Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| interaction of cytolytic toxin cytb with a supported lipid bilayer: study using an acoustic wave device. | an acoustic technique was used to monitor the interaction of the pore-forming cytolytic toxin cytb with a positively charged supported lipid bilayer. the acoustic device, which is based on a waveguide geometry, is sensitive to changes in the mass of the supported bilayer. the specificity of the interaction, rate and extent of the association, reversibility and effect of previous depositions of toxin were investigated. the cytb was found to bind irreversibly to the lipids at all fractional covera ... | 2004 | 15803723 |
| genetic diversity among bacillus anthracis, bacillus cereus and bacillus thuringiensis strains using repetitive element polymorphism-pcr. | repetitive element polymorphism-pcr (rep-pcr) is one of the tools that has been used to elucidate genetic diversity of related microorganisms. using the mb1 primer, rep-pcr fingerprints from 110 bacillus strains within the "b. cereus group" have identified eighteen distinct categories, while other more distantly related bacterial species fell within six additional categories. all bacillus anthracis strains tested were found to be monomorphic by fluorophore-enhanced rep-pcr (ferp) fingerprinting ... | 2004 | 15790070 |
| response of larval chironomus tepperi (diptera: chironomidae) to individual bacillus thuringiensis var. israelensis toxins and toxin mixtures. | the biopesticide bacillus thuringiensis israelensis (b.t.i.) is highly toxic to the larvae of chironomus tepperi, an important pest of aerially sown rice in southern australia. in this study, all of the known cry genes and the cyt1a gene from b.t.i. were expressed and tested for individual toxicity against fourth instar c. tepperi larvae. possible synergism between toxins in two component mixtures involving all toxins except cry10a was also evaluated. of the cry toxins, only cry11a and cry4b dis ... | 2004 | 15707867 |
| characterization of cultured insect cells selected by bacillus thuringiensis crystal toxin. | selection for resistance against bacillus thuringiensis (bt) cry1ac10 in the trichoplusia ni (hubner) cell line bti-tn-5b1-4 (tnh5) was tested, and the development of resistance in the selected cells was like a s-form curve. monitoring at the cry1ac10 50th challenge, the resistance ratio was 1,294-fold as many as that of initial cells. but the resistance to cry1ac10 declined gradually when the selection was relaxed. the resistance declined rapidly at the low level of resistance and slowly at the ... | 2004 | 15780008 |
| [cloning and superexpression of cry1ac gene from 20kb dna associated with bacillus thuringiensis cry1a crystal protein]. | the cryla crystal protein from bacillus thuringiensis is associated with dna, but the role and sequences of these dna molecules are unknown. cryla bipyramidal crystals from b. thuringiensis strain 4.0718 was selectively dissolved and associated dna was extracted from protoxin. the dna was digested with nde i to obtain 3 to 5 kb fragments and then the fragments were subcloned into pmd18-t vector, screening of recombinants were done by pcr-rflp and sequencing. the orf of cry1ac gene was amplified ... | 2004 | 15973985 |
| rotational application of bioinsecticide with deltamethrin-an antilarval measure for the control of filarial vector, culex quinquefasciatus (culicidae: diptera). | a laboratory investigation was undertaken to study the cyclic usage of field recommended doses of bacillus thuringiensis israelensis (bti), bacillus sphaericus (bsp) and combination of bti and bsp (half the recommended dose of each) with deltamethrin 2.8 ec to attain better control of mosquito larvae. to understand the susceptibility status of the culex quinquefasciatus larvae in the field, early fourth instar field collected larvae were exposed to the above treatments of biopesticides and were ... | 2004 | 15907070 |
| redirection of metabolism during nutrient feeding in fed-batch cultures of bacillus thuringiensis. | during sporulation, bacillus thuringiensis produces insecticidal crystal inclusions (cry proteins) encoded by cry genes. in fed-batch cultures (fbcs), spores and cry protein yields are usually low, so we therefore studied the pattern of metabolic changes occurring in batch cultures and fbcs of a b. thuringiensis strain having a cry1aa promoter-lacz fusion, and their effect on sporulation and cry1a gene expression. in fbcs, there was a redirection of bacterial metabolism and a reduction in the sp ... | 2004 | 15834720 |
| an algorithm for estimating potential deposition of corn pollen for environmental assessment. | the safety and impact on the environment of transgenic crops are important issues, and studies have shown that pollen from transgenic bt (bacillus thuringiensis) corn (zea mays l.) may kill nontarget insects. to develop an algorithm for assessing the environmental effect of transgenic crops, we arranged a field experiment in tsukuba, japan. pollen dispersal and deposition were measured inside and outside a cornfield throughout the flowering period. weather conditions such as wind speed and direc ... | 2004 | 16028796 |
| spider web survey or whole plant visual sampling? impact assessment of bt corn on non-target predatory insects with two concurrent methods. | impact assessment studies rely on relevant sampling methods. correct evaluation of methods can be done by their concurrent use in the same sampling site and period. collecting webs of theridion impressum l. koch (araneae: theridiidae) may serve as an arthropod sampling method: empty cuticles of prey items remain attached to the back side of the leaves with adhesive silk. our study aimed to compare the applicability of the two methods concurrently (spider web survey and whole plant visual samplin ... | 2004 | 16028799 |
| [cloning and expression of tyrosinase-encoding gene (mel) of bacillus thuringiensis and its initial research of application]. | tyrosinase, which is encoded by tyrosinase gene (mel), is the key enzyme in the process of melanin formation in animals, plants and microorganisms. using the primers designed by comparing the conserved domain of tyrosinase, a dna fragment was amplified which contain the mel gene from bacillus thuringiensis 4d11. the recombinant e. coli emb1179 was gained by subcloning this dna fragment onto the vector pgem-7zf and transformed it into e. coli dh5alpha. emb1179 express the tyrosinase activity and ... | 2004 | 16110969 |
| a simple and rapid agrobacterium-mediated transformation protocol for cotton (gossypium hirsutum l.): embryogenic calli as a source to generate large numbers of transgenic plants. | a protocol is presented for efficient transformation and regeneration of cotton. embryogenic calli co-cultivated with agrobacterium carrying cry1ia5 gene were cultured under dehydration stress and antibiotic selection for 3-6 weeks to generate several transgenic embryos. an average of 75 globular embryo clusters were observed on selection plates and these embryos were cultured on multiplication medium followed by development of cotyledonary embryos on embryo maturation medium to obtain an averag ... | 2004 | 13680138 |
| protection of mice infected with plasmodium berghei by bacillus thuringiensis crystal proteins. | eight bacillus thuringiensis strains were used to test their activity against plasmodium berghei. when crystal proteins extracted from strains 007, 017, 020, 021, 030, 032, and 037 were injected into plasmodium-infected mice through the tail vein at a rate of 0.45-1.5 mg per mouse, the lengths of survival for the mice were extended up to 5 days (from 8.5 days to 13.5-15 days). blood-cell staining demonstrated that normal erythrocytes were lightly stained and regularly shaped while the erythrocyt ... | 2004 | 14600831 |
| artificial carrier for oxygen supply in biological systems. | several poly (dimethylsiloxanes) (pdms) copolymers of dimethylsiloxane (dms) with ethylene or propylene oxide were tested as artificial carriers for the delivery of oxygen to biological systems. copolymers with a dms content of 33% or lower enhanced glucose oxidation by 200% in contrast to the 25% increase produced by the same concentration of perfluorodecalin. when 0.05% of the copolymer with 18% dms was included in the growth media of bacillus thuriginensis, the biomass (growth rate) increased ... | 2004 | 14593505 |
| functional domains of a pore-forming cardiotoxic protein, volvatoxin a2. | volvatoxin a2 (vva2), a novel pore-forming cardiotoxic protein was isolated from the mushroom volvariella volvacea. we identified an n-terminal fragment (ntf) (1-127 residues) of vva2 as a domain for oligomerization by limited tryptic digestion. on preincubation of ntf with vva2, ntf was found to inhibit vva2 hemolytic activity by inducing vva2 oligomerization in the solution in the same manner as liposomes. by site-directed mutagenesis, the amphipathic alpha-helix b of ntf or vva2 was shown to ... | 2004 | 14645370 |
| stable bacillus thuringiensis (bt) toxin content in interspecific f1 and backcross populations of wild brassica rapa after bt gene transfer. | stable expression of a transgene may lead to increased fitness for wild plants after acquiring the transgene via crop-weed hybridization. here, we investigate the stability of bt toxin content in wild brassica rapa acquiring the bt gene from bt brassica napus. the bt toxin content in nine bt-expressing b. napus lines was 0.80-1.70 micro g/g leaf tissue throughout the growing season. these nine lines were crossed with three accessions of wild b. rapa and the bt gene was successfully transferred t ... | 2004 | 14653804 |
| ion channels formed in planar lipid bilayers by the dipteran-specific cry4b bacillus thuringiensis toxin and its alpha1-alpha5 fragment. | trypsin activation of cry4b, a 130-kda bacillus thuringiensis (bt) protein, produces a 65-kda toxin active against mosquito larvae. the active toxin is made of two protease resistant-products of ca. 45 kda and ca. 20 kda. the cloned 21-kda fragment consisting of the n-terminal region of the toxin was previously shown to be capable of permeabilizing liposomes. the present study was designed to test the following hypotheses: (1) cry4b, like several other bt toxins, is a channel-forming toxin in pl ... | 2004 | 14668140 |
| tryptophan spectroscopy studies and black lipid bilayer analysis indicate that the oligomeric structure of cry1ab toxin from bacillus thuringiensis is the membrane-insertion intermediate. | during intoxication, the cry protoxins must change from insoluble crystals into membrane-inserted toxins, which form ionic pores. binding of cry1a toxins to the cadherin receptor promotes the formation of a 250 kda oligomer. in this work, we analyzed for the first time the structural changes presented by cry1ab toxin upon membrane insertion. trp fluorescence of pure monomeric and oligomeric structures in solution and in a membrane-bound state was analyzed. cry1ab has nine trp residues, seven of ... | 2004 | 14705942 |
| a facile analytical method for the identification of protease gene profiles from bacillus thuringiensis strains. | five pairs of degenerate universal primers have been designed to identify the general protease gene profiles from some distinct bacillus thuringiensis strains. based on the pcr amplification patterns and dna sequences of the cloned fragments, it was noted that the protease gene profiles of the three distinct strains of b. thuringiensis subsp. kurstaki hd73, tenebrionis and israelensis t14001 are varied. seven protease genes, neutral protease b (nprb), intracellular serine protease a (ispa), extr ... | 2004 | 14706757 |
| genetics of zwittermicin a production by bacillus cereus. | zwittermicin a represents a new chemical class of antibiotic and has diverse biological activities, including suppression of oomycete diseases of plants and potentiation of the insecticidal activity of bacillus thuringiensis. to identify genes involved in zwittermicin a production, we generated 4,800 transposon mutants of b. cereus uw101c and screened them for zwittermicin a accumulation. nine mutants did not produce detectable zwittermicin a, and one mutant produced eightfold more than the pare ... | 2004 | 14711631 |
| detection of the bacillus anthracis gyra gene by using a minor groove binder probe. | identification of chromosomal markers for rapid detection of bacillus anthracis is difficult because significant chromosomal homology exists among b. anthracis, bacillus cereus, and bacillus thuringiensis. we evaluated the bacterial gyra gene as a potential chromosomal marker for b. anthracis. a real-time pcr assay was developed for the detection of b. anthracis. after analysis of the unique nucleotide sequence of the b. anthracis gyra gene, a fluorescent 3' minor groove binding probe was tested ... | 2004 | 14715750 |
| reagentless detection and classification of individual bioaerosol particles in seconds. | the rapid chemical analysis of individual cells is an analytical capability that will profoundly impact many fields including bioaerosol detection for biodefense and cellular diagnostics for clinical medicine. this article describes a mass spectrometry-based analytical technique for the real-time and reagentless characterization of individual airborne cells without sample preparation. we characterize the mass spectral signature of individual bacillus spores and demonstrate the ability to disting ... | 2004 | 14719885 |
| identification of 1-lysophosphatidylethanolamine (c(16:1)) as an antimicrobial compound in the housefly, musca domestica. | we observed that a methanolic whole body extract of uninfected last instar larvae of the housefly, musca domestica, displayed antifungal and antibacterial activity. we have further purified this extract to a single active fraction using reversed phase high performance liquid chromatography. the pure fraction inhibited growth of the gram-positive bacteria bacillus thuringiensis and the yeast saccharomyces cerevisiae, but not the gram-negative bacteria escherichia coli. the active compound was det ... | 2004 | 14723896 |
| bacterial challenge stimulates innate immune responses in extra-embryonic tissues of tobacco hornworm eggs. | innate immunity protects juvenile and adult vertebrates and invertebrates against potential pathogens; however, it is unknown when developing embryos become immune competent and just how they are guarded from infection. to address these questions, we studied the effect of immune challenge on early stage eggs of the tobacco hornworm, manduca sexta. we detected many immune-related proteins and mrnas in naive eggs. upon immune challenge, antimicrobial protein genes were up-regulated, and antibacter ... | 2004 | 14728663 |
| expression of modified cry1ac gene of bacillus thuringiensis in transgenic tobacco plants. | several mutations were introduced into the cry1ac toxin gene, resulting in four variants with altered sequences that were responsible for low expression of the toxin in transgenic plants. these variants were as follows: v1, with modified three a/t-rich regions, including the first signal of transcription termination; v2, with modified five putative polyadenylation signals (polyadenylation signals pas) and the second signal of transcription termination; v3, with four initial auuua motifs; v4, wit ... | 2004 | 14734820 |
| effects of bt plants on the development and survival of the parasitoid cotesia plutellae (hymenoptera: braconidae) in susceptible and bt-resistant larvae of the diamondback moth, plutella xylostella (lepidoptera: plutellidae). | a range of crops have been transformed with delta-endotoxin genes from bacillus thuringiensis (bt) to produce transgenic plants with high levels of resistance to lepidopteran pests. parasitoids are important natural enemies of lepidopteran larvae and the effects of bt plants on these non-target insects have to be investigated to avoid unnecessary disruption of biological control. this study investigated the effects of cry1ac-expressing transgenic oilseed rape (brassica napus) on the solitary bra ... | 2004 | 15121457 |
| bt-r1a extracellular cadherin repeat 12 mediates bacillus thuringiensis cry1ab binding and cytotoxicity. | the cadherin protein bt-r(1a) is a receptor for bacillus thuringiensis cry1a toxins in manduca sexta. cry1ab toxin is reported to bind specific epitopes located in extracellular cadherin repeat (cr) 7 and cr11 on bt-r(1) (gomez, b., miranda-rios, j., riudino-pinera, e., oltean, d. i., gill, s. s., bravo, a., and soberon, m. (2002) j. biol. chem. 277, 30137-30143; dorsch, j. a., candas, m., griko, n., maaty, w., midboe, e., vadlamudi, r., and bulla, l. (2002) insect biochem. mol. biol. 32, 1025-1 ... | 2004 | 15123702 |
| an extracytoplasmic-function sigma factor is involved in a pathway controlling beta-exotoxin i production in bacillus thuringiensis subsp. thuringiensis strain 407-1. | beta-exotoxin i is an insecticidal nucleotide analogue secreted by various bacillus thuringiensis strains. in this report, we describe the characterization and transcriptional analysis of a gene cluster, designated sigw-ecfx-ecfy, that is essential for beta-exotoxin i production in b. thuringiensis subsp. thuringiensis strain 407-1. in this strain, the disruption of the sigw cluster resulted in nontoxic culture supernatants. sigw encodes a protein of 177 residues that is 97 and 94% identical to ... | 2004 | 15126472 |
| low-level detection of a bacillus anthracis simulant using love-wave biosensors on 36 degrees yx litao3. | we present an acoustic love-wave biosensor for detection of the bacillus anthracis simulant, bacillus thuringiensis at or below inhalational infectious levels. the present work is an experimental study of 36 degrees yx cut litao3 based love-wave devices for detection of pathogenic spores in aqueous conditions. given that the detection limit (d1) of love-wave-based sensors is a strong function of the overlying waveguide, two waveguide materials have been investigated, which are polyimide and poly ... | 2004 | 15128104 |
| the drosophila melanogaster homologue of the human histo-blood group pk gene encodes a glycolipid-modifying alpha1,4-n-acetylgalactosaminyltransferase. | insects express arthro-series glycosphingolipids, which contain an alpha1,4-linked galnac residue. to determine the genetic basis for this linkage, we cloned a cdna (cg17223) from drosophila melanogaster encoding a protein with homology to mammalian alpha1,4-glycosyltransferases and expressed it in the yeast pichia pastoris. culture supernatants from the transformed yeast were found to display a novel udp-galnac:galnacbeta1,4glcnacbeta1-r alpha-n-acetylgalactosaminyltransferase activity when usi ... | 2004 | 15130086 |
| optimised expression in escherichia coli and purification of the functional form of the bacillus thuringiensis cry4aa delta-endotoxin. | achieving high-level expression of the bacillus thuringiensis cry4aa mosquito-larvicidal protein was demonstrated. the 130-kda cry4aa protoxin was overexpressed as an inclusion body in escherichia coli under the control of the tac promoter together with the cry4ba promoter. the solubility of the toxin inclusions in carbonate buffer, ph 10.0, was markedly enhanced at a cultivation temperature of 30 degrees c. elimination of the tryptic cleavage site at arg-235 in the loop between helices 5 and 6 ... | 2004 | 15135419 |
| contamination of refuges by bacillus thuringiensis toxin genes from transgenic maize. | transgenic crops producing insecticidal toxins from bacillus thuringiensis (bt) are widely used to control pests, but their benefits will be lost if pests evolve resistance. the mandated high-dose/refuge strategy for delaying pest resistance requires planting refuges of toxin-free crops near bt crops to promote survival of susceptible pests. we report that pollen-mediated gene flow up to 31 m from bt maize caused low to moderate bt toxin levels in kernels of non-bt maize refuge plants. immunoass ... | 2004 | 15136739 |
| [techniques of diseases, insect pests and weeds control and their efficacy in bio-rational rice production]. | studies on the efficacy of bio-rational pesticides and agricultural methods against the chief diseases, insect pests and weeds of rice showed that the efficacy of the mixtures of jingangmycin and bacillus-cereus, and jingangmycin and polyoxin against rice sheath blight were 75.16%-94.27% after sprayed once at the tiller and boot end stages of rice, respectively, and better than that of chemical fungicide triadimefon. the efficacy of kasugamycin and blasticidin was 50.54%-72.67% on rice leaf blas ... | 2004 | 15139200 |
| characterization of mexican bacillus thuringiensis strains toxic for lepidopteran and coleopteran larvae. | bacillus thuringiensis strains c-4, c-9, gm-7, and gm-10, isolated from northeast mexico and selected for their high toxicity against lepidopteran and coleopteran pests, were characterized following united states environmental protection agency (epa)'s guidelines. flagellar serotyping revealed that gm-7 and gm-10 belonged to serotype aizawai, whereas c-4, c-9 corresponded to the kumamotoensis serotype. gm-10 and c-9 were also shown to be the most effective against lepidoptera and coleoptera larv ... | 2004 | 15145246 |
| starlink genetically modified corn and allergenicity in an individual. | 2004 | 15148966 | |
| pore worms: using caenorhabditis elegans to study how bacterial toxins interact with their target host. | the interaction of pathogenic bacteria with a target host is regulated both by bacterial virulence factors and by host components that either protect the host or that promote pathogenesis. the soil nematode caenorhabditis elegans is a host for a number of bacterial pathogens, as briefly reviewed here. bacillus thuringiensis (bt) is a pathogenic bacteria that c. elegans is likely to encounter naturally in the soil. the pore-forming crystal (cry) toxins made by bt are recognized as the dominant vi ... | 2004 | 15149037 |
| distinct mutations in plcr explain why some strains of the bacillus cereus group are nonhemolytic. | bacillus thuringiensis, bacillus cereus, and bacillus anthracis are closely related species belonging to the bacillus cereus group. b. thuringiensis and b. cereus generally produce extracellular proteins, including phospholipases and hemolysins. transcription of the genes encoding these factors is controlled by the pleiotropic regulator plcr. disruption of plcr in b. cereus and b. thuringiensis drastically reduces the hemolytic, lecithinase, and cytotoxic properties of these organisms. b. anthra ... | 2004 | 15150241 |
| natural variation in the response of caenorhabditis elegans towards bacillus thuringiensis. | almost nothing is known about the natural ecology of the nematode caenorhabditis elegans, including its interactions with parasites. to help rectify this discrepancy, we assessed natural variation in the response of c. elegans towards a potential parasite, the soil bacterium bacillus thuringiensis. our results show that 10 isolates from across the world differ significantly in survival rate and infection level when confronted with a parasitic strain of b. thuringiensis. furthermore, behavioural ... | 2004 | 15151149 |
| novel oligosaccharide side chains of the collagen-like region of bcla, the major glycoprotein of the bacillus anthracis exosporium. | spores of bacillus anthracis, the causative agent of anthrax, are enclosed by a prominent loose fitting layer called the exosporium. the exosporium consists of a basal layer and an external hairlike nap. the filaments of the nap are composed of a highly immunogenic glycoprotein called bcla, which has a long, central collagen-like region with multiple xxg repeats. most of the triplet repeats are ptg, and nearly all of the triplet repeats contain a threonine residue, providing multiple potential s ... | 2004 | 15152001 |
| screening of the insecticidal activity of bacillus thuringiensis strains against lygus hesperus (hemiptera: miridae) nymphal population. | lygus hesperus knight (hemiptera: miridae) is an economically important insect pest controlled primarily by chemical pesticides. bacillus thuringiensis berliner is a gram-positive bacterium that has been developed for the control of some insect pests in the orders lepidoptera, coleoptera, and diptera. in this study, whole culture extracts of 94 b. thuringiensis strains from 83 serovars were added to an artificial diet and assayed against l. hesperus first and second instars. a total of five b. t ... | 2004 | 15154442 |
| assessment of experimental bt events against fall armyworm and corn earworm in field corn. | performance of experimental bacillus thuringiensis (bt) mon events alone and pyramided with mon810 were evaluated over 3 yr in georgia and alabama. ability of events to prevent whorl defoliation by the fall armyworm, spodoptera frugiperda (j. e. smith), and natural ear feeding damage by the corn earworm, helicoverpa zea (boddie) was assessed. in each year, near-isogenic hybrids with novel single transformation events and crosses pyramided with the mon810 event were compared with the standard sin ... | 2004 | 15154443 |
| biological control of lobesia botrana (lepidoptera: tortricidae) larvae by using different formulations of bacillus thuringiensis in 11 vine cultivars under field conditions. | this work describes the results of an experiment that was conducted in the vineyard of the american farm school, thermi, thessaloniki greece, during 2001. its aim was to study the efficacy of two formulations of bacillus thuringiensis berliner (wettable powder and dust) to control the larvae of lobesia botrana denis & schiffermueler (lepidoptera: tortricidae). the experimental results showed that the two formulations of b. thuringiensis are significantly more effective than the control, the dust ... | 2004 | 15154453 |
| damage loss assessment and control of the cereal leaf beetle (coleoptera: chrysomelidae) in winter wheat. | cereal leaf beetle, oulema melanopus (l.), invaded northern alabama and georgia more than a decade ago and since has become an economic pest of winter wheat and other cereal crops in the southeastern united states. a series of trials was conducted beginning in 1995 to determine optimal rate and timing of applications of selected foliar insecticides for managing cereal leaf beetle in soft red winter wheat. these trials, cage studies with larvae, and a manual defoliation experiment were used to pr ... | 2004 | 15154458 |
| a survey of hymenopteran parasitoids of forest macrolepidoptera in the central appalachians. | in 1995 and 1996, we conducted a study of the hymenopteran parasitoids of macrolepidopteran larvae in the george washington national forest (gwnf), augusta county, virginia, and the monongahela national forest (mnf), pocahontas county, west virginia. macrolepidopteran larvae were collected from canopy foliage and from under canvas bands placed around tree boles. a total of 115 macrolepidopteran species and 5,235 individual larvae were reared. forty-two percent (2,221) of the larvae were gypsy mo ... | 2004 | 15154467 |
| development of a highly efficient system for assessing recombinant gene expression in plant cell suspensions via agrobacterium tumefaciens transformation. | a transient gene-expression system was developed and used to characterize promoter strength, to verify suitability of bacterial gene modifications for expression in plant cells, and to express active antibody molecules. the system is based on suspension tobacco cells transformed by agrobacterium in a transient way. conditions such as pre-culture of tobacco cells and the co-cultivation period were identified as determinants to achieve high expression levels. under established conditions the activ ... | 2004 | 15154849 |
| the catalytic role of aspartate in a short strong hydrogen bond of the asp274-his32 catalytic dyad in phosphatidylinositol-specific phospholipase c can be substituted by a chloride ion. | phosphatidylinositol-specific phospholipase c from bacillus thuringiensis catalyzes the cleavage of the phosphorus-oxygen bond in phosphatidylinositol. the focus of this work is to dissect the roles of the carboxylate side chain of asp(274) in the asp(274)-his(32) dyad, where a short strong hydrogen bond (sshb) was shown to exist based on nmr criteria. a regular hydrogen bond (hb) was observed in d274n, and no low field proton resonance was detected for d274e and d274a. comparison of the activit ... | 2004 | 15155721 |
| interaction between lactic acid bacteria and gastrointestinal nematodes of caprine origin. | to compare the level of parasitism with gastrointestinal nematodes in sheep and goats, several studies have been conducted. they have generally shown that goats were more infected than sheep, as they exhibited higher worm burdens and egg excretion. this difference between two host species has been attributed not only to a difference in feeding behavior, but also to a lesser ability of goats to develop resistance to trichostrongylate infection (in kids and lambs the greatest damage is observed fr ... | 2004 | 15156032 |
| effect of ph and ionic strength on the cytolytic toxin cyt1a: a fluorescence spectroscopy study. | cyt1a is a cytolytic toxin produced by bacillus thuringiensis var. israelensis. due to its toxicity in vivo against mosquitoes and black flies, it is used as an environmentally friendly insecticide, although its mode of action is not completely understood. the toxin is membrane-active, but its membrane-bound conformation is unknown. in the absence of direct structural data, fluorescence spectroscopy was used to obtain indirect information on cyt1a conformation changes in the environment mimickin ... | 2004 | 15158719 |
| isolation, geographical diversity and insecticidal activity of bacillus thuringiensis from soils in spain. | bacillus thuringiensis is a spore-forming bacterium showing the unusual ability to produce endogenous crystals during sporulation that are toxic for some pest insects. this work was performed to study the composition, ecological distribution and insecticidal activity of isolates of this entomopathogenic bacterium from the spanish territory. using a standard isolation method, b. thuringiensis was isolated from 115 out of 493 soil samples collected in the iberian peninsula and the canary and balea ... | 2004 | 15160608 |
| qualitative and quantitative pcr methods for detection of three lines of genetically modified potatoes. | qualitative and quantitative polymerase chain reaction (pcr) methods have been developed for the detection of genetically modified (gm) potatoes. the combination of specific primers for amplification of the promoter region of cry3a gene, potato leafroll virus replicase gene, and potato virus y coat protein gene allows to identify each line of newleaf, newleaf y, and newleaf plus gm potatoes. multiplex pcr method was also established for the simple and rapid detection of the three lines of gm pot ... | 2004 | 15161181 |
| achieving successful deployment of bt rice. | 2004 | 15165560 | |
| microcalorimetric investigation on the growth model and the protein yield of bacillus thuringiensis. | a novel microcalorimetric technique based on the bacterial heat output was applied to evaluate the special growth model, the protein expression and the generation time of bacillus thuringiensis for the first time. the thermogenic curves of the aerobic metabolism of b. thuringiensis strains ybt-833, ybt-1520 and ybt-833-2-1 were determined by using an lkb-2277 bioactivity monitor. the analysis of the thermogenic curves indicated both the mutant strain and the wild-type strains followed the same l ... | 2004 | 15165757 |
| responses of nontarget lepidoptera to foray 48b bacillus thuringiensis var. kurstaki on vancouver island, british columbia, canada. | impacts of a gypsy moth (lymantria dispar) eradication program on native, nontarget lepidoptera were assessed in 1999, on southeastern vancouver island (bc, canada). the microbial insecticide bacillus thuringiensis var. kurstaki (btk) was applied aerially over two areas totalling 12,805 ha on may 8, may 19, and june 8, 1999, at a dosage of 50 billion international units in 4.0 l/ha. lepidoptera were collected from two host plant species: garry oak (quercus garryana) and common snowberry (symphor ... | 2004 | 15180383 |
| enhancement of cry19aa mosquitocidal activity against aedes aegypti by mutations in the putative loop regions of domain ii. | improvements in the mosquitocidal activity of bacillus thuringiensis cry19aa were achieved by protein engineering of putative surface loop residues in domain ii through rational design. the improvement of aedes toxicity in cry19aa was 42,000-fold and did not affect its toxicity against anopheles or culex. | 2004 | 15184189 |
| insecticide resistance and cross-resistance in alabama and florida strains of culex quinquefasciatus [correction]. | insecticide resistance and cross-resistance was determined for three strains of culex quinquefasciatus say in the southeastern united states. hamcq and mamcq strains were collected in 2002 from huntsville and mobile, al. the vbfmcq strain was collected in 1998 from vero beach, fl. vbfmcq, hamcq, and mamcq larvae showed resistance to permethrin with resistance ratios of 13, 100, and 940, respectively, compared with the susceptible s-lab strain. levels of resistance in hamcq and mamcq larvae were ... | 2004 | 15185942 |
| laboratory and simulated field evaluation of a new recombinant of bacillus thuringiensis ssp. israelensis and bacillus sphaericus against culex mosquito larvae (diptera: culicidae). | in the laboratory, three microbial mosquito larvicidal products consisting of bacillus thuringiensis ssp. israelensis de barjac (bti), bacillus sphaericus (neide) (bsph) (strain 2362), and the university of california riverside (ucr) recombinant (producing toxins of both bacillus sphaericus and bacillus thuringiensis ssp. israelensis) were bioassayed against larvae of culex quinequefasciatus say (susceptible and resistant to bsph 2362), and aedes aegypti (l.). bti proved highly effective against ... | 2004 | 15185945 |
| laboratory selection for resistance to bacillus thuringiensis subsp. jegathesan or a component toxin, cry11b, in culex quinquefasciatus (diptera: culicidae). | the bacteria bacillus thuringiensis subsp. israelensis and bacillus sphaericus produce insecticidal toxins used to control mosquito larvae throughout the world. unfortunately, there are few alternative insecticides with similar activity and environmental safety, which may limit the long-term success of these insecticides. bacillus thuringiensis subsp. jegathesan is another bacterium with toxins that are active against mosquitoes and has potential for development as a commercial product. b. t. su ... | 2004 | 15185947 |
| the autolytic phenotype of bacillus thuringiensis. | to evaluate the autolytic phenotype of bacillus thuringiensis. | 2004 | 15186453 |
| bacillus thuringiensis serovar shandongiensis strain 89-t-34-22 produces multiple cytotoxic proteins with similar molecular masses against human cancer cells. | to prove that bacillus thuringiensis serovar shandongiensis strain 89-t-34-22 produces several novel cytotoxic proteins against human leukaemic t cells. | 2004 | 15189293 |
| larvicidal cry proteins from bacillus thuringiensis are released in root exudates of transgenic b. thuringiensis corn, potato, and rice but not of b. thuringiensis canola, cotton, and tobacco. | larvicidal proteins encoded by cry genes from bacillus thuringiensis were released in root exudates from transgenic b. thuringiensis corn, rice, and potato but not from b. thuringiensis canola, cotton, and tobacco. nonsterile soil and sterile hydroponic solution in which b. thuringiensis corn, rice, or potato had been grown were immunologically positive for the presence of the cry proteins; from b. thuringiensis corn and rice, the soil and solution were toxic to the larva of the tobacco hornworm ... | 2004 | 15191740 |
| molecular cloning and sequence analysis of the chitinase gene from bacillus thuringiensis serovar alesti. | endogenous chitinase plays a positive role in the pathogenicity of bacillus thuringiensis to insect pests. the chitinase gene was cloned from b. thuringiensis serovar alesti strain hd-16, and the deduced 676 amino acid sequence showed a high degree of similarity with other bacillus chitinases. additionally, the deduced amino acid sequence showed that the protein contained an amino terminus signal peptide and consisted of a catalytic domain, a fibronectin type iii domain and a chitin-binding doma ... | 2004 | 15200172 |
| genetically modified foods get bad rap. | 2004 | 15204724 | |
| effect of specific mutations in helix alpha7 of domain i on the stability and crystallization of cry3a in bacillus thuringiensis. | insecticidal crystal (cry) proteins of bacillus thuringiensis crystallize after synthesis forming large inclusions that stabilize these toxins in the environment after cell lysis until eaten by an insect. despite the biological importance of crystallization, little is known about the structural elements of cry molecules that facilitate this process. we identified subdomains that affect cry3a structure possibly through improper folding by chimeric-scanning mutagenesis, substituting short peptides ... | 2004 | 15208451 |
| the injection of plasmid dna in mouse muscle results in lifelong persistence of dna, gene expression, and humoral response. | the duration of the immune response against any vaccine is critical. the present study was performed to determine the stability of injected plasmid deoxyribonucleic acid (dna), the duration of gene expression in mouse muscle, as well as the duration of the immune response generated in mice after injection of plasmid pso2c1 harboring the cry11bb gene of bacillus thuringiensis serovar. medellin. the localization and the persistence of the inoculated gene were determined by in situ hybridization an ... | 2004 | 15208453 |
| studies on cultured and uncultured microbiota of wild culex quinquefasciatus mosquito midgut based on 16s ribosomal rna gene analysis. | to describe the midgut microbial diversity and the candidate bacteria for the genetic manipulation for the generation of transgenic mosquitoes refractory to transmission of diseases, the microbiota of wild culex quinquefasciatus mosquito midgut was studied using a conventional culture technique and analysis of a 16s ribosomal rna (rrna) gene sequence library. the culturable microbiota was identified as acinetobacter junii, ac. calcoaceticus, aeromonas culicicola, bacillus thuringiensis, microbac ... | 2004 | 15210998 |
| composition of grain and forage from corn rootworm-protected corn event mon 863 is equivalent to that of conventional corn (zea mays l.). | insect-protected corn hybrids containing event mon 863 protect corn plants against feeding damage from corn rootworm (diabrotica), a major north american insect pest. corn event mon 863 contains a gene that expresses an amino acid sequence variant of the wild-type cry3bb1 insecticidal protein from bacillus thuringiensis. the purpose of this study was to compare the composition of corn containing event mon 863 with that of conventional nontransgenic corn. compositional analyses were conducted to ... | 2004 | 15212462 |
| crystallization and preliminary crystallographic study of the functional form of the bacillus thuringiensis mosquito-larvicidal cry4aa mutant toxin. | the 65 kda functional form of the mosquito-larvicidal cry4aa-r235q mutant toxin has been crystallized. the crystals belong to space group c222(1), with unit-cell parameters a = 91.2, b = 202.1, c = 98.7 a, and contain one molecule per asymmetric unit. the crystals diffract to approximately 2.9 a using synchrotron radiation and a complete native data set has been collected. the structure has been solved using a molecular-replacement method with the cry4ba toxin protein as a search model. | 2004 | 15213403 |
| melanin pigment formation and increased uv resistance in bacillus thuringiensis following high temperature induction. | the pigment melanin is well known to protect against the damaging effects of uv radiation. in this study, we show that thirty-five of thirty-seven tested bacillus thuringiensis strains possess the potential to produce melanin in the presence of l-tyrosin at elevated temperature (42 degrees c). these findings offer a method of protecting insecticidal toxins produced by b. thuringiensis from uv degredation and may therefore have important applications in the field of crop protection. toxicity assa ... | 2004 | 15214633 |
| development of stem borer resistant transgenic parental lines involved in the production of hybrid rice. | stem borer resistant transgenic parental lines, involved in hybrid rice, were produced by agrobacterium-mediated gene transfer method. two psb111 super-binary vectors containing modified cry1ab/cry1ac genes driven by maize ubiquitin promoter, and herbicide resistance gene bar driven by cauliflower mosaic virus 35s promoter were, used in this study. embryogenic calli after co-cultivation with agrobacterium were selected on the medium containing phosphinothricin. southern blot analyses of primary ... | 2004 | 15219400 |
| soil microbial communities associated with bt and non-bt corn in three soils. | the effects of expression of cry endotoxin by bt corn (transgenic corn engineered to express bacillus thuringiensis toxin) on soil microbial community structure were assessed in a growth chamber experiment. two lines of transgenic corn expressing different cry endotoxins were compared with their respective non-transgenic isolines in three soil types with differing textures. phospholipid fatty acid (plfa) profiles from bulk soil and community-level physiological profiles (clpp) from the rhizosphe ... | 2004 | 15224917 |
| is231-mic231 elements from bacillus cereus sensu lato are modular. | summary is231a was originally discovered in bacillus thuringiensis as a typical 1.6 kb insertion sequence (is) displaying 20 bp inverted repeats (ir) flanking a transposase gene. a first major variation of this canonical organization was found in mic231a1. this mobile insertion cassette (mic), delineated by is231a-related extremities, contained an active d-stereospecific endopeptidase (adp) gene instead of a transposase. interestingly, it was shown that mic231a1 can be mobilized in trans by the ... | 2004 | 15228527 |
| susceptibility of the leaf-eating beetle, galerucella calmariensis, a biological control agent for purple loosestrife (lythrum salcaria), to three mosquito control larvicides. | we evaluated the susceptibility of galerucella calmariensis, a species used to control purple loosestrife (lythrum salicaria), to three mosquito control larvicides. larvae and adults were fed loosestrife cuttings dipped in abate (< or = 375 g x l(-1)), altosid (< or = 250 g x l(-1)), and bacillus thuringiensis var israeliensis (bti) (< or = 110 g x l(-1)). eggs on cuttings were dipped in the same concentrations. pupae were immersed in abate and altosid solutions (< or = 474.4 microg x l(-1) and ... | 2004 | 15230319 |
| improvement of bioinsecticides production through mutagenesis of bacillus thuringiensis by u.v. and nitrous acid affecting metabolic pathways and/or delta-endotoxin synthesis. | the present work aimed to obtain bioinsecticide over-producing mutants through classical mutagenesis of vegetative cells of bacillus thuringiensis (bt) by using u.v. and nitrous acid, and to evidence the involvement of cell metabolism in delta-endotoxin synthesis. | 2004 | 15239700 |
| a simple, rapid, high-fidelity and cost-effective pcr-based two-step dna synthesis method for long gene sequences. | chemical synthesis of dna sequences provides a powerful tool for modifying genes and for studying gene function, structure and expression. here, we report a simple, high-fidelity and cost-effective pcr-based two-step dna synthesis (ptds) method for synthesis of long segments of dna. the method involves two steps. (i) synthesis of individual fragments of the dna of interest: ten to twelve 60mer oligonucleotides with 20 bp overlap are mixed and a pcr reaction is carried out with high-fidelity dna ... | 2004 | 15240836 |
| a qtl that enhances and broadens bt insect resistance in soybean. | effective strategies are needed to manage insect resistance to bacillus thuringiensis (bt) proteins expressed in transgenic crops. to evaluate a multiple resistance gene pyramiding strategy, eight soybean (glycine max) lines possessing factorial combinations of two quantitative trait loci (qtls) from plant introduction (pi) 229358 and a synthetic bt cry1ac gene were developed using marker-assisted selection with simple sequence repeat markers. field studies were conducted in 2000 and 2001 to eva ... | 2004 | 15243707 |
| occurrence and significance of bacillus thuringiensis on wine grapes. | wine grapes harvested at different stages during cultivation from several vineyards in new south wales, australia, harboured bacillus thuringiensis at viable populations of 10(2)-10(6) cfu/g. commercial preparations of b. thuringiensis had been sprayed onto the grapes as a biological insecticide. b. thuringiensis (10(1)-10(3) cfu/ml) was isolated from grape juice and fermenting grape juice in a commercial winery. although b. thuringiensis remained viable when inoculated at 10(3)-10(4) cfu/ml int ... | 2004 | 15246241 |
| cryptic endotoxic nature of bacillus thuringiensis cry1ab insecticidal crystal protein. | cry1ab is one of the most studied insecticidal proteins produced by bacillus thuringiensis during sporulation. structurally, this protoxin has been divided in two domains: the n-terminal toxin core and the c-terminal portion. although many studies have addressed the biochemical characteristics of the active toxin that corresponds to the n-terminal portion, there are just few reports studying the importance of the c-terminal part of the protoxin. herein, we show that cry1ab protoxin has a unique ... | 2004 | 15251434 |
| expression of a modified cry1ie gene in e. coli and in transgenic tobacco confers resistance to corn borer. | the wild-type cry1ie gene from bacillus thuringiensis was modified for its efficient expression in transgenic plants. modified cry1ie gene (designated as cry1iem) was cloned into prokaryotic expression vector pet28b and its expression in e. coli was confirmed by sds-page analysis. bioassays using crude expression products in e. coli revealed that cry1iem protein had a similar toxicity to corn borer as wild-type cry1ie. cry1iem gene was then inserted downstream of the maize ubiquitin-1 promoter i ... | 2004 | 15253158 |
| mitogen-activated protein kinase pathways defend against bacterial pore-forming toxins. | cytolytic pore-forming toxins are important for the virulence of many disease-causing bacteria. how target cells molecularly respond to these toxins and whether or not they can mount a defense are poorly understood. by using microarrays, we demonstrate that the nematode caenorhabditis elegans responds robustly to cry5b, a member of the pore-forming crystal toxin family made by bacillus thuringiensis. this genomic response is distinct from that seen with a different stressor, the heavy metal cadm ... | 2004 | 15256590 |
| changes in susceptibility to conventional insecticides of a cry1ac-selected population of helicoverpa armigera (hübner) (lepidoptera: noctuidae). | the changes in the susceptibility of the cotton bollworm, helicoverpa armigera (hübner) to three insecticides (lambda-cyhalothrin, phoxim and endosulfan) commonly used for control of this pest in china were monitored by bioassays at various generations. the insects were originally collected from bt cotton fields and selected with cry1ac over 44 generations. in comparison with a susceptible strain, the larval resistance of the bt-selected populations to cry1ac toxin increased 106-fold. simultaneo ... | 2004 | 15260299 |
| factors affecting the toxicity of bacillus thuringiensis var. israelensis and bacillus sphaericus to fourth instar larvae of chironomus tepperi (diptera: chironomidae). | laboratory bioassays (48h duration, 25+/-1 degrees c) were used to determine the toxicity of bacillus thuringiensis var. israelensis (b.t.i.) and bacillus sphaericus to fourth instar larvae of chironomus tepperi, a major pest of rice in southern australia. bioassays were conducted using different combinations of larval ages and densities to determine if these factors affected toxicity. the effects of temperature and substrate type on b.t.i. toxicity were also investigated. tests were conducted u ... | 2004 | 15261774 |
| comparative analysis of proteinase activities of bacillus thuringiensis-resistant and -susceptible ostrinia nubilalis (lepidoptera: crambidae). | proteinase activities were compared in soluble and membrane fractions of guts obtained from larvae of bacillus thuringiensis-resistant and -susceptible ostrinia nubilalis. overall, serine proteinases from soluble fractions of the susceptible strain were more active than those of the resistant strain. the soluble trypsin-like proteinase activity of the resistant strain was approximately half that of the susceptible strain. the number and relative molecular masses of soluble and membrane serine pr ... | 2004 | 15262280 |
| influence of temperature and concentration of vectobac on control of the salt-marsh mosquito, ochlerotatus squamiger, in monterey county, california. | laboratory susceptibility bioassays were conducted to determine the efficacy of vectobac tp (bacillus thuringiensis var. israelensis [bti]) at different concentrations and temperatures against the salt-marsh mosquito ochlerotatus squamiger. bioassays on late 3rd- and early 4th-stage larvae, read at 72 h and 14 degrees c produced an ld90 of 0.223 mg/liter, whereas more than double this dose was required to produce similar mortality at 6 degrees c. a field trial in the winter of 2001-02 of an aeri ... | 2004 | 15264626 |
| effects of algae on the efficacy of bacillus thuringiensis var. israelensis against larval black flies. | personnel from several black fly control programs have reported that the efficacy of bacillus thuringiensis var. israelesis (bti) is reduced during periods when algal concentrations are high in the waterways. although the reduction in bti-induced mortality in black fly larvae is presumed to be related to the presence of algae, no scientific data support this theory. in this study, 4 genera of algae (microcytis, scenedesmus, dictrosphaerium, and chlorella) commonly detected in pennsylvania rivers ... | 2004 | 15264627 |
| evaluation of calcium-alginate gel as an artificial diet medium for bioassays on common cutworms. | a calcium-alginate gel diet was developed for spodoptera litura larvae, and its reliability as a carrier for incorporating antifeedants as well as insecticides was investigated. the alginate gel diet was prepared with a simple protocol, which does not involve any heating process. when tested using this diet, acephate, a bacillus thuringiensis endotoxin formulation and rotenone reproducibly showed insecticidal activity against the larvae, while neem oil and scabequinone deterred the larval feedin ... | 2004 | 15264908 |
| characterization of a cry1ac-receptor alkaline phosphatase in susceptible and resistant heliothis virescens larvae. | we reported previously a direct correlation between reduced soybean agglutinin binding to 63- and 68-kda midgut glycoproteins and resistance to cry1ac toxin from bacillus thuringiensis in the tobacco budworm (heliothis virescens). in the present work we describe the identification of the 68-kda glycoprotein as a membrane-bound form of alkaline phosphatase we term hvalp. lectin blot analysis of hvalp revealed the existence of n-linked oligosaccharides containing terminal n-acetylgalactosamine req ... | 2004 | 15265032 |
| cloning and nucleotide sequence of a novel cry gene from bacillus thuringiensis. | a cry1ab-type gene was cloned from a new isolate of bacillus thuringiensis by pcr. when restriction pattern was compared with that of known genes it was found to have additional restriction site for clai. nucleotide sequencing and homology search revealed that the toxin shared 95% homology with the known cry1ab proteins as compared to more than 98% homology among the other reported cry1ab toxins. the gene encoded a sequence of 1,177 amino acids compared to 1,155 amino acids encoded by all the ot ... | 2004 | 15266122 |
| delaying evolution of insect resistance to transgenic crops by decreasing dominance and heritability. | the refuge strategy is used widely for delaying evolution of insect resistance to transgenic crops that produce bacillus thuringiensis (bt) toxins. farmers grow refuges of host plants that do not produce bt toxins to promote survival of susceptible pests. many modelling studies predict that refuges will delay resistance longest if alleles conferring resistance are rare, most resistant adults mate with susceptible adults, and bt plants have sufficiently high toxin concentration to kill heterozygo ... | 2004 | 15271091 |
| intranasal coadministration of the cry1ac protoxin with amoebal lysates increases protection against naegleria fowleri meningoencephalitis. | cry1ac protoxin has potent mucosal and systemic adjuvant effects on antibody responses to proteins or polysaccharides. in this work, we examined whether cry1ac increased protective immunity against fatal naegleria fowleri infection in mice, which resembles human primary amoebic meningoencephalitis. higher immunoglobulin g (igg) than iga anti-n. fowleri responses were elicited in the serum and tracheopulmonary fluids of mice immunized by the intranasal or intraperitoneal route with n. fowleri lys ... | 2004 | 15271892 |
| two orthorhombic crystal structures of a galactose-specific lectin from artocarpus hirsuta in complex with methyl-alpha-d-galactose. | based on their carbohydrate specificity, the jacalin family of lectins can be divided into two groups: galactose-specific and mannose-specific. the former are cytoplasmic proteins, whereas the latter are localized in the storage vacuoles of cells. it has been proposed that the post-translational modification in some of the lectins that splits their polypeptide chains into two may be crucial for galactose specificity. the mannose-specific members of the family are single-chain proteins that lack ... | 2004 | 15272163 |
| space spraying of bacterial and chemical insecticides against anopheles balabacensis baisas for the control of malaria in sabah, east malaysia. | a pilot study was undertaken to determine the effectiveness of space application of insecticides for the control of malaria in ranau, a district in sabah. a village each was treated monthly: with chemical adulticide--alpha cypermethrin (fendona sc(r)/10sc(r)) at 2 g a.i./10,000 m2 in pahu; with biological larvicides--bacillus thuringiensis israelensis (vectobac 12as(r)) at 500 ml/10,000 m2 or b. sphaericus (vectolex wg(r)) at 500 g/10,000 m2 in pinawantai; and with a mixture of chemical adultici ... | 2004 | 15272747 |
| selective antagonism to the cadherin bt-r1 interferes with calcium-induced adhesion of epithelial membrane vesicles. | bt-r(1) is a member of the cadherin superfamily of proteins and is expressed in the midgut epithelium of manduca sexta during larval development. previously, we showed that calcium ions influence the structure and stability of bt-r(1) on brush border membrane vesicles (bbmvs) prepared from m. sexta midgut epithelium. in the present study, the effects of calcium and cry1ab toxin, produced by bacillus thuringiensis, on the adhesive properties of bbmvs were investigated. addition of calcium to a su ... | 2004 | 14756577 |
| role of toxin activation on binding and pore formation activity of the bacillus thuringiensis cry3 toxins in membranes of leptinotarsa decemlineata (say). | binding and pore formation constitute key steps in the mode of action of bacillus thuringiensis delta-endotoxins. in this work, we present a comparative analysis of toxin-binding capacities of proteolytically processed cry3a, cry3b and cry3c toxins to brush border membranes (bbmv) of the colorado potato beetle leptinotarsa decemlineata (cpb), a major potato coleopteran-insect pest. competition experiments showed that the three cry3 proteolytically activated toxins share a common binding site. al ... | 2004 | 14757225 |
| [mosquito control based on larvicides in the state of rio grande do sul, brazil: choice of the control agent]. | a comparison between chemical and biological larvicides in routine operations against mosquitoes in rio grande do sul state was carried out in this study. in laboratory bioassays against culex quinquefasciatus, biological formulations vectobac 12 as and teknar 3000 (bacillus thuringiensis israelensis) as well as abg 6262 (b. sphaericus 2362), both in liquid and powder form, were highly effective. locally produced b. thuringiensis israelensis, formulations also yielded good results. among chemica ... | 2004 | 14762563 |
| insecticidal bacillus thuringiensis silences erwinia carotovora virulence by a new form of microbial antagonism, signal interference. | it is commonly known that bacteria may produce antibiotics to interfere with the normal biological functions of their competitors in order to gain competitive advantages. here we report that bacillus thuringiensis suppressed the quorum-sensing-dependent virulence of plant pathogen erwinia carotovora through a new form of microbial antagonism, signal interference. e. carotovora produces and responds to acyl-homoserine lactone (ahl) quorum-sensing signals to regulate antibiotic production and expr ... | 2004 | 14766576 |
| fluorescent amplified fragment length polymorphism analysis of bacillus anthracis, bacillus cereus, and bacillus thuringiensis isolates. | dna from over 300 bacillus thuringiensis, bacillus cereus, and bacillus anthracis isolates was analyzed by fluorescent amplified fragment length polymorphism (aflp). b. thuringiensis and b. cereus isolates were from diverse sources and locations, including soil, clinical isolates and food products causing diarrheal and emetic outbreaks, and type strains from the american type culture collection, and over 200 b. thuringiensis isolates representing 36 serovars or subspecies were from the u.s. depa ... | 2004 | 14766590 |
| conjugative transfer, stability and expression of a plasmid encoding a cry1ac gene in bacillus cereus group strains. | the plasmid pht73 containing cry1ac and tagged with an erythromycin resistance gene was transferred from bacillus thuringiensis subspecies kurstaki kt0 to several bacillus cereus group strains by conjugation. sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) and phase contrast microscopy showed that the transconjugants containing plasmid pht73 could express cry1ac toxin and produce bipyramidal crystalline inclusion bodies during sporulation. the study demonstrated that pht73 c ... | 2004 | 14769465 |
| fluorescent-based assays establish manduca sexta bt-r(1a) cadherin as a receptor for multiple bacillus thuringiensis cry1a toxins in drosophila s2 cells. | a fluorescence-based approach was developed to analyze in vivo the function of manduca sexta cadherin (bt-r(1)) as a cry1 toxin receptor. we cloned a bt-r(1a) cdna that differs from bt-r(1) by 37 nucleotides and two amino acids and expressed it transiently in drosophila melanogaster schneider 2 (s2) cells. cells expressing bt-r(1a) bound cry1aa, cry1ab, and cry1ac toxins on ligand blots, and in saturation binding assays. more cry1ab was bound relative to cry1aa and cry1ac, though each cry1a toxi ... | 2004 | 14871616 |
| the role of bacillus thuringiensis cry1c and cry1e separate structural domains in the interaction with spodoptera littoralis gut epithelial cells. | the bacillus thuringiensis delta-endotoxins cry1c and cry1e share toxicity against several important lepidopteran species. their combined use to delay development of resistance in target insects depends on their differential interaction with the gut epithelial cells. the three structural domains and combinations of two consecutive domains of cry1c and cry1e were separately expressed in escherichia coli, and their interactions with the brush border membrane vesicles (bbmv) of cry1e-tolerant and - ... | 2004 | 14963036 |
| gyrb as a phylogenetic discriminator for members of the bacillus anthracis-cereus-thuringiensis group. | bacillus anthracis, the causative agent of the human disease anthrax, bacillus cereus, a food-borne pathogen capable of causing human illness, and bacillus thuringiensis, a well-characterized insecticidal toxin producer, all cluster together within a very tight clade (b. cereus group) phylogenetically and are indistinguishable from one another via 16s rdna sequence analysis. as new pathogens are continually emerging, it is imperative to devise a system capable of rapidly and accurately different ... | 2004 | 14967230 |
| fate of maize intrinsic and recombinant genes in calves fed genetically modified maize bt11. | the presence of maize intrinsic and recombinant cry1ab genes in the gastrointestinal (gi) contents, peripheral blood mononuclear cells (pbmc), and visceral organs of calves fed genetically modified bt11 maize was examined by pcr in a subchronic 90-day performance study. samples were collected from six japanese black/holstein calves fed bt11 maize and from six calves fed non-bt maize. fragments of maize zein (ze1), invertase, chloroplast, and cry1ab were detected inconsistently in the rumen fluid ... | 2004 | 14968971 |