Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| diseases of mites. | an overview is given of studies on diseases of mites. knowledge of diseases of mites is still fragmentary but in recent years more attention has been paid to acaropathogens, often because of the economic importance of many mite species. most research on mite pathogens concerns studies on fungal pathogens of eriophyoids and spider mites especially. these fungi often play an important role in the regulation of natural mite populations and are sometimes able to decimate populations of phytophagous ... | 2000 | 11201358 |
| pcr-based identification of bacillus thuringiensis isolated from soil samples in nigeria. | six isolates of bacillus thuringiensis isolated from soil samples confirmed to be toxic to mosquito larvae were differentiated using a pcr-based technique. three of these isolates initially identified using a serological technique were further differentiated with the pcr amplification of the delta-endotoxin target sequences. using the total dna of isolates as template, at least four isolates yielded amplicons one or all the crystal protein genes, cryi a, b, c, or ii with sizes ranging from 238-1 ... | 2000 | 11204207 |
| cdna cloning of the cry1aa receptor variants from bombyx mori and their expression in mammalian cells. | we cloned cdna of three variants of btr175, a putative bombyx mori receptor for bacillus thuringiensis cry1aa delta-endotoxin by pcr. these variants were likely to be allelic to btr175. cdna of btr175b, the most distant variant from btr175, was introduced into mammalian cells. btr175b protein was expressed in the plasma membrane of the cells and showed binding activity to cry1aa. | 2000 | 11210135 |
| [duration of the larvicidal effect of spore crystalline mass of bacteria bacillus thuringiensis spp. israelensis and bacillus sphaericus in the laboratory setting]. | the duration of action of sporocrystalline mass of bacillus thuringiensis spp. israelensis (bti) and bacillus sphaericus (bsph) against three-age larvae of an. stephensi mosquitoes was studied in the laboratory setting. the duration of action depends on its initial concentration. the optimal concentration should be at least 10(5) spores/ml for an. stephensi larvae. decreasing the concentration reduces the duration of larvicidal action. increasing the number of the larvae placed also diminishes t ... | 2000 | 11210410 |
| directed molecular evolution in plant improvement. | directed molecular evolution is a powerful tool to evolve genes with commercial applications. its most common application is to evolve enzymes with improved kinetics, altered substrate or product specificities, or improved function in different cellular environments. the technique is beginning to be applied to goals relevant to agriculture. recent examples include the generation of novel carotenoids, enhanced herbicide detoxification, and the improvement of insect resistance genes. | 2001 | 11228439 |
| identification of bacillus thuringiensis subsp. kurstaki strain hd1-like bacteria from environmental and human samples after aerial spraying of victoria, british columbia, canada, with foray 48b. | aerial applications of foray 48b, which contains bacillus thuringiensis strain hd1, were carried out on 9 to 10 may, 19 to 21 may, and 8 to 9 june 1999 to control european gypsy moth (lymantria dispar) populations in victoria, british columbia, canada. a major assessment of the health impact of b. thuringiensis subsp. kurstaki was conducted by the office of the medical health officer of the capital health region during this period. environmental (air and water) and human (nasal swab) samples, co ... | 2001 | 11229889 |
| different mechanisms of resistance to bacillus thuringiensis toxins in the indianmeal moth. | susceptibility to protoxin and toxin forms of cry1ab and the binding of (125)i-labeled cry1ab and cry1ac has been examined in three plodia interpunctella colonies, one susceptible (688(s)) and two resistant (198(r) and dpl(r)) to bacillus thuringiensis. toxicological studies showed that the 198(r) colony was 11-fold more resistant to cry1ab protoxin than to cry1ab activated toxin, whereas the dpl(r) colony was 4-fold more resistant to protoxin versus toxin. binding results with (125)i-labeled to ... | 2001 | 11229895 |
| the bacillus thuringiensis cyt genes for hemolytic endotoxins constitute a gene family. | in the same way that cry genes, coding for larvicidal delta endotoxins, constitute a large and diverse gene family, the cyt genes for hemolytic toxins seem to compose another set of highly related genes in bacillus thuringiensis. although the occurrence of cyt hemolytic factors in b. thuringiensis has been typically associated with mosquitocidal strains, we have recently shown that cyt genes are also present in strains with different pathotypes; this is the case for the morrisoni subspecies, whi ... | 2001 | 11229896 |
| bt toxin uptake from soil by plants. | 2001 | 11231541 | |
| effects of a broad spectrum and biorational insecticides on parasitoids of the nantucket pine tip moth (lepidoptera: tortricidae). | we examined effects of aerial application of acephate (orthene), bacillus thuringiensis variety kurstaki berliner (foray), and tebufenozide (mimic) on larval/pupal parasitoids of the nantucket pine tip moth, rhyacionia frustrana (comstock), in the southwestern georgia coastal plain. parasitism of tip moths in acephate-treated plots was significantly lower than in untreated plots. bacillus thuringiensis and tebufenozide showed no significant effects on parasitism. a tachinid, lixophaga mediocris ... | 2001 | 11233099 |
| field efficacy of sweet corn hybrids expressing a bacillus thuringiensis toxin for management of ostrinia nubilalis (lepidoptera: crambidae) and helicoverpa zea (lepidoptera: noctuidae). | field studies were done in 1995-1996 to assess the efficacy of three sweet corn hybrids that express the bacillus thuringiensis (bt) toxin, crylab, against two lepidopteran pests, ostrinia nubilalis (hubner) and helicoverpa zea (boddie). the bt hybrids tested were developed by novartis seeds, using the event bt-11, which expresses bt toxin in green tissue as well as reproductive tissues including the tassel, silk, and kernel. bt hybrids were compared with a standard non-bt control or the non-bt ... | 2001 | 11233113 |
| greenhouse tests on resistance management of bt transgenic plants using refuge strategies. | experimental evaluation of the effectiveness of resistance management tactics is vital to help provide guidelines for the deployment of transgenic insecticidal crops. transgenic broccoli expressing a cry1ac gene of bacillus thuringiensis (bt) and the diamondback moth, plutella xylostella (l.), were used in greenhouse tests to evaluate the influence of size and placement of nontransgenic refuge plants on changes in resistance allele frequency and pest population growth. in the first test with an ... | 2001 | 11233120 |
| genetics of pink bollworm resistance to bacillus thuringiensis toxin cry1ac. | laboratory selection increased resistance of pink bollworm (pectinophora gossypiella) to the bacillus thuringiensis toxin cry1ac. three selections with cry1ac in artificial diet increased resistance from a low level to >100-fold relative to a susceptible strain. we used artificial diet bioassays to test f1 hybrid progeny from reciprocal crosses between resistant and susceptible strains. the similarity between f1 progeny from the two reciprocal crosses indicates autosomal inheritance of resistanc ... | 2001 | 11233121 |
| field evaluation of resistance of transgenic rice containing a synthetic cry1ab gene from bacillus thuringiensis berliner to two stem borers. | two transgenic rice (oryza sativa l.) lines, kmd1 and kmd2 at the r4 generation, transformed with a synthetic cry1ab gene from bacillus thuringiensis berliner, were first evaluated for stem borer resistance in the field during the rice growing season of 1998 in two areas of zhejiang province, china. both kmd1 and kmd2 were highly resistant to the stem borers chilo suppressalis (walker) and scirpophaga incertulas (walker), and were completely undamaged during the whole rice growing season. in con ... | 2001 | 11233125 |
| correlating differences in larval survival and development of bollworm (lepidoptera: noctuidae) and fall armyworm (lepidoptera: noctuidae) to differential expression of cry1a(c) delta-endotoxin in various plant parts among commercial cultivars of transgenic bacillus thuringiensis cotton. | differences in larval survival and development of bollworm, helicoverpa zea (boddie), and fall armyworm, spodoptera frugiperda (j. e. smith), respectively, were found to exist among commercially available cry1a(c) transgenic bacillus thuringiensis berliner (bt) varieties. using a quantification assay (elisa) to measure the levels of delta-endotoxin in two of these varieties ('dp 451b/rr' and 'nucotn 33b'), differences in the amount of delta-endotoxin present in various plant parts was correlated ... | 2001 | 11233127 |
| spider fauna in apple ecosystem of western oregon and its field susceptibility to chemical and microbial insecticides. | twelve families, 26 genera, and 30 identifiable spider species were found in surveys conducted in apple orchards of western oregon. the salticidae, linyphiidae, clubionidae, philodromidae, and theridiidae comprised 85.56% ofthe total spiders collected. the most common species in order of abundance were metaphidippus aeneolus curtis, spirembolus mundus chamberlin & ivie, cheiracanthium inclusum (hentz), philodromus spectabilis keyserling, eris marginata (walckenaer), and theridion lawrencei gerts ... | 2001 | 11233135 |
| species diagnosis and bacillus thuringiensis resistance monitoring of heliothis virescens and helicoverpa zea (lepidoptera: noctuidae) field strains from the southern united states using feeding disruption bioassays. | validation of a feeding disruption bioassay for the detection of resistance to bacillus thuringiensis toxin and species identification is reported using field strains of heliothis virescens and helicoverpa zea collected from the southern united states in 1998. feeding disruption is measured by a lack of fecal production from larvae exposed to a diagnostic concentration of cryiac in a blue indicator diet. the bioassay provided rapid (24 h) diagnosis of the species composition of larvae tested and ... | 2001 | 11233137 |
| efficacy of insecticides of different chemistries against helicoverpa zea (lepidoptera: noctuidae) in transgenic bacillus thuringiensis and conventional cotton. | six insecticides of different chemistries were evaluated against the cotton bollworm, helicoverpa zea (boddie), in non-b.t. (deltapine 'dp 5415', deltapine 'dp 5415rr') and transgenic bacillus thuringiensis (berliner) (b.t.) (deltapine 'nucotn 33b', deltapine 'dp 458 b/rr') cotton. in 1998, treatments consisted of three rates each of a pyrethroid (lambda-cyhalothrin), spinosyn (spinosad), carbamate (thiodicarb), pyrrole (chlorfenapyr), oxadiazine (indoxacarb), and avermectin (emamectin benzoate) ... | 2001 | 11233138 |
| differential efficacy evaluation of formulations of bacillus thuringiensis var israelensis against mosquitoes: a laboratory investigation. | the efficacy evaluation of three formulations; wettable powder (w.p.) floating pellet and beads of bacillus thuringiensis var israelensis (bti), revealed a greater susceptibility of the early larval instars of mosquitoes to bti, sensitivity of anophelines to floating pellet, culicines to bead and equal efficacy and faster kill of w.p. to all the mosquitoes tested. a greater persistence of the slow release formulations, floating pellet and beads for 49 and 28 days against anophelines and culicine ... | 1999 | 11243064 |
| screening of the bacillus thuringiensis cry1ac delta-endotoxin on the artificial phospholipid monolayer incorporated with brush border membrane vesicles of plutella xylostella by optical biosensor technology. | the binding of cry1ac, an insecticidal protein of bacillus thuringiensis, to a brush border membrane (bbm) isolated from midguts of the diamondback moth plutella xylostella was examined by surface plasmon resonance (spr)-based biosensor. bbm was mixed with 1,3-ditetradecylglycero-2-phosphocholine (pc14), a neutral charged artificial lipid, and was reconstructed to a monolayer on a hydrophobic chip for the biosensor. the binding of cry1ac to the reconstructed monolayer was analyzed by a two-state ... | 2001 | 11245889 |
| cadmium biosorption by a cadmium resistant strain of bacillus thuringiensis: regulation and optimization of cell surface affinity for metal cations. | a marine bacterial strain putatively identified as bacillus thuringiensis strain dm55, showed multiple heavy metal resistance and biosorption phenotypes. electron microscopic studies revealed that dm55 cells are encased in anionic cell wall polymers that can immobilize discrete aggregates of cations. factors affecting cell surface affinity for metal cations, monitored by means of cd2+ binding capability, are investigated. the mechanisms of cadmium resistance and cd2+ biosorption by the bacterium ... | 2000 | 11247032 |
| regeneration of cultured midgut cells after exposure to sublethal doses of toxin from two strains of bacillus thuringiensis. | toxin from two strains of bacillus thuringiensis (bt), aa 1-9 and hd-73, caused dose-dependent destruction of cultured midgut cells from heliothis virescens larvae. hd-73 toxin was more effective although, at the doses used, not all cells were killed. after 2 days of exposure to 0.8 pg/µl aa 1-9 or 0.06 pg/µl hd-73, columnar and goblet cell numbers declined to ca 20% of controls. in contrast, stem and differentiating cells increased to 140-200% of controls. the dynamic of depletion and replaceme ... | 2001 | 11249948 |
| rapid identification of bacillus cereus based on the detection of a 28.5-kilodalton cell surface antigen. | conventional procedures for the identification of suspect bacillus cereus isolated on mannitol-egg yolk-polymyxin (myp) agar may need several days. to facilitate the identification of the bacterium, an enzyme-linked immunosorbent assay (elisa) was developed. the assay was based on the detection of a 28.5-kda cell surface antigen of b. cereus. bacterial colonies grown on myp agar or nutrient agar were suspended in phosphate-buffered saline (ph 7.2) containing 0.1% teepol. the cell suspensions wer ... | 2001 | 11252478 |
| structural and functional studies of alpha-helix 5 region from bacillus thuringiensis cry1ab delta-endotoxin. | the crystal insecticidal proteins from bacillus thuringiensis are modular proteins comprised of three domains connected by single linkers. domain i is a seven alpha-helix bundle, which has been involved in membrane insertion and pore formation activity. site-directed mutagenesis has contributed to identify regions that might play an important role in the structure of the pore-forming domain within the membrane. there are several evidences that support that the hairpin alpha4-alpha5 inserts into ... | 2001 | 11257515 |
| kinetic resolution of chiral amines with omega-transaminase using an enzyme-membrane reactor. | a kinetic resolution process for the production of chiral amines was developed using an enzyme-membrane reactor (emr) and a hollow-fiber membrane contactor with (s)-specific omega-transaminases (omega-ta) from vibrio fluvialis js17 and bacillus thuringiensis js64. the substrate solution containing racemic amine and pyruvate was recirculated through the emr and inhibitory ketone product was selectively extracted by the membrane contactor until enantiomeric excess of (r)-amine exceeded 95%. using ... | 2001 | 11257600 |
| elevating the terms of the gm food debate. | 2001 | 11259173 | |
| [natural insecticides]. | 2001 | 11268634 | |
| reaping a biotech blunder. | 2001 | 11272263 | |
| risk assessment of etofenprox (vectron) on non-target aquatic fauna compared with other pesticides used as simulium larvicide in a tropical environment. | within the rotational scheme developed by the programme to fight the resistance of simulium damnosum to chemical larvicides, there was an operational gap at discharges between 5 and 70 m3 s(-1) for the treatment of rivers where resistance to organophosphates was present. the use of permethrin and carbosulfan was precluded because of risk of environmental impact and, bacillus thuringiensis ser. h-14 treatments were not envisageable due to cost and logistics constraints. among the possible complem ... | 2001 | 11272920 |
| the pathogenicity of bacillus thuringiensis ssp. kurstaki to gamma-irradiated cadra cautella (walker) (lepidoptera: phycitidae). | the present investigation deals with the effects of bacillus thuringiensis ssp. kurstaki on various biological parameters of gamma-irradiated cadra cautella. the pathogen, irradiation, and their combinations significantly affected the insects by increasing their mortality and developmental periods, reducing the pupal and adult survival (%), and the adult longevity and reproductive potential were also significantly reduced. it was observed that irradiation-pathogen combinations produced additive ... | 2001 | 11273688 |
| how bacillus thuringiensis has evolved specific toxins to colonize the insect world. | bacillus thuringiensis is a bacterium of great agronomic and scientific interest. together the subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. this is mainly determined by the arsenal of crystal proteins that the bacterium produces during sporulation. here we describe the properties of these toxin proteins and the current knowledge of the basis for their specificity. assessment of phylog ... | 2001 | 11275324 |
| lack of cross-resistance to cry19a from bacillus thuringiensis subsp. jegathesan in culex quinquefasciatus (diptera: culicidae) resistant to cry toxins from bacillus thuringiensis subsp. israelensis. | culex quinquefasciatus mosquitoes with high levels of resistance to single or multiple toxins from bacillus thuringiensis subsp. israelensis were tested for cross-resistance to the bacillus thuringiensis subsp. jegathesan polypeptide cry19a. no cross-resistance was detected in mosquitoes that had been selected with the cry11a, cry4a and cry4b, or cry4a, cry4b, cry11a, and cyta toxins. a low but statistically significant level of cross-resistance, three to fourfold, was detected in the colony sel ... | 2001 | 11282656 |
| survey raises concerns about bt resistance management. | 2001 | 11283558 | |
| expression of mosquito active toxin genes by a colombian native strain of the gram-negative bacterium asticcacaulis excentricus. | mosquito control with biological insecticides, such as bacillus sp. toxins, has been used widely in many countries. however, rapid sedimentation away from the mosquito larvae feeding zone causes a low residual effect. in order to overcome this problem, it has been proposed to clone the bacillus toxin genes in aquatic bacteria which are able to live in the upper part of the water column. two strains of asticcacaulis excentricus were chosen to introduce the b. sphaericus binary toxin gene and b. t ... | 2001 | 11285507 |
| the tc genes of photorhabdus: a growing family. | the toxin complex (tc) genes of photorhabdus encode insecticidal, high molecular weight tc toxins. these toxins have been suggested as useful alternatives to those derived from bacillus thuringiensis for expression in insect-resistant transgenic plants. although photorhabdus luminescens is symbiotic with nematodes that kill insects, tc genes have recently been described from other insect-associated bacteria such as serratia entomophila, an insect pathogen, and yersinia pestis, the causative agen ... | 2001 | 11286884 |
| antibacterial efficacy of triclosan-incorporated polymers. | triclosan (2, 4, 4'-trichloro-2'-hydroxydiphenyl ether) is a broad-spectrum antimicrobial agent, routinely used in various personal care products.(1) it is also incorporated into polymers through melt-mixing, with the aim of providing persistent antibacterial action on the surface of the polymer.(2,3) such triclosan-incorporated polymers can be promoted for hospital use as fabric seat covers, tables, chairs, and clothing. we assessed the antibacterial efficacy of triclosan-incorporated polymer d ... | 2001 | 11287882 |
| isolation and insecticidal effects of some bacteria from euproctis chrysorrhoea l. (lepidoptera: lymantriidae). | in this study, we investigated the bacterial pathogens of euproctis chrysorrhoea and tested for their insecticidal activities. based on colony color and morphology, four isolates were determined. according to morphological, physiological and biochemical characters of the isolates, they were identified as enterobacter aerogenes, lactobacillus sp., bacillus thuringiensis and micrococcus luteus. the insecticidal effects of these bacterial isolates on third-fourth instar larvae of euproctis chrysorr ... | 2000 | 11293654 |
| thuricin 7: a novel bacteriocin produced by bacillus thuringiensis bmg1.7, a new strain isolated from soil. | detection and identification of new antagonistic activities towards bacillus cereus and relatives. | 2001 | 11298934 |
| immunological analysis of phloem sap of bacillus thuringiensis corn and of the nontarget herbivore rhopalosiphum padi (homoptera: aphididae) for the presence of cry1ab. | phloem sap of transgenic bacillus thuringiensis (bt) corn expressing a truncated form of the b. thuringiensis delta-endotoxin cry1ab, sap sucking aphids feeding on bt corn and their honeydew were analysed for presence of cry1ab using elisa. phloem sap of bt and non-bt corn was collected using a newly developed technique with a microcapillary being directly inserted into the phloem tubes. using this technique, no cry1ab was detected in the phloem sap. in contrast, measurable concentrations of cry ... | 2001 | 11298965 |
| isolation and partial characterization of gypsy moth btr-270, an anionic brush border membrane glycoconjugate that binds bacillus thuringiensis cry1a toxins with high affinity. | btr-270, a gypsy moth (lymantria dispar) brush border membrane molecule that binds bacillus thuringiensis (bt) cry1a toxins with high affinity, was purified by preparative gel electrophoresis. rabbit antibodies specific for the bt toxin-binding molecule were raised. attempts to label btr-270 by protein-directed techniques were futile, but it was degraded by proteases with broad specificity indicating the presence of a peptide. carbohydrate was detected by labeling with digoxigenin hydrazide foll ... | 2001 | 11304752 |
| update on the detection of beta-exotoxin in bacillus thuringiensis strains by hplc analysis. | the current work aimed to study the presence of beta-exotoxin by high-performance liquid chromatography (hplc) in supernatant fluids from final whole cultures of the 69 type strains and 13 subtypes of bacillus thuringiensis strains, as well as from some insecticidal strains. | 2001 | 11309078 |
| bacillus thuringiensis cry3ca1 protein is toxic to the colorado potato beetle, leptinotarsa decemlineata (say). | we expressed the wild-type cry3aa3 and cry3ca1 bacillus thuringiensis genes, which code for insecticidal proteins, in an escherichia coli expression system. highly purified preparations of the soluble delta-endotoxins were used to perform comparative bioassays with third-instar larvae of the colorado potato beetle (cpb). acute mortality data showed that cry3ca1 (ld(50) = 320.1 ng) was 2-fold more toxic than cry3aa3 (ld(50) = 672.9 ng). we also compared the chronic effects of sublethal doses of t ... | 2001 | 11312696 |
| a theoretical model of the tridimensional structure of bacillus thuringiensis subsp. medellin cry 11bb toxin deduced by homology modelling. | cry11bb is an insecticidal crystal protein produced by bacillus thuringiensis subsp. medellin during its stationary phase; this partial differential-endotoxin is active against dipteran insects and has great potential for mosquito borne disease control. here, we report the first theoretical model of the tridimensional structure of a cry11 toxin. the tridimensional structure of the cry11bb toxin was obtained by homology modelling on the structures of the cry1aa and cry3aa toxins. in this work we ... | 2001 | 11313644 |
| specificity of lectin activity of bacillus thuringiensis parasporal inclusion proteins. | sheep erythrocyte-agglutinating parasporal inclusion proteins from four bacillus thuringiensis strains (fitc-20, fitc-73, fitc-76 and ibc-1456) were examined for lectin activity against erythrocytes from four mammalian (rabbit, horse, cow and guinea pig) and an avian (chicken) species. of the five erythrocyte species, only rabbit cells were agglutinated with the protein of the human cancer cell-killing strain ibc-1456. no haemagglutination (ha) activities were shown in other protein-erythrocyte ... | 2001 | 11314244 |
| [characteristic of mutants of pseudomonas putida ipm-36 recombinant strains, selected by anticipating growth on a media containing an inducer of cry3a gene expression]. | induction of the expression of the delta-endotoxin gene from bacillus thuringiensis var. tenebrionis in the recombinant strain pseudomonas putida ipm-36 negatively affected the viability and the growth rate of the culture. in order to optimize the insecticide production by the recombinant strain, mutant clones exhibiting anticipating growth on an inducer-containing medium were selected and studied. these clones differed in such aspects as the localization of mutations (either in plasmid pbtn11, ... | 2000 | 11315669 |
| a general strategy for identification of s-layer genes in the bacillus cereus group: molecular characterization of such a gene in bacillus thuringiensis subsp. galleriae nrrl 4045. | despite its possible role in virulence, there has been little molecular characterization of members of the s-layer protein family of the bacillus cereus group. it is hypothesized that the components of the s-layers are likely to display similar anchoring structures in bacillus thuringiensis and bacillus anthracis. based on inferred sequence similarities, a dna fragment encoding the cell-wall-anchoring domain of an s-layer component of bac: thuringiensis subsp. galleriae nrrl 4045 was isolated. t ... | 2001 | 11320137 |
| a new insertion sequence, is231m, in an autoagglutinable isolate of bacillus thuringiensis. | an insertion sequence was isolated from an autoagglutinable strain of bacillus thuringiensis. analysis of its dna sequence revealed high homology to the is231 family. the name is231m is proposed for this new insertion sequence. is231m is 1652 bp long and is delimited by two imperfect 20-bp inverted repeat sequences with two mismatches, which are flanked by two perfect 11-bp direct repeats (drs). the region upstream of the open reading frame, presumed to be able to form a stable hairpin structure ... | 2001 | 11322825 |
| role of alpha-helix seven of bacillus thuringiensis cry1ab delta-endotoxin in membrane insertion, structural stability, and ion channel activity. | domain i of the cry1ab insecticidal toxic protein has seven alpha-helices and is considered to be involved in the ion channel activity. while other alpha-helices, particularly alpha-4 and alpha-5, have been extensively explored, the remaining alpha-helices have been slightly studied. site-directed mutagenesis was used to generate mutations throughout sequences encoding the alpha-helix 7 to test its role in ion channel function. every amino acid residue in alpha-helix 7 was mutated to alanine. mo ... | 2001 | 11327876 |
| association of pcr and feeding bioassays as a large-scale method to screen tropical bacillus thuringiensis isolates for a cry constitution with higher insecticidal effect against spodoptera frugiperda (lepidoptera: noctuidae) larvae. | to verify whether the presence of any of the cry1c, 1d, 1e and 1f genes could be associated with high toxicity against fall armyworm. | 2001 | 11328507 |
| large-scale management of insect resistance to transgenic cotton in arizona: can transgenic insecticidal crops be sustained? | a major challenge for agriculture is management of insect resistance to toxins from bacillus thuringiensis (bt) produced by transgenic crops. here we describe how a large-scale program is being developed in arizona for management of resistance to bt cotton in the pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), and other insect pests of cotton. financial support from growers makes this program possible. collaboration between the arizona cotton research and protectio ... | 2001 | 11332820 |
| response of cotton to prebloom square loss. | in 1996 and 1997, various intensities of prebloom square removal were applied to three cultivars of cotton grown in mississippi. with the exception of one cultivar in 1997, all cultivars were b. thuringiensis (bt)-transgenic cotton. at harvest, the number of bolls and seed cotton weight was recorded for all plants in each square removal treatment. all cultivars responded similarly to square loss. a yield increase (overcompensation) was observed in the treatment where all squares were removed fro ... | 2001 | 11332830 |
| establishment of cry9c susceptibility baselines for european corn borer and southwestern corn borer (lepidoptera: crambidae). | in 1997 and 1998, cry9c susceptibility baselines were established for field-collected populations of european corn borer, osrinia nubilalis (hubner), and southwestern corn borer, diatraea grandiosella dyar. bioassay of neonate european corn borer larvae of 16 colonies collected from the midwestern united states indicated lc50 values ranging from 13.2 to 65.1 ng of cry9c protein per square centimeter. neonate european corn borer lc50 values ranged from 46.5 to 214 ng/cm2. neonate larvae of three ... | 2001 | 11332831 |
| treatment thresholds for stink bugs (hemiptera: pentatomidae) in cotton. | the green stink bug, acrosternum hilare (say), the southern green stink bug, nezara viridula (l), and the brown stink bug, euschistus servus (say), were predominant phytophagous pentatomidae detected during 1995-1997 in cotton in south carolina. these species occurred in similar numbers in conventional and transgenic cotton 'nucotn33b', containing the gene for expression of cryia(c) delta-endotoxin of bacillus thuringiensis berliner variety kurstaki. adult stink bugs moved into cotton from wild ... | 2001 | 11332832 |
| life history attributes of indian meal moth (lepidoptera: pyralidae) and angoumois grain moth (lepidoptera: gelechiidae) reared on transgenic corn kernels. | the indian meal moth, plodia interpunctella (hübner), and angoumois grain moth, sitotroga cerealella (olivier), are two globally distributed stored-grain pests. laboratory experiments were conducted to examine the impact that corn (zea mays l.) kernels (i.e., grain) of some bacillus thuringiensis berliner (bt) corn hybrids containing crylab bt delta-endotoxin have on life history attributes of indian meal moth and angoumois grain moth. stored grain is at risk to damage from indian meal moth and ... | 2001 | 11332858 |
| lipids of brush border membrane vesicles (bbmv) from plutella xylostella resistant and susceptible to cry1ac delta-endotoxin of bacillus thuringiensis. | plutella xylostella (px) that were 130000-fold more resistant to cry1ac were selected from the susceptible strain and maintained in the laboratory. the lc50 of the susceptible strain (pxs) was 0.38 microg toxin/g diet, whereas that of the resistant strain (pxr) was 4800 microg toxin/g diet. brush border membrane vesicles (bbmv) were prepared from both pxs and pxr. in ligand blot analysis, cry1ac bound to a 120-kda protein of bbmv; however, the intensity of the band was almost equal in both strai ... | 2001 | 11337261 |
| lipid-induced pore formation of the bacillus thuringiensis cry1aa insecticidal toxin. | after activation, bacillus thuringiensis (bt) insecticidal toxin forms pores in larval midgut epithelial cell membranes, leading to host death. although the crystal structure of the soluble form of cry1aa has been determined, the conformation of the pores and the mechanism of toxin interaction with and insertion into membranes are still not clear. here we show that cry1aa spontaneously inserts into lipid mono- and bilayer membranes of appropriate compositions. fourier transform infrared spectros ... | 2001 | 11337891 |
| population genetics of chrysomela tremulae: a first step towards management of transgenic bacillus thuringiensis poplars populus tremula x .p. tremuloides. | many strategies have been proposed for delaying the development of insect resistance to bacillus thuringiensis (bt). the current paradigm for bt resistance management is the high dose-refuge strategy. for this strategy to be successful: (i) heterozygotes must be killed in treated areas, (ii) resistant alleles must be rare (frequency < 10-3), and (iii) there must be a high level of gene flow between populations to ensure random mating. we studied gene flow within and between populations with a vi ... | 2000 | 11338433 |
| a 28 kda protein of the bacillus thuringiensis serovar shandongiensis isolate 89-t-34-22 induces a human leukemic cell-specific cytotoxicity. | a 28 kda protein that exhibits cytocidal activity specific for human leukemic t (molt-4) cells was purified from proteinase k-digested parasporal inclusion of a bacillus thuringiensis serovar shandongiensis isolate. the n-terminal sequence of the protein was identical with that of the 32 kda protein, regarded as a protoxin, of the inclusion proteins. the median effective concentration of this protein was 0.23 microg/ml against molt-4 cells and its specific activity was 7.9 times greater than tha ... | 2001 | 11343791 |
| will genetically modified foods be allergenic? | foods produced through agricultural biotechnology, including such staples as corn, soybeans, canola, and potatoes, are already reaching the consumer marketplace. agricultural biotechnology offers the promise to produce crops with improved agronomic characteristics (eg, insect resistance, herbicide tolerance, disease resistance, and climatic tolerance) and enhanced consumer benefits (eg, better taste and texture, longer shelf life, and more nutritious). certainly, the products of agricultural bio ... | 2001 | 11344340 |
| recovery of commercially produced bacillus thuringiensis var. israelensis and bacillus sphaericus from tires and prevalence of bacilli in artificial and natural containers. | we conducted surveys to identify the species of spore-forming bacteria present in natural and artificial containers. most of our samples came from illinois. identification was based on the cellular fatty acid composition of the bacterial cell wall. in addition, we utilized a custom database for commercially produced strains of bacillus thuringiensis var. israelensis (bti) and b. sphaericus, to differentiate between larvicidal isolates with commercial or native origin. native bti was present at l ... | 2001 | 11345416 |
| evaluation of liquid bacillus thuringiensis var. israelensis products for control of australian aedes arbovirus vectors. | laboratory bioassay studies were conducted in southeast queensland, australia, on the efficacy of teknar, vectobac 12as, and cybate (active ingredient: 1,200 international toxic units bacillus thuringiensis var. israelensis [bti]) against 3rd instars of the arbovirus vectors aedes aegypti, ae. notoscriptus, ae. vigilax, and ae. camptorhynchus. probit analyses were then used to determine ld50 (median lethal dose), ld50, and lethal dose ratios (ldr). aedes aegypti and ae. notoscriptus, both contai ... | 2001 | 11345425 |
| diamondback moth compensatory consumption of protease inhibitor-transformed plants. | prior study of the effect of protease inhibitors (pis) on diamondback moths suggests that moths are resistant to them, so pis represent an ineffective defence against moths. however, our data suggest that diamondback moths do suffer lower growth rates when they consume plants transformed with potato protease inhibitor (pi2), but that effect is hidden by compensatory consumption. plants, instead of gaining an advantage by lowering the insect growth rate, suffer a disadvantage as moths consume mor ... | 2001 | 11348512 |
| development of a self floating slow release formulation of bacillus thuringiensis var. israelensis and its larvicidal activity. | alginate encapsulated b. thuringiensis var. israelensis (b. t. i.) self floating type formulations were prepared. its spore release rate, floating efficacy and larvicidal activity against culex quinquefasiatus were tested in the laboratory. the larval mortality of 91-100% was induced by the floating formulation with a mean spore release of 3.04 x 10(4)/ml/day from 6th day to 27th day. from day 28 to 33 the mean number of spores released were 1.16 x 10(4)/ml/day which caused 72.2-88.2% mortality. ... | 2001 | 11349533 |
| mortality of colorado potato beetle (leptinotarsa decemlineata) after sublethal stress with the cryiiia delta-endotoxin of bacillus thuringiensis and subsequent exposure to beauveria bassiana. | acute or chronic sublethal exposure of colorado potato beetle larvae to the cryiiia delta-endotoxin of bacillus thuringiensis berliner did not significantly (p > 0.05) alter their subsequent susceptibility to beauveria bassiana (balsamo) vuillemin. during the period of exposure to b. bassiana there was continued mortality from previous exposure to delta-endotoxin, and b. bassiana also caused significant mortality. acute and chronic exposure to delta-endotoxin significantly prolonged larval devel ... | 2001 | 11356052 |
| prospects for reducing fumonisin contamination of maize through genetic modification. | fumonisins (fb) are mycotoxins found in (italic)fusarium verticillioides-infected maize grain worldwide. attention has focused on fbs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. fbs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. among the strategies for reducing risk of fb contamination in maize supplied to the market, developme ... | 2001 | 11359705 |
| transformation studies of bacillus thuringiensis cryic gene into a nitrogen-fixing azospirillum lipoferum. | a lepidopteran toxin gene, cryic (psb607) from entomopathogenic bacillus thuringiensis subsp. aizawai was introduced into nitrogen-fixing azospirillum lipoferum by transformation. regeneration of spheroplasts was achieved at 99% with 39% frequency of regeneration. transformants were screened on nb kanamycin with ampicillin plates and 4 transformants were selected after ten generations. sds-page and western blot analysis confirmed the presence of a 68 kda protein in the transformants. studies on ... | 2001 | 11371015 |
| cross-resistance and inheritance of resistance to bacillus thuringiensis toxin cry1ac in diamondback moth (plutella xylostella l) from lowland malaysia. | a field population of plutella xylostella from malaysia (serd4) was divided into five sub-populations and four were selected (g2-g5) with the bacillus thuringiensis insecticidal crystal (cry) toxins cry1ac, cry1ab, cry1ca and cry1da. bioassay at g6 gave resistance ratios of 88, 5, 2 and 3 for cry1ac, cry1ab, cry1ca and cry1da respectively compared with the unselected sub-population (unsel-serd4). the cry1ac-selected population showed little cross-resistance to cry1ab, cry1ca and cry1da, (3-, 2- ... | 2001 | 11374157 |
| exchange of domain i from bacillus thuringiensis cry1 toxins influences protoxin stability and crystal formation. | influence of domain i exchange on the stability and production of bacillus thuringiensis cry1 protoxins as well as on the shape of inclusion and toxicity to spodoptera exigua and plutella xylostella larvae was investigated. chimeric genes were prepared by exchanging the regions coding for domain i between cry1aa, cry1ab, cry1ac, cry1c, and cry1e. the accc chimera accumulated into bipyramidal inclusion bodies, whereas cee produced round-shaped inclusion bodies, and ecc and aaee protoxins produced ... | 2001 | 11375655 |
| cloning and expression of the binary toxin gene from bacillus sphaericus iab872 in a crystal-minus bacillus thuringiensis subsp. israelensis. | bacillus sphaericus iab872 has high toxicity against susceptible culex spp. and medium larvicidal activity against binary toxin-resistant culex spp. sequence analysis revealed that the sequence of the binary toxin gene from iab872 was totally identical to that of the reference strain 2362. the recombinant plasmids were introduced into an acrystalliferous b. thuringiensis strain 4q7, and the resulting transformants produced parasporal inclusion composed of 51 kda and 42 kda proteins during sporul ... | 2001 | 11375659 |
| structure of cry2aa suggests an unexpected receptor binding epitope. | genetically modified (gm) crops that express insecticidal protein toxins are an integral part of modern agriculture. proteins produced by bacillus thuringiensis (bt) during sporulation mediate the pathogenicity of bt toward a spectrum of insect larvae whose breadth depends upon the bt strain. these transmembrane channel-forming toxins are stored in bt as crystalline inclusions called cry proteins. these proteins are the active agents used in the majority of biorational pesticides and insect-resi ... | 2001 | 11377201 |
| mutations at the arginine residues in alpha8 loop of bacillus thuringiensis delta-endotoxin cry1ac affect toxicity and binding to manduca sexta and lymantria dispar aminopeptidase n. | the functional role of the alpha8 loop residues in domain ii of bacillus thuringiensis cry1ac toxin was examined. alanine substitution mutations were introduced in the residues from 275 to 293. among the mutant toxins, substitutions at r281 and r289 affected toxicity to manduca sexta and lymantria dispar. loss of toxicity by these mutant toxins was well correlated with reductions in binding affinity for brush border membrane vesicles and the purified receptor, aminopeptidase n (apn), from both i ... | 2001 | 11377423 |
| cellular localization and characterization of the bacillus thuringiensis orf2 crystallization factor. | in vivo crystallization of the bacillus thuringiensis insecticidal protein toxin cry2aa has been studied in the presence and absence of its associated crystallization factor orf2. when expressed in the same cell, both proteins were localized to the cuboidal cytoplasmic crystal. when expressed in the absence of cry2aa, orf2 was randomly distributed throughout the cytoplasm. cry2aa when expressed in the absence of orf2 did not form visible crystals but could be recovered from the insoluble fractio ... | 2001 | 11381328 |
| bacillus thuringiensis: a common member of microflora in activated sludges of a sewage treatment plant. | bacillus thuringiensis was recovered at a high frequency from activated-sludge system environments in an urban sewage-digestive plant. all of the test materials, sampled at several digesting steps, contained the organism. of 515 colonies belonging to the b. cereus/b. thuringiensis group, 45 (8.7%) were assigned to b. thuringiensis. the highest density of this bacterium was 1.6 x 103 cfu/ml in a scum sample of the first aeration basin. among the 45 isolates, 7 were assigned to the known h serovar ... | 2001 | 11381335 |
| mapping the epitope in cadherin-like receptors involved in bacillus thuringiensis cry1a toxin interaction using phage display. | in susceptible lepidopteran insects, aminopeptidase n and cadherin-like proteins are the putative receptors for bacillus thuringiensis (bt) toxins. using phage display, we identified a key epitope that is involved in toxin-receptor interaction. three different scfv molecules that bind cry1ab toxin were obtained, and these scfv proteins have different amino acid sequences in the complementary determinant region 3 (cdr3). binding analysis of these scfv molecules to different members of the cry1a t ... | 2001 | 11384982 |
| expression in spodoptera frugiperda (sf21) insect cells of bt-r(1), a cadherin-related receptor from manduca sexta for bacillus thuringiensis cry1ab toxin. | the cadherin-related receptor of manduca sexta, bt-r(1), for the cry1a family of bacillus thuringiensis insecticidal toxins, was expressed in cultured spodoptera frugiperda (sf21) insect cells utilizing the expression vector deltaop-gp64. recombinant bt-r(1) was released by the sf21 cells in soluble form into the culture medium and represents approximately 58% of total bt-r(1) produced by the cells. the soluble protein was purified by affinity chromatography using cry1ab toxin coupled to sepharo ... | 2001 | 11388812 |
| highly toxic and broad-spectrum insecticidal bacillus thuringiensis engineered by using the transposon tn917 and protoplast fusion. | the chromosome of the bacillus thuringiensis strain s184 that was toxic against the third instar larvae of spodoptera litura with the lc(50) of 9.74 microg/ml was successfully integrated into two genes of cyt1aa and cry11aa using the transposon tn917, yielding the primary engineered strain tnx. the strain tnx was highly toxic to the third instar larvae of culex pipiens fatigans with the lc(50) of 5.12 ng/ml which was 1.82-fold higher than that of b. thuringiensis subsp. israelensis, but lowly to ... | 2001 | 11391474 |
| comparative sensitivity to uv-b radiation of two bacillus thuringiensis subspecies and other bacillus sp. | susceptibility of bacillus thuringiensis spores and toxins to the uv-b range (280--330 nm) of the solar spectrum reaching earth's surface may be responsible for its inactivation and low persistence in nature. spores of the mosquito larvicidal b. thuringiensis subsp. israelensis were significantly more resistant to uv-b than spores of the lepidopteran-active subsp. kurstaki. spores of subsp. israelensis were as resistant to uv-b as spores of b. subtilis and more resistant than spores of the close ... | 2001 | 11391479 |
| discrimination between bacterial spore types using time-of-flight mass spectrometry and matrix-free infrared laser desorption and ionization. | we demonstrate that molecular ions with mass-to-charge ratios (m/z) ranging from a few hundred to 19 050 can be desorbed from whole bacterial spores using infrared laser desorption and no chemical matrix. we have measured the mass of these ions using time-of-flight mass spectrometry and we observe that different ions are desorbed from spores of bacillus cereus, bacillus thuringiensis, bacillus subtilis, and bacillus niger. our results raise the possibility of identifying microorganisms using mas ... | 2001 | 11393860 |
| cloning and nucleotide sequence of a new insertion sequence, is231n, from a non-serotypable strain of bacillus thuringiensis. | a new is231 variant, is231n, has been isolated from an autoagglutinable, non-serotypable strain of b. thuringiensis. is231n is 1654 bp in length and is delimited by two incomplete 20-bp inverted repeats (irl and irr) with two mismatches. no direct repeats (drs) were found at the right and left borders of is231n. surprisingly, is231n contains three open reading frames (orfs) that could code for polypeptides of 329 (orf1), 118 (orf2), and 17 (orf3) amino acids, respectively. is231n lacks the 5th c ... | 2001 | 11400069 |
| oligopeptide permease is required for expression of the bacillus thuringiensis plcr regulon and for virulence. | plcr is a pleiotropic regulator of virulence factors in the insect pathogen bacillus thuringiensis and in the opportunistic human pathogen bacillus cereus. it activates the transcription of at least 15 genes encoding extracellular proteins, including phospholipases c, proteases and enterotoxins. expression of the plcr gene is autoregulated and activated at the onset of stationary phase. here, we used mini-tn10 transposition to generate a library of b. thuringiensis mutants, with the goal of char ... | 2001 | 11401703 |
| assessment of toxic potential of local jordanian bacillus thuringiensis strains on drosophila melanogaster and culex sp. (diptera). | to assess the toxic potential of different local jordanian bacillus thuringiensis isolates on larvae of drosophila melanogaster and culex sp. | 2001 | 11412316 |
| source-sink dynamics between transgenic and non-transgenic habitats and their role in the evolution of resistance. | the interaction of population dynamics and movement among two habitat types (toxic transgenic fields and nontoxic refuge fields) on the evolution of insecticide resistance was examined in two different simulation models. the two models were developed to test the hypothesis that increasing habitat grain from fine-grained to coarse-grained, and the resultant increase in nonrandom mating, would increase the rate of local adaptation, here the evolution of resistance. the first model, a complex, stoc ... | 2001 | 11425026 |
| effect of planting dates and bacillus thuringiensis corn on the population dynamics of european corn borer (lepidoptera: crambidae). | field studies were conducted to determine how field corn, zea mays l., phenologies in combination with transgenic bacillus thuringiensis berliner (bt) corn and non-bt (near isogenic) corn could affect egg laying by female european corn borer, ostrinia nubilalis (hubner), and subsequent larval injury. transgenic bt (events 176 and bt11) and non-bt corn was planted at three different times to assess the use of early- and late- planted bt corn as a means for egg recruitment to these targeted planti ... | 2001 | 11425031 |
| impact of bt cottons expressing one or two insecticidal proteins of bacillus thuringiensis berliner on growth and survival of noctuid (lepidoptera) larvae. | a series of laboratory assays were performed to compare the relative impact of commercial and experimental cultivars of cotton, gossypium hirsutum (l.), expressing zero, one, or two insecticidal proteins of bacillus thuringiensis berliner, on several lepidopteran pests. assays in which larvae were fed fresh plant tissue indicated that dual-toxin b. thuringiensis (bt) cultivars, expressing both cry1ac and cry2ab endotoxins of b. thuringiensis, were more toxic to bollworms, helicoverpa zea (boddie ... | 2001 | 11425033 |
| expression of the p20 gene from bacillus thuringiensis h-14 increases cry11a toxin production and enhances mosquito-larvicidal activity in recombinant gram-negative bacteria. | experimental analyses with recombinant escherichia coli and pseudomonas putida transformed with plasmids bearing genes coding for the cry11a toxin and p20 protein from bacillus thuringiensis h-14 showed that cells producing both proteins were more toxic when fed to third-instar aedes aegypti larvae than were cells expressing cry11a alone; the 50% lethal concentrations were in the range of 10(4) to 10(5) cells/ml. western blots revealed a higher production of cry11a when the p20 gene was coexpres ... | 2001 | 11425714 |
| cross-resistance and stability of resistance to bacillus thuringiensis toxin cry1c in diamondback moth. | we tested toxins of bacillus thuringiensis against larvae from susceptible, cry1c-resistant, and cry1a-resistant strains of diamondback moth (plutella xylostella). the cry1c-resistant strain, which was derived from a field population that had evolved resistance to b. thuringiensis subsp. kurstaki and b. thuringiensis subsp. aizawai, was selected repeatedly with cry1c in the laboratory. the cry1c-resistant strain had strong cross-resistance to cry1ab, cry1ac, and cry1f, low to moderate cross-resi ... | 2001 | 11425744 |
| cyt1ab1 and cyt2ba1 from bacillus thuringiensis subsp. medellin and b. thuringiensis subsp. israelensis synergize bacillus sphaericus against aedes aegypti and resistant culex quinquefasciatus (diptera: culicidae). | the interaction of two cytolytic toxins, cyt1ab from bacillus thuringiensis subsp. medellin and cyt2ba from bacillus thuringiensis subsp. israelensis, with bacillus sphaericus was evaluated against susceptible and resistant culex quinquefasciatus and the nonsensitive species aedes aegypti. mixtures of b. sphaericus with either cytolytic toxin were synergistic, and b. sphaericus resistance in c. quinquefasciatus was suppressed from >17,000- to 2-fold with a 3:1 mixture of b. sphaericus and cyt1ab ... | 2001 | 11425753 |
| identification of genes involved in the activation of the bacillus thuringiensis inha metalloprotease gene at the onset of sporulation. | the immune inhibitor a (inha) metalloprotease from bacillus thuringiensis specifically cleaves antibacterial proteins produced by the insect host, suggesting that it may contribute to the overall virulence of b. thuringiensis. the transcriptional regulation of the inha gene in both b. thuringiensis and bacillus subtilis was investigated. using a transcriptional inha'-lacz fusion, it was shown that inha expression is activated at the onset of sporulation. however, the transcriptional start site o ... | 2001 | 11429458 |
| india blocks sale of transgenic cotton seeds. | 2001 | 11429564 | |
| crafting crop resistance to corn rootworms. | 2001 | 11433270 | |
| insecticidal proteins from bacillus thuringiensis protect corn from corn rootworms. | field tests of corn co-expressing two new delta-endotoxins from bacillus thuringiensis (bt) have demonstrated protection from root damage by western corn rootworm (diabrotica virgifera virgifera leconte). the level of protection exceeds that provided by chemical insecticides. in the bacterium, these proteins form crystals during the sporulation phase of the growth cycle, are encoded by a single operon, and have molecular masses of 14 kda and 44 kda. corn rootworm larvae fed on corn roots express ... | 2001 | 11433280 |
| mode of action of bacillus thuringiensis ps86q3 strain in hymenopteran forest pests. | the mode of action of cry toxins has been described principally in lepidopteran insects as a multistep process. in this work we describe the mode of action of a cry toxin active in the common pine sawfly diprion pini (hymenoptera, diprionidae), considered a major forest pest in europe. strain ps86q3 contains a long bipyramidal crystal composed of five major proteins. the n-terminal sequence shows that the 155 kda protein corresponds to cry5b toxin and the other proteins belong to the cry5a subgr ... | 2001 | 11439244 |
| bacillus thuringiensis cry1ac and cry1fa delta-endotoxin binding to a novel 110 kda aminopeptidase in heliothis virescens is not n-acetylgalactosamine mediated. | we determined that bacillus thuringiensis cry1ac and cry1fa delta-endotoxins recognize the same 110, 120 and 170 kda aminopeptidase n (apn) molecules in brush border membrane vesicles (bbmv) from heliothis virescens. the 110 kda protein, not previously identified as an apn, contained a variant apn consensus sequence identical to that found in helicoverpa punctigera apn 2. pcr amplification of h. virescens cdna based on this sequence and a conserved apn motif yielded a 0.9 kb product that has 89% ... | 2001 | 11439250 |
| genetic diversity of bacillus thuringiensis serovars revealed by rflp using random dna probes. | ecori and hindiii restriction fragment length polymorphism (rflp) profiles using 2 random dna probes, named 104 and 106, were generated for 85 b. thuringiensis strains. these include 80 serovars, 4 intra-serovar strains: kurstaki hd-1, dendrolimus, tenebrionis and sandiego, and a non-serotypeable strain b. thuringiensis var. wuhanensis. a total of 47 ecori and 65 hindiii restriction patterns were generated when hybridization results from both probes were combined. seventy-seven b. thuringiensis ... | 2001 | 11441463 |
| reversing insect adaptation to transgenic insecticidal plants. | the refuge-high-dose strategy for delaying insect adaptation to transgenic plants produces non-transgenic plants that enable survival of susceptible individuals. previous theoretical work has suggested three requirements for success of the refuge-high-dose strategy: a low initial frequency of the resistance allele, extensive mating between resistant and susceptible adults and recessive inheritance of resistance. in order to understand an observed decrease in resistance frequency and improve the ... | 2001 | 11454291 |
| role of interdomain salt bridges in the pore-forming ability of the bacillus thuringiensis toxins cry1aa and cry1ac. | the four salt bridges (asp(222)-arg(281), arg(233)-glu(288), arg(234)-glu(274), and asp(242)-arg(265)) linking domains i and ii in cry1aa were abolished individually in alpha-helix 7 mutants d222a, r233a, r234a, and d242a. two additional mutants targeting the fourth salt bridge (r265a) and the double mutant (d242a/r265a) were rapidly degraded during trypsin activation. mutations were also introduced in the corresponding cry1ac salt bridge (d242e, d242k, d242n, and d242p), but only d242n and d242 ... | 2001 | 11466307 |
| structure of the insecticidal bacterial delta-endotoxin cry3bb1 of bacillus thuringiensis. | the coleopteran-active delta-endotoxin cry3bb1 from bacillus thuringiensis (bt) strain eg7231 is uniquely toxic to diabrotica undecimpunctata, the southern corn rootworm, while retaining activity against leptinotarsa decemlineata, the colorado potato beetle. the crystal structure of the delta-endotoxin cry3bb1 has been refined using data collected to 2.4 a resolution, with a residual r factor of 17.5% and an r(free) of 25.3%. the structure is made up of three domains: i, a seven-helix bundle (re ... | 2001 | 11468393 |
| thermal application of bacillus thuringiensis serovar israelensis for dengue vector control. | 2001 | 11469179 | |
| entomopathogenic activities of environmental isolates of bacillus thuringiensis against dipteran larvae. | twenty-five field isolates of bacillus thuringiensis from the lower silesia region of poland, the osola plain, and phylloplane niches and soil samples from the karkonosze national park were tested for insecticidal activity against larvae of the dipterans aedes aegypti, drosophila melanogaster and musca domestica. the spore-crystal mixture of b. thuringiensis finitimus (soil isolate) killed nearly half of the fourth instar larvae of ae. aegypti. similar mortality of between 39-61% was recorded af ... | 2001 | 11469180 |
| population-scale laboratory studies of the effect of transgenic plants on nontarget insects. | studies of the effects of insect-resistant transgenic plants on beneficial insects have, to date, concentrated mainly on either small-scale "worst case scenario" laboratory experiments or on field trials. we present a laboratory method using large population cages that represent an intermediate experimental scale, allowing the study of ecological and behavioural interactions between transgenic plants, pests and their natural enemies under more controlled conditions than is possible in the field. ... | 2001 | 11472551 |