Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| 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 melanin produced by a wild-type strain of bacillus thuringiensis. | bt l-7601 is a uv resistant wild-type strain, which belongs to bacillus thuringiensis subsp. dendrolimus serotype h4a4b. it was isolated from nature, and produced a dark brown pigment during the exponential phase of growth. bt l-7601 had the ability to produce pigment in a general nutrition-abundant medium, which had no l-tyrosine. the pigment was identified as melanin based on chemical testing, its light absorbance, and ft-ir analysis. bt l-7601 has a strong resistance to uv light. after 30 min ... | 2004 | 15754243 |
| cry1ab protoxin effects on spodoptera frugiperda (lepidoptera: noctuidae) and its parasitoid cotesia marginiventris (hymenoptera: braconidae). | 2004 | 15759410 | |
| transgenic-bt potato plant resistance to the colorado potato beetle affect the aphid parasitoid aphidius nigripes. | using the biotechnological plant resistance for herbivore control with less reliance on chemicals in integrated pest management (ipm) programs critically depends on predictable interactions with no-target organisms of various trophic levels. plant resistance to insect pests based on recombinant bacillus thuringiensis could interfere with natural enemies of non target pests. performance of the potato aphid parasitoid aphidius nigripes was studied on the 'superior-bt line transgenic for the crylli ... | 2004 | 15759411 |
| bioassay of some egyptian isolates of bacillus thuringiensis against culex pipiens (diptera: culicidae). | some egyptian isolates of bacillus thuringiensis (bt) were grown on economic media contain 4% of fodder yeast in tap water and incubated under shaking conditions for four days. the biological activities of these isolates against culex pipiens (diptera: culicidae) were carried out to determine their effectiveness against field and laboratory strains of 3rd larval instar. all isolates of bt were more pathogenic to laboratory strain. causing up to 84% larval mortality. the insecticidal activities o ... | 2004 | 15759417 |
| seasonal occurrence and relative abundance of aphids on potato plants with classical and transgenic characters of resistance to colorado potato beetle leptinotarsa decemlineata (say). | the seasonal abundance and dynamics of potato-infesting aphids were studied in two seasons, on potato solanum tuberosum l. with various types of transgenic and classical resistance to primary pests, especially the colorado potato beetle (cpb), leptinotarsa decemlineata (say). the lines tested were the newleaf potato, a transgenic expressing the bacillus thuringiensis cryiiia toxin (btt); nyl 235-4 a parental line derived from s. berthaultii (nyl) with a high density of glandular trichomes; and a ... | 2004 | 15759424 |
| combination of mesocyclops thermocyclopoides and bacillus thuringiensis var. israelensis: a better approach for the control of aedes aegypti larvae in water containers. | the efficacy of a local thai-strain of the copepod, mesocyclops thermocyclopoides and the larvicide, bacillus thuringiensis var. israelensis (bti), used jointly and singly, was studied against aedes aegypti in water containers. in a laboratory test, copepods alone produced mortality of 98-100% in 1st instar larvae of ae. aegypti at copepod:larvae ratios ranging from 1:1 to 1:4. in an outdoor field simulated experiment that ran for 16 wk, after a single inoculation, the treatment of copepods and ... | 2004 | 15707281 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| the bacillus thuringiensis cry1aa toxin: effects of trypsin and chymotrypsin site mutations on toxicity and stability. | the objective of the present work was to create an active cry1aa toxin showing enhanced resistance to degradation by spruce budworm (choristoneura fumiferana) midgut proteases by mutating potential chymotrypsin and trypsin sites. fourteen cry1aa mutants were created in an escherichia coli-bacillus shuttle vector and expressed in a crystal minus bacillus thuringiensis host. using spruce budworm gut juice, commercial bovine trypsin and chymotrypsin we performed protease resistance assays with cry1 ... | 2004 | 15050842 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| evaluation of bt (bacillus thuringiensis) corn on mouse testicular development by dual parameter flow cytometry. | the health safety of bt (bacillus thuringiensis) corn (zea mays l.) was studied using mouse testes as a sensitive biomonitor of potential toxic effects. pregnant mice were fed a bt corn or a nontransgenic (conventional) diet during gestation and lactation. after they were weaned, young male mice were maintained on the respective diets. at 8, 16, 26, 32, 63, and 87 days after birth, three male mice and an adult reference mouse were killed, the testes were surgically removed, and the percentage of ... | 2004 | 15053558 |
| functional analysis of two processed fragments of bacillus thuringiensis cry11a toxin. | the 70-kda protoxin of cry11a, a dipteran-specific insecticidal protein, was processed by trypsin into 36- and 32-kda fragments. to investigate the potent function of the two processed fragments, a gst (glutathione-s-transferase) fusion protein of each polypeptide was constructed. while neither the 36- nor the 32-kda fragment was toxic to culex pipiens larvae, coexpression of the two fragments restored the insecticidal activity. furthermore, the coprecipitation experiment demonstrated that the 3 ... | 2004 | 15056882 |
| in vivo binding of the cry11bb toxin of bacillus thuringiensis subsp. medellin to the midgut of mosquito larvae (diptera: culicidae). | bacillus thuringiensis subsp. medellin produces numerous proteins among which 94 kda known as cry11bb, has mosquitocidal activity. the mode of action of the cry11 proteins has been described as similar to those of the cry1 toxins, nevertheless, the mechanism of action is still not clear. in this study we investigated the in vivo binding of the cry11bb toxin to the midgut of the insect species anopheles albimanus, aedes aegypti, and culex quinquefasciatus by immunohistochemical analysis. spodopte ... | 2004 | 15057351 |
| dissection of cry gene profiles of bacillus thuringiensis isolates in taiwan. | on the basis of the newly revised nomenclature system of cry genes, the pcr amplification method has been adopted to resolve the cry gene combinations of 294 bacillus thuringiensis isolates from five selected areas of taiwan. our results indicate that cry1 (especially cry1a + 1b + 1f) and cry2 were the most abundant cry genes in taiwan. in contrast, cry3 and cry6 genes were detected only on yang ming mountain, while the cry13 gene was found only on snow mountain. in addition, some distinctive co ... | 2004 | 15057451 |
| expression of chitinase-encoding genes in bacillus thuringiensis and toxicity of engineered b. thuringiensis subsp. aizawai toward lymantria dispar larvae. | chitinase genes from aeromonas hydrophila and bacillus circulans no.4.1 were cloned into the plasmid phy300plk and designated as phya2 and phyb43, respectively. both plasmids were introduced into various strains of b. thuringiensis by electroporation. plasmid phyb43 was generally structurally stable, but showed lower segregrational stability than phya2 in b. thuringiensis subsp. aizawai when grown under nonselective conditions. the production of chitinase from b. thuringiensis subsp. aizawai har ... | 2004 | 15057461 |
| endospore degradation in an oligosporogenic, crystalliferous mutant of bacillus thuringiensis. | we isolated a new oligosporogenic mutant from bacillus thuringiensis var. kurstaki hd73 that retains the ability to produce insecticidal crystal inclusions. sporulation in this mutant initiates in a manner similar to the wild-type strain, and under the electron microscope endospores are seen, but these do not reach maturity (except for 0.2% of them). at a late stage, the coat surrounding the forespore seems to lack shape and to be empty. most mutant cells exhibit a well-formed bipyramidal crysta ... | 2004 | 15057485 |
| expression and characterization of a recombinant cry1ac crystal protein with enhanced green fluorescent protein in acrystalliferous bacillus thuringiensis. | to investigate fusion expression between bacillus thuringiensis crystal protein and a foreign protein, the expression of a fusion protein comprised of cry1ac, and enhanced green fluorescent protein (egfp) in b. thuringiensis cry(-)b strain was examined. | 2004 | 15059210 |
| why bt cotton pays for small-scale producers in south africa. | 2004 | 15060543 | |
| enhanced expression of insecticidal crystal proteins in wild bacillus thuringiensis strains by a heterogeneous protein p20. | p20 is a small chaperone-like protein encoded by a cry11a operon in bacillus thuringiensis subsp. israelensis (bti); it is essential to cyt1aa expression. in this report, the gene p20 was transformed into wild strains of subsp. kurstaki to raise the yield of crystal proteins. as a result, larger crystals were produced by the transformant than by the wild control, and most were in the form of a big bipyramid (average 2.4 microm long); some were irregular because of too high expression, while the ... | 2004 | 15060726 |
| designing better probes: effect of probe size, mismatch position and number on hybridization in dna oligonucleotide microarrays. | dna microarrays represent a powerful technology whose use has been hampered by the uncertainty of whether the same principles, established on a scale typical for membrane hybridizations, apply when using the smaller, rigid support of microarrays. our goal was to understand how the number and position of base pair mismatches, probe length and their g+c content affect the intensity and specificity of the hybridization signal. one set of oligonucleotides (50-mers) based on three regions of the baci ... | 2004 | 15063067 |
| interaction of two bacillus thuringiensis delta-endotoxins with the digestive system of lygus hesperus. | the active-toxin form of crylac (65 kda) or cry2ab was fed to a non-susceptible insect, lygus hesperus, in an artificial diet. biochemical and immunocytochemical methods were used to determine the distribution of ingested toxin. the toxins did not elicit a feeding deterrent response. crylac and cry2ab were ingested; small amounts were absorbed into the hemolymph as holoproteins, but most was excreted. sds-page analysis of crylac and cry2ab incubations with salivary gland homogenate showed a smal ... | 2004 | 15018095 |
| isolation and characterization of a strain of bacillus thuringiensis subsp. morrisoni pg-14 encoding delta-endotoxin cry1ac. | bacillus thuringiensis 656-3, isolated from a soil sample collected at mushroom houses, showed high toxicity to mushroom flies, lycoriella mali and coboldia fuscipes. b. thuringiensis 656-3 produced bipyramidal inclusions and reacted with the h antiserum of b. thuringiensis subsp. morrisoni (h8a8b). the plasmid and protein profiles of b. thuringiensis 656-3 were similar to those of its reference strain, subsp. morrisoni pg-14. however, pcr analysis using cry gene primers showed that b. thuringie ... | 2004 | 15018102 |
| bacillus thuringiensis toxin (cry1ab) has no direct effect on larvae of the green lacewing chrysoperla carnea (stephens) (neuroptera: chrysopidae). | earlier studies have shown that larvae of the green lacewing predator chrysoperla carnea are negatively affected when preying on lepidopteran larvae that had been fed with transgenic maize expressing the cry1ab gene from bacillus thuringiensis. to test whether the observed effects were directly caused by the cry1ab toxin, we have developed a bioassay which allows us to feed high concentrations of the toxin directly to the predator. the results of these feeding studies show no direct toxic effect ... | 2004 | 15019519 |
| a bacillus thuringiensis crystal protein with selective cytocidal action to human cells. | bacillus thuringiensis crystal proteins, well known to be toxic to certain insects but not pathogenic to mammals, are used as insecticidal proteins in agriculture and forest management. we here identified a crystal protein that is non-insecticidal and non-hemolytic but has strong cytocidal activity against various human cells with a markedly divergent target specificity, e.g. highly cytotoxic to hepg2 and jurkat and less cytotoxic to the normal hepatocyte (hc) and hela. in slices of liver and co ... | 2004 | 15026424 |
| bacillus thuringiensis delta-endotoxin binding to brush border membrane vesicles of rice stem borers. | the receptor binding step in the molecular mode of action of five delta-endotoxins (cry1ab, cry1ac, cry1c, cry2a, and cry9c) from bacillus thuringiensis was examined to find toxins with different receptor sites in the midgut of the striped stem borer (ssb) chilo suppressalis (walker) and yellow stem borer (ysb) scirpophaga incertulas (walker) (lepidoptera: pyralidae). homologous competition assays were used to estimate binding affinities (k(com)) of (125)i-labelled toxins to brush border membran ... | 2004 | 15027071 |
| identification of bacillus anthracis specific chromosomal sequences by suppressive subtractive hybridization. | bacillus anthracis, bacillus thuringiensis and bacillus cereus are closely related members of the b. cereus-group of bacilli. suppressive subtractive hybridization (ssh) was used to identify specific chromosomal sequences unique to b. anthracis. | 2004 | 15028116 |
| shared genetic basis of resistance to bt toxin cry1ac in independent strains of pink bollworm. | classical and molecular genetic analyses show that two independently derived resistant strains of pink bollworm, pectinophora gossypiella (saunders), share a genetic locus at which three mutant alleles confer resistance to bacillus thuringiensis (bt) toxin cry1ac. one laboratory-selected resistant strain (azp-r) was derived from individuals collected in 1997 from 10 arizona cotton fields, whereas the other (aphis-98r) was derived from a long-term susceptible laboratory strain. both strains were ... | 2004 | 15279243 |
| two new bacterial pathogens of colorado potato beetle coleoptera: chrysomelidae). | other than bacillus thuringiensis berliner, few bacteria are lethal to the colorado potato beetle (leptinotarsa decemlineata [say]), a major pest of potatoes and eggplant. expanded use of biologicals for the control of colorado potato beetle will improve resistance management, reduce pesticide use, and produce novel compounds for potential use in transgenic plants. using freeze-dried, rehydrated artificial diet in pellet form to screen bacteria lethal to other insects, we determined that strains ... | 2004 | 15279252 |
| role of egg density on establishment and plant-to-plant movement by western corn rootworm larvae (coleoptera: chrysomelidae). | the effect of egg density on establishment and dispersal of larvae of the western corn rootworm, diabrotica virgifera virgifera leconte, was evaluated in a 3-yr field study. implications of these data for resistance management plans for bt crops are discussed. viable egg levels of 100, 200, 400, 800, and 1600 eggs per infested plant were evaluated in 2000, 2001, and 2002. a 3200 viable egg level was also tested in 2001 and 2002. all eggs were infested on one plant per subplot in a field that was ... | 2004 | 15279266 |
| cross-resistance of cry1ab-selected ostrinia nubilalis (lepidoptera: crambidae) to bacillus thuringiensis delta-endotoxins. | corn plants expressing the toxin from bacillus thuringiensis (berliner) have proven to be effective in controlling lepidopteran pests such as the european corn borer, ostrinia nubilalis (hübner) (lepidoptera: crambidae). several bt toxins are being tested and incorporated into crop genomes, although tests for cross-resistance among different toxins have been limited by a lack of resistant colonies. four different colonies of o. nubilalis selected with full-length cry1ab incorporated into artific ... | 2004 | 15279290 |
| genetics of resistance to transgenic bacillus thuringiensis poplars in chrysomela tremulae (coleoptera: chrysomelidae). | the area under genetically engineered plants producing bacillus thuringiensis (bt) toxins is steadily increasing. this increase has magnified the risk of alleles conferring resistance to these toxins being selected in natural populations of target insect pests. the speed at which this selection is likely to occur depends on the genetic characteristics of bt resistance. we selected a strain of the beetle chrysomela tremulae fabricius on a transgenic bt poplar clone populus tremula l. x populus tr ... | 2004 | 15279291 |
| cloning and partial characterization of zwittermicin a resistance gene cluster from bacillus thuringiensis subsp. kurstaki strain hd1. | the study seeks to shed light on the aminopolyol, broad-spectrum antibiotic zwittermicin a gene cluster of bacillus thuringiensis subsp. kurstaki hd1 and to identify any new uncharacterized genes with an eventual goal to establish a better understanding of the resistance gene cluster. | 2004 | 15281929 |
| potentiation of insecticidal activity of bacillus thuringiensis subsp. kurstaki hd-1 by proteinase inhibitors in the american bollworm, helicoverpa armigera (hübner). | the effect of crude proteinase inhibitor extracts from seeds of different crop plants (black gram, chickpea, chickling vetch, finger millet, french bean, green gram, horse gram, lentil, pea and soybean) on the insecticidal activity of b. thuringiensis var. kurstaki hd-1 was investigated against neonate larvae of h. armigera by diet incorporation method. the larval mortality due to crude proteinase inhibitors alone (5% seed weight equivalent) ranged from 4.1 to 19.1%; the maximum mortality with f ... | 2004 | 15282948 |
| development and mechanisms of resistance to bacillus thuringiensis endotoxin cry1ac in the american bollworm, helicoverpa armigera (hübner). | the american bollworm, h. armigera, evolved 31-fold resistance to selection pressure of b. thuringiensis endotoxin cry1ac within six generations. the cry1ac selected larvae of h. armigera showed cross-resistance to cry1aa and cry1ab both in terms of mortality and growth reduction. studies on mechanisms of resistance to cry1ac showed that proteases of resistant insects degraded cry1ac faster than those of susceptible insects, which led to the relative unavailability of toxin of about 58 kda for b ... | 2004 | 15282949 |
| a rapid screening method for the detection of viable spores in powder using bioluminescence. | a rapid diagnosis of a biological threat in a powder sample is important for fi rst responders who have to make decisions on-site. the present culture-based method does not provide timely results, which is a critical barrier for a quick response when a suspicious powder sample is found. the atp bioluminescence method, combined with a heat shock, was investigated to determine the presence of spores in powder. the results show that only spore-containing powder samples provided a dramatic increase ... | 2004 | 15287006 |
| characterization of a novel plasma membrane protein, expressed in the midgut epithelia of bombyx mori, that binds to cry1a toxins. | we describe the properties of a novel 252-kda protein (p252) isolated from brush border membranes of bombyx mori. p252 was found in a triton x-100-soluble brush border membrane vesicle fraction, suggesting that it may be a component of the midgut epithelial cell membrane. p252 was purified to homogeneity, and the amino acid sequence of two internal peptides was determined, but neither of the peptides matched protein sequences in the available databases. the apparent molecular mass of the purifie ... | 2004 | 15294792 |
| characterization of two bacillus thuringiensis genes identified by in vivo screening of virulence factors. | bacillus thuringiensis vegetative cells are known to be highly pathogenic when injected into the hemocoel of susceptible insect larvae. this pathogenicity is due to the capacity of b. thuringiensis to cause septicemia in the host. we screened a b. thuringiensis mini-tn10 insertion library for loss of virulence against bombyx mori larvae on injection into the hemocoel. three clones with attenuated virulence were isolated, corresponding to two different mini-tn10 insertions mapping to the yqgb/yqf ... | 2004 | 15294815 |
| binary toxins from bacillus thuringiensis active against the western corn rootworm, diabrotica virgifera virgifera leconte. | the western corn rootworm, diabrotica virgifera virgifera leconte, is a significant pest of corn in the united states. the development of transgenic corn hybrids resistant to rootworm feeding damage depends on the identification of genes encoding insecticidal proteins toxic to rootworm larvae. in this study, a bioassay screen was used to identify several isolates of the bacterium bacillus thuringiensis active against rootworm. these bacterial isolates each produce distinct crystal proteins with ... | 2004 | 15294828 |
| signal peptide of potato pinii enhances the expression of cry1ac in transgenic tobacco. | the modified cry1ac was expressed in transgenic tobacco plants. to allow secretion of the cry1ac protein into the intercellular space, the signal peptide sequence of potato proteinase inhibitor ii (pinii) was n-terminally fused to the cry1ac encoding region. expression of cry1ac in transgenic tobacco plants was assayed with elisa. the results showed that pinii signal peptide sequence enhanced the expression of cry1ac protein and led to the secretion of the cry1ac protein in transgenic tobacco pl ... | 2004 | 15295648 |
| evaluation of sampling plans to detect cry9c protein in corn flour and meal. | starlink is a genetically modified corn that produces an insecticidal protein, cry9c. studies were conducted to determine the variability and cry9c distribution among sample test results when cry9c protein was estimated in a bulk lot of corn flour and meal. emphasis was placed on measuring sampling and analytical variances associated with each step of the test procedure used to measure cry9c in corn flour and meal. two commercially available enzyme-linked immunosorbent assay kits were used: one ... | 2004 | 15295890 |
| mics of selected antibiotics for bacillus anthracis, bacillus cereus, bacillus thuringiensis, and bacillus mycoides from a range of clinical and environmental sources as determined by the etest. | this paper presents etest determinations of mics of selected antimicrobial agents for 76 isolates of bacillus anthracis chosen for their diverse histories and 67, 12, and 4 cultures, respectively, of its close relatives b. cereus, b. thuringiensis, and b. mycoides derived from a range of clinical and environmental sources. nccls breakpoints are now available for b. anthracis and ciprofloxacin, penicillin, and tetracycline; based on these breakpoints, the b. anthracis isolates were all fully susc ... | 2004 | 15297508 |
| use of 16s rrna, 23s rrna, and gyrb gene sequence analysis to determine phylogenetic relationships of bacillus cereus group microorganisms. | in order to determine if variations in rrna sequence could be used for discrimination of the members of the bacillus cereus group, we analyzed 183 16s rrna and 74 23s rrna sequences for all species in the b. cereus group. we also analyzed 30 gyrb sequences for b. cereus group strains with published 16s rrna sequences. our findings indicated that the three most common species of the b. cereus group, b. cereus, bacillus thuringiensis, and bacillus mycoides, were each heterogeneous in all three gen ... | 2004 | 15297521 |