host range mutant, VV-hr, and expressed from a viral early promoter. Deletion mapping analyses demonstrated that the N-terminal 352 amino acids of CP77 were sufficient to support vaccinia virus growth in CHO-K1 cells, whereas the C-terminal residues 353 to 668 were dispensable. In yeast two-hybrid analyses, CP77 bound to a cellular protein, HMG20A, and GST pulldown analyses showed that residues 1 to 234 of CP77 were sufficient for this interaction. After VV-hr virus infection of CHO-K1 cells, HMG20A was translocated from the nucleus to viral factories and bound to the viral genome via the HMG box region. In control VV-hr-infected CHO-K1 cells, binding of HMG20A to the viral genome persisted from 2 to 8 h postinfection (h p.i.); in contrast, when CP77 was expressed, the association of HMG20A with viral genome was transient, with little HMG20A remaining bound at 8 h p.i. This indicates that dissociation of HMG20A from viral factories correlates well with CP77 host range activity in CHO-K1 cells. Finally, in cells expressing a CP77 deletion protein (amino acids 277 to 668) or a DeltaANK5 mutant that did not support vaccinia virus growth and did not contain the HMG20A binding site, HMG20A remained bound to viral DNA, demonstrating that the binding of CP77 to HMG20A is essential for its host range function. In summary, our data revealed that a novel cellular protein, HMG20A, the dissociation of which from viral DNA is regulated by CP77, providing the first cellular target regulated by viral host range CP77 protein.

  7. Infections of nervous necrosis virus in wild and cage-reared marine fish from South China Sea with unexpected wide host ranges.

    PubMed

    Liu, X D; Huang, J N; Weng, S P; Hu, X Q; Chen, W J; Qin, Z D; Dong, X X; Liu, X L; Zhou, Y; Asim, M; Wang, W M; He, J G; Lin, L

    2015-06-01

    The concerns about the impact of the nervous necrosis virus (NNV) infections in wild fish have been raised. This paper presents the results of quarterly surveys of NNV in wild and cage-reared marine fish from South China Sea. Samples of 892 wild fish belonging to 69 species and 381 cage-reared fish belonging to 11 species were collected and were detected by seminested PCR and nested PCR. In the case of seminested PCR, the positive signal was detected in 3.0% and 3.1% samples of wild and cage-reared fish, respectively. However, by nested RT-PCR, the positive signal was observed in 42.3% and 63.0% samples of wild and cage-reared fish, respectively. If the fish species were considered, the positive signal was detected in 21.7% and 72.7% species of wild and cage-reared fish by seminested PCR assay, respectively. However, by nested RT-PCR, the positive signal was observed in 65.2% and 100% species of wild and cage-reared fish, respectively. The nucleotide sequences of the nested PCR products were determined. Phylogenetic tree showed that all the obtained viral isolates belonged to the red-spotted grouper nervous necrosis virus (RGNNV) genotype. Thirty-five species of the marine fish were the new hosts of NNV.

  8. Bacterial Genome Partitioning: N-Terminal Domain of IncC Protein Encoded by Broad-Host-Range Plasmid RK2 Modulates Oligomerisation and DNA Binding

    PubMed Central

    Batt, Sarah M.; Bingle, Lewis E.H.; Dafforn, Tim R.; Thomas, Christopher M.

    2009-01-01

    ParA Walker ATPases form part of the machinery that promotes better-than-random segregation of bacterial genomes. ParA proteins normally occur in one of two forms, differing by their N-terminal domain (NTD) of approximately 100 aa, which is generally associated with site-specific DNA binding. Unusually, and for as yet unknown reasons, parA (incC) of IncP-1 plasmids is translated from alternative start codons producing two forms, IncC1 (364 aa) and IncC2 (259 aa), whose ratio varies between hosts. IncC2 could be detected as an oligomeric form containing dimers, tetramers and octamers, but the N-terminal extension present in IncC1 favours nucleotide-stimulated dimerisation as well as high-affinity and ATP-dependent non-specific DNA binding. The IncC1 NTD does not dimerise or bind DNA alone, but it does bind IncC2 in the presence of nucleotides. Mixing IncC1 and IncC2 improved polymerisation and DNA binding. Thus, the NTD may modulate the polymerisation interface, facilitating polymerisation/depolymerisation and DNA binding, to promote the cycle that drives partitioning. PMID:19109978

  9. Vip3A, a novel Bacillus thuringiensis vegetative insecticidal protein with a wide spectrum of activities against lepidopteran insects.

    PubMed

    Estruch, J J; Warren, G W; Mullins, M A; Nye, G J; Craig, J A; Koziel, M G

    1996-05-28

    A novel vegetative insecticidal gene, vip3A(a), whose gene product shows activity against lepidopteran insect larvae including black cutworm (Agrotis ipsilon), fall armyworm (Spodoptera frugiperda), beet armyworm (Spodoptera exigua), tobacco budworm (Heliothis virescens), and corn earworm (Helicoverpa zea) has been isolated from Bacillus thuringiensis strain AB88. VIP3-insecticidal gene homologues have been detected in approximately 15% of Bacillus strains analyzed. The sequence of the vip3A(b) gene, a homologue of vip3A(a) isolated from B. thuringiensis strain AB424 is also reported. Vip3A(a) and (b) proteins confer upon Escherichia coli insecticidal activity against the lepidopteran insect larvae mentioned above. The sequence of the gene predicts a 791-amino acid (88.5 kDa) protein that contains no homology with known proteins. Vip3A insecticidal proteins are secreted without N-terminal processing. Unlike the B. thuringiensis 5-endotoxins, whose expression is restricted to sporulation, Vip3A insecticidal proteins are expressed in the vegetative stage of growth starting at mid-log phase as well as during sporulation. Vip3A represents a novel class of proteins insecticidal to lepidopteran insect larvae.

  10. Comparative Mitochondrial Genome Analysis of Eligma narcissus and other Lepidopteran Insects Reveals Conserved Mitochondrial Genome Organization and Phylogenetic Relationships

    PubMed Central

    Dai, Li-Shang; Zhu, Bao-Jian; Zhao, Yue; Zhang, Cong-Fen; Liu, Chao-Liang

    2016-01-01

    In this study, we sequenced the complete mitochondrial genome of Eligma narcissus and compared it with 18 other lepidopteran species. The mitochondrial genome (mitogenome) was a circular molecule of 15,376 bp containing 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and an adenine (A) + thymine (T) − rich region. The positive AT skew (0.007) indicated the occurrence of more As than Ts. The arrangement of 13 PCGs was similar to that of other sequenced lepidopterans. All PCGs were initiated by ATN codons, except for the cytochrome c oxidase subunit 1 (cox1) gene, which was initiated by the CGA sequence, as observed in other lepidopterans. The results of the codon usage analysis indicated that Asn, Ile, Leu, Tyr and Phe were the five most frequent amino acids. All tRNA genes were shown to be folded into the expected typical cloverleaf structure observed for mitochondrial tRNA genes. Phylogenetic relationships were analyzed based on the nucleotide sequences of 13 PCGs from other insect mitogenomes, which confirmed that E. narcissus is a member of the Noctuidae superfamily. PMID:27222440

  11. Broad-host-range plasmids for red fluorescent protein labeling of gram-negative bacteria for use in the zebrafish model system.

    PubMed

    Singer, John T; Phennicie, Ryan T; Sullivan, Matthew J; Porter, Laura A; Shaffer, Valerie J; Kim, Carol H

    2010-06-01

    To observe real-time interactions between green fluorescent protein-labeled immune cells and invading bacteria in the zebrafish (Danio rerio), a series of plasmids was constructed for the red fluorescent protein (RFP) labeling of a variety of fish and human pathogens. The aim of this study was to create a collection of plasmids that would express RFP pigments both constitutively and under tac promoter regulation and that would be nontoxic and broadly transmissible to a variety of Gram-negative bacteria. DNA fragments encoding the RFP dimeric (d), monomeric (m), and tandem dimeric (td) derivatives d-Tomato, td-Tomato, m-Orange, and m-Cherry were cloned into the IncQ-based vector pMMB66EH in Escherichia coli. Plasmids were mobilized into recipient strains by conjugal mating. Pigment production was inducible in Escherichia coli, Pseudomonas aeruginosa, Edwardsiella tarda, and Vibrio (Listonella) anguillarum strains by isopropyl-beta-d-thiogalactopyranoside (IPTG) treatment. A spontaneous mutant exconjugant of P. aeruginosa PA14 was isolated that expressed td-Tomato constitutively. Complementation analysis revealed that the constitutive phenotype likely was due to a mutation in lacI(q) carried on pMMB66EH. DNA sequence analysis confirmed the presence of five transitions, four transversions, and a 2-bp addition within a 14-bp region of lacI. Vector DNA was purified from this constitutive mutant, and structural DNA sequences for RFP pigments were cloned into the constitutive vector. Exconjugants of P. aeruginosa, E. tarda, and V. anguillarum expressed all pigments in an IPTG-independent fashion. Results from zebrafish infectivity studies indicate that RFP-labeled pathogens will be useful for the study of real-time interactions between host cells of the innate immune system and the infecting pathogen.

  12. Descriptions of Meloidogyne camelliae n.sp. and M. querciana n.sp (Nematoda:Meloidogynidae), with SEM and Host-Range Observations.

    PubMed

    Golden, A M

    1979-04-01

    Meloidogyne camelliae n.sp. on camellia (Camellia japonica) from Japan and M. querciana n.sp. on pin oak (Quercus palustris) from Virginia, USA, are described and illustrated. M. camelliae n.sp. is distingnishable from other species of the genus especially by its striking perineal pattern having heavy ropelike striae forming a squarish to rectangular outline with shoulders or projections, appearing sometimes ahnost starlike. M. querciana differs from other species by its characteristic perineal pattern round to oval in outline, sometimes with a low arch, and sunken vulva surrounded by a prominent obovate area devoid of striae. M. querciana shows some relationship to M. ovalis, but differs further fxom the latter by longer larvae, absence of annules on head of larvae, and rarity of males. Examination of specimens of M. camelliae n.sp. and M. querciana n.sp. with the scanning electron microscope confirmed observations made by optical microscopy and revealed diagnostic and other structures in greater detail. In greenhouse host tests, M. camelliae infected camellia heavily, showed moderate infection on oxalis, only a trace infection on tomato, and no infection on five other plants tested; and M. querciana attacked pin oak, red oak, and American chestnut heavily, but did not infect nine other test plants. In another test, pin oak seedlings did not become infected when heavily inoculated with and grown in the presence of two populations of M. incognita incognita and one of M. incognita acrita. The common names "camellia root-knot nematode" and "oak root-knot nematode" are respectively proposed for M. camelliae and M. querciana.

  13. Descriptions of Meloidogyne camelliae n.sp. and M. querciana n.sp (Nematoda:Meloidogynidae), with SEM and Host-Range Observations

    PubMed Central

    Golden, A. Morgan

    1979-01-01

    Meloidogyne camelliae n.sp. on camellia (Camellia japonica) from Japan and M. querciana n.sp. on pin oak (Quercus palustris) from Virginia, USA, are described and illustrated. M. camelliae n.sp. is distingnishable from other species of the genus especially by its striking perineal pattern having heavy ropelike striae forming a squarish to rectangular outline with shoulders or projections, appearing sometimes ahnost starlike. M. querciana differs from other species by its characteristic perineal pattern round to oval in outline, sometimes with a low arch, and sunken vulva surrounded by a prominent obovate area devoid of striae. M. querciana shows some relationship to M. ovalis, but differs further fxom the latter by longer larvae, absence of annules on head of larvae, and rarity of males. Examination of specimens of M. camelliae n.sp. and M. querciana n.sp. with the scanning electron microscope confirmed observations made by optical microscopy and revealed diagnostic and other structures in greater detail. In greenhouse host tests, M. camelliae infected camellia heavily, showed moderate infection on oxalis, only a trace infection on tomato, and no infection on five other plants tested; and M. querciana attacked pin oak, red oak, and American chestnut heavily, but did not infect nine other test plants. In another test, pin oak seedlings did not become infected when heavily inoculated with and grown in the presence of two populations of M. incognita incognita and one of M. incognita acrita. The common names "camellia root-knot nematode" and "oak root-knot nematode" are respectively proposed for M. camelliae and M. querciana. PMID:19305554

  14. Multi-locus genotypes of Enterocytozoon bieneusi in captive Asiatic black bears in southwestern China: High genetic diversity, broad host range, and zoonotic potential

    PubMed Central

    Cao, Xuefeng; Song, Yuan; Wang, Wuyou; Huang, Xiangming; Liu, Xuehan; Hu, Yanchun; Fu, Hualin; He, Min; Wang, Ya; Zhang, Yue; Wu, Kongju; Peng, Guangneng

    2017-01-01

    Enterocytozoon bieneusi is an obligate eukaryotic intracellular parasite that infects a wide variety of vertebrate and invertebrate hosts. Although considerable research has been conducted on this organism, relatively little information is available on the occurrence of E. bieneusi in captive Asiatic black bears. The present study was performed to determine the prevalence, genetic diversity, and zoonotic potential of E. bieneusi in captive Asiatic black bears in zoos in southwestern China. Fecal specimens from Asiatic black bears in four zoos, located in four different cities, were collected and analyzed for the prevalence of E. bieneusi. The average prevalence of E. bieneusi was 27.4% (29/106), with the highest prevalence in Guiyang Zoo (36.4%, 16/44). Altogether, five genotypes of E. bieneusi were identified among the 29 E. bieneusi-positive samples, including three known genotypes (CHB1, SC02, and horse2) and two novel genotypes named ABB1 and ABB2. Multi-locus sequence typing using three microsatellites (MS1, MS3, and MS7) and one minisatellite (MS4) revealed V, III, V, and IV genotypes at these four loci, respectively. Phylogenetic analysis showed that the genotypes SC02 and ABB2 were clustered into group 1 of zoonotic potential, the genotypes CHB1 and ABB1 were clustered into a new group, and the genotype horse2 was clustered into group 6 of unclear zoonotic potential. In conclusion, this study identified two novel E. bieneusi genotypes in captive Asiatic black bears, and used microsatellite and minisatellite markers to reveal E. bieneusi genetic diversity. Moreover, our findings show that genotypes SC02 (identified in humans) and ABB2 belong to group 1 with zoonotic potential, suggesting the risk of transmission of E. bieneusi from Asiatic black bears to humans and other animals. PMID:28182656

  15. Advanced technologies for genetically manipulating the silkworm Bombyx mori, a model Lepidopteran insect.

    PubMed

    Xu, Hanfu; O'Brochta, David A

    2015-07-07

    Genetic technologies based on transposon-mediated transgenesis along with several recently developed genome-editing technologies have become the preferred methods of choice for genetically manipulating many organisms. The silkworm, Bombyx mori, is a Lepidopteran insect of great economic importance because of its use in silk production and because it is a valuable model insect that has greatly enhanced our understanding of the biology of insects, including many agricultural pests. In the past 10 years, great advances have been achieved in the development of genetic technologies in B. mori, including transposon-based technologies that rely on piggyBac-mediated transgenesis and genome-editing technologies that rely on protein- or RNA-guided modification of chromosomes. The successful development and application of these technologies has not only facilitated a better understanding of B. mori and its use as a silk production system, but also provided valuable experiences that have contributed to the development of similar technologies in non-model insects. This review summarizes the technologies currently available for use in B. mori, their application to the study of gene function and their use in genetically modifying B. mori for biotechnology applications. The challenges, solutions and future prospects associated with the development and application of genetic technologies in B. mori are also discussed.

  16. Venom peptides from solitary hunting wasps induce feeding disorder in lepidopteran larvae.

    PubMed

    Baek, Ji Hyeong; Ji, Yeounjung; Shin, Jeon-Soo; Lee, Seunghwan; Lee, Si Hyeock

    2011-03-01

    The cell lytic activity and toxicity against lepidopteran larvae of 13 venom peptides (4 OdVPs and 9 EpVPs) from two solitary hunting wasps, Orancistrocerus drewseni and Eumenes pomiformis, were examined with mastoparan as a reference peptide. Of the 13 peptides, 7 were predicted to have α-helical structures that exhibit the typical character of amphipathic α-helical antimicrobial peptides. The remaining peptides exhibited coil structures; among these, EpVP5 possesses two Cys residues that form an internal disulfide bridge. All the helical peptides including mastoparan showed antimicrobial and insect cell lytic activities, whereas only two of them were hemolytic against human erythrocytes. The helical peptides induced a feeding disorder when injected into the vicinity of the head and thorax of Spodoptera exigua larvae, perhaps because their non-specific neurotoxic or myotoxic action induced cell lysis. At low concentrations, however, these helical peptides increased cell permeability without inducing cell lysis. These findings suggest that the helical venom peptides may function as non-specific neurotoxins or myotoxins and venom-spreading factors at low concentrations, as well as preservatives for long-term storage of the prey via antimicrobial, particularly antifungal, activities.

  17. A screening of five Bacillus thuringiensis Vip3A proteins for their activity against lepidopteran pests.

    PubMed

    Ruiz de Escudero, Iñigo; Banyuls, Núria; Bel, Yolanda; Maeztu, Mireya; Escriche, Baltasar; Muñoz, Delia; Caballero, Primitivo; Ferré, Juan

    2014-03-01

    Five Bacillus thuringiensis Vip3A proteins (Vip3Aa, Vip3Ab, Vip3Ad, Vip3Ae and Vip3Af) and their corresponding trypsin-activated toxins were tested for their toxicity against eight lepidopteran pests: Agrotis ipsilon, Helicoverpa armigera, Mamestra brassicae, Spodoptera exigua, Spodoptera frugiperda, Spodoptera littoralis, Ostrinia nubilalis and Lobesia botrana. Toxicity was first tested at a high dose at 7 and 10 days. No major differences were found when comparing protoxins vs. trypsin-activated toxins. The proteins that were active against most of the insect species were Vip3Aa, Vip3Ae and Vip3Af, followed by Vip3Ab. Vip3Ad was non-toxic to any of the species tested. Considering the results by insect species, A. ipsilon, S. frugiperda and S. littoralis were susceptible to Vip3Aa, Vip3Ab, Vip3Ae and Vip3Af; S. exigua was susceptible to Vip3Aa and Vip3Ae, and moderately susceptible to Vip3Ab; M. brassicae and L. botrana were susceptible to Vip3Aa, Vip3Ae and Vip3Af; H. armigera was moderately susceptible to Vip3Aa, Vip3Ae and Vip3Af, and O. nubilalis was tolerant to all Vip3 proteins tested, although it showed some susceptibility to Vip3Af. The results obtained will help to design new combinations of insecticidal protein genes in transgenic crops or in recombinant bacteria for the control of insect pests.

  18. New Bacillus thuringiensis toxin combinations for biological control of lepidopteran larvae.

    PubMed

    Elleuch, Jihen; Zghal, Raida Zribi; Jemaà, Mohamed; Azzouz, Hichem; Tounsi, Slim; Jaoua, Samir

    2014-04-01

    Cyt1Aa from Bacillus thuringiensis israelensis is known by its synergistical activity with B. thuringiensis and Bacillus sphaericus toxins. It is able to improve dipteran specific toxins activity and can prevent or overcome larval resistance to those proteins. The objective of the current study was to investigate the possible improvement of larvicidal activity of B. thuringiensis kurstaki expressing heterogeneous proteins Cyt1A and P20. cyt1A98 and p20 genes encoding the cytolytic protein (Cyt1A98) and the accessory protein (P20), respectively, were introduced individually and in combination into B. thuringiensis kurstaki strain BNS3. Immunoblot analysis evidenced the expression of these genes in the recombinant strains and hinted that P20 acts as molecular chaperone protecting Cyt1A98 from proteolytic attack in BNS3. The toxicities of recombinant strains were studied and revealed that BNS3pHTp20 exhibited higher activity than that of the negative control (BNS3pHTBlue) toward Ephestia kuehniella, but not toward Spodoptera littoralis. When expressed in combination with P20, Cyt1A98 enhanced BNS3 activity against E. kuehniella and S. littoralis. Thus, Cyt1Aa protein could enhance lepidopteran Cry insecticidal activity and would prevent larval resistance to the most commercialized B. thuringiensis kurstaki toxins.

  19. High susceptibility of Bt maize to aphids enhances the performance of parasitoids of lepidopteran pests.

    PubMed

    Faria, Cristina A; Wäckers, Felix L; Pritchard, Jeremy; Barrett, David A; Turlings, Ted C J

    2007-07-11

    Concerns about possible undesired environmental effects of transgenic crops have prompted numerous evaluations of such crops. So-called Bt crops receive particular attention because they carry bacteria-derived genes coding for insecticidal proteins that might negatively affect non-target arthropods. Here we show a remarkable positive effect of Bt maize on the performance of the corn leaf aphid Rhopalosiphum maidis, which in turn enhanced the performance of parasitic wasps that feed on aphid honeydew. Within five out of six pairs that were evaluated, transgenic maize lines were significantly more susceptible to aphids than their near-isogenic equivalents, with the remaining pair being equally susceptible. The aphids feed from the phloem sieve element content and analyses of this sap in selected maize lines revealed marginally, but significantly higher amino acid levels in Bt maize, which might partially explain the observed increased aphid performance. Larger colony densities of aphids on Bt plants resulted in an increased production of honeydew that can be used as food by beneficial insects. Indeed, Cotesia marginiventris, a parasitoid of lepidopteran pests, lived longer and parasitized more pest caterpillars in the presence of aphid-infested Bt maize than in the presence of aphid-infested isogenic maize. Hence, depending on aphid pest thresholds, the observed increased susceptibility of Bt maize to aphids may be either a welcome or an undesirable side effect.

  20. Kinetics of plasmid transfer among Bacillus cereus group strains within lepidopteran larvae.

    PubMed

    Yuan, Y M; Hu, X M; Liu, H Z; Hansen, Bjarne Munk; Yan, J P; Yuan, Z M

    2007-06-01

    The cry toxin encoding plasmid pHT73 was transferred from Bacillus thuringiensis subspecies kurstaki KT0 to six B. cereus group strains in three lepidopteran (Spodoptera exigua, Plutella xyllostella and Helicoverpa armigera) larvae by conjugation. The conjugation kinetics of the plasmid was precisely studied during the larval infection using a new protocol. The infections were performed with both vegetative and sporulated strains. However, larval death only occurred when infections were made with spore and toxin preparations. Likewise, spore germinations of both donor and recipient strains were only observed in killed larvae, 44-56 h post-infection. Accordingly, kinetics showed that gene transfer between B. thuringiensis strain KT0 and other B. cereus strains only took place in dead larvae among vegetatively growing bacteria. The conjugational transfer ratios varied among different strain combinations and different larvae. The highest transfer ratio reached 5.83 x 10(-6) CFU/donor between the KT0 and the AW05R recipient in Helicoverpa armigera, and all transconjugants gained the ability to produce the insecticidal crystal. These results indicated that horizontal gene transfer among B. cereus group strains might play a key role for the acquisition of extra plasmids and evolution of these strains in toxin susceptible insect larvae.

  1. Molecular data and phylogeny of Nosema infecting lepidopteran forest defoliators in the genera Choristoneura and Malacosoma.

    PubMed

    Kyei-Poku, George; Gauthier, Debbie; van Frankenhuyzen, Kees

    2008-01-01

    Nosema isolates from five lepidopteran forest defoliators, Nosema fumiferanae from spruce budworm, Choristoneura fumiferana; a Nosema sp. from jack pine budworm, Choristoneura pinus pinus and western spruce budworm, Choristoneura occidentalis (Nosema sp. CPP and Nosema sp. CO, respectively); Nosema thomsoni from large aspen tortrix, Choristoneura conflictana; and Nosema disstriae, from the forest tent caterpillar, Malacosoma disstria were compared based on their small subunit (SSU) ribosomal RNA (rRNA) gene sequences. Four of the species sequenced, N. fumiferanae, Nosema sp. CPP, Nosema sp. CO, and N. disstriae have a high SSU rDNA sequence identity (0.6%-1.5%) and are members of the "true Nosema" clade. They all showed the reverse arrangement of the (large subunit [LSU]-internal transcribed spacer [ITS]-SSU) of the rRNA gene. The fifth species, N. thomsoni has the usual (SSU-ITS-LSU) arrangement and is not a member of this clade showing only an 82% sequence similarity. We speculate, therefore, that a genetic reversal may have occurred in the common ancestor to the "true Nosema" clade. Although, the mechanism for rearrangement of the rRNA gene subunits is not known we provide a possible explanation for the localization. N. fumiferanae, Nosema sp. CPP, and Nosema sp. CO clustered together on the inferred phylogenetic tree. The high sequence similarities, the reverse arrangement in the rRNA gene subunits, and the phylogenetic clustering suggest that these three species are closely related but separate species.

  2. Advanced technologies for genetically manipulating the silkworm Bombyx mori, a model Lepidopteran insect

    PubMed Central

    Xu, Hanfu; O'Brochta, David A.

    2015-01-01

    Genetic technologies based on transposon-mediated transgenesis along with several recently developed genome-editing technologies have become the preferred methods of choice for genetically manipulating many organisms. The silkworm, Bombyx mori, is a Lepidopteran insect of great economic importance because of its use in silk production and because it is a valuable model insect that has greatly enhanced our understanding of the biology of insects, including many agricultural pests. In the past 10 years, great advances have been achieved in the development of genetic technologies in B. mori, including transposon-based technologies that rely on piggyBac-mediated transgenesis and genome-editing technologies that rely on protein- or RNA-guided modification of chromosomes. The successful development and application of these technologies has not only facilitated a better understanding of B. mori and its use as a silk production system, but also provided valuable experiences that have contributed to the development of similar technologies in non-model insects. This review summarizes the technologies currently available for use in B. mori, their application to the study of gene function and their use in genetically modifying B. mori for biotechnology applications. The challenges, solutions and future prospects associated with the development and application of genetic technologies in B. mori are also discussed. PMID:26108630

  3. Triterpene acids from apple peel inhibit lepidopteran larval midgut lipases and larval growth.

    PubMed

    Christeller, John T; McGhie, Tony K; Poulton, Joanne; Markwick, Ngaire P

    2014-07-01

    Fruit extracts from apple, kiwifruit, feijoa, boysenberry, and blueberry were screened for the presence of lipase inhibitory compounds against lepidopteran larval midgut crude extracts. From 120 extracts, six showed significant inhibition with an extract from the peel of Malus × domestica cv. "Big Red" showing highest levels of inhibition. Because this sample was the only apple peel sample in the initial screen, a survey of peels from seven apple cultivars was undertaken and showed that, despite considerable variation, all had inhibitory activity. Successive solvent fractionation and LC-MS of cv. "Big Red" apple peel extract identified triterpene acids as the most important inhibitory compounds, of which ursolic acid and oleanolic acid were the major components and oxo- and hydroxyl-triterpene acids were minor components. When ursolic acid was incorporated into artificial diet and fed to Epiphyas postvittana Walker (Tortricidae: Lepidoptera) larvae at 0.16% w/v, a significant decrease in larval weight was observed after 21 days. This concentration of ursolic acid is less than half the concentration reported in the skin of some apple cultivars.

  4. Main lepidopteran pest species from an eucalyptus plantation in Minas Gerais, Brazil.

    PubMed

    Zanuncio, Teresinha V; Zanuncio, José C; de Freitas, Fernando A; Pratissoli, Dirceu; Sediyama, Camilla A Z; Maffia, Vanessa P

    2006-06-01

    Lepidoptera species were monitored in a plantation of Eucalyptus grandis in the Municipality of Bom Despacho, State of Minas Gerais, Brazil from March 1987 to February 1992. A total of 547 species were collected and divided in: primary pests: 13; secondary pests: 20; species without defined importance to eucalyptus: 79; and non-identified species: 435. These four groups had a mean of 5231.29; 338.18; 438.16 and 2222.87 individuals with a total of 8229.87 individuals collected per trap. The number of species without defined importance to eucalyptus, and non-identified species, increased during the collecting period of five years while those of primary and secondary pests showed similar numbers in all years. The most collected primary pests Thyrinteina arnobia Stoll and Stenalcidia sp. (Geometridae) showed higher frequencies during the driest and coldest periods of the year, whereas Psorocampa denticulata Schaus (Notodontidae) was most frequent during periods of higher rainfall. Species of groups III and IV increased in diversity with eucalyptus age. This area has a high probability of outbreaks of eucalyptus defoliating caterpillars, especially T. arnobia. For this reason, lepidopteran pests should be monitored in this plantation during the driest and coldest periods of the year, when they can reach population peaks.

  5. Chlorophyll degradation in the gut of generalist and specialist Lepidopteran caterpillars.

    PubMed

    Badgaa, Amarsanaa; Jia, Aiqun; Ploss, Kerstin; Boland, Wilhelm

    2014-12-01

    Plant feeding herbivores excrete most of the ingested chlorophyll (Chl) as partly degraded derivatives lacking the phytol side chain and the central magnesium ion. An ecological role of digested and degraded Chls in the interactions between insects, their food plant and other insects has been described recently. To gain more information on common degradation patterns in plant-feeding insects, the orals secretions and frass of five Lepidopteran caterpillars covering generalists and specialists, namely Spodoptera littoralis, Spodoptera eridania, Heliothis virescens, Helicoverpa armigera, Manduca sexta, and, for comparison, of the leaf beetle larva Chrysomela lapponica were analyzed for chlorophyll catabolites. The major degradation products were determined as pheohorbide a/b and pyropheophorbide a/b by using LC-MS, LC-NMR, UV, and fluorescence spectrometry. The compounds were not present in fresh leaves of the food plants (Phaseolus lunatus, Nicotiana tabacum). The catabolite spectrum in generalists and specialists was qualitatively similar and could be attributed to the action of gut proteins and the strongly alkaline milieu in the digestive tract. Due to the anaerobic environment of the larval gut, the tetrapyrrole core of the Chl catabolites was not cleaved. Substantial amounts of Chl a/b metabolites were strongly complexed by a protein in the mid-gut.

  6. Host range and receptor utilization of canine distemper virus analyzed by recombinant viruses: Involvement of heparin-like molecule in CDV infection.

    PubMed

    Fujita, Kentaro; Miura, Ryuichi; Yoneda, Misako; Shimizu, Fusako; Sato, Hiroki; Muto, Yuri; Endo, Yasuyuki; Tsukiyama-Kohara, Kyoko; Kai, Chieko

    2007-03-15

    We constructed recombinant viruses expressing enhanced green fluorescent protein (EGFP) or firefly luciferase from cDNA clones of the canine distemper virus (CDV) (a Japanese field isolate, Yanaka strain). Using these viruses, we examined susceptibilities of different cell lines to CDV infection. The results revealed that the recombinant CDVs can infect a broad range of cell lines. Infectivity inhibition assay using a monoclonal antibody specific to the human SLAM molecule indicated that the infection of B95a cells with these recombinant CDVs is mainly mediated by SLAM but the infection of 293 cell lines with CDV is not, implying the presence of one or more alternative receptors for CDV in non-lymphoid tissue. Infection of 293 cells with the recombinant CDV was inhibited by soluble heparin, and the recombinant virus bound to immobilized heparin. Both F and H proteins of CDV could bind to immobilized heparin. These results suggest that heparin-like molecules are involved in CDV infection.

  7. The translocated Liza haematocheila (Teleostei: Mugilidae) as a new host of four species of Saturnius Manter, 1969 (Digenea: Hemiuridae) within its invasive range in the Black Sea.

    PubMed

    Pankov, Plamen; Gibson, David I; Kostadinova, Aneta

    2009-09-01

    This paper presents the first documented record of four species of Saturnius Manter, 1969 in Liza haematocheila (Temminck & Schlegel) in its invasive Pontic range. S. papernai Overstreet, 1977, S. dimitrovi Blasco-Costa, Pankov, Gibson, Balbuena, Raga, Sarabeev & Kostadinova, 2006, S. minutus Blasco-Costa, Pankov, Gibson, Balbuena, Raga, Sarabeev & Kostadinova, 2006 and Saturnius sp. are described and compared with existing data by means of multivariate morphometric analysis. The morphological and morphometric similarities between the specimens of Saturnius sp. from L. haematocheila and a small form of S. papernai from L. aurata indicate the possible existence of another, cryptic species. Although having acquired at least three species of Saturnius since its establishment in the Black Sea region, there is no evidence that a Pacific congener has been introduced with this fish. This is the first report of S. minutus from the Black Sea.

  8. Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.)

    PubMed Central

    2012-01-01

    Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are α-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris) in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym) that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical rhizobia with common bean

  9. Diversity of alternative hosts of maize stemborers in Trans-Nzoia district of Kenya.

    PubMed

    Kanya, James I; Ngi-Song, Adele J; Sétamou, Mamoudou F; Overholt, William; Ochora, John; Osir, Ellie O

    2004-01-01

    Genetically-engineered (GE) crops such as those expressing insecticidal Bacillus thuringiensis (Bt) toxin genes have the potential to greatly reduce the use of broad spectrum insecticides and increase crop productivity. However, development of resistance by the target insect species is an important consideration in the deployment of this strategy. In areas where GE crops are deployed on a large scale, current resistance management strategies rely on a 'refuge strategy', comprising the incorporation of a certain proportion of non-GE plants in the agro-ecosystems, to conserve susceptible individuals of the target pests. In the USA, simulation models indicate that at least 20% of the crop should be non-Bt plants. In Africa, the target lepidopteran stemborers attack a wide range of wild grass species as well as cultivated cereal crops. Wild grasses generally occur in the vicinity of maize and other cereal fields, and may provide a refuge if GE crops are in the farming systems. To assess the quality of these grasses as refuges, it is critical to obtain information about their size and spatial distribution. In this study, we have assessed the abundance and diversity of alternative refuge of stemborers, mainly wild grasses occurring in the proximity of maize fields, in Trans-Nzoia district, one of the most important maize growing areas in Kenya. The proportion of wild host plants relative to maize was found to decline from 100% during the non-cropping season to <8% during the maize-growing season. The Shannon-Weaver diversity index indicated high variation in the diversity of wild hosts of stemborers between agro-ecological zones in the district. The results of this study are discussed in light of the possible role that wild host plant species might play in stemborer resistance management following the introduction of Bt maize.

  10. Biology and Host Range of Digitivalva delaireae (Lepidoptera: Glyphipterigidae), a Candidate Agent for Biological Control of Cape-ivy (Delairea odorata) in California and Oregon.

    PubMed

    Mehelis, Christopher N; Balciunas, Joe K; Reddy, Angelica M; Van Der Westhuizen, Liame; Neser, Stefan; Moran, Patrick J

    2015-04-01

    Cape-ivy (Delairea odorata Lemaire) is an ornamental vine native to South Africa that has escaped into natural areas in coastal California and Oregon, displacing native vegetation. Surveys in South Africa led to the discovery of the leaf- and stem-mining moth Digitivalva delaireae Gaedike and Kruger (Lepidoptera: Glyphipterigidae: Acrolepiinae) as one of several common and damaging native herbivores on Cape-ivy. In greenhouse studies, adult female life span averaged 16 d (46 d maximum). Most (72%) mated females began laying eggs within 72 h of emergence. Females had an average lifetime fecundity of 52 eggs, with >70% laid on leaf laminae, and 89% of eggs were laid by the 15th day postemergence. Lifetime fertility (adult production) averaged three to four offspring per female. At 25 °C, egg hatch required 10 d, pupal formation 26 d, and adult emergence 41 d, while under variable greenhouse and laboratory conditions development to adult required 54-60 d. In four-way choice tests, involving 100 plant species other than Cape-ivy, including 11 genera and 37 species in the Asteraceae, subtribe Senecioninae from both native and invaded ranges, D. delaireae inflicted damage and produced pupae only on Cape-ivy. Leaf mining damage occurred on 30% of leaves of native Senecio hydrophilus in no-choice tests and on 2% of leaves in dual-choice tests, but no pupation occurred. If approved for field release in the continental United States, the moth D. delaireae is expected to produce multiple generations per year on Cape-ivy, and to pose little risk of damage to native plants.

  11. A Proposal for a Genome Similarity-Based Taxonomy for Plant-Pathogenic Bacteria that Is Sufficiently Precise to Reflect Phylogeny, Host Range, and Outbreak Affiliation Applied to Pseudomonas syringae sensu lato as a Proof of Concept.

    PubMed

    Vinatzer, Boris A; Weisberg, Alexandra J; Monteil, Caroline L; Elmarakeby, Haitham A; Sheppard, Samuel K; Heath, Lenwood S

    2017-01-01

    Taxonomy of plant pathogenic bacteria is challenging because pathogens of different crops often belong to the same named species but current taxonomy does not provide names for bacteria below the subspecies level. The introduction of the host range-based pathovar system in the 1980s provided a temporary solution to this problem but has many limitations. The affordability of genome sequencing now provides the opportunity for developing a new genome-based taxonomic framework. We already proposed to name individual bacterial isolates based on pairwise genome similarity. Here, we expand on this idea and propose to use genome similarity-based codes, which we now call life identification numbers (LINs), to describe and name bacterial taxa. Using 93 genomes of Pseudomonas syringae sensu lato, LINs were compared with a P. syringae genome tree whereby the assigned LINs were found to be informative of a majority of phylogenetic relationships. LINs also reflected host range and outbreak association for strains of P. syringae pathovar actinidiae, a pathovar for which many genome sequences are available. We conclude that LINs could provide the basis for a new taxonomic framework to address the shortcomings of the current pathovar system and to complement the current taxonomic system of bacteria in general.

  12. Physiological and biochemical effect of neem and other Meliaceae plants secondary metabolites against Lepidopteran insects

    PubMed Central

    Senthil-Nathan, Sengottayan

    2013-01-01

    This review described the physiological and biochemical effects of various secondary metabolites from Meliaceae against major Lepidopteran insect pest including, Noctuidae and Pyralidae. The biochemical effect of major Meliaceae secondary metabolites were discussed more in this review. Several enzymes based on food materials have critical roles in nutritional indices (food utilization) of the insect pest population. Several research work has been referred and the effect of Meliaceae secondary metabolites on feeding parameters of insects by demonstrating food consumption, approximate digestibility of consumed food, efficiency of converting the ingested food to body substance, efficiency of converting digested food to body substance and consumption index was reviewed in detail. Further how the digestive enzymes including a-Amylases, α and β-glucosidases (EC 3.2.1.1), lipases (EC 3.1.1) Proteases, serine, cysteine, and aspartic proteinases affected by the Meliaceae secondary metabolites was reviewed. Further effect of Meliaceae secondary metabolites on detoxifying enzymes have been found to react against botanical insecticides including general esterases (EST), glutathione S-transferase (GST) and phosphatases was reviewed. Alkaline phosphatase (ALP, E.C.3.1.3.1) and acid phosphatase (ACP, E.C.3.1.3.2) are hydrolytic enzymes, which hydrolyze phosphomonoesters under alkaline or acid conditions, respectively. These enzymes were affected by the secondary metabolites treatment. The detailed mechanism of action was further explained in this review. Acethylcholine esterase (AChE) is a key enzyme that terminates nerve impulses by catalyzing the hydrolysis of neurotransmitter, acetylcholine, in the nervous system of various organisms. How the AChE activity was altered by the Meliaceae secondary metabolites reviewed in detail. PMID:24391591

  13. Repetitive flanking sequences challenge microsatellite marker development: a case study in the lepidopteran Melanargia galathea.

    PubMed

    Schmid, Max; Csencsics, Daniela; Gugerli, Felix

    2016-11-01

    Microsatellite DNA families (MDF) are stretches of DNA that share similar or identical sequences beside nuclear simple-sequence repeat (nSSR) motifs, potentially causing problems during nSSR marker development. Primers positioned within MDFs can bind several times within the genome and might result in multiple banding patterns. It is therefore common practice to exclude MDF loci in the course of marker development. Here, we propose an approach to deal with multiple primer-binding sites by purposefully positioning primers within the detected repetitive element. We developed a new protocol to determine the family type and the primer position in relation to MDFs using the software packages repark and repeatmasker together with an in-house R script. We re-evaluated newly developed nSSR markers for the lepidopteran Marbled White (Melanargia galathea) and explored the implications of our results with regard to published data sets of the butterfly Euphydryas aurinia, the grasshopper Stethophyma grossum, the conifer Pinus cembra and the crucifer Arabis alpina. For M. galathea, we show that it is not only possible to develop reliable nSSR markers for MDF loci, but even to benefit from their presence in some cases: We used one unlabelled primer, successfully binding within an MDF, for two different loci in a multiplex PCR, combining this family primer with uniquely binding and fluorescently labelled primers outside of MDFs, respectively. As MDFs are abundant in many taxa, we propose to consider these during nSSR marker development in taxa concerned. Our new approach might help in reducing the number of tested primers during nSSR marker development.

  14. Lepidopteran insect susceptibility to silver nanoparticles and measurement of changes in their growth, development and physiology.

    PubMed

    Yasur, Jyothsna; Rani, Pathipati Usha

    2015-04-01

    Increased use of nanomaterials in various fields of science has lead for the need to study the impact of nanomaterial on the environment in general and on insect and plant life in particular. We studied the impact of silver nanoparticles (AgNPs) on growth and feeding responses of two lepidopteran pests of castor plant (Ricinus communis L.) namely Asian armyworm, Spodoptera litura F. and castor semilooper, Achaea janata L. Larvae were fed with PVP coated-AgNPs treated castor leaf at different concentrations and their activity was compared to that of silver nitrate (AgNO3) treated leaf diets. Larval and pupal body weights decreased along with the decrease in the concentrations of AgNPs and AgNO3 in both the test insects. Low amounts of silver were accumulated in the larval guts, but major portion of it was eliminated through the feces. Ultrastructural studies of insect gut cell using Transmission Electron Microscopy (TEM) showed accumulation of silver nanoparticles in cell organelles. Changes in the antioxidative and detoxifying enzymes of the treated larva were estimated. The effect of treatments showed differences in the activities of detoxifying enzymes, carboxylesterases (CarE), glucosidases (Glu) and glutathione S-transferases (GST) in the larval gut. Activities of superoxide dismutase, catalase, and peroxidase were also altered in the larval bodies due to the AgNPs treatments, suggesting that exposure of larvae to nanoparticles induces oxidative stress, which is countered by antioxidant enzymes. Induction of these enzymes may be an effective detoxification mechanism by which the herbivorous insect defends itself against nanoparticle treatment.

  15. Cloning and localization of the lepidopteran protoxin gene of Bacillus thuringiensis subsp. kurstaki.

    PubMed Central

    Held, G A; Bulla, L A; Ferrari, E; Hoch, J; Aronson, A I; Minnich, S A

    1982-01-01

    Bacillus thuringiensis subsp. kurstaki produces a proteinaceous crystalline inclusion that is toxic for lepidopteran larvae. There are several size classes of plasmids in this organism and the presence of one or more has been correlated with production of this protein, defined as a protoxin. DNA fragments of B. thuringiensis subsp. kurstaki, obtained by EcoRI digestion, were cloned into the vector Charon 4A. Recombinant phage were screened immunologically for the production of protoxin. Cells infected with one phage, C4K6c, produced antigen that was the same size as the protoxin and was toxic to Manduca sexta larvae. A 4.6-kilobase-pair (kbp) EcoRI fragment from C4K6c was subcloned into pBR328 and in both orientations in pHV33. Both Escherichia coli and Bacillus subtilis containing these recombinant plasmids produced antigen that crossreacted with antibody directed against the protoxin. The various sized plasmids of B. thuringiensis were purified and only an EcoRI fragment from the 45-kbp plasmid hybridized to phage C4K6c. One of the pHV33 subclones, pSM36, hybridized to the same size EcoRI/HindIII restriction fragments from plasmid or chromosomal DNA. The cloned EcoRI fragment contained a 0.9-kbp Pvu II fragment that was also present in chromosomal but not in plasmid digests. The original clone was therefore of chromosomal origin, although very similar or identical protoxin genes were present in both the 45-kbp plasmid and the chromosome. Several acrystalliferous nontoxic mutants have been isolated that lacked the 45-kbp plasmid and in some cases all plasmids. All of the mutants contained the chromosomal gene but did not produce protoxin antigen. Images PMID:6310560

  16. The genome of a lepidopteran model insect, the silkworm Bombyx mori.

    PubMed

    2008-12-01

    Bombyx mori, the domesticated silkworm, is a major insect model for research, and the first lepidopteran for which draft genome sequences became available in 2004. Two independent data sets from whole-genome shotgun sequencing were merged and assembled together with newly obtained fosmid- and BAC-end sequences. The remarkably improved new assembly is presented here. The 8.5-fold sequence coverage of an estimated 432 Mb genome was assembled into scaffolds with an N50 size of approximately 3.7 Mb; the largest scaffold was 14.5 million base pairs. With help of a high-density SNP linkage map, we anchored 87% of the scaffold sequences to all 28 chromosomes. A particular feature was the high repetitive sequence content estimated to be 43.6% and that consisted mainly of transposable elements. We predicted 14,623 gene models based on a GLEAN-based algorithm, a more accurate prediction than the previous gene models for this species. Over three thousand silkworm genes have no homologs in other insect or vertebrate genomes. Some insights into gene evolution and into characteristic biological processes are presented here and in other papers in this issue. The massive silk production correlates with the existence of specific tRNA clusters, and of several sericin genes assembled in a cluster. The silkworm's adaptation to feeding on mulberry leaves, which contain toxic alkaloids, is likely linked to the presence of new-type sucrase genes, apparently acquired from bacteria. The silkworm genome also revealed the cascade of genes involved in the juvenile hormone biosynthesis pathway, and a large number of cuticular protein genes.

  17. Growth and reproductive costs of larval defence in the aposematic lepidopteran Pieris brassicae.

    PubMed

    Higginson, Andrew D; Delf, Jon; Ruxton, Graeme D; Speed, Michael P

    2011-03-01

    1. Utilization of plant secondary compounds for antipredator defence is common in immature herbivorous insects. Such defences may incur a cost to the animal, either in terms of survival, growth rate or in the reproductive success. 2. A common defence in lepidopterans is the regurgitation of semi-digested material containing the defensive compounds of the food plant, a defence which has led to gut specialization in this order. Regurgitation is often swift in response to cuticular stimulation and deters predators from consuming or parasitizing the larva. The loss of food and other gut material seems likely to impact on fitness, but evidence is lacking. 3. Here, we raised larvae of the common crop pest Pieris brassicae on commercial cabbage leaves, simulated predator attacks throughout the larval period, and measured life-history responses. 4. We found that the probability of survival to pupation decreased with increasing frequency of attacks, but this was because of regurgitation rather than the stimulation itself. There was a growth cost to the defence such that the more regurgitant that individuals produced over the growth period, the smaller they were at pupation. 5. The number of mature eggs in adult females was positively related to pupal mass, but this relationship was only found when individuals were not subjected to a high frequency of predator simulation. This suggests that there might be cryptic fitness costs to common defensive responses that are paid despite apparent growth rate being maintained. 6. Our results demonstrate a clear life-history cost of an antipredator defence in a model pest species and show that under certain conditions, such as high predation threat, the expected relationship between female body size and potential fecundity can be disrupted.

  18. Evidence of horizontal transfer of non-autonomous Lep1 Helitrons facilitated by host-parasite interactions.

    PubMed

    Guo, Xuezhu; Gao, Jingkun; Li, Fei; Wang, Jianjun

    2014-05-30

    Horizontal transfer (HT) of transposable elements has been recognized to be a major force driving genomic variation and biological innovation of eukaryotic organisms. However, the mechanisms of HT in eukaryotes remain poorly appreciated. The non-autonomous Helitron family, Lep1, has been found to be widespread in lepidopteran species, and showed little interspecific sequence similarity of acquired sequences at 3' end, which makes Lep1 a good candidate for the study of HT. In this study, we describe the Lep1-like elements in multiple non-lepidopteran species, including two aphids, Acyrthosiphon pisum and Aphis gossypii, two parasitoid wasps, Cotesia vestalis, and Copidosoma floridanum, one beetle, Anoplophora glabripennis, as well as two bracoviruses in parasitoid wasps, and one intracellular microsporidia parasite, Nosema bombycis. The patchy distribution and high sequence similarity of Lep1-like elements among distantly related lineages as well as incongruence of Lep1-like elements and host phylogeny suggest the occurrence of HT. Remarkably, the acquired sequences of both NbLep1 from N. bombycis and CfLep1 from C. floridanum showed over 90% identity with their lepidopteran host Lep1. Thus, our study provides evidence of HT facilitated by host-parasite interactions. Furthermore, in the context of these data, we discuss the putative directions and vectors of HT of Lep1 Helitrons.

  19. Identification of Restriction Factors by Human Genome-Wide RNA Interference Screening of Viral Host Range Mutants Exemplified by Discovery of SAMD9 and WDR6 as Inhibitors of the Vaccinia Virus K1L−C7L− Mutant

    PubMed Central

    Sivan, Gilad; Ormanoglu, Pinar; Buehler, Eugen C.; Martin, Scott E.

    2015-01-01

    ABSTRACT RNA interference (RNAi) screens intended to identify host factors that restrict virus replication may fail if the virus already counteracts host defense mechanisms. To overcome this limitation, we are investigating the use of viral host range mutants that exhibit impaired replication in nonpermissive cells. A vaccinia virus (VACV) mutant with a deletion of both the C7L and K1L genes, K1L−C7L−, which abrogates replication in human cells at a step prior to late gene expression, was chosen for this strategy. We carried out a human genome-wide small interfering RNA (siRNA) screen in HeLa cells infected with a VACV K1L−C7L− mutant that expresses the green fluorescent protein regulated by a late promoter. This positive-selection screen had remarkably low background levels and resulted in the identification of a few cellular genes, notably SAMD9 and WDR6, from approximately 20,000 tested that dramatically enhanced green fluorescent protein expression. Replication of the mutant virus was enabled by multiple siRNAs to SAMD9 or WDR6. Moreover, SAMD9 and WDR6 clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 knockout HeLa cell lines were permissive for replication of the K1L−C7L− mutant, in agreement with the siRNA data. Expression of exogenous SAMD9 or interferon regulatory factor 1 restricted replication of the K1L−C7L− mutant in the SAMD9−/− cells. Independent interactions of SAMD9 with the K1 and C7 proteins were suggested by immunoprecipitation. Knockout of WDR6 did not reduce the levels of SAMD9 and interactions of WDR6 with SAMD9, C7, and K1 proteins were not detected, suggesting that these restriction factors act independently but possibly in the same innate defense pathway. PMID:26242627

  20. Integrating augmentative biocontrol and inherited sterility for management of lepidopteran pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect pest management can benefit from the integration of biological control agents and the release of sterile insect pests (hosts). Released sterile or semi-sterile insects and their sterile progeny may augment natural enemies by serving as hosts for build-up of the natural enemies prior to the t...

  1. Population densities of lepidopteran pests in selected cranberry cultivars in Wisconsin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host plant resistance, an important strategy of integrated pest management (IPM), was examined in the American Cranberry, Vaccinium macrocarpon Aiton (Ericaceae). Despite the pressure for cranberry growers to reduce pesticide usage, host plant resistance is not used to help manage insect populations...

  2. Silent Mischief: Bacteriophage Mu Insertions Contaminate Products of Escherichia coli Random Mutagenesis Performed Using Suicidal Transposon Delivery Plasmids Mobilized by Broad-Host-Range RP4 Conjugative Machinery ▿

    PubMed Central

    Ferrières, Lionel; Hémery, Gaëlle; Nham, Toan; Guérout, Anne-Marie; Mazel, Didier; Beloin, Christophe; Ghigo, Jean-Marc

    2010-01-01

    Random transposon mutagenesis is the strategy of choice for associating a phenotype with its unknown genetic determinants. It is generally performed by mobilization of a conditionally replicating vector delivering transposons to recipient cells using broad-host-range RP4 conjugative machinery carried by the donor strain. In the present study, we demonstrate that bacteriophage Mu, which was deliberately introduced during the original construction of the widely used donor strains SM10 λpir and S17-1 λpir, is silently transferred to Escherichia coli recipient cells at high frequency, both by hfr and by release of Mu particles by the donor strain. Our findings suggest that bacteriophage Mu could have contaminated many random-mutagenesis experiments performed on Mu-sensitive species with these popular donor strains, leading to potential misinterpretation of the transposon mutant phenotype and therefore perturbing analysis of mutant screens. To circumvent this problem, we precisely mapped Mu insertions in SM10 λpir and S17-1 λpir and constructed a new Mu-free donor strain, MFDpir, harboring stable hfr-deficient RP4 conjugative functions and sustaining replication of Π-dependent suicide vectors. This strain can therefore be used with most of the available transposon-delivering plasmids and should enable more efficient and easy-to-analyze mutant hunts in E. coli and other Mu-sensitive RP4 host bacteria. PMID:20935093

  3. Does Aphid Infestation Interfere with Indirect Plant Defense against Lepidopteran Caterpillars in Wild Cabbage?

    PubMed

    Li, Yehua; Weldegergis, Berhane T; Chamontri, Surachet; Dicke, Marcel; Gols, Rieta

    2017-04-12

    Attraction of parasitoids to plant volatiles induced by multiple herbivory depends on the specific combinations of attacking herbivore species, especially when their feeding modes activate different defense signalling pathways as has been reported for phloem feeding aphids and tissue feeding caterpillars. We studied the effects of pre-infestation with non-host aphids (Brevicoryne brassicae) for two different time periods on the ability of two parasitoid species to discriminate between volatiles emitted by plants infested by host caterpillars alone and those emitted by plants infested with host caterpillars plus aphids. Using plants originating from three chemically distinct wild cabbage (Brassica oleracea) populations, Diadegma semiclausum switched preference for dually infested plants to preference for plants infested with Plutella xylostella hosts alone when the duration of pre-aphid infestation doubled from 7 to 14 days. Microplitis mediator, a parasitoid of Mamestra brassicae caterpillars, preferred dually-infested plants irrespective of aphid-infestation duration. Separation of the volatile blends emitted by plants infested with hosts plus aphids or with hosts only was poor, based on multivariate statistics. However, emission rates of individual compounds were often reduced in plants infested with aphids plus hosts compared to those emitted by plants infested with hosts alone. This effect depended on host caterpillar species and plant population and was little affected by aphid infestation duration. Thus, the interactive effect of aphids and hosts on plant volatile production and parasitoid attraction can be dynamic and parasitoid specific. The characteristics of the multi-component volatile blends that determine parasitoid attraction are too complex to be deduced from simple correlative statistical analyses.

  4. The first vitellogenin receptor from a Lepidopteran insect: molecular characterization, expression patterns and RNA interference analysis.

    PubMed

    Shu, Y H; Wang, J W; Lu, K; Zhou, J L; Zhou, Q; Zhang, G R

    2011-02-01

    The vitellogenin receptor (VgR) belongs to the low-density lipoprotein receptor (LDLR) superfamily, and is an important carrier for the uptake of vitellogenin (Vg) into developing oocytes of all oviparous species. The first full-length message for a VgR from a Lepidopteran insect was cloned and sequenced from the ovary of Spodoptera litura Fabricius (GenBank accession no. GU983858). The coding region consisted of 5370 bp flanked by a 49 bp 5'-untranslated region (UTR) and a 177 bp 3'-UTR, which encoded a 1798-residue protein with a predicted molecular weight (MW) of 201.69 kDa. S. litura VgR (SlVgR)comprised two ligand binding sites with four LDLR class A repeats in the first domain and seven in the second domain, an epidermal growth factor-like domain containing an LDLR class B repeat and a YWXD motif, a transmembrane domain and a cytoplasmic domain. A phylogenetic relationship placed SlVgR as a separate group from the other insects. SlVgR messenger RNA (mRNA) was specifically expressed in the ovarian tissues. The developmental expression patterns showed that VgR mRNA was first transcribed in 6(th) day female pupae and the maximum level of VgR mRNA appeared in 36-h-old adults. Immunoblot analysis detected an ovary-specific VgR protein with a MW of ∼200 kDa, whose development profiles were consistent with VgR mRNA expression patterns. RNA inteference (RNAi) specifically disrupted the VgR gene by injection of 3 or 5 µg VgR double-stranded RNA per insect in 4(th) or 6(th) day pupae. RNAi of SlVgR led to a phenotype characterized by high Vg accumulation in the haemolymph, low Vg deposition in the ovary and the failure of insect spawning. These results mean that VgR is critical for binding Vg and transporting it into the oocytes of the insect ovary, thus playing an important role in insect reproduction.

  5. Forest lepidopteran communities are more resilient to shelterwood harvests compared to more intensive logging regimes.

    PubMed

    Summerville, Keith S

    2013-07-01

    A common measure of ecosystem resilience is the time course to recovery for a system that has been previously disturbed. The goal of this study was to assess whether forest lepidopteran communities displayed three different forms of resilience following experimental timber harvest. Specifically, I examined whether moth species assemblages returned to pre-logging composition (compositional resilience), species richness (structural resilience), and guild diversity (functional resilience) after forest management. Lepidoptera were sampled from 16 forest stands managed with one of four harvest treatments: no logging, clear-cutting, shelterwood harvests, and group selection harvests. Moths were sampled from all forest stands one year prior to harvest in 2007 and immediately postharvest in 2009-2011. Moth community composition only appeared to be resilient to timber harvest in stands managed with shelterwood methods (15% biomass removed) or in the unlogged stands within managed concession units. Both total species richness and species richness of Quercus-feeding moths also appeared to recover to a near original condition three years post-shelterwood logging. In contrast, moth assemblages in clear-cut stands and group selection stands (80% biomass removed) remained impoverished. Tests of functional resilience suggested that richness of species known to be pollinators was largely unaffected by timber management, and the number of moth species known to feed on herbaceous vegetation doubled in stands logged using group selection methods. Dietary specialists were disproportionately abundant in the unlogged stands postharvest, suggesting that species with more narrow dietary niches have the lowest resilience to timber management. These results suggest that most methods of forest management have short-term negative impacts on woody-plant-feeding Lepidoptera, but that the effects are limited to a few years when the harvest method involves shelterwood cuts. Herbaceous

  6. Host Preference and Performance of the Yellow Peach Moth (Conogethes punctiferalis) on Chestnut Cultivars.

    PubMed

    Du, Yanli; Zhang, Jiaxin; Yan, Zengguang; Ma, Yongqiang; Yang, Mengmeng; Zhang, Minzhao; Zhang, Zhiyong; Qin, Ling; Cao, Qingqin

    2016-01-01

    Suitability of plant tissues as food for insects varies from plant to plant. In lepidopteran insects, fitness is largely dependent on the host-finding ability of the females. Existing studies have suggested that polyphagous lepidopterans preferentially select certain host plant species for oviposition. However, the mechanisms for host recognition and selection have not been fully elucidated. For the polyphagous yellow peach moth Conogethes punctiferalis, we explored the effect of chestnut cultivar on the performance and fitness and addressed the mechanisms of plant-volatile-mediated host recognition. By carrying out laboratory experiments and field investigation on four chestnut Castanea mollissima cultivars (Huaihuang, Huaijiu, Yanhong, and Shisheng), we found that C. punctiferalis females preferentially select Huaijiu for oviposition and infestation, and caterpillars fed on Huaijiu achieved slightly greater fitness than those fed on the other three chestnut cultivars, indicating that Huaijiu was a better suitable host for C. punctiferalis. Plant volatiles played important roles in host recognition by C. punctiferalis. All seven chestnut volatile compounds, α-pinene, camphene, β-thujene, β-pinene, eucalyptol, 3-carene, and nonanal, could trigger EAG responses in C. punctiferalis. The ubiquitous plant terpenoids, α-pinene, camphene and β-pinene, and their specific combination at concentrations and proportions similar to the emissions from the four chestnut cultivars, was sufficient to elicit host recognition behavior of female C. punctiferalis. Nonanal and a mixture containing nonanal, that mimicked the emission of C. punctiferalis infested chestnut fruits, caused avoidance response. The outcome demonstrates the effects of chestnut cultivars on the performance of C. punctiferalis and reveals the preference-performance relationship between C. punctiferalis adults and their offspring. The observed olfactory plasticity in the plant-volatile-mediated host

  7. Host Preference and Performance of the Yellow Peach Moth (Conogethes punctiferalis) on Chestnut Cultivars

    PubMed Central

    Du, Yanli; Zhang, Jiaxin; Yan, Zengguang; Ma, Yongqiang; Yang, Mengmeng; Zhang, Minzhao; Zhang, Zhiyong; Qin, Ling; Cao, Qingqin

    2016-01-01

    Suitability of plant tissues as food for insects varies from plant to plant. In lepidopteran insects, fitness is largely dependent on the host-finding ability of the females. Existing studies have suggested that polyphagous lepidopterans preferentially select certain host plant species for oviposition. However, the mechanisms for host recognition and selection have not been fully elucidated. For the polyphagous yellow peach moth Conogethes punctiferalis, we explored the effect of chestnut cultivar on the performance and fitness and addressed the mechanisms of plant-volatile-mediated host recognition. By carrying out laboratory experiments and field investigation on four chestnut Castanea mollissima cultivars (Huaihuang, Huaijiu, Yanhong, and Shisheng), we found that C. punctiferalis females preferentially select Huaijiu for oviposition and infestation, and caterpillars fed on Huaijiu achieved slightly greater fitness than those fed on the other three chestnut cultivars, indicating that Huaijiu was a better suitable host for C. punctiferalis. Plant volatiles played important roles in host recognition by C. punctiferalis. All seven chestnut volatile compounds, α-pinene, camphene, β-thujene, β-pinene, eucalyptol, 3-carene, and nonanal, could trigger EAG responses in C. punctiferalis. The ubiquitous plant terpenoids, α-pinene, camphene and β-pinene, and their specific combination at concentrations and proportions similar to the emissions from the four chestnut cultivars, was sufficient to elicit host recognition behavior of female C. punctiferalis. Nonanal and a mixture containing nonanal, that mimicked the emission of C. punctiferalis infested chestnut fruits, caused avoidance response. The outcome demonstrates the effects of chestnut cultivars on the performance of C. punctiferalis and reveals the preference-performance relationship between C. punctiferalis adults and their offspring. The observed olfactory plasticity in the plant-volatile-mediated host

  8. Lepidopterans as Potential Agents for the Biological Control of the Invasive Plant, Miconia calvescens

    PubMed Central

    Morais, Elisangela G.F.; Picanço, Marcelo C.; Semeão, Altair A.; Barreto, Robert W.; Rosado, Jander F.; Martins, Julio C.

    2012-01-01

    This work investigated eight species of Lepidoptera associated with Miconia calvescens DC. (Myrtales: Melastomataceae) in Brazil, including six defoliators, Salbia lotanalis Druce (Lepidoptera: Pyralidae), Druentia inscita Schaus (Mimallonidae), Antiblemma leucocyma Hampson (Noctuidae), three Limacodidae species, a fruit borer Carposina cardinata Meyrick (Carposinidae), and a damager of flowers Pleuroprucha rudimentaria Guenée (Geometridae). Based on host specificity and the damage caused to plants, S. lotanalis and D. inscita are the most promising species for biological control of M. calvescens. Furthermore, if C. cardinata and P. rudimentaria have host specificity in future tests, these caterpillars could also be considered as appropriate biocontrol agents. PMID:22938203

  9. Development of a new Sindbis virus transducing system and its characterization in three Culicine mosquitoes and two Lepidopteran species.

    PubMed

    Foy, B D; Myles, K M; Pierro, D J; Sanchez-Vargas, I; Uhlírová, M; Jindra, M; Beaty, B J; Olson, K E

    2004-02-01

    Alphavirus transducing systems (ATSs) are alphavirus-based tools for expressing genes in insects. Here we describe an ATS (5'dsMRE16ic) based entirely on Sindbis MRE16 virus. GFP expression was used to characterize alimentary tract infections and dissemination in three Culicine and two Lepidopteran species. Following per os infection, 5'dsMRE16ic-EGFP efficiently infected Aedes aegypti and Culex tritaeniorhynchus, but not Culex pipiens pipiens. Ae. aegypti clearly showed accumulation of green fluorescent protein (GFP) in the posterior midgut and foregut/midgut junction within 2-3 days postinfection. Following parenteral infection of larvae, Bombyx mori had extensive GFP expression in larvae and adults, but Manduca sexta larvae were mostly resistant. 5'dsMRE16ic should be a valuable tool for gene expression in several important insect species that are otherwise difficult to manipulate genetically.

  10. Chapter 15. transforming lepidopteran insect cells for continuous recombinant protein expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The baculovirus expression vector system (BEVS) is widely used to produce large quantities of recombinant proteins. However, yields of extracellular and membrane-bound proteins obtained with this system often are very low, possibly due to the adverse effects of baculovirus infection on the host ins...

  11. Nucleotide sequences of gag-pol regions that determine the Fv-1 host range property of BALB/c N-tropic and B-tropic murine leukemia viruses

    SciTech Connect

    Ou, C.Y.; Boone, L.R.; Koh, C.K.; Tennant, R.W.; Yang, W.K.

    1983-12-01

    Previously, in virto recombinant DNA studies demonstrated that genetic determinants of N-tropism and B-tropism, or Fv-1-related host range properties of murine leukemia viruses, were located in a BamHI-HindIII DNA segment derived from the 5' portion of the coloned viral genome. We sequenced this segment and its immediate 5' region from cloned DNA of two BALB/c mouse C-type viruses (WN1802N and WN1802B) and found base differences at 12 positions out of the otherwise identical 1390-base-pair sequences. Analysis of the most likely reading frame showed that 6 of the 12 base differences would result in four encoded amino acid changes, three of which occur at positions 109 (glutamine in WN1802N versus threonine in WN1802B), 110 (arginine in WN1802N versus glutamic acid in WN1802B), and 159 (glutamic acid in WN1802N versus glycine in WN1802B) of the p30 protein. The remaining one is located at position 36 (threonine in WN1802N versus isoleucine in WN1802B) of the viral polymerase protein. Significant conformational alteration of the p30 protein could be predicted from these amino acid changes.

  12. Plant volatile eliciting FACs in lepidopteran caterpillars, fruit flies, and crickets: a convergent evolution or phylogenetic inheritance?

    PubMed

    Yoshinaga, Naoko; Abe, Hiroaki; Morita, Sayo; Yoshida, Tetsuya; Aboshi, Takako; Fukui, Masao; Tumlinson, James H; Mori, Naoki

    2014-01-01

    Fatty acid amino acid conjugates (FACs), first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of FAC analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of FACs is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of FACs is also unclear. In this study, the biosynthesis of FACs was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata), fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo FAC patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that FACs in these insects are results of convergent evolution cannot be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a different way.

  13. Plant volatile eliciting FACs in lepidopteran caterpillars, fruit flies, and crickets: a convergent evolution or phylogenetic inheritance?

    PubMed Central

    Yoshinaga, Naoko; Abe, Hiroaki; Morita, Sayo; Yoshida, Tetsuya; Aboshi, Takako; Fukui, Masao; Tumlinson, James H.; Mori, Naoki

    2013-01-01

    Fatty acid amino acid conjugates (FACs), first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of FAC analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of FACs is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of FACs is also unclear. In this study, the biosynthesis of FACs was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata), fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo FAC patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that FACs in these insects are results of convergent evolution cannot be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a different way. PMID

  14. Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

    PubMed Central

    Caccia, Silvia; Di Lelio, Ilaria; La Storia, Antonietta; Marinelli, Adriana; Varricchio, Paola; Franzetti, Eleonora; Banyuls, Núria; Tettamanti, Gianluca; Casartelli, Morena; Giordana, Barbara; Ferré, Juan; Gigliotti, Silvia; Pennacchio, Francesco

    2016-01-01

    Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. Here this key issue is addressed by RNAi-mediated silencing of an immune gene in a lepidopteran host Spodoptera littoralis, leaving the midgut microbiota unaltered. The resulting cellular immunosuppression was characterized by a reduced nodulation response, which was associated with a significant enhancement of host larvae mortality triggered by B. thuringiensis and a Cry toxin. This was determined by an uncontrolled proliferation of midgut bacteria, after entering the body cavity through toxin-induced epithelial lesions. Consequently, the hemolymphatic microbiota dramatically changed upon treatment with Cry1Ca toxin, showing a remarkable predominance of Serratia and Clostridium species, which switched from asymptomatic gut symbionts to hemocoelic pathogens. These experimental results demonstrate the important contribution of host enteric flora in B. thuringiensis-killing activity and provide a sound foundation for developing new insect control strategies aimed at enhancing the impact of biocontrol agents by reducing the immunocompetence of the host. PMID:27506800

  15. Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism.

    PubMed

    Caccia, Silvia; Di Lelio, Ilaria; La Storia, Antonietta; Marinelli, Adriana; Varricchio, Paola; Franzetti, Eleonora; Banyuls, Núria; Tettamanti, Gianluca; Casartelli, Morena; Giordana, Barbara; Ferré, Juan; Gigliotti, Silvia; Ercolini, Danilo; Pennacchio, Francesco

    2016-08-23

    Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. Here this key issue is addressed by RNAi-mediated silencing of an immune gene in a lepidopteran host Spodoptera littoralis, leaving the midgut microbiota unaltered. The resulting cellular immunosuppression was characterized by a reduced nodulation response, which was associated with a significant enhancement of host larvae mortality triggered by B. thuringiensis and a Cry toxin. This was determined by an uncontrolled proliferation of midgut bacteria, after entering the body cavity through toxin-induced epithelial lesions. Consequently, the hemolymphatic microbiota dramatically changed upon treatment with Cry1Ca toxin, showing a remarkable predominance of Serratia and Clostridium species, which switched from asymptomatic gut symbionts to hemocoelic pathogens. These experimental results demonstrate the important contribution of host enteric flora in B. thuringiensis-killing activity and provide a sound foundation for developing new insect control strategies aimed at enhancing the impact of biocontrol agents by reducing the immunocompetence of the host.

  16. Global Transcriptional Regulation of Backbone Genes in Broad-Host-Range Plasmid RA3 from the IncU Group Involves Segregation Protein KorB (ParB Family)

    PubMed Central

    Godziszewska, Jolanta; Wojciechowska, Anna; Ludwiczak, Marta; Jagura-Burdzy, Grazyna

    2016-01-01

    The KorB protein of the broad-host-range conjugative plasmid RA3 from the IncU group belongs to the ParB family of plasmid and chromosomal segregation proteins. As a partitioning DNA-binding factor, KorB specifically recognizes a 16-bp palindrome which is an essential motif in the centromere-like sequence parSRA3, forms a segrosome, and together with its partner IncC (ParA family) participates in active DNA segregation ensuring stable plasmid maintenance. Here we show that by binding to this palindromic sequence, KorB also acts as a repressor for the adjacent mobC promoter driving expression of the mobC-nic operon, which is involved in DNA processing during conjugation. Three other promoters, one buried in the conjugative transfer module and two divergent promoters located at the border between the replication and stability regions, are regulated by KorB binding to additional KorB operators (OBs). KorB acts as a repressor at a distance, binding to OBs separated from their cognate promoters by between 46 and 1,317 nucleotides. This repressor activity is facilitated by KorB spreading along DNA, since a polymerization-deficient KorB variant with its dimerization and DNA-binding abilities intact is inactive in transcriptional repression. KorB may act as a global regulator of RA3 plasmid functions in Escherichia coli, since its overexpression in trans negatively interferes with mini-RA3 replication and stable maintenance of RA3. PMID:26850301

  17. Comparing N-glycan processing in mammalian cell lines to native and engineered lepidopteran insect cell lines.

    PubMed

    Tomiya, Noboru; Narang, Someet; Lee, Yuan C; Betenbaugh, Michael J

    2004-01-01

    enzymes responsible for generating the essential donor sugar nucleotide, CMP- N -acetylneuraminic acid, required for sialylation. Inhibition of N -acetylglucosaminidase has also been applied to alter N-glycan processing in insect cells. This review summarizes current knowledge on N-glycan processing in lepidopteran insect cell lines, and recent progress in glycoengineering lepidopteran insect cells to produce glycoproteins containing complex N-glycans.

  18. Controlled-release of Bacillus thurigiensis formulations encapsulated in light-resistant colloidosomal microcapsules for the management of lepidopteran pests of Brassica crops

    PubMed Central

    Bashir, Oumar; Lemoyne, Pierre

    2016-01-01

    Bacillus thuringiensis (B. t.) based formulations have been widely used to control lepidopteran pests in agriculture and forestry. One of their weaknesses is their short residual activity when sprayed in the field. Using Pickering emulsions, mixtures of spores and crystals from three B. t. serovars were successfully encapsulated in colloïdosomal microparticles (50 μm) using innocuous chemicals (acrylic particles, sunflower oil, iron oxide nanoparticles, ethanol and water). A pH trigger mechanism was incorporated within the particles so that B. t. release occurred only at pH > 8.5 which corresponds to the midgut pH of the target pests. Laboratory assays performed on Trichoplusia ni (T. ni) larvae demonstrated that the microencapsulation process did not impair B. t. bioactivity. The best formulations were field-tested on three key lepidopteran pests that attack Brassica crops, i.e., the imported cabbageworm, the cabbage looper and the diamondback moth. After 12 days, the mean number of larvae was significantly lower in microencapsulated formulations than in a commercial B. t. formulation, and the effect of microencapsulated formulations was comparable to a chemical pesticide (lambda-cyhalothrin). Therefore, colloïdosomal microcapsule formulations successfully extend the bioactivity of B. t. for the management of lepidopteran pests of Brassica crops. PMID:27761325

  19. Controlled-release of Bacillus thurigiensis formulations encapsulated in light-resistant colloidosomal microcapsules for the management of lepidopteran pests of Brassica crops.

    PubMed

    Bashir, Oumar; Claverie, Jerome P; Lemoyne, Pierre; Vincent, Charles

    2016-01-01

    Bacillus thuringiensis (B. t.) based formulations have been widely used to control lepidopteran pests in agriculture and forestry. One of their weaknesses is their short residual activity when sprayed in the field. Using Pickering emulsions, mixtures of spores and crystals from three B. t. serovars were successfully encapsulated in colloïdosomal microparticles (50 μm) using innocuous chemicals (acrylic particles, sunflower oil, iron oxide nanoparticles, ethanol and water). A pH trigger mechanism was incorporated within the particles so that B. t. release occurred only at pH > 8.5 which corresponds to the midgut pH of the target pests. Laboratory assays performed on Trichoplusia ni (T. ni) larvae demonstrated that the microencapsulation process did not impair B. t. bioactivity. The best formulations were field-tested on three key lepidopteran pests that attack Brassica crops, i.e., the imported cabbageworm, the cabbage looper and the diamondback moth. After 12 days, the mean number of larvae was significantly lower in microencapsulated formulations than in a commercial B. t. formulation, and the effect of microencapsulated formulations was comparable to a chemical pesticide (lambda-cyhalothrin). Therefore, colloïdosomal microcapsule formulations successfully extend the bioactivity of B. t. for the management of lepidopteran pests of Brassica crops.

  20. A New Method for in Situ Measurement of Bt-Maize Pollen Deposition on Host-Plant Leaves.

    PubMed

    Hofmann, Frieder; Otto, Mathias; Kuhn, Ulrike; Ober, Steffi; Schlechtriemen, Ulrich; Vögel, Rudolph

    2011-02-21

    Maize is wind pollinated and produces huge amounts of pollen. In consequence, the Cry toxins expressed in the pollen of Bt maize will be dispersed by wind in the surrounding vegetation leading to exposure of non-target organisms (NTO). NTO like lepidopteran larvae may be affected by the uptake of Bt-pollen deposited on their host plants. Although some information is available to estimate pollen deposition on host plants, recorded data are based on indirect measurements such as shaking or washing off pollen, or removing pollen with adhesive tapes. These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves. Here, we present a new method for recording in situ the amount and the distribution of Bt-maize pollen deposited on host plant leaves. The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software), which can be used in combination with a notebook in the field. The method was evaluated during experiments in 2008 to 2010. Maize pollen could be correctly identified and pollen deposition as well as the spatial heterogeneity of maize pollen deposition was recorded on maize and different lepidopteran host plants (Centaurea scabiosa, Chenopodium album, Rumex spp., Succina pratensis and Urtica dioica) growing adjacent to maize fields.

  1. Characterization of the Complete Mitochondrial Genome of Leucoma salicis (Lepidoptera: Lymantriidae) and Comparison with Other Lepidopteran Insects

    PubMed Central

    Sun, Yu-Xuan; Wang, Lei; Wei, Guo-Qing; Qian, Cen; Dai, Li-Shang; Sun, Yu; Abbas, Muhammad Nadeem; Zhu, Bao-Jian; Liu, Chao-Liang

    2016-01-01

    The complete mitochondrial genome (mitogenome) of Leucoma salicis (Lepidoptera: Lymantriidae) was sequenced and annotated. It is a circular molecule of 15,334 bp, containing the 37 genes usually present in insect mitogenomes. All protein-coding genes (PCGs) are initiated by ATN codons, other than cox1, which is initiated by CGA. Three of the 13 PCGs had an incomplete termination codon, T or TA, while the others terminated with TAA. The relative synonymous codon usage of the 13 protein-coding genes (PCGs) was consistent with those of published lepidopteran sequences. All tRNA genes had typical clover-leaf secondary structures, except for the tRNASer (AGN), in which the dihydrouridine (DHU) arm could not form a stable stem-loop structure. The A + T-rich region of 325 bp had several distinctive features, including the motif ‘ATAGA’ followed by an 18 bp poly-T stretch, a microsatellite-like (AT)7 element, and an 11-bp poly-A present immediately upstream of tRNAMet. Relationships among 32 insect species were determined using Maximum Likelihood (ML), Neighbor Joining (NJ) and Bayesian Inference (BI) phylogenetic methods. These analyses confirm that L. salicis belongs to the Lymantriidae; and that Lymantriidae is a member of Noctuoidea, and is a sister taxon to Erebidae, Nolidae and Noctuidae, most closely related to Erebidae. PMID:27974854

  2. [Bacillus thuringiensis: general aspects. An approach to its use in the biological control of lepidopteran insects behaving as agricultural pests].

    PubMed

    Sauka, Diego H; Benintende, Graciela B

    2008-01-01

    Bacillus thuringiensis is the most widely applied biological pesticide used to control insects that affect agriculture and forestry and which transmit human and animal pathogens. During the past decades B. thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the relationships between the structure, mechanism of action, and genetics of their pesticidal crystal proteins. As a result, a coherent picture of these relationships has emerged. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins and their performance in agricultural and other natural settings. With this knowledge as background and the help of biotechnological tools, researchers are now reporting promising results in the development of more useful toxins, recombinant bacteria, new formulations and transgenic plants that express pesticidal activity, in order to assure that these products are utilized with the best efficiency and benefit. This article is an attempt to integrate all these recent developments in the study of B. thuringiensis into a context of biological control of lepidopteran insect pest of agricultural importance.

  3. Activity of vegetative insecticidal proteins Vip3Aa58 and Vip3Aa59 of Bacillus thuringiensis against lepidopteran pests.

    PubMed

    Baranek, Jakub; Kaznowski, Adam; Konecka, Edyta; Naimov, Samir

    2015-09-01

    Vegetative insecticidal proteins (Vips) secreted by some isolates of Bacillus thuringiensis show activity against insects and are regarded as insecticides against pests. A number of B. thuringiensis strains harbouring vip3A genes were isolated from different sources and identified by using a PCR based approach. The isolates with the highest insecticidal activity were indicated in screening tests, and their vip genes were cloned and sequenced. The analysis revealed two polymorphic Vip protein forms, which were classified as Vip3Aa58 and Vip3Aa59. After expression of the vip genes, the proteins were isolated and characterized. The activity of both toxins was estimated against economically important lepidopteran pests of woodlands (Dendrolimus pini), orchards (Cydia pomonella) and field crops (Spodoptera exigua). Vip3Aa58 and Vip3Aa59 were highly toxic and their potency surpassed those of many Cry proteins used in commercial bioinsecticides. Vip3Aa59 revealed similar larvicidal activity as Vip3Aa58 against S. exigua and C. pomonella. Despite 98% similarity of amino acid sequences of both proteins, Vip3Aa59 was significantly more active against D. pini. Additionally the effect of proteolytic activation of Vip58Aa and Vip3Aa59 on toxicity of D. pini and S. exigua was studied. Both Vip3Aa proteins did not show any activity against Tenebrio molitor (Coleoptera) larvae. The results suggest that the Vip3Aa58 and Vip3Aa59 toxins might be useful for controlling populations of insect pests of crops and forests.

  4. Roles and regulation of autophagy and apoptosis in the remodelling of the lepidopteran midgut epithelium during metamorphosis

    PubMed Central

    Romanelli, Davide; Casartelli, Morena; Cappellozza, Silvia; de Eguileor, Magda; Tettamanti, Gianluca

    2016-01-01

    We previously showed that autophagy and apoptosis occur in the removal of the lepidopteran larval midgut during metamorphosis. However, their roles in this context and the molecular pathways underlying their activation and regulation were only hypothesized. The results of the present study better clarify the timing of the activation of these two processes: autophagic and apoptotic genes are transcribed at the beginning of metamorphosis, but apoptosis intervenes after autophagy. To investigate the mechanisms that promote the activation of autophagy and apoptosis, we designed a set of experiments based on injections of 20-hydroxyecdysone (20E). Our data demonstrate that autophagy is induced at the end of the last larval stage by the 20E commitment peak, while the onset of apoptosis occurs concomitantly with the 20E metamorphic peak. By impairing autophagic flux, the midgut epithelium degenerated faster, and higher caspase activity was observed compared to controls, whereas inhibiting caspase activation caused a severe delay in epithelial degeneration. Our data demonstrate that autophagy plays a pro-survival function in the silkworm midgut during metamorphosis, while apoptosis is the major process that drives the demise of the epithelium. The evidence collected in this study seems to exclude the occurrence of autophagic cell death in this setting. PMID:27609527

  5. Roles and regulation of autophagy and apoptosis in the remodelling of the lepidopteran midgut epithelium during metamorphosis.

    PubMed

    Romanelli, Davide; Casartelli, Morena; Cappellozza, Silvia; de Eguileor, Magda; Tettamanti, Gianluca

    2016-09-09

    We previously showed that autophagy and apoptosis occur in the removal of the lepidopteran larval midgut during metamorphosis. However, their roles in this context and the molecular pathways underlying their activation and regulation were only hypothesized. The results of the present study better clarify the timing of the activation of these two processes: autophagic and apoptotic genes are transcribed at the beginning of metamorphosis, but apoptosis intervenes after autophagy. To investigate the mechanisms that promote the activation of autophagy and apoptosis, we designed a set of experiments based on injections of 20-hydroxyecdysone (20E). Our data demonstrate that autophagy is induced at the end of the last larval stage by the 20E commitment peak, while the onset of apoptosis occurs concomitantly with the 20E metamorphic peak. By impairing autophagic flux, the midgut epithelium degenerated faster, and higher caspase activity was observed compared to controls, whereas inhibiting caspase activation caused a severe delay in epithelial degeneration. Our data demonstrate that autophagy plays a pro-survival function in the silkworm midgut during metamorphosis, while apoptosis is the major process that drives the demise of the epithelium. The evidence collected in this study seems to exclude the occurrence of autophagic cell death in this setting.

  6. Characterization of Tunisian Bacillus thuringiensis strains with abundance of kurstaki subspecies harbouring insecticidal activities against the lepidopteran insect Ephestia kuehniella.

    PubMed

    Saadaoui, Imen; Al-Thani, Roda; Al-Saadi, Fatma; Belguith-Ben Hassan, Najeh; Abdelkefi-Mesrati, Lobna; Schultz, Patrick; Rouis, Souad; Jaoua, Samir

    2010-12-01

    The study of 257 crystal-producing Bacillus thuringiensis isolates from bioinsecticide free soil samples collected from different sites in Tunisia, was performed by PCR amplification, using six primer pairs specific for cry1, cry2, cry3, cry4, and vip3A genes, by the investigation of strain plasmid pattern, crystal morphology and delta-endotoxin content and by the assessment of insecticidal activities against the lepidopteran insect Ephestia kuehniella. Based on plasmid pattern study, 11 representative strains of the different classes were subjected to morphological and molecular analyses. The comparison of the PFGE fingerprints confirmed the heterogeneity of these strains. B. thuringiensis kurstaki strains, harbouring at the same time the genes cry1A, cry2, cry1Ia, and vip3A, were the most abundant (65.4%). 33.34% of the new isolates showed particular delta-endotoxin profiles but no PCR products with the used primer sets. B. thuringiensis israelensis was shown to be also very rare among the Tunisian B. thuringiensis isolates diversity. These findings could have considerable impacts for the set up of new pest control biological agents.

  7. Specificity in ecological interactions: attack from the same lepidopteran herbivore results in species-specific transcriptional responses in two solanaceous host plants.

    PubMed

    Schmidt, Dominik D; Voelckel, Claudia; Hartl, Markus; Schmidt, Silvia; Baldwin, Ian T

    2005-07-01

    Model systems have proven enormously useful in elucidating the biochemical function of plant genes. However their ecological function, having been sculpted by evolutionary forces specific to a species, may be less conserved across taxa. Responses to wounding and herbivore attack differ among plant families and are known to be mediated by oxylipin, ethylene, and systemin-signaling networks. We analyzed transcriptional responses of two native Solanaceous species to the attack of an herbivore whose elicitors are known not to be influenced by diet. With The Institute for Genomic Research 10k-cDNA potato (Solanum tuberosum) microarray, we compared the transcriptional responses of Nicotiana attenuata with those of black nightshade (Solanum nigrum) when both were attacked by the Solanaceous generalist herbivore, Manduca sexta. Based on an NADH dehydrogenase subunit F phylogeny, S. nigrum is more closely related to potato than N. attenuata but responded significantly less to M. sexta attack. Apart from transcriptional differences anticipated from their differences in secondary metabolism, both species showed distinct transcriptional patterns (with only 10% overlap in significantly regulated genes), which point to fundamental differences in the signaling cascades and downstream genes mediating herbivore resistance. The lackluster transcriptional response of S. nigrum could not be attributed to its inability to respond to elicitation, because methyl jasmonate elicitation of S. nigrum resulted in a strong transcriptional response. Given that attack from the same herbivore elicits profoundly different responses in two Solanaceaous taxa, we conclude that blueprints for commonly regulated responses to plant-herbivore interactions appear unlikely.

  8. Plant or fungal-produced conophthorin as an important component of host plant volatile-based attractants for agricultural lepidopteran insect pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conophthorin (7-methyl-1,6-dioxaspiro[4.5]decane) is a semiochemical common to numerous coleopteran and hymenopteran insects, and possess varying semiochemical behavior among these species. Conophthorin has recently gained attention as a semiochemical for navel orangeworm, Amyelois transitella (Lepi...

  9. Fungal infection dynamics in response to temperature in the lepidopteran insect Galleria mellonella.

    PubMed

    Kryukov, Vadim Y; Yaroslavtseva, Olga N; Whitten, Miranda M A; Tyurin, Maksim V; Ficken, Katherine J; Greig, Carolyn; Melo, Nadja R; Glupov, Viktor V; Dubovskiy, Ivan M; Butt, Tariq M

    2016-11-29

    This study examines how the dynamics of fungus-insect interactions can be modulated by temperature. The wax moth, Galleria mellonella, is a well-studied and important model insect whose larvae in the wild develop optimally at around 34 °C in beehives. However, surprisingly little research on wax moths has been conducted at relevant temperatures. In this study, the entomopathogenic fungus Metarhizium robertsii inflicted rapid and substantial mortality on wax moth larvae maintained at a constant temperature of 24 °C, but at 34 °C a 10 fold higher dose was required to achieve an equivalent mortality. The cooler temperature favored fungal pathogenicity, with condial adhesion to the cuticle, germination and hemocoel invasion all significantly enhanced at 24 °C, compared with 34 °C. The wax moth larvae immune responses altered with the temperature, and with the infective dose of the fungus. Enzyme-based immune defenses (lysozyme and phenoloxidase) exhibited enhanced activity at the warmer temperature. A dramatic upregulation in the basal expression of galiomicin and gallerimycin was triggered by cooling, and this was augmented in the presence of the fungus. Profiling of the predominant insect epicuticular fatty acids revealed a 4-7 fold increase in palmetic, oleic and linoleic acids in larvae maintained at 24 °C compared with those at 34 °C, but these failed to exert fungistatic effects on topically applied fungus. This study demonstrates the importance of choosing environmental conditions relevant to the habitat of the insect host when determining the dynamics and outcome of insect/fungus interactions, and has particular significance for the application of entomopathogens as biocontrol agents.

  10. Parasitism rate, parasitoid community composition and host specificity on exposed and semi-concealed caterpillars from a tropical rainforest.

    PubMed

    Hrcek, Jan; Miller, Scott E; Whitfield, James B; Shima, Hiroshi; Novotny, Vojtech

    2013-10-01

    The processes maintaining the enormous diversity of herbivore-parasitoid food webs depend on parasitism rate and parasitoid host specificity. The two parameters have to be evaluated in concert to make conclusions about the importance of parasitoids as natural enemies and guide biological control. We document parasitism rate and host specificity in a highly diverse caterpillar-parasitoid food web encompassing 266 species of lepidopteran hosts and 172 species of hymenopteran or dipteran parasitoids from a lowland tropical forest in Papua New Guinea. We found that semi-concealed hosts (leaf rollers and leaf tiers) represented 84% of all caterpillars, suffered a higher parasitism rate than exposed caterpillars (12 vs. 5%) and their parasitoids were also more host specific. Semi-concealed hosts may therefore be generally more amenable to biological control by parasitoids than exposed ones. Parasitoid host specificity was highest in Braconidae, lower in Diptera: Tachinidae, and, unexpectedly, the lowest in Ichneumonidae. This result challenges the long-standing view of low host specificity in caterpillar-attacking Tachinidae and suggests higher suitability of Braconidae and lower suitability of Ichneumonidae for biological control of caterpillars. Semi-concealed hosts and their parasitoids are the largest, yet understudied component of caterpillar-parasitoid food webs. However, they still remain much closer in parasitism patterns to exposed hosts than to what literature reports on fully concealed leaf miners. Specifically, semi-concealed hosts keep an equally low share of idiobionts (2%) as exposed caterpillars.

  11. The evolution of host associations in the parasitic wasp genus Ichneumon (Hymenoptera: Ichneumonidae): convergent adaptations to host pupation sites

    PubMed Central

    2013-01-01

    Background The diversification of organisms with a parasitic lifestyle is often tightly linked to the evolution of their host associations. If a tight host association exists, closely related species tend to attack closely related hosts; host associations are less stable if associations are determined by more plastic traits like parasitoid searching and oviposition behaviour. The pupal-parasitoids of the genus Ichneumon attack a variety of macrolepidopteran hosts. They are either monophagous or polyphagous, and therefore offer a promissing system to investigate the evolution of host associations. Ichneumon was previously divided into two groups based on general body shape; however, a stout shape has been suggested as an adaptation to buried host pupation sites, and might thus not represent a reliable phylogenetic character. Results We here reconstruct the first molecular phylogeny of the genus Ichneumon using two mitochondrial (CO1 and NADH1) and one nuclear marker (28S). The resulting phylogeny only supports monophyly of Ichneumon when Ichneumon lugens Gravenhorst, 1829 (formerly in Chasmias, stat. rev.) and Ichneumon deliratorius Linnaeus, 1758 (formerly Coelichneumon) are included. Neither parasitoid species that attack hosts belonging to one family nor those attacking butterflies (Rhopalocera) form monophyletic clades. Ancestral state reconstructions suggest multiple transitions between searching for hosts above versus below ground and between a stout versus elongated body shape. A model assuming correlated evolution between the two characters was preferred over independent evolution of host-searching niche and body shape. Conclusions Host relations, both in terms of phylogeny and ecology, evolved at a high pace in the genus Ichneumon. Numerous switches between hosts of different lepidopteran families have occurred, a pattern that seems to be the rule among idiobiont parasitoids. A stout body and antennal shape in the parasitoid female is confirmed as an

  12. The myxoma virus m-t5 ankyrin repeat host range protein is a novel adaptor that coordinately links the cellular signaling pathways mediated by Akt and Skp1 in virus-infected cells.

    PubMed

    Werden, Steven J; Lanchbury, Jerry; Shattuck, Donna; Neff, Chris; Dufford, Max; McFadden, Grant

    2009-12-01

    Most poxviruses express multiple proteins containing ankyrin (ANK) repeats accounting for a large superfamily of related but unique determinants of poxviral tropism. Recently, select members of this novel family of poxvirus proteins have drawn considerable attention for their potential roles in modulating intracellular signaling networks during viral infection. The rabbit-specific poxvirus, myxoma virus (MYXV), encodes four unique ANK repeat proteins, termed M-T5, M148, M149, and M150, all of which include a carboxy-terminal PRANC domain which closely resembles a cellular protein motif called the F-box domain. Here, we show that each MYXV-encoded ANK repeat protein, including M-T5, interacts directly with the Skp1 component of the host SCF ubiquitin ligase complex, and that the binding of M-T5 to cullin 1 is indirect via binding to Skp1 in the host SCF complex. To understand the significance of these virus-host protein interactions, the various binding domains of M-T5 were mapped. The N-terminal ANK repeats I and II were identified as being important for interaction with Akt, whereas the C-terminal PRANC/F-box-like domain was essential for binding to Skp1. We also report that M-T5 can bind Akt and the host SCF complex (via Skp1) simultaneously in MYXV-infected cells. Finally, we report that M-T5 specifically mediates the relocalization of Akt from the nucleus to the cytoplasm during infection with the wild-type MYXV, but not the M-T5 knockout version of the virus. These results indicate that ANK/PRANC proteins play a critical role in reprogramming disparate cellular signaling cascades to establish a new cellular environment more favorable for virus replication.

  13. Biology of Cryptosporidium from marsupial hosts.

    PubMed

    Power, Michelle L

    2010-01-01

    The majority of biological data on Cryptosporidium has been collected from humans and domestic animal hosts which creates a bias in knowledge on the biodiversity and evolution of this parasite genus. Further to understanding Cryptosporidium biology are studies encompassing broad hosts that represent diverse taxa sampled across wide geographic ranges. Marsupials represent a group of wildlife hosts from which limited information on Cryptosporidium is available. As marsupial hosts are an ancient mammalian lineage they represent an important group for studying parasite evolution. This review summarises information of the biology, epidemiology and evolution of Cryptosporidium in marsupial hosts, and discusses the importance of further understanding interactions in this parasite-host system.

  14. Pinellia ternata agglutinin expression in chloroplasts confers broad spectrum resistance against aphid, whitefly, Lepidopteran insects, bacterial and viral pathogens

    PubMed Central

    Jin, Shuangxia; Zhang, Xianlong; Daniell, Henry

    2012-01-01

    Summary Broad spectrum protection against different insects and pathogens requires multigene engineering. However, such broad spectrum protection against biotic stress is provided by a single protein in some medicinal plants. Therefore, tobacco chloroplasts were transformed with the agglutinin gene from Pinellia ternata (pta), a widely cultivated Chinese medicinal herb. Pinellia ternata agglutinin (PTA) was expressed up to 9.2% of total soluble protein in mature leaves. Purified PTA showed similar hemagglutination activity as snowdrop lectin. Artificial diet with purified PTA from transplastomic plants showed marked and broad insecticidal activity. In planta bioassays conducted with T0 or T1 generation PTA lines showed that the growth of aphid Myzus persicae (Sulzer) was reduced by 89%–92% when compared with untransformed (UT) plants. Similarly, the larval survival and total population of whitefly (Bemisia tabaci) on transplastomic lines were reduced by 91%–93% when compared with UT plants. This is indeed the first report of lectin controlling whitefly infestation. When transplastomic PTA leaves were fed to corn earworm (Helicoverpa zea), tobacco budworm (Heliothis virescens) or the beet armyworm (spodoptera exigua), 100% mortality was observed against all these three insects. In planta bioassays revealed Erwinia population to be 10 000-fold higher in control than in PTA lines. Similar results were observed with tobacco mosaic virus (TMV) challenge. Therefore, broad spectrum resistance to homopteran (sap-sucking), Lepidopteran insects as well as anti-bacterial or anti-viral activity observed in PTA lines provides a new option to engineer protection against biotic stress by hyper-expression of an unique protein that is naturally present in a medicinal plant. PMID:22077160

  15. Salmonellae interactions with host processes.

    PubMed

    LaRock, Doris L; Chaudhary, Anu; Miller, Samuel I

    2015-04-01

    Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.

  16. Host defense reinforces host–parasite cospeciation

    PubMed Central

    Clayton, Dale H.; Bush, Sarah E.; Goates, Brad M.; Johnson, Kevin P.

    2003-01-01

    Cospeciation occurs when interacting groups, such as hosts and parasites, speciate in tandem, generating congruent phylogenies. Cospeciation can be a neutral process in which parasites speciate merely because they are isolated on diverging host islands. Adaptive evolution may also play a role, but this has seldom been tested. We explored the adaptive basis of cospeciation by using a model system consisting of feather lice (Columbicola) and their pigeon and dove hosts (Columbiformes). We reconstructed phylogenies for both groups by using nuclear and mitochondrial DNA sequences. Both phylogenies were well resolved and well supported. Comparing these phylogenies revealed significant cospeciation and correlated evolution of host and parasite body size. The match in body size suggested that adaptive constraints limit the range of hosts lice can use. We tested this hypothesis by transferring lice among hosts of different sizes to simulate host switches. The results of these experiments showed that lice cannot establish viable populations on novel hosts that differ in size from the native host. To determine why size matters, we measured three components of louse fitness: attachment, feeding, and escape from host defense (preening). Lice could remain attached to, and feed on, hosts varying in size by an order of magnitude. However, they could not escape from preening on novel hosts that differed in size from the native host. Overall, our results suggest that host defense reinforces cospeciation in birds and feather lice by preventing lice from switching between hosts of different sizes. PMID:14673114

  17. In vitro and in vivo application of RNA interference for targeting genes involved in peritrophic matrix synthesis in a lepidopteran system.

    PubMed

    Toprak, Umut; Baldwin, Doug; Erlandson, Martin; Gillott, Cedric; Harris, Stephanie; Hegedus, Dwayne D

    2013-02-01

    The midgut of most insects is lined with a semipermeable acellular tube, the peritrophic matrix (PM), composed of chitin and proteins. Although various genes encoding PM proteins have been characterized, our understanding of their roles in PM structure and function is very limited. One promising approach for obtaining functional information is RNA interference, which has been used to reduce the levels of specific mRNAs using double-stranded RNAs administered to larvae by either injection or feeding. Although this method is well documented in dipterans and coleopterans, reports of its success in lepidopterans are varied. In the current study, the silencing midgut genes encoding PM proteins (insect intestinal mucin 1, insect intestinal mucin 4, PM protein 1) and the chitin biosynthetic or modifying enzymes (chitin synthase-B and chitin deacetylase 1) in a noctuid lepidopteran, Mamestra configurata, was examined in vitro and in vivo. In vitro studies in primary midgut epithelial cell preparations revealed an acute and rapid silencing (by 24 h) for the gene encoding chitin deacetylase 1 and a slower rate of silencing (by 72 h) for the gene encoding PM protein 1. Genes encoding insect intestinal mucins were slightly silenced by 72 h, whereas no silencing was detected for the gene encoding chitin synthase-B. In vivo experiments focused on chitin deacetylase 1, as the gene was silenced to the greatest extent in vitro. Continuous feeding of neonates and fourth instar larvae with double-stranded RNA resulted in silencing of chitin deacetylase 1 by 24 and 36 h, respectively. Feeding a single dose to neonates also resulted in silencing by 24 h. The current study demonstrates that genes encoding PM proteins can be silenced and outlines conditions for RNA interference by per os feeding in lepidopterans.

  18. Early leaf miners and the ground plan of the lepidopteran larval trunk: caterpillar morphology of the basal moths Heterobathmia, Eriocrania, and Acanthopteroctetes.

    PubMed

    Dupont, Steen

    2013-11-01

    The larval trunk morphology including chaetotaxy, locomotory structures, and trunk musculature of Heterobathmia pseuderiocrania, Eriocrania cicatricella, and Acanthopteroctetes unifascia is described using conventional light, polarization, and scanning electron microscopy. The ground plan morphology of the lepidopteran larva and neolepidopteran caterpillar is discussed in light of the life history succession from free soil dwelling organism to endophagous and finally to a primarily free living, angiosperm associated organism. I suggest that the larval morphology is argued to be strongly influenced by the shift in number of surfaces present in the larval environment. Especially the environment of the endophagous species, where the upper surface of the leaf mine is linked to the presence of dorsal locomotory structures such as the retractable calli and dorsal friction patches is proposed to have had a significant impact on the morphology and locomotory mechnism of the lepidopteran caterpillar. The chaetotaxy of the lepidopteran ground plan is found to be simple, consisting only of primary and secondary tactile setae and segmental proprioceptors. The presumption of Gerasimov ([1935] Zool Anz 112:177-194) that MXD1 of the prothorax is a shifted mesothoracic MD setae is supported. I suggest that the serial arrangement of the proprioceptors MD1, present on all trunk segments except the prothorax, and a trisetous MV group on all the thoracic segments is part of the lepidopteran larval ground plan. The absence of apodeme structures associated with trunk musculature in the nonglossatans suggests that this is an autapomorphic character of the Lepidoptera and it is further found to have been influential in the evolution of the typical caterpillar trunk. The attachments of the thoracic muscles directly to the trunk integument, suggest that the apodemal structures ancestral to the Amphiesmenoptera have been reduced in the Lepidoptera. Within the non-Neolepidoptera, the

  19. Bacteriophage ϕMAM1, a viunalikevirus, is a broad-host-range, high-efficiency generalized transducer that infects environmental and clinical isolates of the enterobacterial genera Serratia and Kluyvera.

    PubMed

    Matilla, Miguel A; Salmond, George P C

    2014-10-01

    Members of the enterobacterial genus Serratia are ecologically widespread, and some strains are opportunistic human pathogens. Bacteriophage ϕMAM1 was isolated on Serratia plymuthica A153, a biocontrol rhizosphere strain that produces the potently bioactive antifungal and anticancer haterumalide oocydin A. The ϕMAM1 phage is a generalized transducing phage that infects multiple environmental and clinical isolates of Serratia spp. and a rhizosphere strain of Kluyvera cryocrescens. Electron microscopy allowed classification of ϕMAM1 in the family Myoviridae. Bacteriophage ϕMAM1 is virulent, uses capsular polysaccharides as a receptor, and can transduce chromosomal markers at frequencies of up to 7 × 10(-6) transductants per PFU. We also demonstrated transduction of the complete 77-kb oocydin A gene cluster and heterogeneric transduction of a plasmid carrying a type III toxin-antitoxin system. These results support the notion of the potential ecological importance of transducing phages in the acquisition of genes by horizontal gene transfer. Phylogenetic analyses grouped ϕMAM1 within the ViI-like bacteriophages, and genomic analyses revealed that the major differences between ϕMAM1 and other ViI-like phages arise in a region encoding the host recognition determinants. Our results predict that the wider genus of ViI-like phages could be efficient transducing phages, and this possibility has obvious implications for the ecology of horizontal gene transfer, bacterial functional genomics, and synthetic biology.

  20. NolX of Sinorhizobium fredii USDA257, a Type III-Secreted Protein Involved in Host Range Determination, Is Localized in the Infection Threads of Cowpea (Vigna unguiculata [L.] Walp) and Soybean (Glycine max [L.] Merr.) Nodules

    PubMed Central

    Krishnan, Hari B.

    2002-01-01

    Sinorhizobium fredii USDA257 forms nitrogen-fixing nodules on soybean (Glycine max [L.] Merr.) in a cultivar-specific manner. This strain forms nodules on primitive soybean cultivars but fails to nodulate agronomically improved North American cultivars. Soybean cultivar specificity is regulated by the nolXWBTUV locus, which encodes part of a type III secretion system (TTSS). NolX, a soybean cultivar specificity protein, is secreted by TTSS and shows homology to HrpF of the plant pathogen Xanthomonas campestris pv. vesicatoria. It is not known whether NolX functions at the bacterium-plant interface or acts inside the host cell. Antibodies raised against S. fredii USDA257 NolX were used in immunocytochemical studies to investigate the subcellular localization of this protein. Immunostaining of paraffin-embedded sections of developing soybean and cowpea (Vigna unguiculata [L.] Walp) nodules revealed localization of NolX in the infection threads. Protein A-gold immunocytochemical localization studies utilizing affinity-purified NolX antibodies revealed specific deposition of gold particles in the fibrillar material inside infection threads. Similar immunogold localization studies failed to detect NolX in thin sections of mature soybean and cowpea nodules. The results from this study indicate that NolX is expressed in planta only during the early stages of nodule development. PMID:11790754

  1. Viral cystatin evolution and three-dimensional structure modelling: A case of directional selection acting on a viral protein involved in a host-parasitoid interaction

    PubMed Central

    Serbielle, Céline; Chowdhury, Shafinaz; Pichon, Samuel; Dupas, Stéphane; Lesobre, Jérôme; Purisima, Enrico O; Drezen, Jean-Michel; Huguet, Elisabeth

    2008-01-01

    Background In pathogens, certain genes encoding proteins that directly interact with host defences coevolve with their host and are subject to positive selection. In the lepidopteran host-wasp parasitoid system, one of the most original strategies developed by the wasps to defeat host defences is the injection of a symbiotic polydnavirus at the same time as the wasp eggs. The virus is essential for wasp parasitism success since viral gene expression alters the immune system and development of the host. As a wasp mutualist symbiont, the virus is expected to exhibit a reduction in genome complexity and evolve under wasp phyletic constraints. However, as a lepidopteran host pathogenic symbiont, the virus is likely undergoing strong selective pressures for the acquisition of new functions by gene acquisition or duplication. To understand the constraints imposed by this particular system on virus evolution, we studied a polydnavirus gene family encoding cyteine protease inhibitors of the cystatin superfamily. Results We show that cystatins are the first bracovirus genes proven to be subject to strong positive selection within a host-parasitoid system. A generated three-dimensional model of Cotesia congregata bracovirus cystatin 1 provides a powerful framework to position positively selected residues and reveal that they are concentrated in the vicinity of actives sites which interact with cysteine proteases directly. In addition, phylogenetic analyses reveal two different cystatin forms which evolved under different selective constraints and are characterized by independent adaptive duplication events. Conclusion Positive selection acts to maintain cystatin gene duplications and induces directional divergence presumably to ensure the presence of efficient and adapted cystatin forms. Directional selection has acted on key cystatin active sites, suggesting that cystatins coevolve with their host target. We can strongly suggest that cystatins constitute major virulence

  2. Hosts and parasites as aliens.

    PubMed

    Taraschewski, H

    2006-06-01

    Over the past decades, various free-living animals (hosts) and their parasites have invaded recipient areas in which they had not previously occurred, thus gaining the status of aliens or exotics. In general this happened to a low extent for hundreds of years. With variable frequency, invasions have been followed by the dispersal and establishment of non-indigenous species, whether host or parasite. In the literature thus far, colonizations by both hosts and parasites have not been treated and reviewed together, although both are usually interwoven in various ways. As to those factors permitting invasive success and colonization strength, various hypotheses have been put forward depending on the scientific background of respective authors and on the conspicuousness of certain invasions. Researchers who have tried to analyse characteristic developmental patterns, the speed of dispersal or the degree of genetic divergence in populations of alien species have come to different conclusions. Among parasitologists, the applied aspects of parasite invasions, such as the negative effects on economically important hosts, have long been at the centre of interest. In this contribution, invasions by hosts as well as parasites are considered comparatively, revealing many similarities and a few differences. Two helminths, the liver fluke, Fasciola hepatica, of cattle and sheep and the swimbladder nematode, Anguillicola crassus, of eels are shown to be useful as model parasites for the study of animal invasions and environmental global change. Introductions of F. hepatica have been associated with imports of cattle or other grazing animals. In various target areas, susceptible lymnaeid snails serving as intermediate hosts were either naturally present and/or were introduced from the donor continent of the parasite (Europe) and/or from other regions which were not within the original range of the parasite, partly reflecting progressive stages of a global biota change. In several

  3. Two genetically related begomoviruses causing tomato leaf curl disease in Togo and Nigeria differ in virulence and host range but do not require a betasatellite for induction of disease symptoms.

    PubMed

    Kon, Tatsuya; Gilbertson, Robert L

    2012-01-01

    host-dependent manner, it does not appear to play a role in ToLCD and may have been present with ToLCKuV-TG as a reassortant.

  4. Sulfur-, oxygen-, and carbon-isotope studies of Ag-Pb-Zn vein-breccia occurrences, sulfide-bearing concretions, and barite deposits in the north-central Brooks Range, with comparisons to shale-hosted stratiform massive sulfide deposits: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

    USGS Publications Warehouse

    Kelley, Karen D.; Leach, David L.; Johnson, Craig A.

    2000-01-01

    Stratiform shale-hosted massive sulfide deposits, sulfidebearing concretions and vein breccias, and barite deposits are widespread in sedimentary rocks of Late Devonian to Permian age in the northern Brooks Range. All of the sulfide-bearing concretions and vein breccias are hosted in mixed continental-marine clastic rocks of the Upper Devonian to Lower Mississippian Endicott Group. The clastic rocks and associated sulfide occurrences underlie chert and shale of Mississippian-Pennsylvanian(?) age that contain large stratiform massive sulfide deposits like that at Red Dog. The relative stratigraphic position of the vein breccias, as well as previously published mineralogical, geochemical, and lead-isotope data, suggest that the vein breccias formed coevally with overlying shale-hosted massive sulfide deposits and that they may represent pathways of oreforming hydrothermal fluids. Barite deposits are hosted either in Mississippian chert and limestone (at essentially the same stratigraphic position as the shale-hosted massive sulfide deposits) or Permian chert and shale. Although most barite deposits have no associated base-metal mineralization, barite occurs with massive sulfide deposits at the Red Dog deposit.Galena and sphalerite from most vein breccias have δ34S values from –7.3 to –0.7‰ (per mil) and –5.1 to 3.6‰, respectively; sphalerite from sulfide-bearing concretions have δ34S values of 0.7 and 4.7‰. This overall range in δ34S values largely overlaps with the range previously determined for galena and sphalerite from shale-hosted massive sulfide deposits at Red Dog and Drenchwater. The Kady vein-breccia occurrence is unusual in having higher δ34S values for sphalerite (12.1 to 12.9‰) and pyrite (11.3‰), consistent with previously published values for the shale-hosted Lik deposit. The correspondence in sulfur isotopic compositions between the stratiform and vein-breccia deposits suggests that they share a common source of reduced sulfur, or

  5. Shifting preference between oviposition vs. host-feeding under changing host densities in two aphelinid parasitoids.

    PubMed

    Yang, Nian-Wan; Ji, Lu-Lu; Lövei, Gabor L; Wan, Fang-Hao

    2012-01-01

    Destructive host-feeding is common in hymenopteran parasitoids. Such feeding may be restricted to host stages not preferred for oviposition. However, whether this is a fixed strategy or can vary according to resource levels or parasitoid needs is less clear. We tested the trade-off between host feeding and oviposition on two whitefly parasitoids under varying host densities. Females of two aphelinid parasitoids, Eretmocerus hayati and Encarsia sophia were exposed to nine different densities of their whitefly host, Bemisia tabaci, in single-instar tests to identify their functional response. Mixed-instar host choice tests were also conducted by exposing whiteflies at four densities to the parasitoids. We hypothesized that the parasitoid females can detect different host densities, and decide on oviposition vs. host-feeding accordingly. The results showed that both Er. hayati and En. sophia females tended to increase both oviposition and host-feeding with increased host density within a certain range. Oviposition reached a plateau at lower host density than host-feeding in Er. hayati, while En. sophia reached its oviposition plateau at higher densities. At low densities, Er. hayati parasitized most on first and second (the optimal ones), and fed most on third nymphal instars (the suboptimal one) of the whitefly host as theory predicts, while at high densities, both parasitism and host-feeding occurred on first and second instars which are preferred for oviposition. En. sophia parasitized most on third and fourth (the optimal ones), while fed on first instars (the suboptimal one) at low densities, and utilized third and fourth instars for both at high densities. In conclusion, oviposition vs. host-feeding strategy of parasitoid females was found to vary at different host densities. The balance between reserving optimal hosts for oviposition or using them for host-feeding depended on parasitoid life history and the availability of host resources.

  6. Shifting Preference between Oviposition vs. Host-Feeding under Changing Host Densities in Two Aphelinid Parasitoids

    PubMed Central

    Yang, Nian-Wan; Ji, Lu-Lu; Lövei, Gabor L.; Wan, Fang-Hao

    2012-01-01

    Destructive host-feeding is common in hymenopteran parasitoids. Such feeding may be restricted to host stages not preferred for oviposition. However, whether this is a fixed strategy or can vary according to resource levels or parasitoid needs is less clear. We tested the trade-off between host feeding and oviposition on two whitefly parasitoids under varying host densities. Females of two aphelinid parasitoids, Eretmocerus hayati and Encarsia sophia were exposed to nine different densities of their whitefly host, Bemisia tabaci, in single-instar tests to identify their functional response. Mixed-instar host choice tests were also conducted by exposing whiteflies at four densities to the parasitoids. We hypothesized that the parasitoid females can detect different host densities, and decide on oviposition vs. host-feeding accordingly. The results showed that both Er. hayati and En. sophia females tended to increase both oviposition and host-feeding with increased host density within a certain range. Oviposition reached a plateau at lower host density than host-feeding in Er. hayati, while En. sophia reached its oviposition plateau at higher densities. At low densities, Er. hayati parasitized most on first and second (the optimal ones), and fed most on third nymphal instars (the suboptimal one) of the whitefly host as theory predicts, while at high densities, both parasitism and host-feeding occurred on first and second instars which are preferred for oviposition. En. sophia parasitized most on third and fourth (the optimal ones), while fed on first instars (the suboptimal one) at low densities, and utilized third and fourth instars for both at high densities. In conclusion, oviposition vs. host-feeding strategy of parasitoid females was found to vary at different host densities. The balance between reserving optimal hosts for oviposition or using them for host-feeding depended on parasitoid life history and the availability of host resources. PMID:22815964

  7. Local host specialization, host-switching, and dispersal shape the regional distributions of avian haemosporidian parasites

    PubMed Central

    Ellis, Vincenzo A.; Collins, Michael D.; Medeiros, Matthew C. I.; Sari, Eloisa H. R.; Coffey, Elyse D.; Dickerson, Rebecca C.; Lugarini, Camile; Stratford, Jeffrey A.; Henry, Donata R.; Merrill, Loren; Matthews, Alix E.; Hanson, Alison A.; Roberts, Jackson R.; Joyce, Michael; Kunkel, Melanie R.; Ricklefs, Robert E.

    2015-01-01

    The drivers of regional parasite distributions are poorly understood, especially in comparison with those of free-living species. For vector-transmitted parasites, in particular, distributions might be influenced by host-switching and by parasite dispersal with primary hosts and vectors. We surveyed haemosporidian blood parasites (Plasmodium and Haemoproteus) of small land birds in eastern North America to characterize a regional parasite community. Distributions of parasite populations generally reflected distributions of their hosts across the region. However, when the interdependence between hosts and parasites was controlled statistically, local host assemblages were related to regional climatic gradients, but parasite assemblages were not. Moreover, because parasite assemblage similarity does not decrease with distance when controlling for host assemblages and climate, parasites evidently disperse readily within the distributions of their hosts. The degree of specialization on hosts varied in some parasite lineages over short periods and small geographic distances independently of the diversity of available hosts and potentially competing parasite lineages. Nonrandom spatial turnover was apparent in parasite lineages infecting one host species that was well-sampled within a single year across its range, plausibly reflecting localized adaptations of hosts and parasites. Overall, populations of avian hosts generally determine the geographic distributions of haemosporidian parasites. However, parasites are not dispersal-limited within their host distributions, and they may switch hosts readily. PMID:26305975

  8. Local host specialization, host-switching, and dispersal shape the regional distributions of avian haemosporidian parasites.

    PubMed

    Ellis, Vincenzo A; Collins, Michael D; Medeiros, Matthew C I; Sari, Eloisa H R; Coffey, Elyse D; Dickerson, Rebecca C; Lugarini, Camile; Stratford, Jeffrey A; Henry, Donata R; Merrill, Loren; Matthews, Alix E; Hanson, Alison A; Roberts, Jackson R; Joyce, Michael; Kunkel, Melanie R; Ricklefs, Robert E

    2015-09-08

    The drivers of regional parasite distributions are poorly understood, especially in comparison with those of free-living species. For vector-transmitted parasites, in particular, distributions might be influenced by host-switching and by parasite dispersal with primary hosts and vectors. We surveyed haemosporidian blood parasites (Plasmodium and Haemoproteus) of small land birds in eastern North America to characterize a regional parasite community. Distributions of parasite populations generally reflected distributions of their hosts across the region. However, when the interdependence between hosts and parasites was controlled statistically, local host assemblages were related to regional climatic gradients, but parasite assemblages were not. Moreover, because parasite assemblage similarity does not decrease with distance when controlling for host assemblages and climate, parasites evidently disperse readily within the distributions of their hosts. The degree of specialization on hosts varied in some parasite lineages over short periods and small geographic distances independently of the diversity of available hosts and potentially competing parasite lineages. Nonrandom spatial turnover was apparent in parasite lineages infecting one host species that was well-sampled within a single year across its range, plausibly reflecting localized adaptations of hosts and parasites. Overall, populations of avian hosts generally determine the geographic distributions of haemosporidian parasites. However, parasites are not dispersal-limited within their host distributions, and they may switch hosts readily.

  9. Diversity of aminopeptidases, derived from four lepidopteran gene duplications, and polycalins expressed in the midgut of Helicoverpa armigera: Identification of proteins binding the δ-endotoxin, Cry1Ac of Bacillus thuringiensis

    PubMed Central

    Angelucci, Constanza; Barrett-Wilt, Gregory A.; Hunt, Donald F.; Akhurst, Raymond J.; East, Peter D.; Gordon, Karl H.J.; Campbell, Peter M.

    2010-01-01

    Helicoverpa armigera midgut proteins that bind the Bacillus thuringiensis (Bt) δ-endotoxin Cry1Ac were purified by affinity chromatography. SDS-PAGE showed that several proteins were eluted with N-acetylgalactosamine and no further proteins were detected after elution with urea. Tandem mass spectral data for tryptic peptides initially indicated that the proteins resembled aminopeptidases (APNs) from other lepidopterans and cDNA sequences for seven APNs were isolated from H. armigera through a combination of cloning with primers derived from predicted peptide sequences and established EST libraries. Phylogenetic analysis showed lepidopteran APN genes in nine clades of which five were part of a lepidopteran-specific radiation. The Cry1Ac-binding proteins were then identified with four of the seven HaAPN genes. Three of those four APNs are likely orthologs of APNs characterised as Cry1Ac-binding proteins in other lepidopterans. The fourth Cry1Ac-binding APN has orthologs not previously identified as Cry1Ac-binding partners. The HaAPN genes were expressed predominantly in the midgut through larval development. Each showed consistent expression along the length of the midgut but five of the genes were expressed at levels about two orders of magnitude greater than the remaining two. The remaining mass spectral data identified sequences encoding polycalin proteins with multiple lipocalin-like domains. A polycalin has only been previously reported in another lepidopteran, Bombyx mori, but polycalins in both species are now linked with binding of Bt Cry toxins. This is the first report of hybrid, lipocalin-like domains in shorter polycalin sequences that are not present in the longest sequence. We propose that these hybrid domains are generated by alternative splicing of the mRNA. PMID:18549954

  10. Thirteen new Costa Rican species belonging to the genus Triraphis Ruthe (Braconidae: Rogadinae) with their host records.

    PubMed

    Valerio, Alejandro A; Shaw, Scott R

    2015-01-08

    Thirteen new species belonging to the genus Triraphis Ruthe are described and illustrated: Triraphis baios sp. nov., T. balteus sp. nov., T. chinusi sp. nov., T. cortazari sp. nov., T. defectus sp. nov., T. guarusa sp. nov., T. huidobroi sp. nov., T. ikelosops sp. nov., T. melasops sp. nov., T. paraholos sp. nov., T. proxilus sp. nov., T. simphlex sp. nov. and T. willei sp. nov. The lepidopteran hosts were feeding on 17 genera of plants within 16 families. Two families of Lepidoptera are reported as new hosts for Triraphis: Acraga sp. (Dalceridae) parasitized by T. paraholos sp. nov. and Norape sp. (Megalopygidae) by T. guarusa sp. nov. Moreover, four Triraphis species are treated as new combinations under the genus Triraphis sensu van Achterberg: Triraphis areatus (Cresson) comb. n., T. fasciipennis (Cresson) comb. n., T. fusciceps (Cresson) comb. n. and T. ornatus (Cresson) comb. n.. 

  11. The α1,6-fucosyltransferase gene (fut8) from the Sf9 lepidopteran insect cell line: insights into fut8 evolution.

    PubMed

    Juliant, Sylvie; Harduin-Lepers, Anne; Monjaret, François; Catieau, Béatrice; Violet, Marie-Luce; Cérutti, Pierre; Ozil, Annick; Duonor-Cérutti, Martine

    2014-01-01

    The core alpha1,6-fucosyltransferase (FUT8) catalyzes the transfer of a fucosyl moiety from GDP-fucose to the innermost asparagine-linked N-acetylglucosamine residue of glycoproteins. In mammals, this glycosylation has an important function in many fundamental biological processes and although no essential role has been demonstrated yet in all animals, FUT8 amino acid (aa) sequence and FUT8 activity are very well conserved throughout the animal kingdom. We have cloned the cDNA and the complete gene encoding the FUT8 in the Sf9 (Spodoptera frugiperda) lepidopteran cell line. As in most animal genomes, fut8 is a single-copy gene organized in different exons. The open reading frame contains 12 exons, a characteristic that seems to be shared by all lepidopteran fut8 genes. We chose to study the gene structure as a way to characterize the evolutionary relationships of the fut8 genes in metazoans. Analysis of the intron-exon organization in 56 fut8 orthologs allowed us to propose a model for fut8 evolution in metazoans. The presence of a highly variable number of exons in metazoan fut8 genes suggests a complex evolutionary history with many intron gain and loss events, particularly in arthropods, but not in chordata. Moreover, despite the high conservation of lepidoptera FUT8 sequences also in vertebrates and hymenoptera, the exon-intron organization of hymenoptera fut8 genes is order-specific with no shared exons. This feature suggests that the observed intron losses and gains may be linked to evolutionary innovations, such as the appearance of new orders.

  12. Large scale full-length cDNA sequencing reveals a unique genomic landscape in a lepidopteran model insect, Bombyx mori.

    PubMed

    Suetsugu, Yoshitaka; Futahashi, Ryo; Kanamori, Hiroyuki; Kadono-Okuda, Keiko; Sasanuma, Shun-ichi; Narukawa, Junko; Ajimura, Masahiro; Jouraku, Akiya; Namiki, Nobukazu; Shimomura, Michihiko; Sezutsu, Hideki; Osanai-Futahashi, Mizuko; Suzuki, Masataka G; Daimon, Takaaki; Shinoda, Tetsuro; Taniai, Kiyoko; Asaoka, Kiyoshi; Niwa, Ryusuke; Kawaoka, Shinpei; Katsuma, Susumu; Tamura, Toshiki; Noda, Hiroaki; Kasahara, Masahiro; Sugano, Sumio; Suzuki, Yutaka; Fujiwara, Haruhiko; Kataoka, Hiroshi; Arunkumar, Kallare P; Tomar, Archana; Nagaraju, Javaregowda; Goldsmith, Marian R; Feng, Qili; Xia, Qingyou; Yamamoto, Kimiko; Shimada, Toru; Mita, Kazuei

    2013-09-04

    The establishment of a complete genomic sequence of silkworm, the model species of Lepidoptera, laid a foundation for its functional genomics. A more complete annotation of the genome will benefit functional and comparative studies and accelerate extensive industrial applications for this insect. To realize these goals, we embarked upon a large-scale full-length cDNA collection from 21 full-length cDNA libraries derived from 14 tissues of the domesticated silkworm and performed full sequencing by primer walking for 11,104 full-length cDNAs. The large average intron size was 1904 bp, resulting from a high accumulation of transposons. Using gene models predicted by GLEAN and published mRNAs, we identified 16,823 gene loci on the silkworm genome assembly. Orthology analysis of 153 species, including 11 insects, revealed that among three Lepidoptera including Monarch and Heliconius butterflies, the 403 largest silkworm-specific genes were composed mainly of protective immunity, hormone-related, and characteristic structural proteins. Analysis of testis-/ovary-specific genes revealed distinctive features of sexual dimorphism, including depletion of ovary-specific genes on the Z chromosome in contrast to an enrichment of testis-specific genes. More than 40% of genes expressed in specific tissues mapped in tissue-specific chromosomal clusters. The newly obtained FL-cDNA sequences enabled us to annotate the genome of this lepidopteran model insect more accurately, enhancing genomic and functional studies of Lepidoptera and comparative analyses with other insect orders, and yielding new insights into the evolution and organization of lepidopteran-specific genes.

  13. Large Scale Full-Length cDNA Sequencing Reveals a Unique Genomic Landscape in a Lepidopteran Model Insect, Bombyx mori

    PubMed Central

    Suetsugu, Yoshitaka; Futahashi, Ryo; Kanamori, Hiroyuki; Kadono-Okuda, Keiko; Sasanuma, Shun-ichi; Narukawa, Junko; Ajimura, Masahiro; Jouraku, Akiya; Namiki, Nobukazu; Shimomura, Michihiko; Sezutsu, Hideki; Osanai-Futahashi, Mizuko; Suzuki, Masataka G; Daimon, Takaaki; Shinoda, Tetsuro; Taniai, Kiyoko; Asaoka, Kiyoshi; Niwa, Ryusuke; Kawaoka, Shinpei; Katsuma, Susumu; Tamura, Toshiki; Noda, Hiroaki; Kasahara, Masahiro; Sugano, Sumio; Suzuki, Yutaka; Fujiwara, Haruhiko; Kataoka, Hiroshi; Arunkumar, Kallare P.; Tomar, Archana; Nagaraju, Javaregowda; Goldsmith, Marian R.; Feng, Qili; Xia, Qingyou; Yamamoto, Kimiko; Shimada, Toru; Mita, Kazuei

    2013-01-01

    The establishment of a complete genomic sequence of silkworm, the model species of Lepidoptera, laid a foundation for its functional genomics. A more complete annotation of the genome will benefit functional and comparative studies and accelerate extensive industrial applications for this insect. To realize these goals, we embarked upon a large-scale full-length cDNA collection from 21 full-length cDNA libraries derived from 14 tissues of the domesticated silkworm and performed full sequencing by primer walking for 11,104 full-length cDNAs. The large average intron size was 1904 bp, resulting from a high accumulation of transposons. Using gene models predicted by GLEAN and published mRNAs, we identified 16,823 gene loci on the silkworm genome assembly. Orthology analysis of 153 species, including 11 insects, revealed that among three Lepidoptera including Monarch and Heliconius butterflies, the 403 largest silkworm-specific genes were composed mainly of protective immunity, hormone-related, and characteristic structural proteins. Analysis of testis-/ovary-specific genes revealed distinctive features of sexual dimorphism, including depletion of ovary-specific genes on the Z chromosome in contrast to an enrichment of testis-specific genes. More than 40% of genes expressed in specific tissues mapped in tissue-specific chromosomal clusters. The newly obtained FL-cDNA sequences enabled us to annotate the genome of this lepidopteran model insect more accurately, enhancing genomic and functional studies of Lepidoptera and comparative analyses with other insect orders, and yielding new insights into the evolution and organization of lepidopteran-specific genes. PMID:23821615

  14. Evidence for involvement of cytosolic thioredoxin peroxidase in the excessive resistance of Sf9 Lepidopteran insect cells against radiation-induced apoptosis.

    PubMed

    Hambarde, Shashank; Singh, Vijaypal; Chandna, Sudhir

    2013-01-01

    Lepidopteran insect cells display 50-100 times higher radioresistance compared to human cells, and reportedly have more efficient antioxidant system that can significantly reduce radiation-induced oxidative stress and cell death. However, the antioxidant mechanisms that contribute substantially to this excessive resistance still need to be understood thoroughly. In this study, we investigated the role of thioredoxin peroxidase (TPx) in high-dose γ-radiation response of Sf9 cell line derived from Spodoptera frugiperda, the Fall armyworm. We identified a TPx orthologue (Sf-TPx) in Spodoptera system, with primarily cytosolic localization. Gamma-irradiation at 500 Gy dose significantly up-regulated Sf-TPx, while higher doses (1000 Gy-2000 Gy) had no such effect. G2/M checkpoint induced following 500 Gy was associated with transition of Sf-TPx decamer into enzymatically active dimer. Same effect was observed during G2/M block induced by 5 nM okadaic acid or 10 µM CDK1 (cycline dependent kinase-1) inhibitor roscovitine, thus indicating that radiation-induced Sf-TPx activity is mediated by CDKs. Accumulation of TPx dimer form during G2/M checkpoint might favour higher peroxidase activity facilitating efficient survival at this dose. Confirming this, higher lethal doses (1000 Gy-2000 Gy) caused significantly less accumulation of dimer form and induced dose-dependent apoptosis. A ∼50% knock-down of Sf-TPx by siRNA caused remarkable increase in radiation-induced ROS as well as caspase-3 dependent radiation-induced apoptosis, clearly implying TPx role in the radioresistance of Sf9 cells. Quite importantly, our study demonstrates for the first time that thioredoxin peroxidase contributes significantly in the radioresistance of Lepidopteran Sf9 insect cells, especially in their exemplary resistance against radiation-induced apoptosis. This is an important insight into the antioxidant mechanisms existing in this highly stress-resistant model cell system.

  15. The α1,6-Fucosyltransferase Gene (fut8) from the Sf9 Lepidopteran Insect Cell Line: Insights into fut8 Evolution

    PubMed Central

    Juliant, Sylvie; Harduin-Lepers, Anne; Monjaret, François; Catieau, Béatrice; Violet, Marie-Luce; Cérutti, Pierre; Ozil, Annick; Duonor-Cérutti, Martine

    2014-01-01

    The core alpha1,6-fucosyltransferase (FUT8) catalyzes the transfer of a fucosyl moiety from GDP-fucose to the innermost asparagine-linked N-acetylglucosamine residue of glycoproteins. In mammals, this glycosylation has an important function in many fundamental biological processes and although no essential role has been demonstrated yet in all animals, FUT8 amino acid (aa) sequence and FUT8 activity are very well conserved throughout the animal kingdom. We have cloned the cDNA and the complete gene encoding the FUT8 in the Sf9 (Spodoptera frugiperda) lepidopteran cell line. As in most animal genomes, fut8 is a single-copy gene organized in different exons. The open reading frame contains 12 exons, a characteristic that seems to be shared by all lepidopteran fut8 genes. We chose to study the gene structure as a way to characterize the evolutionary relationships of the fut8 genes in metazoans. Analysis of the intron-exon organization in 56 fut8 orthologs allowed us to propose a model for fut8 evolution in metazoans. The presence of a highly variable number of exons in metazoan fut8 genes suggests a complex evolutionary history with many intron gain and loss events, particularly in arthropods, but not in chordata. Moreover, despite the high conservation of lepidoptera FUT8 sequences also in vertebrates and hymenoptera, the exon-intron organization of hymenoptera fut8 genes is order-specific with no shared exons. This feature suggests that the observed intron losses and gains may be linked to evolutionary innovations, such as the appearance of new orders. PMID:25333276

  16. Avian host defense peptides.

    PubMed

    Cuperus, Tryntsje; Coorens, Maarten; van Dijk, Albert; Haagsman, Henk P

    2013-11-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense of many organisms. It is becoming increasingly clear that in the animal kingdom the functions of HDPs are not confined to direct antimicrobial actions. Research in mammals has indicated that HDPs have many immunomodulatory functions and are also involved in other physiological processes ranging from development to wound healing. During the past five years our knowledge about avian HDPs has increased considerably. This review addresses our current knowledge on the evolution, regulation and biological functions of HDPs of birds.

  17. Passive Ranging

    DTIC Science & Technology

    1988-08-01

    1981). 5. R. Courant and D. Hilbert, Methods of Mathematical Physics , Vol. I, English ed., * Interscience, New York, 1953. 32 32 APPENDIX A CALCULATION...K Courant and D. Hilbert, Methods of Mathematical Physics , Vol. I, English ed., * Interscience, New York, 1953. A-8 APPENDIX B * RANGING ACCURACY IN

  18. Continuous Influx of Genetic Material from Host to Virus Populations

    PubMed Central

    Gilbert, Clément; Peccoud, Jean; Chateigner, Aurélien; Moumen, Bouziane

    2016-01-01

    Many genes of large double-stranded DNA viruses have a cellular origin, suggesting that host-to-virus horizontal transfer (HT) of DNA is recurrent. Yet, the frequency of these transfers has never been assessed in viral populations. Here we used ultra-deep DNA sequencing of 21 baculovirus populations extracted from two moth species to show that a large diversity of moth DNA sequences (n = 86) can integrate into viral genomes during the course of a viral infection. The majority of the 86 different moth DNA sequences are transposable elements (TEs, n = 69) belonging to 10 superfamilies of DNA transposons and three superfamilies of retrotransposons. The remaining 17 sequences are moth sequences of unknown nature. In addition to bona fide DNA transposition, we uncover microhomology-mediated recombination as a mechanism explaining integration of moth sequences into viral genomes. Many sequences integrated multiple times at multiple positions along the viral genome. We detected a total of 27,504 insertions of moth sequences in the 21 viral populations and we calculate that on average, 4.8% of viruses harbor at least one moth sequence in these populations. Despite this substantial proportion, no insertion of moth DNA was maintained in any viral population after 10 successive infection cycles. Hence, there is a constant turnover of host DNA inserted into viral genomes each time the virus infects a moth. Finally, we found that at least 21 of the moth TEs integrated into viral genomes underwent repeated horizontal transfers between various insect species, including some lepidopterans susceptible to baculoviruses. Our results identify host DNA influx as a potent source of genetic diversity in viral populations. They also support a role for baculoviruses as vectors of DNA HT between insects, and call for an evaluation of possible gene or TE spread when using viruses as biopesticides or gene delivery vectors. PMID:26829124

  19. Host nutritive quality and host plant choice in two grass miners: primary roles for primary compounds?

    PubMed

    Scheirs, Jan; De Bruyn, Luc; Verhagen, Ron

    2003-06-01

    The relationship between host plant choice and plant nutritional quality was investigated in two oligophagous grass miners Chromatomyia milii and C. nigra (Diptera, Agromyzidae). We tested whether host choice is determined by chemically mediated host suitability for offspring performance and/or adult performance. A second goal was to relate the observed variation among the different fitness parameters to quantitative and qualitative variation in foliar food quality. Choice experiments illustrated that both miners discriminated among grass species, and that C. milii has a smaller host range than C. nigra, as observed under natural conditions. Oviposition preference was correlated with adult feeding preference and related adult performance (longevity and fecundity) for both miners. Offspring performance measures (survival and pupal size) of at least C. nigra were more weakly related to host preference. Nearly all variation in adult performance of both miners was explained by foliar protein content, which had a positive effect on adult longevity and fecundity. Pupal size of both miners was positively related to foliar water and amino acid content and negatively related to lignin content. No clear relationship between host chemistry and offspring survival was observed. These observations show that fitness parameters are differentially related to host chemistry. Secondly, they suggest that chemically mediated host suitability for adult performance is an important determinant of host choice in this species. Finally, the results suggest a primary role for foliar protein content in host choice of the study species in general and in shaping the host range of C. milii in particular.

  20. Host-parasite associations and host-specificity in haemoparasites of reed bed passerines.

    PubMed

    Ventim, Rita; Morais, Joana; Pardal, Sara; Mendes, Luísa; Ramos, Jaime A; Pérez-Tris, Javier

    2012-03-01

    The host specificity and host sharing of avian haemoparasites (genera Haemoproteus and Plasmodium) is still poorly known, although they infect a large proportion of several studied bird populations. This study used molecular techniques to detect haemoparasites in marsh warblers and in other passerines that feed in reed beds, at 4 sites in Portugal. The host-specificity of the parasite lineages was analysed and compared with other cases described in the literature to assess whether apparent host specificity changes according to the studied system. Nine lineages of Haemoproteus and 15 of Plasmodium were found, of which only 10 Plasmodium were proven to have local transmission. Each lineage was confined to a distinct set of host species. The distribution of parasites in the host species was non-nested, meaning that specialist lineages did not always share hosts with generalists. The most prevalent lineages were those with a wider host range, indicating that the ability to infect more hosts will enhance a parasite's prevalence in its entire host range. We also found that in our areas, a specialist parasite (H. MW1) appears to have a more generalist character than described in the literature, suggesting that a parasite's apparent specialization can depend on the type of host species sampled.

  1. Understanding Host-Switching by Ecological Fitting

    PubMed Central

    Araujo, Sabrina B. L.; Braga, Mariana Pires; Brooks, Daniel R.; Agosta, Salvatore J.; Hoberg, Eric P.; von Hartenthal, Francisco W.; Boeger, Walter A.

    2015-01-01

    Despite the fact that parasites are highly specialized with respect to their hosts, empirical evidence demonstrates that host switching rather than co-speciation is the dominant factor influencing the diversification of host-parasite associations. Ecological fitting in sloppy fitness space has been proposed as a mechanism allowing ecological specialists to host-switch readily. That proposal is tested herein using an individual-based model of host switching. The model considers a parasite species exposed to multiple host resources. Through time host range expansion can occur readily without the prior evolution of novel genetic capacities. It also produces non-linear variation in the size of the fitness space. The capacity for host colonization is strongly influenced by propagule pressure early in the process and by the size of the fitness space later. The simulations suggest that co-adaptation may be initiated by the temporary loss of less fit phenotypes. Further, parasites can persist for extended periods in sub-optimal hosts, and thus may colonize distantly related hosts by a "stepping-stone" process. PMID:26431199

  2. Toxocara spp. infections in paratenic hosts.

    PubMed

    Strube, Christina; Heuer, Lea; Janecek, Elisabeth

    2013-04-15

    The zoonotic roundworms Toxocara canis and T. cati are not only present worldwide in their definitive hosts; they also frequently occur in other animal species, including humans. In those so-called paratenic hosts, the larvae do not develop into the adult stage, but rather migrate throughout the somatic tissue and persist as infectious L3 stage for extensive periods. Those arrested larvae may lead to severe inflammatory reactions and consequently to a wide range of pathological and clinical manifestations. However, the infected paratenic hosts also constitute a potential source of infection for the definitive hosts or humans who may also function as paratenic hosts. In the present review, current knowledge of larval migration in a variety of possible paratenic hosts is summarized including variations of migration routes and susceptibilities. Furthermore, information about the clinical and pathological changes for the presented species and possible consequences of the somatic migration of larvae, i.e. the resulting tissue damage as well as adverse host reactions to arrested larvae are reviewed. There are still many questions unanswered regarding larval behaviour in hosts other than their definitive host. Therefore, it is of great importance to continue further elaboration on the biology of Toxocara spp. to prevent further spreading of larvae in both the paratenic and the definitive host.

  3. Host defenses against cryptococcosis.

    PubMed

    Price, Michael S; Perfect, John R

    2011-01-01

    The interaction of pathogenic Cryptococcus species with their various hosts is somewhat unique compared to other fungal pathogens such as Aspergillus fumigatus and Candida albicans. Cryptococcus shares an intimate association with host immune cells, leading to enhanced intracellular growth. Furthermore, unlike most other fungal pathogens, the signs and symptoms of cryptococcal disease are typically self-inflicted by the host during the host's attempt to clear this invader from sensitive organ systems such as the central nervous system. In this review, we will summarize the story of host-Cryptococcus interactions to date and explore strategies to exploit the current knowledge for treatment of cryptococcal infections.

  4. Host specificity of the badger's flea (Paraceras melis) and first detection on a bat host.

    PubMed

    Ancillotto, Leonardo; Mazza, Giuseppe; Menchetti, Mattia; Mori, Emiliano

    2014-10-01

    Defining the whole spectrum of potential hosts of a parasite has large epidemiological and evolutionary implications in biology. Specialized parasites might be able to occasionally exploit a range of different host species, increasing the individual survival and the chances of successful dispersal. For long time Paraceras melis has been considered a specific flea of European badger Meles meles. Anyway, it has occasionally been reported on different hosts. In this work, we summarize the host spectrum of P. melis from literature and we report its first detection on a bat host. Ten species were identified as occasional hosts, man included, and the plasticity of this flea in host exploitation is noteworthy because of possible increase of pathogens transmission to humans and domestic species.

  5. Sugarcane aphid resistance in sorghum and a host range

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sugarcane aphid (SCA), Melanaphis sacchari, has been present in the United States primarily on sugarcane in Florida, Hawaii, and Louisiana until 2013 where it was found on grain sorghum near Beaumont, Texas. Since 2013, the SCA has been rapidly spreading and overwintering. Depending on the plant...

  6. Emergence of host-adapted Salmonella Enteritidis through rapid evolution in an immunocompromised host

    PubMed Central

    Klemm, Elizabeth J; Gkrania-Klotsas, Effrossyni; Hadfield, James; Forbester, Jessica L; Harris, Simon R; Hale, Christine; Heath, Jennifer N; Wileman, Thomas; Clare, Simon; Kane, Leanne; Goulding, David; Otto, Thomas D; Kay, Sally; Doffinger, Rainer; Cooke, Fiona J; Carmichael, Andrew; Lever, Andrew ML; Parkhill, Julian; MacLennan, Calman A; Kumararatne, Dinakantha

    2016-01-01

    Summary Host adaptation is a key factor contributing to the emergence of new bacterial, viral and parasitic pathogens. Many pathogens are considered promiscuous because they cause disease across a range of host species, while others are host-adapted, infecting particular hosts1. Host adaptation can potentially progress to host restriction where the pathogen is strictly limited to a single host species and is frequently associated with more severe symptoms. Host-adapted and host-restricted bacterial clades evolve from within a broader host-promiscuous species and sometimes target different niches within their specialist hosts, such as adapting from a mucosal to a systemic lifestyle. Genome degradation, marked by gene inactivation and deletion, is a key feature of host adaptation, although the triggers initiating genome degradation are not well understood. Here, we show that a chronic systemic non-typhoidal Salmonella infection in an immunocompromised human patient resulted in genome degradation targeting genes that are expendable for a systemic lifestyle. We present a genome-based investigation of a recurrent blood-borne Salmonella enterica serotype Enteritidis (S. Enteritidis) infection covering 15 years in an interleukin (IL)-12 β-1 receptor-deficient individual that developed into an asymptomatic chronic infection. The infecting S. Enteritidis harbored a mutation in the mismatch repair gene mutS that accelerated the genomic mutation rate. Phylogenetic analysis and phenotyping of multiple patient isolates provides evidence for a remarkable level of within-host evolution that parallels genome changes present in successful host-restricted bacterial pathogens but never before observed on this timescale. Our analysis identifies common pathways of host adaptation and demonstrates the role that immunocompromised individuals can play in this process. PMID:27127642

  7. Undiscovered Bat Hosts of Filoviruses

    PubMed Central

    Schmidt, John Paul; Alexander, Laura W.; Bowden, Sarah E.; Hayman, David T. S.; Drake, John M.

    2016-01-01

    Ebola and other filoviruses pose significant public health and conservation threats by causing high mortality in primates, including humans. Preventing future outbreaks of ebolavirus depends on identifying wildlife reservoirs, but extraordinarily high biodiversity of potential hosts in temporally dynamic environments of equatorial Africa contributes to sporadic, unpredictable outbreaks that have hampered efforts to identify wild reservoirs for nearly 40 years. Using a machine learning algorithm, generalized boosted regression, we characterize potential filovirus-positive bat species with estimated 87% accuracy. Our model produces two specific outputs with immediate utility for guiding filovirus surveillance in the wild. First, we report a profile of intrinsic traits that discriminates hosts from non-hosts, providing a biological caricature of a filovirus-positive bat species. This profile emphasizes traits describing adult and neonate body sizes and rates of reproductive fitness, as well as species’ geographic range overlap with regions of high mammalian diversity. Second, we identify several bat species ranked most likely to be filovirus-positive on the basis of intrinsic trait similarity with known filovirus-positive bats. New bat species predicted to be positive for filoviruses are widely distributed outside of equatorial Africa, with a majority of species overlapping in Southeast Asia. Taken together, these results spotlight several potential host species and geographical regions as high-probability targets for future filovirus surveillance. PMID:27414412

  8. Glob-Hosts

    SciTech Connect

    Behlendorf, B.; Garlick, J.

    2007-08-31

    The glob-hosts utility manipulates hostlist strings in UNIX shell scripts. Hostlists are a parseable string representatin of list of hosts, which compress nicely when a group of hosts are named with contiguous numeric suffixes. For example, the hosts blue1, blue2, and blue3 can be represented by the hostlist string "blue1, blue2, blue3" or equivalently "blue[1-3]". The globhost utility cn peform the following operations on a hostlist string: count, size, expand, nth, union, minus, intersection, and exclude.

  9. Synthetic fusion-protein containing domains of Bt Cry1Ac and Allium sativum lectin (ASAL) conferred enhanced insecticidal activity against major lepidopteran pests.

    PubMed

    Tajne, Sunita; Boddupally, Dayakar; Sadumpati, Vijayakumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

    2014-02-10

    Different transgenic crop plants, developed with δ-endotoxins of Bacillus thuringiensis (Bt) and mannose-specific plant lectins, exhibited significant protection against chewing and sucking insects. In the present study, a synthetic gene (cry-asal) encoding the fusion-protein having 488 amino acids, comprising DI and DII domains from Bt Cry1Ac and Allium sativum agglutinin (ASAL), was cloned and expressed in Escherichia coli. Ligand blot analysis disclosed that the fusion-protein could bind to more number of receptors of brush border membrane vesicle (BBMV) proteins of Helicoverpa armigera. Artificial diet bioassays revealed that 0.025 μg/g and 0.50 μg/g of fusion-protein were sufficient to cause 100% mortality in Pectinophora gossypiella and H. armigera insects, respectively. As compared to Cry1Ac, the fusion-protein showed enhanced (8-fold and 30-fold) insecticidal activity against two major lepidopteran pests. Binding of fusion-protein to the additional receptors in the midgut cells of insects is attributable to its enhanced entomotoxic effect. The synthetic gene, first of its kind, appears promising and might serve as a potential candidate for engineering crop plants against major insect pests.

  10. Evaluation of in vitro and in vivo effects of semipurified proteinase inhibitors from Theobroma seeds on midgut protease activity of Lepidopteran pest insects.

    PubMed

    Paulillo, Luis Cesar Maffei Sartini; Sebbenn, Alexandre Magno; de Carvalho Derbyshire, Maria Tereza Vitral; Góes-Neto, Aristóteles; de Paula Brotto, Marco Aurélio; Figueira, Antonio

    2012-09-01

    We have characterized in vitro and in vivo effects of trypsin inhibitors from Theobroma seeds on the activity of trypsin- and chymotrypsin-like proteins from Lepidopteran pest insects. The action of semipurified trypsin inhibitors from Theobroma was evaluated by the inhibition of bovine trypsin and chymotrypsin activities determined by the hydrolysis of N-Benzoyl-DL-Arginine-p-Nitroanilide (BAPA) and N-Succinyl-Ala-Ala-Pho-Phe p-Nitroanilide (S-(Ala)2ProPhe-pNA). Proteinase inhibitor activities from Theobroma cacao and T. obovatum seeds were the most effective in inhibiting trypsin-like proteins, whereas those from T. obovatum and T. sylvestre were the most efficient against chymotrypsin-like proteins. All larvae midgut extracts showed trypsin-like proteolytic activities, and the putative trypsin inhibitors from Theobroma seeds significantly inhibited purified bovine trypsin. With respect to the influence of Theobroma trypsin inhibitors on intact insects, the inclusion of T. cacao extracts in artificial diets of velvet bean caterpillars (Anticarsia gemmatalis) and sugarcane borer (Diatraea saccharalis) produced a significant increase in the percentage of adult deformation, which is directly related to both the survival rate of the insects and oviposition.

  11. Detoxification of hostplant's chemical defence rather than its anti-predator co-option drives β-glucosidase-mediated lepidopteran counteradaptation

    PubMed Central

    Poreddy, Spoorthi; Mitra, Sirsha; Schöttner, Matthias; Chandran, Jima; Schneider, Bernd; Baldwin, Ian T.; Kumar, Pavan; Pandit, Sagar S.

    2015-01-01

    The evolutionary plant–herbivore arms race sometimes gives rise to remarkably unique adaptation strategies. Here we report one such strategy in the lepidopteran herbivore Manduca sexta against its hostplant Nicotiana attenuata's major phytotoxins, 17-hydroxygeranyllinalool diterpene glycoside, lyciumoside IV and its malonylated forms. We show that alkalinity of larval regurgitant non-enzymatically demalonylates the malonylated forms to lyciumoside IV. Lyciumoside IV is then detoxified in the midgut by β-glucosidase 1-catalysed deglycosylation, which is unusual, as typically the deglycosylation of glycosylated phytochemicals by insects results in the opposite: toxin activation. Suppression of deglucosylation by silencing larval β-glucosidase 1 by plant-mediated RNAi causes moulting impairments and mortality. In the native habitat of N. attenuata, β-glucosidase 1 silencing also increases larval unpalatability to native predatory spiders, suggesting that the defensive co-option of lyciumoside IV may be ecologically advantageous. We infer that M. sexta detoxifies this allelochemical to avoid its deleterious effects, rather than co-opting it against predators. PMID:26443324

  12. Proteolytic activation of pro-spätzle is required for the induced transcription of antimicrobial peptide genes in lepidopteran insects

    PubMed Central

    Wang, Yang; Cheng, Tingcai; Rayaprolu, Subrahmanyam; Zou, Zhen; Xia, Qingyou; Xiang, Zhonghuai; Jiang, Haobo

    2007-01-01

    Microbial infection leads to proteolytic activation of Drosophila spätzle, which binds to the toll receptor and induces the synthesis of immune proteins. To test whether or not this mechanism exists in lepidopteran insects, we cloned the cDNA of Bombyx mori spätzle-1 and overexpressed the full-length and truncated BmSpz1 cDNA in Escherichia coli. The insoluble fusion proteins were affinity-purified under denaturing condition. After the silkworm larvae were injected with renatured BmSpz1, mRNA levels of antimicrobial peptide genes greatly increased. Similar transcriptional up-regulation was also found in Manduca sexta. Injection of pro-BmSpz1 had no such effect. When pro-BmSpz1 and Micrococcus luteus were incubated with the plasma from M. sexta larvae, we detected proteolytic processing of pro-BmSpz1. These results suggest that active spätzle is required for the induced production of antimicrobial peptides in B. mori and M. sexta. PMID:17337053

  13. Cloning and characterization of a riboflavin-binding hexamerin from the larval fat body of a lepidopteran stored grain pest, Corcyra cephalonica.

    PubMed

    Rao, V Venkat; Ningshen, Thuirei Jacob; Chaitanya, R K; Senthilkumaran, B; Dutta-Gupta, Aparna

    2016-01-01

    In the present study, a riboflavin-binding hexamerin (RbHex) was cloned and characterized from the larval fat body of Corcyra cephalonica. The complete cDNA (2121bp) encodes a 706-amino acid protein with a molecular mass ~82kDa. Expression of RbHex 82 was predominant in fat body among larval tissues. Further, it is prominently expressed during the last instar larval development. Homology modeling and docking studies predicted riboflavin binding site of the hexamerin. Spectrofluorimetric analysis further confirmed riboflavin release from the hexamerin fraction. Quantitative RT-PCR studies demonstrated hormonal regulation of RbHex 82. 20-Hydroxyecdysone (20HE) had a stimulatory effect on its transcription whereas JH alone did not show any effect. However, JH in the presence of 20HE maintains the RbHex 82 expression which indicates the JH's role as a status quo factor. This study is the first to report the characterization of riboflavin-binding hexamerin in a lepidopteran pest. Further, the possibility of RbHex 82 as a pest control target is discussed.

  14. MbIDGF, a novel member of the imaginal disc growth factor family in Mamestra brassicae, stimulates cell proliferation in two lepidopteran cell lines without insulin.

    PubMed

    Zhang, Jun; Iwai, Sachio; Tsugehara, Taketo; Takeda, Makio

    2006-07-01

    Imaginal disc growth factor (IDGF) is a soluble polypeptide growth factor that was first identified from the conditioned medium of Drosophilia imaginal disc C1.8+ cells. Working with insulin, IDGF stimulated the growth of cultured imaginal disk cells, which suggested that IDGF might function as a cofactor of Drosophila insulin or insulin like peptide. Here we report a new member of the IDGF family, named MbIDGF, from the cabbage armyworm, Mamestra brassicae. Using a cloned cDNA of MbIDGF, recombinant MbIDGF protein was expressed in baculovirus-infected Sf9 cells and purified. Without insulin, the recombinant MbIDGF protein stimulated cell growth of SES-MaBr-4 and NIAS-MaBr-93 cell lines that were derived from the fat bodies and hemocytes of M. brassicae, in a dose-dependent manner. The saturation of growth stimulation by MbIDGF was attained for the two types of cells at 80 ng/ml (0.8 nM) and 300 ng/ml (6 nM), respectively. The results suggest that MbIDGF may stimulate the growth of lepidopteran cells by a new mechanism without associating with the insulin pathway.

  15. Endosymbiont Tolerance and Control within Insect Hosts

    PubMed Central

    Ratzka, Carolin; Gross, Roy; Feldhaar, Heike

    2012-01-01

    Bacterial endosymbioses are very common in insects and can range from obligate to facultative as well as from mutualistic to pathogenic associations. Several recent studies provide new insight into how endosymbionts manage to establish chronic infections of their hosts without being eliminated by the host immune system. Endosymbiont tolerance may be achieved either by specific bacterial adaptations or by host measurements shielding bacteria from innate defense mechanisms. Nevertheless, insect hosts also need to sustain control mechanisms to prevent endosymbionts from unregulated proliferation. Emerging evidence indicates that in some cases the mutual adaptations of the two organisms may have led to the integration of the endosymbionts as a part of the host immune system. In fact, endosymbionts may provide protective traits against pathogens and predators and may even be required for the proper development of the host immune system during host ontogeny. This review gives an overview of current knowledge of molecular mechanisms ensuring maintenance of chronic infections with mutualistic endosymbionts and the impact of endosymbionts on host immune competence. PMID:26466544

  16. Nestedness of Ectoparasite-Vertebrate Host Networks

    PubMed Central

    Graham, Sean P.; Hassan, Hassan K.; Burkett-Cadena, Nathan D.; Guyer, Craig; Unnasch, Thomas R.

    2009-01-01

    Determining the structure of ectoparasite-host networks will enable disease ecologists to better understand and predict the spread of vector-borne diseases. If these networks have consistent properties, then studying the structure of well-understood networks could lead to extrapolation of these properties to others, including those that support emerging pathogens. Borrowing a quantitative measure of network structure from studies of mutualistic relationships between plants and their pollinators, we analyzed 29 ectoparasite-vertebrate host networks—including three derived from molecular bloodmeal analysis of mosquito feeding patterns—using measures of nestedness to identify non-random interactions among species. We found significant nestedness in ectoparasite-vertebrate host lists for habitats ranging from tropical rainforests to polar environments. These networks showed non-random patterns of nesting, and did not differ significantly from published estimates of nestedness from mutualistic networks. Mutualistic and antagonistic networks appear to be organized similarly, with generalized ectoparasites interacting with hosts that attract many ectoparasites and more specialized ectoparasites usually interacting with these same “generalized” hosts. This finding has implications for understanding the network dynamics of vector-born pathogens. We suggest that nestedness (rather than random ectoparasite-host associations) can allow rapid transfer of pathogens throughout a network, and expand upon such concepts as the dilution effect, bridge vectors, and host switching in the context of nested ectoparasite-vertebrate host networks. PMID:19924299

  17. Cucumis melo endornavirus: Genome organization, host range and codivergence with the host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high molecular weight dsRNA was isolated from a Cucumis melo plant (referred to as“CL01”) of an unknown cultivar and completely sequenced. Sequence analyses showed similarities with members of the Endornaviridae. The name Cucumis melo endornavirus (CmEV) is proposed. The genome of CmEV-CL01 consis...

  18. A Virulence Factor Encoded by a Polydnavirus Confers Tolerance to Transgenic Tobacco Plants against Lepidopteran Larvae, by Impairing Nutrient Absorption

    PubMed Central

    Coppola, Mariangela; Buonanno, Martina; Di Prisco, Gennaro; Varricchio, Paola; Franzetti, Eleonora; Corrado, Giandomenico; Monti, Simona M.; Rao, Rosa; Casartelli, Morena; Pennacchio, Francesco

    2014-01-01

    The biological control of insect pests is based on the use of natural enemies. However, the growing information on the molecular mechanisms underpinning the interactions between insects and their natural antagonists can be exploited to develop “bio-inspired” pest control strategies, mimicking suppression mechanisms shaped by long co-evolutionary processes. Here we focus on a virulence factor encoded by the polydnavirus associated with the braconid wasp Toxoneuron nigriceps (TnBV), an endophagous parasitoid of noctuid moth larvae. This virulence factor (TnBVANK1) is a member of the viral ankyrin (ANK) protein family, and appears to be involved both in immunosuppression and endocrine alterations of the host. Transgenic tobacco plants expressing TnBVANK1 showed insecticide activity and caused developmental delay in Spodoptera littoralis larvae feeding on them. This effect was more evident in a transgenic line showing a higher number of transcripts of the viral gene. However, this effect was not associated with evidence of translocation into the haemocoel of the entire protein, where the receptors of TnBVANK1 are putatively located. Indeed, immunolocalization experiments evidenced the accumulation of this viral protein in the midgut, where it formed a thick layer coating the brush border of epithelial cells. In vitro transport experiments demonstrated that the presence of recombinant TnBVANK1 exerted a dose-dependent negative impact on amino acid transport. These results open new perspectives for insect control and stimulate additional research efforts to pursue the development of novel bioinsecticides, encoded by parasitoid-derived genes. However, future work will have to carefully evaluate any effect that these molecules may have on beneficial insects and on non-target organisms. PMID:25438149

  19. Host acceptance, suitability, and effects of host deprivation on the West African egg parasitoid Telenomus isis (Hymenoptera: Scelionidae) reared on East African stemborers under varying temperature and relative humidity regimens.

    PubMed

    Bruce, Anani Yaovi; Schulthess, Fritz; Mueke, Jones

    2009-06-01

    Scelionid egg parasitoids of Telenomus spp. have been shown to significantly affect noctuid stemborer populations and yields of maize in western Africa. One of them, T. isis, has never been reported from eastern Africa and was introduced into the laboratories of the International Centre of Insect Physiology and Ecology, Kenya. This study evaluates the biotic potential of T. isis using East African stemborers as hosts. Host acceptance was tested using 15 lepidopteran borer species. Only noctuid stemborers were accepted for oviposition by T. isis. Sesamia calamistis Hampson, Sesamia nonagrioides (Lefebvre), and Busseola fusca (Fuller) were further used to study the effect of host species, host age, duration of host deprivation, temperature, and humidity on the performance of the parasitoid. In contrast to sex ratio, developmental time, parasitism, and parasitoid emergence varied significantly with host species, and the former two decreased with the age of host eggs. Female longevity increased with duration of host deprivation, whereas average lifetime fecundity decreased, probably because of oocyte resorption. T. isis successfully developed between 18 and 32 degrees C at both low (40-50%) and high (70-80%) relative humidity regimens, but temperature played a more critical role. Using the modified Logan model, the lower and upper temperature thresholds for development were estimated at 11.5 and 37.5 degrees C, respectively, with an optimum at 30.5 degrees C for both humidity regimens. Depending on temperature and relative humidity regimen, the intrinsic rate of increase (r(m)) varied from 0.077 to 0.300, net reproductive rate (R(o)) from 7.70 to 83.96, and generation time (G) from 11 to 38 d. The results of this study indicate that T. isis is likely to establish in eastern Africa.

  20. Interaction of glucosinolate content of Arabidopsis thaliana mutant lines and feeding and oviposition by generalist and specialist lepidopterans.

    PubMed

    Badenes-Perez, Francisco R; Reichelt, Michael; Gershenzon, Jonathan; Heckel, David G

    2013-02-01

    The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), is an insect specialized on glucosinolate-containing Brassicaceae that uses glucosinolates in host-plant recognition. We used wild-type and mutants of Arabidopsis thaliana (L.) Heynh. (Brassicaceae) to investigate the interaction between plant glucosinolate and myrosinase content and herbivory by larvae of the generalist Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) and the specialist P. xylostella. We also measured glucosinolate changes as a result of herbivory by these larvae to investigate whether herbivory and glucosinolate induction had an effect on oviposition preference by P. xylostella. Feeding by H