Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| [control of chironomids in water by immobilized bacillus thuringiensis var. israelensis de barjac]. | a strain from bacillus thuringiensis var. israelensis de barjac (b. t. i), having a fatal toxicity to chironomids, was immobilized in the pva-h3bo3 gel beads confected with a bit of sodium alginate and activated carbon. the result showed that optimal weight ratios were 10% pva, 1% sodium alginate and 20% activated carbon, respectively. when 4% calcium chloride saturated boric acid solution (ph=6.7) was used as gelatin agent for gelating 24 h, the produced gel beads had good performance in mechan ... | 2004 | 15623035 |
| [expression and root exudation of cry1ab toxin protein in cry1ab transgenic rice and its residue in rhizosphere soil]. | the expression and root exudation of cry1ab toxin protein in cry1ab transgenic rice (kmd) and its residue in rhizosphere soil were investigated. the results showed that content of cry1ab toxin protein in the shoot and root of kmd were 3.23-8.22 and 0.68-0.89 microg/g from early tillering to maturing stage, respectively. the content of the cry1ab toxin proteins via root exudation were 1.66-48.02 ng/(individual x d) at that phase. the results also demonstrated that the residue of the cry1ab toxin ... | 2004 | 15623037 |
| comparison of broiler chicken performance when fed diets containing meals of bollgard ii hybrid cotton containing cry-x gene (cry1ac and cry2ab gene), parental line or commercial cotton. | (1) total and free gossypol contents were 6.2 and 0.8, 5.4 and 0.5, and 6.1 and 0.7 g/kg in meals processed (solvent extracted) from bollgard (bg) ii, non-bg ii or commercial cottonseeds, respectively. (2) broiler chicks were given one of 7 dietary treatments (iso-nitrogenous, 220 and 195 g crude protein/ kg diet at 0 to 21 and 21 to 42 d, respectively, at a metabolisable energy concentration of 12.15 mj/kg). the treatments were: d1 (control, soybean meal [sbm] based), d2 and d3 (commercial csm ... | 2004 | 15623220 |
| [photosynthetic characters and bt toxin content of different transgenic bt cottons]. | the study on the photosynthetic characters and bt toxin content of different bt cottons (zk, gk) and non-bt cotton (cz) indicated that bt cottons gk and zk had different total expressed amount of bt toxin and its distribution in different tissues. the bt cottons had obviously different chlorophyll contents, responses of photosynthetic rate to photosynthetic active radiation, and diurnal changes of photosynthetic rate and transpiration rate, but the diurnal change of leaf temperature, co2 concent ... | 2004 | 15624827 |
| cloning and localization of vip3a gene of bacillus thuringiensis. | an insecticidal protein gene, vip3a, was cloned from bacillus thuringiensis strain wb50. the nucleotide sequence of 2,460 bp (genbank acc. no. ay295778) showed 99% homology with the known vip3a genes. using specific primers for vip3a gene, pcr was performed to demonstrate that the gene was not located on the bacterial chromosome and this was confirmed by southern blotting using an internal fragment (486 bp) from vip3a gene as a probe. the gene was carried on a plasmid of 31.8 kb. | 2004 | 15604775 |
| cloning, characterization and expression of a new cry 1ab gene from bacillus thuringiensis wb9. | a new cry 1ab-type gene, cry 1ab17, was cloned from bacillus thuringiensis wb9 by pcr. nucleotide sequence indicated that the open reading frames (orfs) consists of 3471 bases and encodes a protein of 1156 residues with a calculated molecular weight of 130.5 kda and an pi value of 5.04. homology comparison revealed that the deduced amino acid sequence of cry1ab17 had 95.4% to 99.7% identity with those of the known cry1ab proteins. the cry1ab17 was one residue longer than the known cry1ab (except ... | 2004 | 15604796 |
| genome update: promoter profiles. | 2004 | 15347738 | |
| patch-clamp study of the apical membrane of the midgut of manduca sexta larvae: direct demonstration of endogenous channels and effect of a bacillus thuringiensis toxin. | the patch-clamp technique was applied to the apical membrane of epithelial midgut cells of a lepidoptera, manduca sexta l. access to the apical membrane, the main target site of bacillus thuringiensis (bt) toxins, was achieved by using freshly isolated larval midgut preparations mounted onto holding glass pipettes. the epithelial cells retained their functional integrity, as evidenced by the magnitude of intracellular potentials recorded with microelectrodes. with standard 32 mm k(+) solution in ... | 2004 | 15350500 |
| laboratory and field evaluation of teknar hp-d, a biolarvicidal formulation of bacillus thuringiensis ssp. israelensis, against mosquito vectors. | larvicidal efficacy of teknar hp-d, an improved biolarvicidal formulation of bacillus thuringiensis ssp. israelensis (bti), against anopheles stephensi, culex quinquefasciatus and aedes aegypti was determined in the laboratory, and in field the efficacy of the formulation was tested against cx. quinquefasciatus breeding in cesspits, unused wells and drains. the toxicity of the formulation to gambusia affinis (larvivorous fish), notonecta sp. and diplonychus indicus (water bugs) was also evaluate ... | 2004 | 15350862 |
| binding analyses of cry1ab and cry1ac with membrane vesicles from bacillus thuringiensis-resistant and -susceptible ostrinia nubilalis. | the binding properties of bacillus thuringiensis toxins to brush border membrane vesicles of dipel-resistant and -susceptible ostrinia nubilalis larvae were compared using ligand-toxin immunoblot analysis, surface plasmon resonance (spr), and radiolabeled toxin binding assays. in ligand-toxin immunoblot analysis, the number of cry1ab or cry1ac toxin binding proteins and the relative toxin binding intensity were similar in vesicles from resistant and susceptible larvae. surface plasmon resonance ... | 2004 | 15351700 |
| inheritance of gfp-bt transgenes from brassica napus in backcrosses with three wild b. rapa accessions. | transgenes from transgenic oilseed rape, brassica napus (aacc genome), can introgress into populations of wild b. rapa (aa genome), but little is known about the long-term persistence of transgenes from different transformation events. for example, transgenes that are located on the crop's c chromosomes may be lost during the process of introgression. we investigated the genetic behavior of transgenes in backcross generations of wild b. rapa after nine gfp (green fluorescent protein)-bt (bacillu ... | 2004 | 15612354 |
| monitoring the impact of bt maize on butterflies in the field: estimation of required sample sizes. | the monitoring of genetically modified organisms (gmos) after deliberate release is important in order to assess and evaluate possible environmental effects. concerns have been raised that the transgenic crop, bt maize, may affect butterflies occurring in field margins. therefore, a monitoring of butterflies was suggested accompanying the commercial cultivation of bt maize. in this study, baseline data on the butterfly species and their abundance in maize field margins is presented together with ... | 2004 | 15612355 |
| hybridization and backcrossing between transgenic oilseed rape and two related weed species under field conditions. | determining the frequency of crop-wild transgene flow under field conditions is a necessity for the development of regulatory strategies to manage transgenic hybrids. gene flow of green fluorescent protein (gfp) and bacillus thuringiensis (bt) transgenes was quantified in three field experiments using eleven independent transformed brassica napus l. lines and the wild relatives, b. rapa l. and raphanus raphanistrum l. under a high crop to wild relative ratio (600:1), hybridization frequency with ... | 2004 | 15612504 |
| characterization of cry34ab1 and cry35ab1 insecticidal crystal proteins expressed in transgenic corn plants and pseudomonas fluorescens. | cry34ab1 and cry35ab1 proteins, identified from bacillus thuringiensis strain ps149b1, act together to control corn rootworms. transgenic corn lines coexpressing the two proteins were developed to protect corn against rootworm damage. large quantities of the two proteins were needed to conduct studies required for assessing the safety of this transgenic corn crop. because it was technically infeasible to obtain sufficient quantities of high purity cry34ab1 and cry35ab1 proteins from the transgen ... | 2004 | 15612796 |
| evaluation of broiler performance when fed insect-protected, control, or commercial varieties of dehulled soybean meal. | we evaluated the nutritional value of broiler diets containing approximately 35% soybean meal from insect-protected soybean containing crylac protein, or from a similar nontransgenic control, or from 7 reference commercial soybean varieties. the feeding trial lasted 41 d, and each treatment consisted of 10 replicates of 1-d-old ross 508 broilers (5 pens males and 5 pens females). each pen contained 12 birds, and at d 13, birds were randomly removed until 9 birds remained. body weight and feed in ... | 2004 | 15615017 |
| boiling and bacillus spores. | 2004 | 15515252 | |
| the hevcalp protein mediates binding specificity of the cry1a class of bacillus thuringiensis toxins in heliothis virescens. | retrotransposon-mediated disruption of the btr-4 gene encoding the heliothis virescens cadherin-like protein (hevcalp) is linked to high levels of resistance in the yhd2 strain to cry1ac toxin from bacillus thuringiensis. this suggests that hevcalp functions as a cry1ac toxin receptor on the surface of midgut cells in susceptible larvae and that the btr-4 gene disruption eliminates this protein in resistant larvae. however, cry1ac toxin binding to hevcalp is yet to be reported. we used the polym ... | 2004 | 15518581 |
| dna-based detection of bt resistance alleles in pink bollworm. | evolution of resistance by pests is the main threat to long-term insect control by transgenic crops that produce bacillus thuringiensis (bt) toxins. we previously identified three mutant alleles (r1, r2, r3) of a cadherin gene in pink bollworm (pectinophora gossypiella) linked with recessive resistance to bt toxin cry1ac and survival on transgenic bt cotton. here we describe a polymerase chain reaction (pcr)-based method that detects the mutation in genomic dna of each of the three resistant all ... | 2004 | 15522618 |
| antimicrobial effect of water extract of sumac (rhus coriaria l.) on the growth of some food borne bacteria including pathogens. | the antimicrobial effect of water extracts of sumac (rhus coriaria l.) at concentrations of 0.1%, 0.5%, 1.0%, 2.5% and 5.0% (w/v), non-neutralized and after neutralization to ph 7.2+/-0.1, was studied on the growth of 12 bacterial strains (six gram positive strains and six gram negative strains), mostly food borne including pathogens. it was found to be effective against all the test organisms with gram positive strains being more sensitive than gram negative strains. significant differences (p< ... | 2004 | 15527919 |
| display of biologically functional insecticidal toxin on the surface of lambda phage. | the successful use of bacillus thuringiensis insecticidal toxins to control agricultural pests could be undermined by the evolution of insect resistance. under selection pressure in the laboratory, a number of insects have gained resistance to the toxins, and several cases of resistance in the diamondback moth have been reported from the field. the use of protein engineering to develop novel toxins active against resistant insects could offer a solution to this problem. the display of proteins o ... | 2004 | 15528522 |
| capacity of bacillus thuringiensis s-layer protein displaying polyhistidine peptides on the cell surface. | s-layer protein of bacillus thuringiensis strain ctc was used as the carrier protein to display polyhistidine (poly[6his]) peptides on the cell surface. poly(6his)n was fused with s-layer protein at two different sites, inserting just downstream of the s-layer protein homologous domain (slh) and replacing the non-slh region of s-layer protein, respectively. the two series chimeric proteins were both expressed by crystal negative b. thuringiensis strain 4q7 and strain 171, respectively, as shown ... | 2004 | 15531784 |
| larvicidal persistence of formulations of bacillus thuringiensis var. israelensis to control larval aedes aegypti. | after detection of resistance to the organophosphate temephos in populations of aedes aegypti in brazil, corncob granule (cg) and water-dispersible granule (wdg) formulations of bacillus thuringiensis var. israelensis (bti) were introduced in routine focal treatments. larvicidal persistence and the influence of exposure to sunlight on vectobac formulations of bti were compared in 250-liter fiberglass water containers. production of pupal ae. aegypti in containers was used to indicate control. in ... | 2004 | 15532933 |
| oligomerization triggers binding of a bacillus thuringiensis cry1ab pore-forming toxin to aminopeptidase n receptor leading to insertion into membrane microdomains. | bacillus thuringiensis cry1a toxins, in contrast to other pore-forming toxins, bind two putative receptor molecules, aminopeptidase n (apn) and cadherin-like proteins. here we show that cry1ab toxin binding to these two receptors depends on the toxins' oligomeric structure. toxin monomeric structure binds to bt-r1, a cadherin-like protein, that induces proteolytic processing and oligomerization of the toxin (gomez, i., sanchez, j., miranda, r., bravo a., soberon, m., febs lett. (2002) 513, 242-2 ... | 2004 | 15533304 |
| expression of vip1/vip2 genes in escherichia coli and bacillus thuringiensis and the analysis of their signal peptides. | to determine the expression time courses and high expression level of vip2a(c) and vip1a(c) in bacillus thuringiensis, and survey their insecticidal toxicity and insecticidal spectrum. | 2004 | 15357725 |
| modeling the invasion of recessive bt-resistant insects: an impact on transgenic plants. | there is a growing public concern on ecological and evolutionary consequence of the use of genetically modified organisms. we study the impact of bt-resistant pests on genetically modified bt crops. we develop and analyse a conceptual reaction-diffusion model of the bt crop-bt-susceptible insects-bt-resistant insects to simulate the invasion of bt-resistant insects. we show by means of computer simulations that there is a key parameter, which we define as the growth number that characterizes the ... | 2004 | 15363934 |
| ige sensitization to bacterial and fungal biopesticides in a cohort of danish greenhouse workers: the biogart study. | the use of biopesticides in agriculture may implicate new risks of work-related allergic reactions. | 2004 | 15376210 |
| a novel bacillus thuringiensis (ps149b1) containing a cry34ab1/cry35ab1 binary toxin specific for the western corn rootworm diabrotica virgifera virgifera leconte forms ion channels in lipid membranes. | the binary bacillus thuringiensis ps149b1 insecticidal crystal (cry) protein is comprised of two components, cry34ab1, a 14-kda protein, and cry35ab1, a 44-kda protein, the combination of which forms a novel binary toxin active on western corn rootworm larvae. the permeabilizing behavior of the native binary toxin and its two individual components expressed as recombinant proteins was studied using calcein efflux determination in liposomes and by ion channel activity measurements in planar lipid ... | 2004 | 15379574 |
| rapid report acetamiprid resistance and cross-resistance in the diamondback moth, plutella xylostella. | a 110-fold acetamiprid-resistant plutella xylostella (l) strain was established after four selection experiments (in five generations) on a 9.5-fold resistant colony in the laboratory. the resistant strain did not show cross-resistance to chlorfluazuron or bacillus thuringiensis subsp kurstaki berliner, but displayed low resistance to cartap and phenthoate. | 2004 | 15382497 |
| selection and heritability of resistance to bacillus thuringiensis subsp kurstaki and transgenic cotton in helicoverpa armigera (lepidoptera: noctuidae). | compared with an unselected susceptible population, a cotton bollworm, helicoverpa armigera (hübner), population selected for 22 generations with transgenic cotton leaves (modified cry1a) in the laboratory developed 11.0-fold resistance to cry1ac (one single-protein product mvpii). resistance to bacillus thuringiensis berliner subsp kurstaki (btk) was selected for 22 generations with a 5.2-fold increase in lc50. the estimated realized heritabilities (h2) of resistance for transgenic-cotton- and ... | 2004 | 15382503 |
| growth, development, and survival of nosema pyrausta-infected european corn borers (lepidoptera: crambidae) reared on meridic diet and cry1ab. | transgenic corn, zea mays l., hybrids expressing crystal protein endotoxin genes from bacillus thuringiensis berliner are an increasingly popular tactic for managing the european corn borer, ostrinia nubilalis (hübner), in north america. o. nubilalis populations also are often vulnerable to the ubiquitous entomopathogenic microsporidium nosema pyrausta (paillot). we examined the effect of feeding meridic diet incorporated with purified cry1ab on growth, development, and survival of nosema-infect ... | 2004 | 15384327 |
| effects of insect population size on evolution of resistance to transgenic crops. | models of the evolution of insect resistance to transgenic crops have often assumed that population size is infinite or that carrying capacity is fixed. to evaluate potential effects of population size on resistance evolution, we conducted sensitivity analyses by using a stochastic, spatially explicit model based partly on the interaction between pink bollworm and bacillus thuringiensis (bt) cotton. we examined interactions of carrying capacity, region size, dispersal, and percentage of fields p ... | 2004 | 15384355 |
| field and storage testing bt potatoes for resistance to potato tuberworm (lepidoptera: gelichiidae). | potato tuberworm, phthorimaea operculella (zeller), is the most serious insect pest of potatoes worldwide. the introduction of the bacillus thuringiensis (bt) toxin gene through genetic engineering offers host plant resistance for the management of potato tuberworm. we report on the field and storage studies to evaluate bt-cry5 potato lines for resistance to potato tuberworm in egypt under natural infestations and their agronomic performance in both egypt and michigan. from 1997 to 2001, field e ... | 2004 | 15384356 |
| a spontaneous translational fusion of bacillus cereus plcr and papr activates transcription of plcr-dependent genes in bacillus anthracis via binding with a specific palindromic sequence. | transformation of bacillus anthracis with plasmid pute29-plcr-papr carrying the native bacillus cereus plcr-papr gene cluster did not activate expression of b. anthracis hemolysin genes, even though these are expected to be responsive to activation by the global regulator plcr. to further characterize the action of plcr, we examined approximately 3,000 b. anthracis transformants containing pute29-plcr-papr and found a single hemolytic colony. the hemolytic strain contained a plasmid having a spo ... | 2004 | 15385482 |
| crystal structures and electron micrographs of fungal volvatoxin a2. | membrane adhesion and insertion of protein are essential to all organisms, but the underlying mechanisms remain largely unknown. membrane pore-forming toxins (pfts) are potential model systems for studying these mechanisms. we have determined the crystal structures of volvatoxin a2 (vva2), a fungal pft from volvariella volvacea, using br-multiple-wavelength anomalous diffraction (mad). the vva2 structures obtained at ph 4.6, ph 5.5 and ph 6.5 were refined to resolutions of 1.42 a, 2.6 a and 3.2 ... | 2004 | 15451675 |
| synergy between toxins of bacillus thuringiensis subsp. israelensis and bacillus sphaericus. | synergistic interactions among the multiple endotoxins of bacillus thuringiensis subsp. israelensis de barjac play an important role in its high toxicity to mosquito larvae and the absence of insecticide resistance in populations treated with this bacterium. a lack of toxin complexity and synergism are the apparent causes of resistance to bacillus sphaericus neide in particular culex field populations. to identify endotoxin combinations of the two bacillus species that might improve insecticidal ... | 2004 | 15535624 |
| insecticide resistance in alabama and florida mosquito strains of aedes albopictus. | the susceptibility of four strains of aedes albopictus (skuse) to permethrin, deltamethrin, resmethrin, chlorpyrifos, malathion, propoxur, fipronil, imidacloprid, spinosad, and bacillus thuringiensis variety israelensis (bti) was determined. the hamaal and mamaal strains were collected in 2002 and 2003, respectively, from huntsville and mobile, al, and the vbfmaal and sfmaal strains were collected in 1998 from vero beach and southern florida, respectively. the hamaal strain showed a 22-fold elev ... | 2004 | 15535626 |
| bollgard ii cotton: compositional analysis and feeding studies of cottonseed from insect-protected cotton (gossypium hirsutum l.) producing the cry1ac and cry2ab2 proteins. | bollgard ii cotton event 15985 producing the cry1ac and cry2ab2 proteins has been developed by genetic modification to broaden the spectrum of insects to which the plant is tolerant and to provide an insect resistance management tool to impede the onset of resistance. the purpose of this study was to evaluate the composition and nutrition of bollgard ii cotton, relative to the use for food and animal feed, compared to that of conventional cotton varieties. compositional analyses were conducted t ... | 2004 | 15537305 |
| histopathological and ultrastructural effects of delta-endotoxins of bacillus thuringiensis serovar israelensis in the midgut of simulium pertinax larvae (diptera, simuliidae). | the bacterium bacillus thuringiensis (bt) produces parasporal crystals containing delta-endotoxins responsible for selective insecticidal activity on larvae. upon ingestion, these crystals are solubilized in the midgut lumen and converted into active toxins that bind to receptors present on the microvilli causing serious damage to the epithelial columnar cells. we investigated the effect of these endotoxins on larvae of the simulium pertinax, a common black fly in brazil, using several concentra ... | 2004 | 15543412 |
| population structure and evolution of the bacillus cereus group. | representative strains of the bacillus cereus group of bacteria, including bacillus anthracis (11 isolates), b. cereus (38 isolates), bacillus mycoides (1 isolate), bacillus thuringiensis (53 isolates from 17 serovars), and bacillus weihenstephanensis (2 isolates) were assigned to 59 sequence types (sts) derived from the nucleotide sequences of seven alleles, glpf, gmk, ilvd, pta, pur, pyca, and tpi. comparisons of the maximum likelihood (ml) tree of the concatenated sequences with individual ge ... | 2004 | 15547268 |
| detection and identification of bacteria in a juice matrix with fourier transform-near infrared spectroscopy and multivariiate analysis. | the use of fourier transform-near infrared (ft-nir) spectroscopy combined with multivariate pattern recognition techniques was evaluated to address the need for a fast and senisitive method for the detection of bacterial contamination in liquids. the complex cellular composition of bacteria produces ft-nir vibrational transitions (overtone and combination bands), forming the basis for identification and subtyping. a database including strains of escherichia coli, pseudomonas aeruginosa, bacillus ... | 2004 | 15553641 |
| identification, distribution pattern of is231 elements in bacillus thuringiensis and their phylogenetic analysis. | in order to better understand the fundamental biology of bacillus thuringiensis, a single oligonucleotide primer (5'-catssccatcaasytaavr-3') was used to investigate the distribution pattern of is231 elements in b. thuringiensis by pcr. the results indicated that is231 elements appeared in 20 standard strains and 107 of 111 china isolates. three novel is231, is231j, is231o and is231q, five variants and a mobile insertion cassette micbth4 were cloned from eight standard strains of b. thuringiensis ... | 2004 | 15556706 |
| plant-incorporated bacillus thuringiensis resistance for control of fall armyworm and corn earworm (lepidoptera: noctuidae) in corn. | fall armyworm, spodoptera frugiperda (j.e. smith), and corn earworm, helicoverpa zea (boddie), perennially cause leaf and ear damage to corn, zea mays l., in the southeastern united states. transgenic bacillus thuringiensis (bt) hybrids with the bt11, mon810, or 176 events expressing the cry1ab insecticidal endotoxin from were evaluated for control fall armyworm and corn earworm at seven locations in georgia during 1999 and 2000. corn was planted at the recommended time for each location and 1 a ... | 2004 | 15568349 |
| bacillus thuringiensis subsp. kurstaki aerial spray prescriptions for balsam fir stand protection against spruce budworm (lepidoptera: tortricidae). | although commercial formulations of bacillus thuringiensis subsp. kurstaki (btk) are being widely used in forest protection against lepidopteran defoliators, optimal application prescriptions have often yet to be worked out in detail. we conducted field experiments over a 6-yr period (1996-2001) in southwestern québec to determine application prescriptions for optimal protection of balsam fir, abies balsamea (l.), healthy stands against the spruce budworm, choristoneura fumiferana (clemens) (lep ... | 2004 | 15568352 |
| relative fitness of cry1a-resistant and -susceptible helicoverpa armigera (lepidoptera: noctuidae) on conventional and transgenic cotton. | glasshouse and laboratory experiments were conducted to evaluate the relative fitness of cry1a-susceptible and laboratory-selected resistant strains of helicoverpa armigera (hübner). life history parameters of h. armigera larvae feeding on young cotton plants showed a significant developmental delay of up to 7 d for the resistant strain compared with the susceptible strain on non-bacillus thuringiensis (bt) cotton. this fitness cost was not evident on artificial diet. there was no developmental ... | 2004 | 15568362 |
| effects of gossypol on fitness costs associated with resistance to bt cotton in pink bollworm. | fitness costs associated with insect resistance to bacillus thuringiensis (bt) crops may help to delay or prevent the spread of resistance alleles, especially when refuges of non-bt host plants are present. the potential for such delays increases as the magnitude and dominance of fitness costs increase. here, we examined the idea that plant secondary chemicals affect expression of fitness costs associated with resistance to bt cotton in pectinophora gossypiella (saunders). specifically, we teste ... | 2004 | 15568363 |
| comparative production of helicoverpa zea (lepidoptera: noctuidae) from transgenic cotton expressing either one or two bacillus thuringiensis proteins with and without insecticide oversprays. | transgenic cotton, gossypium hirsutum (l.), expressing either one or two bacillus thuringiensis ssp. kurstaki berliner (bt) proteins was compared with the conventional sister line in field experiments with regard to production of bollworm, helicoverpa zea (boddie), and bolls damaged by bollworm. the relative numbers of bollworms that developed on bollgard (monsanto co., st. louis, mo), bollgard ii (monsanto co.), and conventional cotton were estimated under nontreated conditions in 2000 and both ... | 2004 | 15568364 |
| relative concentration of cry1a in maize leaves and cotton bolls with diverse chlorophyll content and corresponding larval development of fall armyworm (lepidoptera: noctuidae) and southwestern corn borer (lepidoptera: crambidae) on maize whorl leaf profiles. | to manage insect resistance to transgenic crops that express insecticidal proteins from bacillus thuringiensis (bt) berliner, the u.s. environmental protection agency recommends a refuge-based insect resistance management strategy where a percentage of non-bt (refuge) crop is grown in proximity to a bt-expressing crop. an important requirement for this strategy is that the toxin exists at a high effective dose for control of the target pest(s), so that heterozygous individuals in the population ... | 2004 | 15568367 |
| flocculation of cellular suspensions by polyelectrolytes. | the regularities, kinetics and mechanisms of flocculation of escherichia coli and b. thuringiensis var. israelensis (bti) cellular suspensions by water-soluble polymers-and first of all cationic polyelectrolytes of different charge density and stiffness of the macromolecule chain have been investigated. the effect of the focculant dose and nature, its charge density, the hydrophobic-hydrophilic balance in macromolecule, the suspension concentration, the mode of adding the reagent, the ph and the ... | 2004 | 15571665 |
| single amino acid mutations in the cadherin receptor from heliothis virescens affect its toxin binding ability to cry1a toxins. | bacillus thuringiensis cry protein exerts its toxic effect through a receptor-mediated process. both aminopeptidases and cadherin proteins were identified as putative cry1a receptors from heliothis virescens and manduca sexta. the importance of cadherin was implied by its correlation with a cry1ac resistant h. virescens strain (gahan, l. j., gould, f., and heckel, d. g. (2001) science 293, 857-860). in this study, the cry1ac toxin-binding region in h. virescens cadherin was mapped to a 40-amino- ... | 2004 | 15572369 |
| genetic and biochemical characterization of field-evolved resistance to bacillus thuringiensis toxin cry1ac in the diamondback moth, plutella xylostella. | the long-term usefulness of bacillus thuringiensis cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. managing the evolution of resistance to b. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. to date, laboratory-selected populations have provided information on the diverse genetics and mechanisms of resistance to b. thuringiensis, highly resistant field popul ... | 2004 | 15574894 |
| activity of gut proteinases from cry1ab-selected colonies of the european corn borer, ostrinia nubilalis (lepidoptera: crambidae). | susceptibility to the cry1ab protoxin and toxin from bacillus thuringiensis (berliner) and activity of gut proteinases were assessed in both susceptible and cry1ab-selected colonies of european corn borer, ostrinia nubilalis (hubner). resistance in two different selected colonies was at least 6- and 15-fold for the cry1ab protoxin and 108- and 484-fold for the cry1ab toxin. activities of trypsin-like, chymotrypsin-like and elastase-like proteinases were variable among the colonies tested and not ... | 2004 | 15578599 |
| the development of the endoparasitoid venturia canescens in bt-tolerant, immune induced larvae of the flour moth ephestia kuehniella. | we examined the survival and development of the endoparasitoid venturia canescens in a bt-tolerant laboratory strain of the flour moth ephestia kuehniella, in which bt-tolerance has been shown to be associated with an inducible elevation of the insect's immune response. the results indicate the elevated immune status associated with bt-tolerance does not confer cross-protection against parasitism by v. canescens. no significant difference was observed in the rate of emergent wasps from parasitis ... | 2004 | 15579322 |
| development of sludge based stable aqueous bacillus thuringiensis formulations. | this study focuses on development of aqueous flowable (suspension) formulations for bacillus thuringiensis (bt) based biopesticides from wastewater sludge. different inerts like sorbitol, sodium monophosphate, sodium metabisulphite, sorbic acid, propionic acid, tween-80, triton x-100 and glycerol were tested for formulations. five different formulations for non-hydrolyzed (nh) secondary sludges were tried and the best combination selected on the basis of various physical parameters like viscosit ... | 2004 | 15581017 |
| glycoconjugates for the recognition of bacillus spores. | carbohydrates act as ligands in many biological processes, including the folding and secretion of proteins, cell-cell recognition, adhesion, and sporulation in the bacillus genus. fluorescent-labeled disaccharide glycoconjugates have been applied to evaluate binding to bacterial spores assuming that the spore surface is covered with carbohydrates. this study has shown that specific recognition of bacterial spores is based on interactions between disaccharide glycoconjugates acting as ligands and ... | 2004 | 15582612 |
| crystallization of parasporin-2, a bacillus thuringiensis crystal protein with selective cytocidal activity against human cells. | bacillus thuringiensis is a valuable source of protein toxins that are specifically effective against certain insects and worms but harmless to mammals. in contrast, a protein toxin obtained from b. thuringiensis strain a1547, designated parasporin-2, is not insecticidal but has a strong cytocidal activity against human cells with markedly divergent target specificity. the 37 kda inactive protein is proteolytically activated to a 30 kda active form. the active form of the recombinant protein tox ... | 2004 | 15583389 |
| development of a hybrid delta-endotoxin and its expression in tobacco and cotton for control of a polyphagous pest spodoptera litura. | a hybrid delta-endotoxin protein was designed against a polyphagous lepidopteran insect pest spodoptera litura, which is tolerant to most of the known delta-endotoxins. the hybrid delta-endotoxin was created by replacing amino acid residues 530-587 in a poorly active natural cry1ea protein, with a highly homologous 70 amino acid region of cry1ca in domain iii. the truncated delta-endotoxins cry1ea, cry1ca and the hybrid protein cry1ec accumulated in escherichia coli to form inclusion bodies. the ... | 2004 | 15587265 |
| [response of parasitic wasps of cotton bollworm to different cotton varieties with transgenic bacillus thringienthsis genes]. | the relationship between the parasitic wasp population number of cotton bollworm (helicoverpa armigera) and the varieties of cotton was studied by releasing and collecting the eggs and larvae of cotton bollworm on transgenic and non-transgenic cottons. the research results from 2000 to 2003 showed that the parasitic rates of the eggs and larvae of cotton bollworm were notably lower in transgenic cotton field than in non-transgenic cotton field. at the same time, the effect of transgenic and non- ... | 2004 | 15320406 |
| mutations in the bacillus thuringiensis cry1ca toxin demonstrate the role of domains ii and iii in specificity towards spodoptera exigua larvae. | several mutants of the bacillus thuringiensis cry1ca toxin affected with regard to specific activity towards spodoptera exigua were studied. alanine was used to replace single residues in loops 2 and 3 of domain ii (mutant ppb19) and to replace residues 541-544 in domain iii (mutant ppb20). additionally, a cry1ca mutant combining all mutations was constructed (mutant ppb21). toxicity assays showed a marked decrease in toxicity against s. exigua for all mutants, while they retained their activity ... | 2004 | 15320864 |
| the bacillus thuringiensis phage gil01 encodes two enzymes with peptidoglycan hydrolase activity. | bacteriophage gil01, infecting bacillus thuringiensis serovar israelensis, possesses a linear dsdna genome of 14,931 bp with proteins attached to its 5' extremities and terminal inverted repeats at both ends. viral particles are sensitive to organic solvents, suggesting that a lipid membrane is present in the capsid. all these characteristics are reminiscent of those found in members of the tectiviridae family. sequence analysis of gil01 revealed the presence of two open reading frames (orf25 an ... | 2004 | 15321675 |
| population structure of the bacillus cereus group as determined by sequence analysis of six housekeeping genes and the plcr gene. | the population structure of the bacillus cereus group (52 strains of b. anthracis, b. cereus, and b. thuringiensis) was investigated by sequencing seven gene fragments (rpob, gyrb, pyca, mdh, mbl, muts, and plcr). most of the strains were classifiable into two large subgroups in six housekeeping gene trees but not in the plcr tree. in addition, several consistent clusters were identified, which were unrelated to species distinction. moreover, interrelationships among these clusters were incongru ... | 2004 | 15322020 |
| [characterization of resistant cell line of trichoplusia ni to bacillus thuringiensis toxin cry1ac]. | the cell line (bti-tn-5b1-4) of trichoplusia ni had been selected by bacilllus thuringiensis (bt) toxin cry1ac for 86 generations continuously. a high level of resistance was achieved and the partial characterizations of the resistance-selected bti-tn-5b1-4 cells were studied in order to explore the mechanism of the resistance to bt toxin. the cells selected by cry1ac had low level of cross-resistance (19.7 fold) to cry1c, their ability of tolerance in the hypotonic solution increased evidently ... | 2004 | 15323422 |
| micropatterns of spores displaying heterologous proteins. | micropatterns of bacillus thuringiensis spores were generated by a combination of surface chemistry, microcontact printing, and spore surface display technique. the outermost layers of b. thuringiensis spores were engineered to present enhanced green fluorescent protein (egfp), and the biospecific interaction between biotin and streptavidin was utilized to spatially direct the egfp-presenting spores onto the micropatterned surfaces. the viability of the micropatterned spores was confirmed by the ... | 2004 | 15327288 |
| lethality of chlorine, chlorine dioxide, and a commercial fruit and vegetable sanitizer to vegetative cells and spores of bacillus cereus and spores of bacillus thuringiensis. | chlorine, clo2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of bacillus cereus and spores of bacillus thuringiensis. the ultimate goal was to use one or both species as a potential surrogate(s) for bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. treatment with alkaline (ph 10.5 to 11.0) clo2 (200 microg/ml) produced by ... | 2004 | 15330537 |
| cloning, sequencing, and sequence analysis of two novel plasmids from the thermophilic anaerobic bacterium anaerocellum thermophilum. | the nucleotide sequence of two novel plasmids isolated from the extreme thermophilic anaerobic bacterium anaerocellum thermophilum dsm6725 (a. thermophilum), growing optimally at 70 degrees c, has been determined. pbas2 was found to be a 3653 bp plasmid with a gc content of 43%, and the sequence revealed 10 open reading frames (orfs). the two largest of these, namely orf21 and orf41, showed similarity to a bacillus plasmid recombinase and a pseudoalteromonas plasmid replication protein, respecti ... | 2004 | 15336490 |
| transgenic insect-resistant corn affects the fourth trophic level: effects of bacillus thuringiensis-corn on the facultative hyperparasitoid tetrastichus howardi. | as hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of bacillus thuringiensis-plants ("bt-plants") on hyperparasitoids is of interest. laboratory-scale experiments were conducted in order to assess the potential effect of bt-corn leaf material on the facultative hyperparasitoid tetrastichus howardi (olliff) (hymenoptera: eulophidae), mediated through the herbivore chilo partellus swinhoe (lepidoptera: crambidae) and i ... | 2004 | 15338032 |
| new qualitative detection methods of genetically modified potatoes. | in japan, 8 lines of genetically modified (gm) potato (2 lines of newleaf potato; nl, 3 lines of newleaf plus potato; nlp, and 3 lines of newleaf y potato; nly) have already been authorized as safe for use in foods and feeds. we have developed polymerase chain reaction (pcr) methods for the qualitative detection of the gm potatoes for the screening and the identification of nl, nlp and nly. the gene encoding uridine diphosphate (udp)-glucose pyrophosphorylase (ugpase) was used as a taxon specifi ... | 2004 | 15340215 |
| impact of ecological factors on the initial invasion of bt transgenes into wild populations of birdseed rape (brassica rapa). | the inevitable escape of transgenic pollen from cultivated fields will lead to the emergence of transgenic crop-wild plant hybrids in natural patches of wild plants. the fate of these hybrids and that of the transgene depend on their ability to compete with their wild relatives. here we study ecological factors that may enhance the fitness of genetically modified hybrids relative to wild plants for a bacillus thuringiensis ( bt) transgene conferring resistance to insects. mixed stands of wild pl ... | 2004 | 15340690 |
| [susceptibility of archaea to the antibiotic effect of the parasporal inclusion proteins from bacillus thuringiensis subspecies]. | the proteins of parasporal inclusions from three bacillus thuringiensis subspecies (kurstaki, amagiensis, and monterrey) inhibited growth of methanogenic archaea of two species belonging to two genera, methanobrevibacter arboriphilus and methanosarcina barkeri. the minimal inhibitory concentrations of these proteins were 20 to 50 micrograms/ml. lysozyme exhibited similar bactericidal effect on archaea. the perspective of comparative studies on the effect of polyfunctional proteins on bacteria an ... | 2004 | 15074036 |
| trp132, trp154, and trp157 are essential for folding and activity of a cyt toxin from bacillus thuringiensis. | cyt2aa2 is a cytolytic and mosquito larvicidal toxin produced by bacillus thuringiensis subsp. darmstadiensis. the toxin contains 3 tryptophan residues at positions 132, 154, and 157. to study the role of tryptophan on protein structure and functions, each tryptophan residue was substituted by phenylalanine and other different amino acids. expression test in escherichia coli showed that all mutant proteins were highly produced as inclusion bodies similar to that of the wild type. the mutant w157 ... | 2004 | 15081403 |
| procedures for the evaluation of field efficacy of slow-release formulations of larvicides against aedes aegypti in water-storage containers. | in thailand, water-storage jars, barrels, drums, pails, and tanks constitute vast developmental sites for aedes aegypti in urban, semiurban, and rural areas. earthen water jars, cement jars, and concrete tanks constitute the greatest proportion of artificial containers where ae. aegypti breed. this species is a major vector of the causal agents of dengue and dengue hemorrhagic fever, and vector control by larviciding is one of the main approaches to disease control. at present, temephos sand gra ... | 2004 | 15088706 |
| molecular characterization of bacillus thuringiensis strains from argentina. | bacillus thuringiensis inta 7-3, inta 51-3, inta mo9-5 and inta mo14-4 strains were obtained from argentina and characterized by determination of serotype, toxicity, plasmid composition, insecticidal gene content ( cry and vip ) and the cloning of the single- vip3a gene of the inta mo9-5 strain. the serotype analysis identified the serovars tohokuensis and darmstadiensis for the inta 51-3 and inta mo14-4 strains, respectively, whereas the inta mo9-5 strain was classified as "autoagglutinated". i ... | 2004 | 15103240 |
| improving the insecticidal activity of bacillus thuringiensis subsp. aizawai against spodoptera exigua by chromosomal expression of a chitinase gene. | a transcriptionally fused gene comprising the p19 gene from bacillus thuringiensis subsp. israelensis fused with a chitinase gene (chibla) from b. licheniformis was integrated into the b. thuringiensis subsp. aizawai bta1 genome by homologous recombination. the resulting b. thuringiensis subsp. aizawai strain (int1) showed growth and sporulation comparable with that of the wild-type strain. int1 produced four chitinases of different molecular masses (i.e., 66, 55, 39, 36 kda). three of these (66 ... | 2004 | 15107949 |
| lyophilization of lepidopteran midguts: a preserving method for bacillus thuringiensis toxin binding studies. | binding assays with brush border membrane vesicles (bbmv) from insect midguts are commonly used in the study of the interactions between bacillus thuringiensis cry toxins and their receptors. collaboration between laboratories often require that frozen insect samples are sent in dry ice. because of customs restrictions and delays, sample thawing is always a risk and often the biological material becomes ruined during shipping. we have tested lyophilization as an alternative method for preserving ... | 2004 | 15109901 |
| phospholipid molecular species profiles of tectiviruses infecting gram-negative and gram-positive hosts. | the phospholipid (pl) molecular species compositions of bacteriophages prd1 and bam35 as well as their respective hosts were determined quantitatively using liquid chromatography/electrospray ionization mass-spectrometry (lc-esi-ms) and backed up by gas-chromatographic/mass-spectrometric (gc-ms) analysis of the total fatty acids (fas). the results showed that both viruses contain significantly more phosphatidylglycerol (pg) and less phosphatidylethanolamine (pe) than the host membranes. only mod ... | 2004 | 15110530 |
| bioprocess design and economic analysis for the commercial production of environmentally friendly bioinsecticides from bacillus thuringiensis hd-1 kurstaki. | a production process for b. thuringiensis (bt) bioinsecticides was designed in detail, including alternative batch, low-density fed-batch (ldfb), and high-density fed-batch (hdfb) fermentation configurations. capital and operating costs, as well as profitability based on simple rate of return, were performed using a purpose-written fortran program, explicitly analyzing production of a water-based flowable product used in forestry applications. the total capital cost was 18 million dollars (canad ... | 2004 | 15112290 |
| compositional equivalency of cry1f corn event tc6275 and conventional corn (zea mays l.). | maize (zea mays l.) plants have been transformed to express a cry1f insecticidal crystal protein originally isolated from bacillus thuringiensis berliner. this protein controls lepidopteran pests of maize, including the european corn borer, ostrinia nubilalis (hübner). as part of the safety assessment for crops containing transgenes, a compositional analysis of the food and feed is conducted. this analysis is designed to detect unintended changes in the nutrient and antinutrient content of the r ... | 2004 | 15113183 |
| chitosanase activity in bacillus thuringiensis. | the ability to produce extracellular chitosanase (ec 3.2.1.132) was found by plate assays in 18 (23%) out of 77 crystalliferous strains of bacillus thuringiensis. the best chitosanase producer was selected after the growth chosen in a liquid medium with colloidal chitosan as carbon source. enzyme production was optimized (a 4-d incubation at 32 degrees c with shaking in a medium of ph 6.5 with 4% colloidal chitosan) and the enzyme was partially characterized. this is the first report on the chit ... | 2004 | 15114873 |
| bacterial insecticidal toxins. | over the years it has been important for humans to control the populations of harmful insects and insecticides have been used for this purpose in agricultural and horticultural sectors. synthetic insecticides, owing to their various side effects, have been widely replaced by biological insecticides. in this review we attempt to describe three bacterial species that are known to produce insecticidal toxins of tremendous biotechnological, agricultural, and economic importance. bacillus thuringiens ... | 2004 | 15116762 |
| protein proteinase inhibitor genes in combat against insects, pests, and pathogens: natural and engineered phytoprotection. | the continual need to increase food production necessitates the development and application of novel biotechnologies to enable the provision of improved crop varieties in a timely and cost-effective way. a milestone in this field was the introduction of bacillus thuringiensis (bt) entomotoxic proteins into plants. despite the success of this technology, there is need for development of alternative strategies of phytoprotection. biotechnology offers sustainable solutions to the problem of pests, ... | 2004 | 15464737 |
| inheritance of resistance to bacillus thuringiensis subsp. kurstaki in trichoplusia ni. | the genetic inheritance of resistance to a commercial formulation of bacillus thuringiensis subsp. kurstaki was examined in a trichoplusia ni colony initiated from a resistant population present in a commercial vegetable greenhouse in british columbia, canada. progeny of f(1) reciprocal crosses and backcrosses between f(1) larvae and resistant (p(r)) and susceptible (p(s)) populations were assayed at different b. thuringiensis subsp. kurstaki concentrations. the responses of progeny of reciproca ... | 2004 | 15466525 |
| helix 4 mutants of the bacillus thuringiensis insecticidal toxin cry1aa display altered pore-forming abilities. | the role played by alpha-helix 4 of the bacillus thuringiensis toxin cry1aa in pore formation was investigated by individually replacing each of its charged residues with either a neutral or an oppositely charged amino acid by using site-directed mutagenesis. the majority of the resulting mutant proteins were considerably less toxic to manduca sexta larvae than cry1aa. most mutants also had a considerably reduced ability to form pores in midgut brush border membrane vesicles isolated from this i ... | 2004 | 15466558 |
| diversity of cry genes and genetic characterization of bacillus thuringiensis isolated from brazil. | two hundred and eighteen bacillus thuringiensis isolates from brazil were characterized by the presence of crystal protein genes by pcr with primers specific to different cry and cyt genes. among these isolates, 95 were selected according to their geographic origin for genetic characterization with the 16s rrna gene, rapd, and plasmid profile. isolates containing cry1 genes were the most abundant (48%) followed by the cry11 and cyt (7%) and cry8 genes (2%). finally, 40.3% of the isolates did not ... | 2004 | 15467786 |
| aromaticity of tyr-202 in the alpha4-alpha5 loop is essential for toxicity of the bacillus thuringiensis cry4a toxin. | the current model for the mechanism of action of the bacillus thuringiensis cry delta-endotoxins involves the penetration of the alpha4-alpha5 hairpin into the target midgut epithelial cell membranes, followed by pore formation. in this study, pcr-based mutagenesis was employed to identify a critical residue within the alpha4-alpha5 loop of the 130kda cry4a mosquito-larvicidal protein. alanine-substitutions of two charged (asp-198 and asp-200) and four polar (asn-190, asn-195, tyr-201 and tyr-20 ... | 2004 | 15469709 |
| bacillus thuringiensis cry4a and cry4b mosquito-larvicidal proteins: homology-based 3d model and implications for toxin activity. | three-dimensional (3d) models for the 65-kda activated cry4a and cry4b delta-endotoxins from bacillus thuringiensis subsp. israelensis that are specifically toxic to mosquito-larvae were constructed by homology modeling, based on atomic coordinates of the cry1aa and cry3aa crystal structures. they were structurally similar to the known structures, both derived 3d models displayed a three-domain organization: the n-terminal domain (i) is a seven-helix bundle, while the middle and c-terminal domai ... | 2004 | 15469711 |
| analysis of insecticidal proteins from bacillus thuringiensis and recombinant escherichia coli by capillary electrokinetic chromatography. | bacillus thuringiensis and recombinant escherichia coli proteinaceous protoxins were subject to proteolysis and analyzed by capillary electrokinetic chromatography. three resulting toxins (65 kda) were baseline-resolved within 22 min using a 10 mm borate, ph 11 separation buffer consisting of 25 mm sodium dodecyl sulfate (sds) and 30 mm phytic acid. the toxins displayed differential interactions with the sds and phytic acid phases to effect their separation. the ion-pairing interaction between t ... | 2004 | 15472953 |
| genetically modified cotton and farmers' health in china. | this study provides the first evidence of a direct link between the adoption of a genetically modified (gm) crop and improvements in human health. estimation of the impact of bacillus thuringiensis (bt) cotton adoption on pesticide use from data from a survey of cotton farmers in northern china, 1999-2001, showed that bt cotton adoption reduced pesticide use. assessment of a health-production function showed that predicted pesticide use had a positive impact on poisoning incidence. taken togethe ... | 2004 | 15473084 |
| expression of bacillus anthracis protective antigen in transgenic chloroplasts of tobacco, a non-food/feed crop. | the centers for disease control (cdc) lists bacillus anthracis as a category a agent and estimates the cost of an anthrax attack to exceed us$ 26 billion per 100,000 exposed individuals. concerns regarding anthrax vaccine purity, a requirement for multiple injections, and a limited supply of the protective antigen (pa), underscore the urgent need for an improved vaccine. therefore, the 83 kda immunogenic bacillus anthracis protective antigen was expressed in transgenic tobacco chloroplasts. the ... | 2004 | 15474731 |
| managing the evolution of bacillus thuringiensis resistance in natural populations of the european corn borer, ostrinia nubilalis: host plant, host race and pherotype of adult males at aggregation sites. | the european corn borer (ecb) consists of at least two, genetically differentiated host races: one feeding on maize, the other feeding on mugwort and hop. it is unclear to what extent individuals feeding on these, or other host plants, contribute to natural ecb populations. the mechanisms underlying the genetic differentiation between both races are not well understood; they may include sexual attraction via different pheromone blends (e or z) and differences in the location of mating sites. we ... | 2004 | 15475339 |
| purification and characterization of a lipopeptide produced by bacillus thuringiensis cmb26. | to isolate an antagonist for use in the biological control of phytopathogenic fungi including colletotrichum gloeosporioides, then to purify and characterize the biocontrol agent produced by the antagonist. | 2004 | 15479409 |
| a heat inducible tyrosinase with distinct properties from bacillus thuringiensis. | the objective of this work was to purify the tyrosinase from bacillusthuringiensis subsp. kurstaki (bt) (cctcc ab 90010) and study its enzymatic properties. | 2004 | 15482430 |
| structural implication of the induced immune response by bacillus thuringiensis cry proteins: role of the n-terminal region. | the potential role of the regions (carboxil and amino) of the cry proteins in the ability of these proteins to elicit strong immune responses was investigated. intraperitoneal immunization of mice with the homologous cry1a protoxins (130-133 kda), with the long c-terminal half gave rise mostly to similar, strong serum and mucosal igg and igm antibody response but a lower induction of these ab by intranasal route. remarkably, cry3a protoxin, devoid of c-terminal half was able to induce a signific ... | 2004 | 15482853 |
| high-resolution 31p field cycling nmr as a probe of phospholipid dynamics. | we have used high-resolution field-cycling 31p nmr spectroscopy to measure spin-lattice relaxation rates (r1 = 1/t1) of multicomponent phospholipid vesicle and micelle samples over a large field range, from 0.1 to 11.7 t. the shape of the curve for r1 as a function of field and a model-free analysis were used to extract tauc, a correlation time for each type of phospholipid molecule in the bilayer that is likely to reflect rotation of the molecule about the axis perpendicular to the membrane sur ... | 2004 | 15493936 |
| galnac pretreatment inhibits trapping of bacillus thuringiensis cry1ac on the peritrophic membrane of bombyx mori. | bombyx mori (shunreixshogetsu) is sensitive to cry1aa and resistant to cry1ac, both insecticidal proteins of bacillus thuringiensis. cry1aa passed through the peritrophic membrane (pm) much faster (0.37 microg/mm2 pm/h) than cry1ac (0.05 microg/mm2 pm/h) during the initial observation period. both cry1aa and cry1ac bound to the pm but only the binding of cry1ac was specifically inhibited by n-acetylgalactosamine (galnac). when cry1ac was pretreated with galnac, cry1ac permeated the pm much faste ... | 2004 | 15498557 |
| unfolding events in the water-soluble monomeric cry1ab toxin during transition to oligomeric pre-pore and membrane-inserted pore channel. | the insecticidal crystal (cry) proteins produced by bacillus thuringiensis undergo several conformational changes from crystal inclusion protoxins to membrane-inserted channels in the midgut epithelial cells of the target insect. here we analyzed the stability of the different forms of cry1ab toxin, monomeric toxin, pre-pore complex, and membrane-inserted channel, after urea and thermal denaturation by monitoring intrinsic tryptophan fluorescence of the protein and 1-anilinonaphthalene-8-sulfoni ... | 2004 | 15498772 |
| diversity of alternative hosts of maize stemborers in trans-nzoia district of kenya. | 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 incorporat ... | 2004 | 15901098 |
| bt transgenic crops do not have favorable effects on resistant insects. | sayyed et al. (ecology letters (2003) 6: 167-169) hypothesized that insecticidal bacillus thuringiensis (bt) toxins produced by transgenic crops could have nutritionally favorable effects that increase the fitness of resistant insects eating such crops. this idea was based on increased pupal weight of resistant larvae of diamondback moth, plutella xylostella (l.), fed leaf discs treated externally with a bt toxin. we summarize evidence from diamondback moth and other pests showing that the bt to ... | 2004 | 15861220 |
| entomopathogenic fungi for mosquito control: a review. | fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. virtually all insect orders are susceptible to fungal diseases, including dipterans. fungal pathogens such as lagenidium, coelomomyces and culicinomyces are known to affect mosquito populations, and have been studied extensively. there are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. the discovery, in 1977, of the selective mosquito-pa ... | 2004 | 15861235 |
| development of bollworms, helicoverpa zea, on two commercial bollgard cultivars that differ in overall cry1ac levels. | research was conducted to quantify the development of the corn earworm (= bollworm), helicoverpa zea (boddie), on two different transgenic cotton cultivars (dp 50b and nucotn 33b) that contained different levels of the cry1ac endotoxin from the soil bacterium, bacillus thuringiensis berliner. using a field cage, an inverse relationship between the amount of cry1ac among cultivars versus the weight of bollworm larvae was observed. larvae that were recovered from the dp 50b cultivar expressing low ... | 2004 | 15861247 |
| [use of the restriction analysis in the quality control of the strain of cuban biolarvicide bactivec]. | the genomic characterization of the strain used in manufacturing biolarvicide bactivet was shown in this paper. digestion patterns of bacillus thuringiensis reference strain 266 from the collection of pushkin institute located in former leningrad and of two strains isolated from 2 batches of biolarvicide were compared. chromosomal dna digestion was performed by enzymes hindlll and ecori. the same restriction pattern was observed in all cases, which is indicative of genetic stability of the activ ... | 2004 | 15846913 |
| [effects of bacillus thuringiensis transgenic rice and chemical insecticides on arthropod communities in paddy-fields]. | this paper assessed the effects of cry1abl/cry1ac-carrying transgenic bacillus thuringiensis rice (bt rice) and chemical insecticides on the arthropod communities under paddy-field conditions in terms of arthropod guild dominance, family composition and dominance distribution of each guild, individuals of each guild, some common indices of arthropod communities, and community dissimilarity. in most cases, no significant differences were found between the bt and control rice plots without any che ... | 2004 | 15825447 |