Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| improving the insecticidal activity against resistant culex quinquefasciatus mosquitoes by expression of chitinase gene chiac in bacillus sphaericus. | expression of a chitinase gene, chiac, from bacillus thuringiensis in b. sphaericus 2297 using the binary toxin promoter yielded a recombinant strain that was 4,297-fold more toxic than strain 2297 against resistant culex quinquefasciatus. these results show that this chitinase can synergize the toxicity of the binary toxin against mosquitoes and thus may be useful in managing mosquito resistance to b. sphaericus. | 2007 | 17933917 |
| larval gut ph profile in pestiferous chironomus crassicaudatus and glyptotendipes paripes (chironomidae: diptera) in reference to the toxicity potential of bacillus thuringiensis serovar israelensis. | gut ph and ph optimum of amylase were measured in 4th-stage larvae of 2 pestiferous chironomid species, chironomus crassicaudatus and glyptotendipes paripes. the gut ph in both species was close to neutral, varying from 6.7 to 7.4 and 6.9 to 7.6 ph units for c. crassicaudatus and g. paripes, respectively. in both species, slightly alkaline ph values were measured in the anterior part of the mesenteron, whereas slightly acidic ph values were recorded in gastric caecae and the posterior part of me ... | 2007 | 17939521 |
| [deletion of spoivf operon affects the sporulation and the production of crystal in bacillus thuringiensis g03]. | the spoivf operon exists in bacillus universally. two proteins encoded by the spoivf operon are essential for the sporulation of bacillus subtilis. in this study, a spoivf operon disruption mutant g03 (spoivf-), in which the spoivf operon was deleted, was constructed by homologous recombination. the result showed that the mutant strain lost the ability of sporulation. at the same time, the expression of insecticidal crystal protein (icp) was severely reduced in g03 (spoivf-) mutant strain and re ... | 2007 | 17944354 |
| carrier potential properties of bacillus thuringiensis cry1a toxins for a diphtheria toxin epitope. | the n-terminal half or toxic fragment of bacillus thuringiensis cry proteins is comprised of three structural domains. in a previous paper, we showed that this region plays an important role in the immunogenicity of the b. thuringiensis cry proteins. due to this ability and along with their stability it is worthy of investigating whether this region has carrier potential. to approach this, an eight amino acid hydrophobic motif in alpha-helix 7 of wild-type (wt) cry1a toxins was exchanged for a d ... | 2007 | 17949406 |
| changes of inheritance mode and fitness in helicoverpa armigera (hübner) (lepidoptera: noctuidae) along with its resistance evolution to cry1ac toxin. | the changes of inheritance mode and fitness of resistance in helicoverpa armigera (hübner) along with its resistance evolution to cry1ac toxin were evaluated in the laboratory. the resistance levels reached 170.0-, 209.6- and 2893.3-fold, on selection of the field population in the 16th (btr-f(16)), 34th (btr-f(34)) and 87th (btr-f(87)) generation with artificial diet containing cry1ac toxin, respectively. as the resistance levels increased, more larvae feeding on the bt cotton expressing cry1ac ... | 2008 | 17950749 |
| the requirement for early exposure of haemonchus contortus larvae to bacillus thuringiensis for effective inhibition of larval development. | the potential for a nematocidal bacillus thuringiensis (bt) to target the free-living larval stages of haemonchus contortus was examined using in vitro larval development and migration assays. bt toxicity in larval development assays decreased as the time period between egg hatch and initial exposure to the bt was increased; a time lag of 48 h resulted in a 350-fold increase in the ic(50) (from 2.6 ng/ml to 910 ng/ml). the effects on larval migration largely paralleled the effects on larval deve ... | 2007 | 17951006 |
| characterization, n-terminal sequencing and classification of cerein mrx1, a novel bacteriocin purified from a newly isolated bacterium: bacillus cereus mrx1. | to purify and characterize the bacteriocin produced by strain mrx1. | 2007 | 17953573 |
| coconut water as a cheap source for the production of delta endotoxin of bacillus thuringiensis var. israelensis, a mosquito control agent. | bacillus thuringiensis var. israelensis (b. t. i.) is being widely used in mosquito control programs. however, the large-scale production of this bacillus is expensive due to the high cost of the production medium. in this study, we attempted to develop a cost-effective medium, based on a locally available raw material namely coconut water which is available in plenty as waste product from coconut oil industry. the yield of cell mass, sporulation and mosquito larvicidal activity were studied by ... | 2008 | 17963708 |
| [control of culicides by using bacillus thuringiensis sh-14 var. israelensis in permanent breeding places of fomento, province of sancti spiritus, cuba]. | an ecological evaluation of retrospective and descriptive temporary trend was conducted from 1999 to 2000 .in 8 water bodies of fomento, province of sancti spiritus. to evaluate the effectiveness and permanence of the biolarvicide, there were used data of systematic samplings and of control actions of the provincial surveillance and antivectorial fight programs taken from the records of each breeding place in the municipal unit of higiene and epidemiology of the locality. doses of 10 ml of activ ... | 2005 | 17969274 |
| control of arbovirus vector verrallina funerea (diptera: culicidae) in southeast queensland, australia. | in australia, the brackish water mosquito verrallina funerea (theobald) (diptera: culicidae) is a serious pest and vector of ross river and barmah forest viruses in coastal areas in the northeast of the continent. we report on the first extensive evaluation of the efficacy of various pesticides against this species, including laboratory dose-response assays and small plot field trials. in the laboratory, ve. funerea was susceptible to temephos (abate 100e) (lethal concentration, 95% endpoint [lc ... | 2007 | 17972627 |
| using stable isotope analysis to examine fall armyworm (lepidoptera: noctuidae) host strains in a cotton habitat. | spodoptera frugiperda (j.e. smith) (lepidoptera: noctuidae), or fall armyworm, is an important agricultural pest of several crops in the western hemisphere, including cotton (gossypium l.). two morphologically identical host strains of fall armyworm exist that differ in plant host use and habitat distribution. the corn-strain is a primary pest of corn, zea mays l., whereas the rice-strain is the majority population infesting rice (oryza spp.) and turfgrass (cynodon spp.). with the increased use ... | 2007 | 17972634 |
| susceptibility of four species of turfgrass-infesting scarabs (coleoptera: scarabaeidae) to bacillus thuringiensis serovar japonensis strain buibui. | bacillus thuringiensis serovar japonensis strain buibui experimental formulations containing cry8cal delta-endotoxin were evaluated in the field for the control of oriental beetle, anomala orientalis waterhouse; japanese beetle, popillia japonica newman; asiatic garden beetle, maladera castanea (arrow); and european chafer, rhizotrogus majalis (razoumowsky) larvae infesting turfgrasses. in 17 fall applications, control of a. orientalis and p. japonica was achieved at rates as low as 100 g of tox ... | 2007 | 17972638 |
| managing insecticide resistance by mass release of engineered insects. | transgenic crops producing insecticidal toxins are now widely used to control insect pests. the benefits of this method would be lost if resistance to the toxins spread to a significant proportion of the pest population. the primary resistance management method, mandatory in the united states, is the high-dose/ refuge strategy, requiring toxin-free crops as refuges near the insecticidal crops, and the use of toxin doses sufficiently high to kill insects heterozygous for a resistance allele, ther ... | 2007 | 17972643 |
| the insecticidal crystal protein cry2ab10 from bacillus thuringiensis: cloning, expression, and structure simulation. | the cry2ab-type gene was cloned from bacillus thuringiensis and designated as cry2ab10. the recombinant cry2ab10 protein expressed in e. coli cells shows high toxicity against plutella xylostella. the protein structure was constructed by homology modeling, and the receptor-binding sites were predicted by a molecular docking method. | 2008 | 17973088 |
| the ecology of bacillus thuringiensis on the phylloplane: colonization from soil, plasmid transfer, and interaction with larvae of pieris brassicae. | seedlings of clover (triflorium hybridum) were colonized by bacillus thuringiensis when spores and seeds were co-inoculated into soil. both a strain isolated in the vegetative form from the phylloplane of clover, 2810-s-4, and a laboratory strain, hd-1, were able to colonize clover to a density of about 1000 cfu/g leaf when seeds were sown in sterile soil and to a density of about 300 cfu/g leaf in nonsterile soil. a strain lacking the characteristic insecticidal crystal proteins produced a simi ... | 2008 | 17973155 |
| [analysis of the morphological variants arising during s <--> r dissociation in bacillus thuringiensis]. | physiological, biochemical, and serologic characteristics of 24 clones of r variants spontaneously emerging from the wild type strain of bacillus thuringiensis biotype dendrolimus and of 25 clones of s revertants resulting from the plating of one of the r variants are investigated. it is shown that the efficiency of spore formation is the only characteristic among those investigated which correlated with colony morphology of the s or r type. all r variants were oligo- or asporogenous; they usual ... | 2007 | 17974208 |
| engineering modified bt toxins to counter insect resistance. | the evolution of insect resistance threatens the effectiveness of bacillus thuringiensis (bt) toxins that are widely used in sprays and transgenic crops. resistance to bt toxins in some insects is linked with mutations that disrupt a toxin-binding cadherin protein. we show that susceptibility to the bt toxin cry1ab was reduced by cadherin gene silencing with rna interference in manduca sexta, confirming cadherin's role in bt toxicity. native cry1a toxins required cadherin to form oligomers, but ... | 2007 | 17975031 |
| plant science. the power of the pyramid. | 2007 | 17975032 | |
| exploring the evolution of the bacillus cereus group repeat element bcr1 by comparative genome analysis of closely related strains. | bcr1 is a chromosomal approximately 155 bp repeated element found uniquely and ubiquitously in the bacillus cereus group of gram-positive bacteria; it exhibits several features characteristic of mobile elements, including a variable distribution pattern between strains. here, highly similar bcr1 elements in non-conserved genomic loci are identified in a set of closely related b. cereus and bacillus thuringiensis strains near the bacillus anthracis phylogenetic cluster. it is also shown that bcr1 ... | 2007 | 17975097 |
| structure of the claudin-binding domain of clostridium perfringens enterotoxin. | clostridium perfringens enterotoxin is a common cause of food-borne and antibiotic-associated diarrhea. the toxin's receptors on intestinal epithelial cells include claudin-3 and -4, members of a large family of tight junction proteins. toxin-induced cytolytic pore formation requires residues in the nh(2)-terminal half, whereas residues near the cooh terminus are required for binding to claudins. the claudin-binding cooh-terminal domain is not toxic and is currently under investigation as a pote ... | 2008 | 17977833 |
| uses of plant lectins in bioscience and biomedicine. | new research directions in the last decade have led to major developments in the uses of plant lectins in bioscience and biomedicine. major advances have been made in our understanding how lectins in the diet can act on the gastrointestinal tract and the physiological consequences of their actions, and how they can modulate body- and organ metabolism, the immune system and the gut microflora. particularly striking progress has been made in unravelling the effects, often beneficial, of both orall ... | 2008 | 17981618 |
| comparison and validation of methods to quantify cry1ab toxin from bacillus thuringiensis for standardization of insect bioassays. | standardization of toxin preparations derived from bacillus thuringiensis (berliner) used in laboratory bioassays is critical for accurately assessing possible changes in the susceptibility of field populations of target pests. different methods were evaluated to quantify cry1ab, the toxin expressed by 80% of the commercially available transgenic maize that targets the european corn borer, ostrinia nubilalis (hübner). we compared three methods of quantification on three different toxin preparati ... | 2008 | 17981939 |
| cell wall carbohydrate compositions of strains from the bacillus cereus group of species correlate with phylogenetic relatedness. | members of the bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl compositions. recent multilocus sequence typing (mlst) refined the relatedness of b. cereus group members by separating them into clades and lineages. based on mlst, we selected several b. anthracis, b. cereus, and b. thuringiensis strains and compared their cell wall carbohydrates. the cell walls of different b. anthracis strains (clade 1/anthracis) were composed of glucose (glc), galactose (gal), n ... | 2008 | 17981984 |
| supercat: a supertree database for combined and integrative multilocus sequence typing analysis of the bacillus cereus group of bacteria (including b. cereus, b. anthracis and b. thuringiensis). | the bacillus cereus group of bacteria is an important group including mammalian and insect pathogens, such as b. anthracis, the anthrax bacterium, b. thuringiensis, used as a biological pesticide and b. cereus, often involved in food poisoning incidents. to characterize the population structure and epidemiology of these bacteria, five separate multilocus sequence typing (mlst) schemes have been developed, which makes results difficult to compare. therefore, we have developed a database that comp ... | 2008 | 17982177 |
| control of coleopteran insect pests through rna interference. | commercial biotechnology solutions for controlling lepidopteran and coleopteran insect pests on crops depend on the expression of bacillus thuringiensis insecticidal proteins, most of which permeabilize the membranes of gut epithelial cells of susceptible insects. however, insect control strategies involving a different mode of action would be valuable for managing the emergence of insect resistance. toward this end, we demonstrate that ingestion of double-stranded (ds)rnas supplied in an artifi ... | 2007 | 17982443 |
| evidence of the importance of the met115 for bacillus thuringiensis subsp. israelensis cyt1aa protein cytolytic activity in escherichia coli. | cyt1aa is a cytolytic toxin, found together with the delta-endotoxins in bacillus thuringiensis subsp. israelensis parasporal insecticidal crystals. the latter are used as an environmental friendly insecticide against mosquitoes and black flies. contrary to cry delta-endotoxin, the mode of action of cyt1aa is not completely understood. in the absence of direct structural data, a novel mutated cyt1aa gene was used to obtain indirect informations on cyt1aa conformation changes in the lipid membran ... | 2008 | 17989942 |
| sequential transformation to pyramid two bt genes in vegetable indian mustard (brassica juncea l.) and its potential for control of diamondback moth larvae. | vegetable indian mustard (brassica juncea cv. "green wave") plants that control plutella xylostella (diamondback moth) (dbm) were produced by introduction of one or two bacillus thuringiensis (bt) genes. a cry1ac bt gene associated with the nptii gene for kanamycin selection or a cry1c bt gene with the hpt gene for hygromycin selection was introduced individually through agrobacterium-mediated transformation of seedling explants. a cry1c line was then transformed with the cry1ac gene to produce ... | 2008 | 17989981 |
| development of a thermostable glucose dehydrogenase by a structure-guided consensus concept. | instability under non-native processing conditions, especially at elevated temperatures, is a major factor preventing the widespread adoption of biocatalysts for industrial synthesis. a crucial distinction of many redox enzymes used to synthesize chiral compounds is the need for cofactors (e.g., nad(p)(h)) for function. because of the prohibitively high prices of nicotinamide cofactors, a robust cofactor-regenerating enzyme is required for the economical synthesis of fine chemicals by biocatalys ... | 2007 | 17990264 |
| comparison of nutritional quality between chinese indica rice with sck and cry1ac genes and its nontransgenic counterpart. | nutritional assessment of transgenic crops used for human food and animal feed is an important aspect of safety evaluations. an insect-resistant rice (irr) was generated by the stable insertion of sck, a modified cowpea trypsin inhibitor gene, and cry1ac, encoding a crystal protein from bacillus thuringiensis into the genome of a common variety of chinese indica rice. the composition of the brown and milled rice grain from the resulted irr line designated liangyou kefeng no. 6 was compared with ... | 2007 | 17995700 |
| temporal detection of cry1ab-endotoxins in coccinellid predators from fields of bacillus thuringiensis corn. | the area planted to genetically engineered crops has increased dramatically in the last ten years. this has generated many studies examining non-target effects of bioengineered plants expressing bacillus thuringiensis endotoxins. to date, most have focused on population-level effects in the field or laboratory evaluation of specific plant-herbivore or plant-herbivore-predator trophic pathways. using a post-mortem enzyme-linked immunosorbent assay, we examined the uptake of cry1ab-endotoxins by p ... | 2007 | 17997879 |
| distribution and diversity of dipteran-specific cry and cyt genes in native bacillus thuringiensis strains obtained from different ecosystems of iran. | one hundred and twenty-eight bacillus thuringiensis isolates from fields of different ecological regions of iran were collected to study the distribution and diversity of dipteran-specific cry and cyt genes. the percentage of samples with bt showed significant differences between different regions and also between different fields. the most bt frequency was observed in the soil samples collected from caspianic zone (7%) and soils of cotton (17%). characterization of isolates was based on morphol ... | 2008 | 17999100 |
| raft-targeting and oligomerization of parasporin-2, a bacillus thuringiensis crystal protein with anti-tumour activity. | parasporin-2 is a newly classified bacillus thuringiensis crystal toxin with strong cytocidal activities toward human liver and colon cancer cells. similar to other insecticidal b. thuringiensis crystal toxins, parasporin-2 shows target specificity and damages the cellular membrane. however, the mode of parasporin-2 actions toward the cell membrane remains unknown. here, we show that this anti-tumour crystal toxin targets lipid rafts and assembles into oligomeric complexes in the membrane of hum ... | 2008 | 18006515 |
| optimization of spray-drying conditions for the large-scale preparation of bacillus thuringiensis var. israelensis after downstream processing. | reduction of water activity in the formulations of mosquito biocontrol agent, bacillus thuringiensis var. israelensis is very important for long term and successful storage. a protocol for spray drying of b. thuringiensis var. israelensis was developed through optimizing parameters such as inlet temperature and atomization type. a indigenous isolate of b. thuringiensis var. israelensis (vcrc b-17) was dried by freeze and spray drying methods and the moisture content and mosquito larvicidal activ ... | 2008 | 18023058 |
| an engineered chymotrypsin/cathepsin g site in domain i renders bacillus thuringiensis cry3a active against western corn rootworm larvae. | the western corn rootworm remains one of the most important pests of corn in the united states despite the use of many pest management tools. cry3a, the first coleopteran-active bacillus thuringiensis toxin isolated, has not been useful for control of the corn rootworm pest complex. modification of cry3a so that it contained a chymotrypsin/cathepsin g protease recognition site in the loop between alpha-helix 3 and alpha-helix 4 of domain i, however, resulted in consistent activity of the toxin ( ... | 2008 | 18024675 |
| production and characterization of bacillus thuringiensis cry1ac-resistant cotton bollworm helicoverpa zea (boddie). | laboratory-selected bacillus thuringiensis-resistant colonies are important tools for elucidating b. thuringiensis resistance mechanisms. however, cotton bollworm, helicoverpa zea, a target pest of transgenic corn and cotton expressing b. thuringiensis cry1ac (bt corn and cotton), has proven difficult to select for stable resistance. two populations of h. zea (ar and mr), resistant to the b. thuringiensis protein found in all commercial bt cotton varieties (cry1ac), were established by selection ... | 2008 | 18024681 |
| plasmid patterns of bacillus thuringiensis type strains. | practically all bacillus thuringiensis strains contain a set of self-replicating, extrachromosomal dna molecules or plasmids, which vary in number and size in the different strains. the plasmid patterns obtained from gel electrophoresis have previously been used as a tool to characterize strains, but comparison of the plasmid patterns has been limited in the number and diversity of strains analyzed. in this report, we were able to compare the plasmid patterns of 83 type strains (out of 84) and 4 ... | 2008 | 18024687 |
| discovery of crystalline inclusions in bacillus licheniformis that resemble parasporal crystals of bacillus thuringiensis. | crystalline inclusions were discovered in stationary and sporulating cells of the spore-forming bacterium bacillus licheniformis atcc 9945a. as detected by electron microscopy, dying or sporulating bacterial cells contain a single crystal of strikingly large size. the crystals in sporulating cells are located next to nascent spores and can be several times larger than the spores. morphologically, most crystals are rhomboid with uniformly spaced grids. these newly discovered crystalline inclusion ... | 2007 | 18026233 |
| degradation of the insecticidal toxin produced by bacillus thuringiensis var. kurstaki by extracellular proteases produced by chrysosporium sp. | some cry proteins produced by the soil bacterium bacillus thuringiensis (bt) or by transgenic bt plants persist in agricultural soils for an extended period of time, which may pose a hazard for nontarget soil organisms. the aims of our study were to screen for soil fungi capable of degrading the cry1ac toxin and to identify the mechanisms that lead to the inactivation of this protein. | 2008 | 18028364 |
| a pair of adjacent genes, cry5ad and orf2-5ad, encode the typical n- and c-terminal regions of a cry5adelta-endotoxin as two separate proteins in bacillus thuringiensis strain l366. | a new dna sequence cry5ad/orf2-5ad (genbank accession number ef219060) was isolated from bacillus thuringiensis strain l366. this dna sequence contains two orfs: cry5ad (a previously unreported member of the cry5a gene family) and orf2-5ad. cry5ad is unique among cry5a genes in that it encodes only the n-terminal region of a typical cry5adelta-endotoxin. the cry5ad sequence includes homology blocks 1-5, which are present in most b. thuringiensisdelta-endotoxins. the usual c-terminal region of a ... | 2008 | 18028391 |
| identification and expression of gh-8 family chitosanases from several bacillus thuringiensis subspecies. | the gram-positive spore-forming bacterium, bacillus thuringiensis, a member of the bacillus cereus group, produces chitosanases that catalyze the hydrolysis of chitosan to chitosan-oligosaccharides (cos). although fungal and bacterial chitosanases belonging to other glycoside hydrolase (gh) families have been characterized in a variety of microorganisms, knowledge on the genetics and phylogeny of the gh-8 chitosanases remains limited. nine genes encoding chitosanases were cloned from 29 differen ... | 2007 | 18031332 |
| unconventional giy-yig homing endonuclease encoded in group i introns in closely related strains of the bacillus cereus group. | several group i introns have been previously found in strains of the bacillus cereus group at three different insertion sites in the nrde gene of the essential nrdief operon coding for ribonucleotide reductase. here, we identify an uncharacterized group ia intron in the nrdf gene in 12 strains of the b. cereus group and show that the pre-mrna is efficiently spliced. the bacillus thuringiensis ssp. pakistani nrdf intron encodes a homing endonuclease, denoted i-bthii, with an unconventional giy-(x ... | 2008 | 18032435 |
| comparative study of bacillus thuringiensis cry1aa and cry1ac delta-endotoxin activation, inactivation and in situ histopathological effect in ephestia kuehniella (lepidoptera: pyralidae). | a comparative study of different steps in the mode of action of the individual bacillus thuringiensis kurstaki bns3 cry1aa and cry1ac delta-endotoxins on e. kuehniella larvae was performed in order to investigate the origin of the difference in the response of this larvae to each of the latter. proteolytic activation was shown to be one of the main steps impaired in e. kuehniella tolerance to cry1aa. the absence of two proteinase activities as well as an altered activity level observed in the ca ... | 2008 | 18040897 |
| germination and conjugation of bacillus thuringiensis subsp. israelensis in the intestine of gnotobiotic rats. | to study the ability of bacillus thuringiensis subsp. israelensis spores to germinate and subsequently transfer a conjugative plasmid in the intestinal tract of gnotobiotic rats. | 2008 | 18042185 |
| in situ fluorescence microscopy of bacteriophage aggregates. | virus aggregation is analyzed because of its potential use for both classifying viruses and understanding virus ecology and evolution. virus aggregation is, however, problematic because aggregation causes loss of virions during processing for microscopy of any type. thus, here we detect virus aggregation by fluorescence microscopy of wet-mounted dissections of dilute gel-supported plaques (in situ fluorescence microscopy) of a test virus, the long-tail aggregating bacillus thuringiensis bacterio ... | 2007 | 18045325 |
| immigration of bacillus thuringiensis to bean leaves from soil inoculum or distal plant parts. | we addressed the process of immigration of bacillus thuringiensis from soil to leaves and its capacity to grow on bean diffusate medium (bdm), a medium designed to simulate the nutrient composition of the phylloplane. | 2007 | 18045443 |
| prediction-based protein engineering of domain i of cry2a entomocidal toxin of bacillus thuringiensis for the enhancement of toxicity against lepidopteran insects. | issues relating to sustenance of the usefulness of genetically modified first generation bt crop plants in the farmer's field are of great concern for crop scientists. additional biotechnological strategies need to be in place to safeguard the possibility for yield loss of bt crop by other lepidopteran insects that are insensitive to the cry1a toxin, and also against the possibility for emergence of resistant insects. in this respect, cry2a toxin has figured as a prospective candidate to be the ... | 2007 | 18048477 |
| interactions with microbial pathogens. | a wide variety of bacterial pathogens, as well as several fungi, kill c. elegans or produce non-lethal disease symptoms. this allows the nematode to be used as a simple, tractable model host for infectious disease. human pathogens that affect c. elegans include gram-negative bacteria of genera burkholderia, pseudomonas, salmonella, serratia and yersinia; gram-positive bacteria enterococcus, staphylococcus and streptococcus; and the fungus cryptococcus neoformans. microbes that are not pathogenic ... | 2005 | 18050390 |
| bacillus thuringiensis as a specific, safe, and effective tool for insect pest control. | bacillus thuringiensis (bt) was first described by berliner [10] when he isolated a bacillus species from the mediterranean flour moth, anagasta kuehniella, and named it after the province thuringia in germany where the infected moth was found. although this was the first description under the name b. thuringiensis, it was not the first isolation. in 1901, a japanese biologist, ishiwata shigetane, discovered a previously undescribed bacterium as the causative agent of a disease afflicting silkwo ... | 2007 | 18051264 |
| production of recombinant polyhedra containing cry1ac fusion protein in insect cell lines. | insect cell lines and the control of infection for obtaining the maximum amount of polyhedrin-crylac-polyhedrin fusion protein from bactrus in monolayer and suspension culture systems were tested. growth rates of the trichoplusia ni (high-five) cell line in both culture systems were better than the other insect cell lines, spodoptera fiugiferda (sf-9, sf-21), trichoplusia ni (tn5), and spodoptera exigua (se301). the expression of the fusion protein in a monolayer culture showed that se301 cells ... | 2007 | 18051294 |
| generation of a specific marker to discriminate gacillus anthracis from other bacteria of the bacillus cereus group. | bacillus anthracis is a soil pathogen capable of causing anthrax that is closely related to several environmental species, including b. cereus, b. mycoides, and b. thuringiensis. dna homology studies showed that b. anthracis, b. cereus, b. mycoides, and b. thuringiensis are closely related, with a high sequence homology. to establish a method to specifically detect b. anthracis in situations such as environmental contamination, we initially performed rapd-pcr with a 10-mer random primer and conf ... | 2007 | 18051303 |
| simultaneous detection and identification of bacillus cereus group bacteria using multiplex pcr. | bacillus cereus group bacteria share a significant degree of genetic similarity. thus, to differentiate and identify the bacillus cereus group efficiently, a multiplex pcr method using the gyrb and groel genes as diagnostic markers is suggested for simultaneous detection. the assay yielded a 400 bp amplicon for the groel gene from all the b. cereus group bacteria, and a 253 bp amplicon from b. anthracis, 475 bp amplicon from b. cereus, 299 bp amplicon from b. thuringiensis, and 604 bp amplicon f ... | 2007 | 18051330 |
| identification and molecular characterization of novel cry1-type toxin genes from bacillus thuringiensis k1 isolated in korea. | to clone novel cry1-type genes from the bacillus thuringiensis k1 isolate, about 2.4-kb-long pcr fragments were amplified with two primer sets of atg1-f/n400-r and 1beatg1-f/n400-r. using pcr-rflp, three novel cry1-type genes, cry1-1, cry1-7, and cry1-44, were obtained from b. thuringiensis k1 and the complete coding sequences of these novel genes were analyzed. the cry1-1, cry1-7, and cry1-44 proteins showed maximum similarities of about 78.0%, 99.7%, and 91.0% with the cry1ha1, cry1be1, and cr ... | 2007 | 18051348 |
| aggregates of bacteriophage 0305phi8-36 seed future growth. | lytic bacteriophage 0305phi8-36 forms visually observed aggregates during plaque formation. aggregates intrinsically lower propagation potential. in the present study, the following observations indicate that lost propagation potential is regained with time: (1) aggregates sometimes concentrate at the edge of clear plaques. (2) a semi-clear ring sometimes forms beyond the plaques. (3) formation of a ring is completely correlated with the presence of aggregates at the same angular displacement al ... | 2007 | 18053210 |
| amino acid substitutions in alphaa and alphac of cyt2aa2 alter hemolytic activity and mosquito-larvicidal specificity. | cyt2aa2 produced by bacillus thuringiensis subsp. darmstadiensis exhibits in vitro cytolytic activity against broad range of cells but shows specific in vivo toxicity against larvae of dipteran insects. to investigate the role of amino acids in alphaa and alphac of this toxin, 3 single-point mutants (a61c, s108c and v109a) were generated. all 3 mutant proteins were highly produced as inclusion bodies that could be solubilized and activated by proteinase k similar to that of the wild type. hemoly ... | 2008 | 18054404 |
| immobilization in alginate as a technique for the preservation of bacillus thuringiensis var. israelensis for long-term preservation. | technique for immobilization using sodium alginate as the matrix to preserve bacillus thuringiensis var. israelensis isolates for long time storage was developed. two strains of b. thuringiensis var. israelensis viz., vcrc b-17 and who standard strain ips-82 were immobilized in alginate matrix and preserved at 4 degrees c and when tested both were found to have maintained excellent viability and mosquito larvicidal activity for 10 years. mosquito larvicidal activity of b-17 and ips-82 alginate b ... | 2008 | 18054810 |
| detection of bacillus cereus virulence factors in commercial products of bacillus thuringiensis and expression of diarrheal enterotoxins in a target insect. | we examined isolates from 4 commercial bioinsecticides based on different strains of bacillus thuringiensis subspecies (kurstaki, israelensis, aizawai, and tenebrionis) for the presence of genes encoding proteins with known enterotoxigenicity (nhe, hbl, cytk, ces) and various other putative virulence genes (piplc, sph, bcet, entfm, ents, entt). the piplc and bcet sequences were present in all the isolates; sph was found in aizawai and israelensis; entfm only in israelensis; and ents in kurstaki, ... | 2007 | 18059560 |
| [association of bioassays and molecular characterization to select new bacillus thuringiensis isolates effective against spodoptera frugiperda (j. e. smith) (lepidoptera: noctuidae)]. | the fall armyworm, spodoptera frugiperda (j. e. smith), is one of the main corn pests and bacillus thuringiensis is important in its control because of its entomopathogenic property. the objective of this study was the molecular characterization of b. thuringiensis isolates for cry1 locus presence and the assessment of the efficiency of these isolates in controlling s. frugiperda caterpillars. gral-cry1 was used in the pcr analyses to confirm the presence of the cry1 locus in 15 isolates. a 3 x ... | 2007 | 18060300 |
| isolation and characterization of strain of bacillus thuringiensis subsp. kenyae containing two novel cry1-type toxin genes. | to identify novel crystal proteins, bacillus thuringiensis 2385-1 was isolated from korean soil samples and characterized. the h-serotype of 2385-1 was identical to that of subsp. kenyae (h4a4c), and its crystal toxin was bipyramidal-shaped. however, 2385-1 showed a much higher toxicity towards plutella xylostella and spodoptera exigua larvae than subsp. kenyae. in addition, the crystal protein profile and plasmid dna pattern of 2385-1 differed from those of subsp. kenyae. to verify the crystal ... | 2007 | 18062228 |
| [cloning, expression and sequence analysis of chia, chib in bacillus thuringiensis subsp. colmeri 15a3]. | two dna fragments encoding chitinase a and b were amplified from total genomic dna of bacillus thuringiensis subsp. colmeri 15a3, and then ligated with pucm-t cloning vector. the recombinant plasmids pucm-chia and pucm-chib were transformed into escherichia coli xl-blue respectively. both chia and chib were successfully expressed in e. coli with their natural promoters independent of any chitin. additionally, the expressed chia and chib could be secreted from e. coli cells. it was proved that tw ... | 2007 | 18062260 |
| [cloning and expression of nematicidal crystal protein gene cry6aa of bacillus thuringiensis]. | on the basis of the sequencing of the n-terminal amino acid of the crystal protein, a nucleotide acid fragment harboring a novel nematicidal gene cry6aa2 was obtained from bacillus thuringiensis strain ybt-1518. this fragment contains two orfs: orf1 and orf2, while a "stem-loop" exists between orf1 and orf2. blast showed the similarity of orf1 nucleotide acid sequence with cry6aa1 is 98%, and has been deposited in the genbank database (acc. no. af499736). the cloning fragment was transferred to ... | 2007 | 18062264 |
| effects of defoliating insect resistance qtls and a cry1ac transgene in soybean near-isogenic lines. | the crystal proteins coded by transgenes from bacillus thuringiensis (bt) have shown considerable value in providing effective insect resistance in a number of crop species, including soybean, glycine max (l.) merr. additional sources of soybean insect resistance would be desirable to manage the development of tolerance/resistance to crystal proteins by defoliating insects and to sustain the deployment of bt crops. the objective of this study was to evaluate the effects and interactions of three ... | 2008 | 18064435 |
| effects of transgenic corn and cry1ab protein on the nematode, caenorhabditis elegans. | the effects of the insecticidal cry1ab protein from bacillus thuringiensis (bt) on the nematode, caenorhabditis elegans, were studied with soil from experimental fields cultivated with transgenic bt corn (mon810) and with trypsinized cry1ab protein expressed in escherichia coli. the content of cry1ab protein was above the detection limit of an elisa test in only half of the soil samples obtained from transgenic plots, ranging from 0.19 to 1.31 ng g(-1) dry weight. in a laboratory bioassay, c. el ... | 2008 | 18068780 |
| broad distribution of enterotoxin genes (hblcda, nheabc, cytk, and entfm) among bacillus thuringiensis and bacillus cereus as shown by novel primers. | eight new pairs of pcr primers were designed and efficiently detect eight toxin genes (hblc, hbld, hbla, nhea, nheb, nhec, cytk, and entfm) in 411 b. cereus strains (121 food- and 290 soil isolates) and 205 b. thuringiensis strains (43 serovars, 10 food- and 152 soil isolates). according to the presence of these eight toxin genes, they were divided into four groups among the total 616 isolates. in group i, all eight genes occurred simultaneously in 403 (65.42%) isolates, while group ii (134 isol ... | 2008 | 18068844 |
| endospore dipicolinic acid detection during bacillus thuringiensis culture. | the aim of this work was to detect bacillus thuringiensis endospore production during fermentation under conditions hindering endospore detection, i.e. in a complex undefined industrial medium with a high content of solids in suspension. | 2008 | 18069985 |
| isolation and characterization of nonrhizobial plant growth promoting bacteria from nodules of kudzu (pueraria thunbergiana) and their effect on wheat seedling growth. | the leguminous vine kudzu (pueraria thunbergiana) is an introduction into the n. w. himalayan region of india. despite its value as a fodder and cover crop, little is known about the nature of the nodule microflora. in an attempt to study the nodule bacteria, we isolated and characterized three nonrhizobial plant growth promoting bacteria from surface sterilized nodules of kudzu. based on the sequencing of the 16 s r rna gene, the isolates were designated as bacillus thuringiensis kr-1, enteroba ... | 2008 | 18074178 |
| the occurrence of bacillus cereus, b. thuringiensis and b. mycoides in chinese pasteurized full fat milk. | in 2006, a total of 54 samples of pasteurized full fat milk packaged in cartons were collected in spring and in autumn from chain supermarkets in wuhan, china. the samples were examined and enumerated by mpn methods strictly according to guidelines laid out in us fda/cfsan bam chapter 14. among 102 isolated b. cereus-like bacteria, 92 isolates were identified to be b. cereus, 9 b. thuringiensis and 1 b. mycoides. it was found that the occurrences of b. cereus were 71.4% and 33.3% in spring and i ... | 2008 | 18077041 |
| molecular and biochemical characterization of an endochitinase (chia-hd73) from bacillus thuringiensis subsp. kurstaki hd-73. | an endochitinase gene (chia-hd73) from the insecticidal bacterium bacillus thuringiensis subsp. kurstaki hd-73 was cloned, sequenced, and expressed in escherichia coli dh5alphaf'. the chitinase activity of the encoded protein was studied in assays with different fluorogenic substrates. the chia-hd73 gene contained an open-reading frame that encoded an endochitinase with a deduced molecular weight and an isoelectric point of, respectively, 74.5 kda and 5.75. a putative signal peptide with cleavag ... | 2008 | 18080218 |
| susceptibility of spodoptera exigua to 9 toxins from bacillus thuringiensis. | nine of the most common lepidopteran active cry proteins from bacillus thuringiensis have been tested for activity against spodoptera exigua. because of possible intraspecific variability, three laboratory strains (fra, hol, and mur) have been used. mortality assays were performed with the three strains. lc(50) values for the active toxins were determined to the fra and the hol strains, whereas susceptibility of the mur strain was assessed using only two concentrations. the results showed that c ... | 2008 | 18082763 |
| hydrogen and polyhydroxybutyrate producing abilities of microbes from diverse habitats by dark fermentative process. | thirty five bacterial isolates from diverse environmental sources such as contaminated food, nitrogen rich soil, activated sludges from pesticide and oil refineries effluent treatment plants were found to belong to bacillus, bordetella, enterobacter, proteus, and pseudomonas sp. on the basis of 16s rrna gene sequence analysis. under dark fermentative conditions, maximum hydrogen (h(2)) yields (mol/mol of glucose added) were recorded to be 0.68 with enterobacter aerogenes egu16 followed by 0.63 w ... | 2008 | 18083024 |
| novel isolate of bacillus thuringiensis subsp. thuringiensis that produces a quasicuboidal crystal of cry1ab21 toxic to larvae of trichoplusia ni. | a new isolate (is5056) of bacillus thuringiensis subsp. thuringiensis that produces a novel variant of cry1ab, cry1ab21, was isolated from soil collected in northeastern poland. cry1ab21 was composed of 1,155 amino acids and had a molecular mass of 130.5 kda, and a single copy of the gene coding for this endotoxin was located on a approximately 75-kbp plasmid. when synthesized by the wild-type strain, cry1ab21 produced a unique, irregular, bipyramidal crystal whose long and short axes were both ... | 2008 | 18083867 |
| intranasal immunization with naegleria fowleri lysates and cry1ac induces metaplasia in the olfactory epithelium and increases iga secretion. | according to previous reports, intranasal administration of the cry1ac protein alone or with amoebic lysates increases protection against naegleria fowleri meningoencephalitis in mice, apparently by eliciting iga responses in the nasal mucosa. in the current study, we performed an immunohistochemical analysis of iga in the nasal mucosa of mice immunized intranasally with cry1ac, and amoebic lysates or a combination of both. the animals were sacrificed 24 h after the last immunization or after an ... | 2008 | 18086014 |
| toxicological safety assessment of genetically modified bacillus thuringiensis with additional n-acyl homoserine lactonase gene. | the aim of the present study is to evaluate the toxicology safety to mammals of a genetically modified (gm) bacillus thuringiensis with an additional n-acyl homoserine lactones gene (aiia), which possesses insecticidal activity together with restraint of bacterial pathogenicity and is intended for use as a multifunctional biopesticide. safety assessments included an acute oral toxicity test and 28-d animal feeding study in wistar rats, primary eye and dermal irritation in zealand white rabbits, ... | 2008 | 18092859 |
| retention of mosquito larvicidal activity of lyophilized cells and wdp formulation of bacillus thuringiensis var. israelensis on long-term storage. | lyophilized cells (sealed and unsealed) and water dispersible powders (wdps) of two indigenous isolates of bacillus thuringiensis var.israelensis were stored at -10, 4, 30 and 40 degrees c for up to 4 years and checked for activity. lyophilized cells stored in sealed condition at -10, 4 and 30 degrees c and wdps stored at -10 and 4 degrees c were found to maintain the activity fairly well. the lyophilized cells stored at 30 degrees c and wdps stored at 4 degrees c maintained their larvicidal pro ... | 2008 | 18155180 |
| development and validation of a sensitive enzyme immunoassay for surveillance of cry1ab toxin in bovine blood plasma of cows fed bt-maize (mon810). | the increasing global adoption of genetically modified (gm) plant derivatives in animal feed has provoked a strong demand for an appropriate detection method to evaluate the existence of transgenic protein in animal tissues and animal by-products derived from gm plant fed animals. a highly specific and sensitive sandwich enzyme immunoassay for the surveillance of transgenic cry1ab protein from bt-maize in the blood plasma of cows fed on bt-maize was developed and validated according to the crite ... | 2008 | 18155416 |
| genetic evidence for the actin homolog gene mrebh and the bacitracin resistance gene bcrc as targets of the alternative sigma factor sigi of bacillus subtilis. | the bacillus subtilis sigi gene, which is a member of the class vi heat shock genes of the b. subtilis heat shock stimulon, encodes an alternative sigma factor whose regulon is poorly defined. in this study, by using a binary vector system, we showed that b. subtilis sigi could drive expression of a transcriptional fusion between the sigi regulatory region from bacillus licheniformis, bacillus sp. strain nrrl b-14911, b. subtilis, or bacillus thuringiensis and the xyle reporter gene in b. subtil ... | 2008 | 18156261 |
| antifungal activities of bacillus thuringiensis isolates on barley and cucumber powdery mildews. | fourteen bacillus thuringiensis isolates having both insecticidal activity and in vitro antifungal activity were selected and tested for in vivo antifungal activity against tomato late blight, wheat leaf rust, tomato gray mold, and barley powdery mildew in growth chambers. all the isolates represented more than 70% disease control efficacy against at least one of four plant diseases. specifically, 12 isolates exhibited strong control activity against barley powdery mildew. under glasshouse condi ... | 2007 | 18167458 |
| a highly pathogenic strain of bacillus thuringiensis serovar kurstaki in lepidopteran pests. | in order to detect and identify the most toxic bacillus thuringiensis strains against pests, we isolated a b. thuringiensis strain (bn1) from balaninus nucum (coleoptera: curculionidae), the most damaging hazelnut pest. bn1 was characterized via morphological, biochemical, and molecular techniques. the isolate was serotyped, and the results showed that bn1 was the b. thuringiensis serovar, kurstaki (h3abc). the scanning electron microscopy indicated that bn1 has crystals with cubic and bipyramid ... | 2007 | 18176540 |
| detection of large plasmids from the bacillus cereus group. | the members of the bacillus cereus group, bacillus anthracis, bacillus thuringiensis, and b. cereus senso stricto, are largely defined by their content of large plasmids, which encode major virulence factors. here we offer an easy, fast, and reliable protocol for the isolation and detection of large plasmids up to the size of at least 350kb. furthermore, using this method, we report that bacillus mycoides contain large plasmids. | 2008 | 18179822 |
| mineralization of the bacillus thuringiensis cry1ac endotoxin in soil. | although a number of studies have been done describing the fate of bacillus thuringiensis insecticidal endotoxins in soil, there is conflicting information on the persistence of this class of insecticidal toxins. this is partly due to methodological limitations in many of the previous studies. in the experiments reported here, 14c-labeled b. thuringiensis cry1ac endotoxin was used to study its mineralization in soil incubated under controlled conditions. fifty-nine percent of the radiolabeled cr ... | 2008 | 18181567 |
| a meta-analysis of effects of bt crops on honey bees (hymenoptera: apidae). | honey bees (apis mellifera l.) are the most important pollinators of many agricultural crops worldwide and are a key test species used in the tiered safety assessment of genetically engineered insect-resistant crops. there is concern that widespread planting of these transgenic crops could harm honey bee populations. | 2008 | 18183296 |
| binding properties of a monoclonal antibody against the cry1ab from bacillus thuringensis for the development of a capillary electrophoresis competitive immunoassay. | experimental work performed was aimed at the assessment of a competitive capillary electrophoresis immunoassay with laser-induced fluorescence (ceia-lif) detection for the determination of the cry1ab endotoxin from bacillus thuringensis. the binding constant of a monoclonal antibody, raised against the insecticide protein cry1ab, was determined on a microplate by indirect enzyme-linked immunosorbent assay (elisa) and compared with that obtained in-capillary under nonequilibrium separation condit ... | 2008 | 18185920 |
| suppression of dengue transmission by application of integrated vector control strategies at sero-positive gis-based foci. | a serological survey of primary school children from six schools in chachoengsao province, thailand, was performed at the end of the peak of dengue transmission. gis analysis of sero-positive cases was carried out to determine transmission foci. vector control implementation was conducted in the foci and also within 100 meters around the foci in the treated areas by community participation in collaboration with the local government. vector control strategies included source reduction together wi ... | 2008 | 18187787 |
| bombyx mori midgut membrane protein p252, which binds to bacillus thuringiensis cry1a, is a chlorophyllide-binding protein, and the resulting complex has antimicrobial activity. | the epithelial cell membrane 252-kda protein (p252) isolated in our laboratory from bombyx mori midgut was shown to bind strongly with cry1aa, cry1ab, and cry1ac toxins of bacillus thuringiensis (15). in the current paper, p252 was shown to bind with chlorophyllide (chlide) to form red fluorescent protein (rfp) complex, termed bm252rfp, with absorbance and fluorescence emission peaks at 600 nm and 620 nm, respectively. p252 at a concentration of 1 microm is shown to bind with about 50 microm chl ... | 2008 | 18192432 |
| detection and characterization of cry1ac transgene construct in bt cotton: multiple polymerase chain reaction approach. | to comply with international labeling regulations for genetically modified (gm) crops and food, and to enable proper identification of gm organisms (gmos), effective methodologies and reliable approaches are needed. the spurious and unapproved gm planting has contributed to crop failures and commercial losses. to ensure effective and genuine gm cultivation, a methodology is needed to detect and identify the trait of interest and concurrently evaluate the structural and functional stability of th ... | 2007 | 18193727 |
| in vitro assembly studies of ftsz/tubulin-like proteins (tubz) from bacillus plasmids: evidence for a capping mechanism. | proteins with a weak sequence similarity to tubulin and ftsz are expressed from large plasmids of bacillus anthracis and bacillus thuringiensis and are probably involved in plasmid segregation. previously designated repx and tubz, we designate them here as tubz-ba and tubz-bt. we have expressed and purified the proteins for in vitro studies. tubz-ba and tubz-bt share only 21% amino acid identity, but they have remarkably similar biochemical properties. they both assemble into two-stranded filame ... | 2008 | 18198178 |
| plant cyclotides disrupt epithelial cells in the midgut of lepidopteran larvae. | several members of the rubiaceae and violaceae plant families produce a series of cyclotides or macrocyclic peptides of 28-37 aa with an embedded cystine knot. the cyclic peptide backbone together with the knotted and strongly braced structure confers exceptional chemical and biological stability that has attracted attention for potential pharmaceutical applications. cyclotides display a diverse range of biological activities, such as uterotonic action, anti-hiv activity, and neurotensin antagon ... | 2008 | 18202177 |
| does cry1ab protein affect learning performances of the honey bee apis mellifera l. (hymenoptera, apidae)? | genetically modified bt crops are increasingly used worldwide but side effects and especially sublethal effects on beneficial insects remain poorly studied. honey bees are beneficial insects for natural and cultivated ecosystems through pollination. the goal of the present study was to assess potential effects of two concentrations of cry1ab protein (3 and 5000 ppb) on young adult honey bees. following a complementary bioassay, our experiments evaluated effects of the cry1ab on three major life ... | 2008 | 18206234 |
| genetic mapping of bt-toxin binding proteins in a cry1a-toxin resistant strain of diamondback moth plutella xylostella. | a major mechanism of resistance to bacillus thuringiensis (bt) toxins in lepidoptera is a reduction of toxin binding to sites in the midgut membrane. genetic studies of three different species have shown that mutations in a candidate bt receptor, a 12-cadherin-domain protein, confer cry1a toxin resistance. despite a similar resistance profile in a fourth lepidopteran species, plutella xylostella, we have previously shown that the cadherin orthologue maps to a different linkage group (lg8) than c ... | 2008 | 18207074 |
| the influence of different nutrient levels on insect-induced plant volatiles in bt and conventional oilseed rape plants. | transgenic bt (expressing the cry1ac endotoxin gene) and conventional oilseed rape plants grown in different soils were used to study nutrient uptake and emission of volatiles after herbivore damage. all plants were greenhouse-grown in soils representing low-, medium- and high-nutrient levels. the concentrations of n, p, k, mg and zn were significantly affected by the transgene, while the main effect of soil type appeared in n, p, ca, mg, b, mn and zn concentrations in the plants. plants with fo ... | 2008 | 18211550 |
| immunotoxicological studies of genetically modified rice expressing pha-e lectin or bt toxin in wistar rats. | as part of the safotest project the immunmodulating effect of cry1ab protein from bacillus thuringiensis (bt) and pha-e lectin from kidney bean (phaseolus vulgaris erythroagglutinin) was examined in 28- and 90-day feeding studies in wistar rats. pha-e lectin was chosen as positive control. rats were fed control rice, transgenic rice expressing cry1ab protein or pha-e lectin, or transgenic rice spiked with the purified recombinant protein. total immunoglobulin levels, mitogen-induced cell prolife ... | 2008 | 18215453 |
| molecular characterization of virulence defects in bacillus thuringiensis mutants. | sequence analysis of a virulence-attenuated bacillus thuringiensis signature tagged mutant 6f8 led to the identification of an 18 182 bp locus encoding 29 potential protein-coding orfs. thirteen of the 29 putative orfs were found to share extensive homology with genes on plasmid pe33l466 of the pathogenic bacillus cereus e33l strain. nine orfs were not only found in a cluster, but also in the same gene order, in both organisms. a number of mobile elements, including a transposon tn4430, a novel ... | 2008 | 18218018 |
| blocking binding of bacillus thuringiensis cry1aa to bombyx mori cadherin receptor results in only a minor reduction of toxicity. | bacillus thuringiensis cry1aa insecticidal protein is the most active known b. thuringiensis toxin against the forest insect pest lymantria dispar (gypsy moth), unfortunately it is also highly toxic against the non-target insect bombyx mori (silk worm). | 2008 | 18218126 |
| a tool box for operational mosquito larval control: preliminary results and early lessons from the urban malaria control programme in dar es salaam, tanzania. | as the population of africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. | 2008 | 18218148 |
| study of bt impact on caddisflies overstates its conclusions: response to rosi-marshall et al. | 2008 | 18218776 | |
| molecular characterization of spodoptera frugiperda-bacillus thuringiensis cry1ca toxin interaction. | the use of bacillus thuringiensis cry delta-endotoxins as bioinsecticides is threatened by the possibility of pest resistance. determining transcriptional profiles of midgut cells early in cry toxin poisoning is crucial for understanding the biochemical and molecular aspects of insect detoxification and for sustained use of such toxins. in this study, transcriptional responses of midgut cells from spodoptera frugiperda third-instar larvae following treatment with cry1ca were investigated. suppre ... | 2008 | 18222513 |
| bacillus thuringiensis cry1ac toxin-binding and pore-forming activity in brush border membrane vesicles prepared from anterior and posterior midgut regions of lepidopteran larvae. | it is generally accepted that bacillus thuringiensis cry toxins insert into the apical membrane of the larval midgut after binding to specific receptors, and there is evidence that the distribution of binding molecules along the midgut is not uniform. by use of the voltage-sensitive dye disc(3)(5) and (125)i-labeled cry1ac, we have measured the effect of cry1ac in terms of permeabilization capacity and of binding parameters on brush border membrane vesicles (bbmv) prepared from the anterior and ... | 2008 | 18223107 |
| employing phage display to study the mode of action of bacillus thuringiensis cry toxins. | phage display is an in vitro method for selecting polypeptides with desired properties from a large collection of variants. the insecticidal cry toxins produced by bacillus thuringiensis are highly specific to different insects. various proteins such as cadherin, aminopeptidase-n (apn) and alkaline phosphatase (alp) have been characterized as potential cry-receptors. we used phage display to characterize the cry toxin-receptor interaction(s). by employing phage-libraries that display single-chai ... | 2008 | 18226423 |
| the pre-pore from bacillus thuringiensis cry1ab toxin is necessary to induce insect death in manduca sexta. | the insecticidal cry toxins from bacillus thuringiensis bacteria are pore-forming toxins that lyse midgut epithelial cells in insects. we have previously proposed that they form pre-pore oligomeric intermediates before membrane insertion. for formation of these oligomers coiled-coil structures are important, and helix alpha-3 from cry toxins could form coiled-coils. our data shows that different mutations in helix alpha-3 are affected in pore formation and toxicity. mutants affected in toxicity ... | 2008 | 18226424 |
| enhanced exocytosis of the receptor bt-r(1) induced by the cry1ab toxin of bacillus thuringiensis directly correlates to the execution of cell death. | cry1ab toxin produced by bacillus thuringiensis exerts insecticidal action upon binding to bt-r(1), a cadherin receptor localized in the midgut epithelium of the tobacco hornworm manduca sexta. the univalent binding of toxin to receptor transmits a death signal into the cell and turns on a multi-step signal transduction pathway involving adenylyl cyclase (ac) and protein kinase a (pka), which drives the biochemical events that culminate in oncotic cell death. here, we report that cell killing by ... | 2008 | 18230416 |
| frequency of alleles conferring resistance to the bt toxins cry1ac and cry2ab in australian populations of helicoverpa armigera (lepidoptera: noctuidae). | helicoverpa armigera (hübner) (lepidoptera: noctuidae) is an important lepidopteran pest of cotton (gossypium spp.) in australia and the old world. from 2002, f2 screens were used to examine the frequency of resistance alleles in australian populations of h. armigera to bacillus thuringiensis (bt) crylac and cry2ab, the two insecticidal proteins present in the transgenic cotton bollgard ii. at that time, ingard (expressing cry1ac) cotton had been grown in australia for seven seasons, and bollgar ... | 2007 | 18232402 |