Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| effects of sublethal concentrations of bacillus thuringiensis on larval development of sesamia nonagrioides. | in the mediterranean basin, developed diapausing larvae of the borer sesamia nonagrioides lefèbvre are found consistently during autumn in transgenic corn, zea mays l., expressing bacillus thuringiensis berliner (bt) toxins derived from event 176. these larvae can feed on sublethal concentrations of bt toxins because the expression of this corn toxin declines after flowering. to evaluate the possible consequences of this phenomenon, the effect of sublethal concentrations of the natural toxin pro ... | 2005 | 15889739 |
| laboratory and field evaluations of transgenic soybean exhibiting high-dose expression of a synthetic bacillus thuringiensis cry1a gene for control of lepidoptera. | transgenic lines of soybean, glycine max (l.) merrill, expressing a synthetic cry1a gene (tic107) from bacillus thuringiensis (bt), were evaluated in screenhouse and conventional field trials for efficacy against lepidopteran pests. in screenhouse trials, bt soybean and negative checks (isogenic segregants and parental lines) were evaluated against anticarsia gemmatalis hübner and pseudoplusia includens (walker) in the united states and against a. gemmatalis, epinotia aporema (walsingham), rachi ... | 2005 | 15889751 |
| comprehensive assignment of mass spectral signatures from individual bacillus atrophaeus spores in matrix-free laser desorption/ionization bioaerosol mass spectrometry. | we have fully characterized the mass spectral signatures of individual bacillus atrophaeus spores obtained using matrix-free laser desorption/ionization bioaerosol mass spectrometry (bams). mass spectra of spores grown in unlabeled, 13c-labeled, and 15n-labeled growth media were used to determine the number of carbon and nitrogen atoms associated with each mass peak observed in mass spectra from positive and negative ions. to determine the parent ion structure associated with fragment ion peaks, ... | 2005 | 15889924 |
| many roads to resistance: how invertebrates adapt to bt toxins. | the cry family of bacillus thuringiensis insecticidal and nematicidal proteins constitutes a valuable source of environmentally benign compounds for the control of insect pests and disease agents. an understanding of cry toxin resistance at a molecular level will be critical to the long-term utility of this technology; it may also shed light on basic mechanisms used by other bacterial toxins that target specific organisms or cell types. selection and cross-resistance studies have confirmed that ... | 2005 | 15892110 |
| the synergistic activity between cry1aa and cry1c from bacillus thuringiensis against spodoptera exigua and helicoverpa armigera. | to investigate the interaction between two crystal proteins, cry1aa and cry1c, for future development of biopesticides based on bacillus thuringiensis, toxicities of the two individual proteins and in combinations have been determined against spodoptera exigua and helicoverpa armigera larvae, and synergism between the proteins has been evaluated using synergistic factor. | 2005 | 15892743 |
| is the mature endotoxin cry1ac from bacillus thuringiensis inactivated by a coagulation reaction in the gut lumen of resistant helicoverpa armigera larvae? | bacillus thuringiensis endotoxins (bt-toxins) are the most important biopesticides used in controlling insect pests and vectors of diseases. the emergence of widespread resistance to bt in some insect species is a serious threat to agricultural production. analysis of bt-resistant and susceptible laboratory strains of helicoverpa armigera revealed elevated immune responses involving increased melanization and the presence of a soluble toxin-binding glycoprotein in the hemolymph and gut lumen of ... | 2005 | 15894190 |
| crystallization and preliminary crystallographic analysis of bacillus thuringiensis ahl-lactonase. | the quorum sensing (qs) systems in gram-negative bacteria are mostly associated with diffusible n-acyl-l-homoserine lactones (ahls). ahl-degrading enzymes hydrolyze the ahls into inactive molecules, thereby blocking the qs systems that are closely linked to virulence factor production and biofilm formation. consequently, these enzymes have recently attracted intense interest for the development of anti-infection therapies for plants and animals. however, despite significant progress in the inves ... | 2005 | 15894524 |
| the quorum-quenching lactonase from bacillus thuringiensis is a metalloprotein. | lactonases from bacillus species hydrolyze the n-acylhomoserine lactone (ahl) signaling molecules used in quorum-sensing pathways of many gram-negative bacteria, including pseudomonas aeruginosa and erwinia carotovora, both significant pathogens. because of sequence similarity, these ahl lactonases have been assigned to the metallo-beta-lactamase superfamily of proteins, which includes metalloenzymes of diverse activity, mechanism, and metal content. however, a recent study claims that ahl lacto ... | 2005 | 15895999 |
| toxicity of several delta-endotoxins of bacillus thuringiensis against helicoverpa armigera (lepidoptera: noctuidae) from spain. | toxicity and larval growth inhibition of 11 insecticidal proteins of bacillus thuringiensis were evaluated against neonate larvae of helicoverpa armigera, a major pest of important crops in spain and other countries, by a whole-diet contamination method. the most active toxins were cry1ac4 and cry2aa1, with lc50 values of 3.5 and 6.3 microg/ml, respectively. at the concentrations tested, cry1ac4, cry2aa1, cry9ca, cry1fa1, cry1ab3, cry2ab2, cry1da, and cry1ja1, produced a significant growth inhib ... | 2005 | 15913643 |
| cytotoxicity of bacillus thuringiensis cry1ab toxin depends on specific binding of the toxin to the cadherin receptor bt-r1 expressed in insect cells. | the specific role of cadherin receptors in cytotoxicity involving cry toxins of bacillus thuringiensis and their interactions with cell membrane has not been defined. to elucidate the involvement of toxin-membrane and toxin-receptor interactions in cytotoxicity, we established a cell-based system utilizing high five insect cells stably expressing bt-r1, the cadherin receptor for cry1ab toxin. cry1ab toxin is incorporated into cell membrane in both oligomeric and monomeric form. monomeric toxin b ... | 2005 | 15920532 |
| a simple purification and activity assay of the coagulant protein from moringa oleifera seed. | use of extracts from moringa oleifera (mo) is of great interest for low-cost water treatment. this paper discusses water and salt extraction of a coagulant protein from the seed, purification using ion exchange, its chemical characteristics, coagulation and antimicrobial properties. the coagulant from both extracts is a cationic protein with pi greater than 9.6 and molecular mass less than 6.5 kda. mass spectrometric analysis of the purified water extract indicated that it contained at least fou ... | 2005 | 15921719 |
| regulating insect resistance management: the case of non-bt corn refuges in the us. | in this paper, we analyze the insect resistance management (irm) plan put in place by the us environmental protection agency (epa) to delay the evolution of resistance to bt corn in natural populations of the european corn borer, ostrinia nubilalis hübner. this irm plan is the most impressive mandatory irm system ever developed. it forms a coherent whole and includes mandatory refuges, actions to increase growers' compliance and a program for monitoring the evolution of resistance. however, our ... | 2005 | 15922504 |
| evolutionary trade-offs of insect resistance to bacillus thuringiensis crops: fitness cost affecting paternity. | evolution of resistance to insecticides provides a useful model for examining fitness trade-offs associated with adaptation to stress. here, we examined male reproductive costs in pink bollworm (pectinophora gossypiella) resistant to an insecticidal protein of bacillus thuringiensis (bt) produced by transgenic cotton, using contrasts between two pairs of related susceptible and resistant strains. without competition for access to females, no costs affecting reproductive success of resistant male ... | 2005 | 15926701 |
| novel genetic basis of field-evolved resistance to bt toxins in plutella xylostella. | insecticidal toxins from bacillus thuringiensis (bt) are widely used to control pest insects, but evolution of resistance threatens their continued efficacy. the most common type of bt resistance ('mode 1') is characterized by recessive inheritance, > 500-fold resistance to at least one cry1a toxin, negligible cross-resistance to cry1c, and reduced binding of bt toxins to midgut membrane target sites. mutations affecting a cry1a-binding midgut cadherin protein are linked to laboratory-selected m ... | 2005 | 15926902 |
| identification of a promoter for the vegetative insecticidal protein-encoding gene vip3lb from bacillus thuringiensis. | the expression of vip3lb, one of the vegetative insecticidal protein-encoding genes of bacillus thuringiensis, was studied at the transcriptional level. by primer extension analysis, we have identified, for the first time, the transcription start point of vip3-type gene. upstream from vip3lb transcription start point, was found a nucleotide sequence partially homologous to the consensus sequence for the e sigma(e) holoenzyme of b. subtilis. thus, it was strongly suggested that the identified vip ... | 2005 | 15927753 |
| dielectric monitoring of growth and sporulation of bacillus thuringiensis. | on-line permittivity and optical density measurements have been used to monitor biomass concentration and sporulation status during growth of a spore-forming bacterium, bacillus thuringiensis, in fed-batch culture. the correlation between permittivity, optical density and other observations showed three distinct phases of growth: growth itself, transition and sporulation. the permittivity variations during the transition and sporulation phases could be related to the sporulation development: the ... | 2005 | 15928859 |
| cloning and expression of mel gene from bacillus thuringiensis in escherichia coli. | previous work from our laboratory has shown that most of bacillus thuringiensis strains possess the ability to produce melanin in the presence of l -tyrosine at elevated temperatures (42 degrees c). furthermore, it was shown that the melanin produced by b. thuringiensis was synthesized by the action of tyrosinase, which catalyzed the conversion of l -tyrosine, via l -dopa, to melanin. in this study, the tyrosinase-encoding gene (mel) from b. thuringiensis 4d11 was cloned using pcr techniques and ... | 2005 | 15928981 |
| surface display of recombinant proteins on bacillus thuringiensis spores. | the insecticidal protoxin from bacillus thuringiensis has been shown to be a major component of the spore coat. we have developed a novel surface display system using b. thuringiensis spores in which the n-terminal portion of the protoxin is replaced with a heterologous protein. the expression vector with a sporulation-specific promoter was successfully used to display green fluorescent protein and a single-chain antibody (scfv) gene that encodes anti-4-ethoxymethylene-2-phenyl-2-oxazolin-5-one ... | 2005 | 15933037 |
| concurrent use of transgenic plants expressing a single and two bacillus thuringiensis genes speeds insect adaptation to pyramided plants. | transgenic plants expressing insecticidal proteins from the bacterium bacillus thuringiensis (bt) were grown on over 13 million ha in the united states and 22.4 million ha worldwide in 2004. preventing or slowing the evolution of resistance by insects ("resistance management") is critical for the sustainable use of bt crops. plants containing two dissimilar bt toxin genes in the same plant ("pyramided") have the potential to delay insect resistance. however, the advantage of pyramided bt plants ... | 2005 | 15939892 |
| environmental fate and effects of bacillus thuringiensis (bt) proteins from transgenic crops: a review. | this paper reviews the scientific literature addressing the environmental fate and nontarget effects of the cry protein toxins from bacillus thuringiensis (bt), specifically resulting from their expression in transgenic crops. published literature on analytical methodologies for the detection and quantification of the cry proteins in environmental matrices is also reviewed, with discussion of the adequacy of the techniques for determining the persistence and mobility of the bt proteins. in gener ... | 2005 | 15941295 |
| identification of cry-type genes on 20-kb dna associated with cry1 crystal proteins from bacillus thuringiensis. | heterologous dna fragments (20-kb) associated with cry1 crystal proteins (protoxins) from a soil-isolated bacillus thuringiensis strain 4.0718 were isolated and analyzed. rflp patterns of the pcr products showed that the 20-kb dna fragments harbored cry1aa, cry1ac, cry2aa, and cry2ab genes. furthermore, a 4.2-kb dna fragment, which contained the promoter, the coding region, and the terminator of cry1ac gene, was cloned from the 20-kb dnas by pcr, and then the cry1ac gene was expressed in an acry ... | 2005 | 15942699 |
| characterization of cdnas encoding three trypsin-like proteinases and mrna quantitative analysis in bt-resistant and -susceptible strains of ostrinia nubilalis. | our previous studies suggested that bacillus thuringiensis (bt) resistance in a dipel-resistant strain of ostrinia nubilalis was primarily due to reduced trypsin-like proteinase activity. in this study, we demonstrated a 254-fold resistance to cry1ab protoxin but only 12-fold to trypsin-activated cry1ab toxin in the dipel-resistant strain. significantly higher resistance to cry1ab protoxin than to trypsin-activated cry1ab toxin further supports the hypothesis that reduced trypsin-like proteinase ... | 2005 | 15944081 |
| phosphatidylinositol-specific phospholipase c of bacillus anthracis down-modulates the immune response. | phosphatidylinositol-specific phospholipases (pi-plcs) are virulence factors produced by many pathogenic bacteria, including bacillus anthracis and listeria monocytogenes. bacillus pi-plc differs from listeria pi-plc in that it has strong activity for cleaving gpi-anchored proteins. treatment of murine dcs with bacillus, but not listeria, pi-plc inhibited dendritic cell (dc) activation by tlr ligands. infection of mice with listeria expressing b. anthracis pi-plc resulted in a reduced ag-specifi ... | 2005 | 15944308 |
| expanding the bactericidal action of the food color additive phloxine b to gram-negative bacteria. | phloxine b (d&c red no. 28) is a color additive for food, drugs, and cosmetics. it has been previously shown to have anti-staphylococcus aureus activities. in this work, the effect of phloxine b on various gram-negative bacteria and other gram-positive bacteria including bacillus cereus, bacillus thuringiensis, bacillus mycoides, bacillus subtilis, bacillus aureus, salmonella, escherichia coli and shigella was studied, along with the mechanism of anti-microbial activity. in the presence of fluor ... | 2005 | 15949926 |
| construction of a pseudomonas sp. derivative carrying the cry9aa gene from bacillus thuringiensis and a proposal for new standard criteria to assess entomocidal properties of bacteria. | an isolate of pseudomonas sp. (16s rdna sequence 98% homologous to p. graminis and p. lutea) was isolated from the phyllosphere of black pine in northern italy and used as a host for the gene encoding the cry9aa entomocidal toxin from bacillus thuringiensis subsp. galleriae. an expression system featuring a synthetic highest-consensus promoter specifically tailored for the regulated induction of cloned genes over a broad range of gram-negative bacteria was used to drive the production of the int ... | 2005 | 15950125 |
| a cryptic bacillus isolate exhibited narrow 16s rrna gene sequence divergence with bacillus thuringiensis and showed low maintenance requirements in hyper-osmotic complex substrate cultivations. | a cryptic bacillus (k90) isolate obtained from soil samples from the kuwait desert exhibited lower maintenance requirements in complex substrate cultivations than bacillus thuringiensis. a mathematical model was used to estimate apparent maintenance coefficients (m(c)) and these were found to be 0.336 and 0.041/h for b. thuringiensis and k90, respectively. the results also showed that the values of apparent maintenance coefficients were inversely related to the specific growth rates. furthermore ... | 2005 | 15959906 |
| laboratory studies of the effects of reduced prey choice caused by bt plants on a predatory insect. | crops transformed to express bacillus thuringiensis (bt) toxins can cause close to 100% mortality of certain target pest species. this study assessed the effect of target pest reduction on the predatory insect chrysoperla carnea (stephens) in the presence of alternative prey. numbers of lacewings recovered from bt oilseed rape (cultivar oscar, event o52) did not differ significantly from numbers of lacewings recovered from conventional oilseed rape in cage experiments with the target pest plutel ... | 2005 | 15960878 |
| synthesis of additional endotoxins in bacillus thuringiensis subsp. morrisoni pg-14 and bacillus thuringiensis subsp. jegathesan significantly improves their mosquitocidal efficacy. | a fundamental principal of resistance management is that the more complex and potent a toxin mixture, the slower resistance will develop to the mixture in an insect population. thus, to develop more complex and potent mosquitocidal bacteria, we genetically engineered bacillus thuringiensis subsp. morrisoni pg-14 and bacillus thuringiensis subsp. jegathesan, to synthesize, respectively, the binary (bin) toxin of bacillus sphaericus or a combination of bin and the cytla protein of bacillus thuring ... | 2005 | 15962784 |
| cry11aa toxin from bacillus thuringiensis binds its receptor in aedes aegypti mosquito larvae through loop alpha-8 of domain ii. | bacillus thuringiensis subs israelensis produces cry toxins active against mosquitoes. receptor binding is a key determinant for specificity of cry toxins composed of three domains. we found that exposed loop alpha-8 of cry11aa toxin, located in domain ii, is an important epitope involved in receptor interaction. synthetic peptides corresponding to exposed regions in domain ii (loop alpha-8, beta-4 and loop 3) competed binding of cry11aa to membrane vesicles from aedes aegypti midgut microvilli. ... | 2005 | 15963509 |
| toxicity of bacillus thuringiensis to parasitic and free-living life-stages of nematode parasites of livestock. | a collection of bacillus thuringiensis (bt) strains (bts) were screened for activity against the free-living larval stages of nematode parasites of livestock. two strains were identified with significant activity in inhibiting larval development of haemonchus contortus, trichostrongylus colubriformis and ostertagia circumcincta. these strains were also toxic to the adult parasitic stages of these nematode species in vitro. adult h. contortus and o. circumcincta showed complete cessation of movem ... | 2005 | 15964574 |
| recombinant larvicidal bacteria with markedly improved efficacy against culex vectors of west nile virus. | an urgent need exists for new agents to control mosquito vectors of disease. mosquito larvicides based on the bacteria bacillus thuringiensis subsp. israelensis (bti) or b. sphaericus (bs) are effective in many habitats, but use is limited by their high cost. moreover, mosquito resistance evolves rapidly to bs where it is used intensively. the efficacy of these bacteria is due to a binary protein (bsb) in bs and four proteins (cry4a, cry4b, cry11a, and cyt1a) in bti. here we report the use of cy ... | 2005 | 15964958 |
| using worms to better understand how bacillus thuringiensis kills insects. | bacillus thuringiensis is widely used as a biological pesticide to control insects that either cause damage to crops or transmit disease. that it can also target the model organism caenorhabditis elegans has not only provided exciting new insights into how the toxins produced by the bacterium target their victims but also how target insects counter the attack. modern approaches such as reverse genetics and microarray technology have revealed novel receptors for the toxins and possible signal tra ... | 2005 | 15967665 |
| green fluorescent protein quantification in whole plants. | as future biotechnology applications utilize recombinant proteins as commercial products, nondestructive assays will be necessary to determine protein concentrations accurately within plant tissues. green fluorescent protein (gfp) has been proposed as a potential marker for the monitoring of transgenic plants and quantifying recombinant protein levels under field conditions. this chapter discusses the utility of using gfp fluorescence as an indicator of protein concentrations and the methods use ... | 2005 | 15310924 |
| the evolution of cotton pest management practices in china. | the development of cotton pest management practices in china has followed a pattern seen for many crops that rely heavily on insecticides. helicoverpa armigera resistance to chemical pesticides resulted in the unprecedented pest densities of the early 1990s. transgenic cotton that expresses a gene derived from the bacterium bacillus thuringiensis (bt) has been deployed for combating h. armigera since 1997. the pest management tactics associated with bt cotton have resulted in a drastic reduction ... | 2005 | 15355239 |
| effects of plants genetically modified for insect resistance on nontarget organisms. | insect resistance, based on bacillus thuringiensis (bt) endotoxins, is the second most widely used trait (after herbicide resistance) in commercial genetically modified (gm) crops. other modifications for insect resistance, such as proteinase inhibitors and lectins, are also being used in many experimental crops. the extensive testing on nontarget plant-feeding insects and beneficial species that has accompanied the long-term and wide-scale use of bt plants has not detected significant adverse e ... | 2005 | 15355241 |
| the high-resolution architecture and structural dynamics of bacillus spores. | the capability to image single microbial cell surfaces at nanometer scale under native conditions would profoundly impact mechanistic and structural studies of pathogenesis, immunobiology, environmental resistance, and biotransformation. here, using in vitro atomic force microscopy, we have directly visualized high-resolution native structures of bacterial endospores, including the exosporium and spore coats of four bacillus species in air and water environments. our results demonstrate that the ... | 2005 | 15501940 |
| managing eastern tent caterpillars malacosoma americanum (f) on horse farms to reduce risk of mare reproductive loss syndrome. | an equine disease now known as mare reproductive loss syndrome (mrls) struck the ohio valley in 2001-2002 causing thousands of foal abortions and enormous economic loss. evidence that pregnant mares' exposure to eastern tent caterpillars malacosoma americanum (f) induces mrls created an urgent call for control measures suitable for use on horse farms. we surveyed egg mass distribution and monitored emergence in wild cherry trees, and evaluated reduced-risk treatment strategies including foliage ... | 2005 | 15593079 |
| identification, cloning and expression of a cry1ab cadherin receptor from european corn borer, ostrinia nubilalis (hubner) (lepidoptera: crambidae). | transgenic corn expressing the cry1ab toxin from bacillus thuringiensis is highly toxic to european corn borer, ostrinia nubilalis, larvae. a putative cry1ab receptor (onbt-r(1)) molecule was cloned and sequenced from a cdna library prepared from midgut tissue of o. nubilalis larvae. the 5.6 kb gene is homologous with a number of cadherin genes identified as cry1 binding proteins in other lepidopterans. brush border membrane vesicles were prepared using dissected midguts from late instars. a 220 ... | 2005 | 15607653 |
| identification of a chitinase-producing bacterium c4 and histopathologic study on locusts. | in order to develop the potential of chitinase-producing micro-organisms as biocontrol agents for insect pests, five chitinase-producing bacterial strains (c1, c2, c3, c4 and c5) previously isolated from soil samples were chosen to infect grassland locusts. the data showed that the mortality rate of locusts fed with strain c4 was significantly higher than that of other groups, and its pathogenicity was confirmed by koch's law. midgut tissues of locusts infected with c4 were examined with a light ... | 2005 | 15619732 |
| targeted mutagenesis of loop residues in the receptor-binding domain of the bacillus thuringiensis cry4ba toxin affects larvicidal activity. | loop residues in domain ii of bacillus thuringiensis cry delta-endotoxins have been demonstrated to be involved in insecticidal specificity. in this study, selected residues in loops beta6-beta7 (s(387)sps(390)), beta8-beta9 (s(410), n(411), t(413), t(415), e(417) and g(418)) and beta10-beta11 (d(454)yns(457)) in domain ii of the cry4ba mosquito-larvicidal protein were changed individually to alanine by pcr-based directed mutagenesis. all mutant toxins were expressed in escherichia coli jm109 ce ... | 2005 | 15621455 |
| cyt1a of bacillus thuringiensis delays evolution of resistance to cry11a in the mosquito culex quinquefasciatus. | insecticides based on bacillus thuringiensis subsp. israelensis have been used for mosquito and blackfly control for more than 20 years, yet no resistance to this bacterium has been reported. moreover, in contrast to b. thuringiensis subspecies toxic to coleopteran or lepidopteran larvae, only low levels of resistance to b. thuringiensis subsp. israelensis have been obtained in laboratory experiments where mosquito larvae were placed under heavy selection pressure for more than 30 generations. s ... | 2005 | 15640186 |
| a detergent-like mechanism of action of the cytolytic toxin cyt1a from bacillus thuringiensis var. israelensis. | the cytolytic delta-endotoxin cyt1a from bacillus thuringiensis var. israelensis is used in commercial preparations of environmentally safe insecticides. the current hypothesis on its mode of action is that the toxin self-assembles into well-defined cation-selective channels or pores, which results in colloid-osmotic lysis of the cell. recently, a new hypothesis has been put forward suggesting that cyt1a rather nonspecifically aggregates on the membrane surface and acts in a detergent-like manne ... | 2005 | 15641784 |
| regional reversion of insecticide resistance in helicoverpa armigera (lepidoptera: noctuidae) is associated with the use of bt cotton in northern china. | a continuous programme for monitoring resistance of helicoverpa armigera (hubner) to commonly used insecticides was undertaken for assessing the impact of bt cotton planting on the evolution of the pest resistance from 1994 to 2002 in china. the bioassay results showed that the resistance levels per year in field populations of h armigera to lambda-cyhalothrin, phoxim and endosulfan decreased, respectively, to 9-15-fold, 11-14-fold and 6-8-fold in 2001-2002 from 197-262-fold, 52-74-fold and 18-3 ... | 2005 | 15643649 |
| the clonal structure of bacillus thuringiensis isolates from north-east poland does not correlate with their cry gene diversity. | the genetic relationship among 103 natural bacillus thuringiensis isolates was investigated on the basis of polymerase chain reaction amplification of their specific crystal (cry) protein type genes and chromosomal dna profiling by pulsed-field gel electrophoresis (pfge). the strains were recovered from the intestines of small wild rodents and insectivores from the biebrza national park and the lomza landscape park of the narew river valley in north-east poland. the percentage of b. thuringiensi ... | 2005 | 15643933 |
| the cry3aa gene of bacillus thuringiensis bt886 encodes a toxin against long-horned beetles. | this report describes the identification of a new toxigenic strain of bacillus thuringiensis specific for long-horned beetles. b. thuringiensis bt866 encodes a cry3aa-like gene (bt886cry3aa) that is 1,956 bp in length and is predicted to encode an 85.78-kda protein. the gene is highly similar to cry3aa1, differing in only six nucleotides and four amino acids. the four disparate amino acids occur within the conserved domains of the cry3aa toxin. the expression of bt866cry3a in escherichia coli ce ... | 2005 | 15647932 |
| insect-resistant transgenic pinus radiata. | transgenic radiata pine (pinus radiata d. don) plants containing a bacillus thuringiensis (bt) toxin gene, crylac, were produced by means of biolistic transformation of embryogenic tissue. using the selectable marker gene nptii and corresponding geneticin selection, 20 independent transgenic lines from five genotypes were established. over 200 plants regenerated from ten transgenic lines were successfully transferred to soil. the integration and expression of the introduced genes in transgenic t ... | 2005 | 15668791 |
| potentiation and cellular phenotypes of the insecticidal toxin complexes of photorhabdus bacteria. | the toxin complex (tc) genes of bacteria comprise a large and growing family whose mode of action remains obscure. in the insect pathogen photorhabdus, tc genes encode high molecular weight insecticidal toxins with oral activity against caterpillar pests. one protein, tcda, has recently been expressed in transgenic plants and shown to confer insect resistance. these toxins therefore represent alternatives to toxins from bacillus thuringiensis (bt) for deployment in transgenic crops. levels of tc ... | 2005 | 15679840 |
| sequence variation in the cadherin gene of ostrinia nubilalis: a tool for field monitoring. | toxin-binding proteins of insect midgut epithelial cells are associated with insect resistance to bacillus thuringiensis (bt) cry toxins. a 5378 nt cdna encoding a 1717 amino acid putative midgut cadherin-like glycoprotein and candidate cry1ab toxin-binding protein was characterized from ostrinia nubilalis. intraspecific alignment of partial o. nubilalis cadherin gene sequences identified variance within proposed cry1a toxin binding region 2 (tbr2), 1328iplqtsilvvt[i/v] n1340, and flanking cry1a ... | 2005 | 15681223 |
| cellular fatty-acid analysis of bacillus thuringiensis var. kurstaki commercial preparations. | cellular fatty acid (cfa) composition of bacillus thuringiensis var. kurstaki (btk) preparations was determined by use of the midi sherlock microbial identification system on a hewlett-packard 5890 gas chromatograph. four commercial preparations--one btk sample obtained from the u.s. forest service, one btk sample obtained from dugway proving ground, and btk and bacillus thuringiensis var. israelensis (bti) preparations obtained from american type culture collection (atcc)--were analyzed and eva ... | 2005 | 15686395 |
| isolation, characterization and expression of a novel vegetative insecticidal protein gene of bacillus thuringiensis. | twenty-four serovars of bacillus thuringiensis (bt) were screened by polymerase chain reaction to detect the presence of vegetative insecticidal protein gene (vip)-like sequences by using vip3aa1-specific primers. vip-like gene sequences were identified in eight serovars. these genes were cloned and sequenced. the deduced amino acid sequence of the vip3aa14 gene from bacillus thuringiensis tolworthi showed considerable differences as compared to those of vips reported so far. the vip3aa14 gene f ... | 2005 | 15686851 |
| new strategy for identification of novel cry-type genes from bacillus thuringiensis strains. | we designed five degenerate primers for detection of novel cry genes from bacillus thuringiensis strains. an efficient strategy was developed based on a two-step pcr approach with these primers in five pair combinations. in the first step, only one of the primer pairs is used in the pcr, which allows amplification of dna fragments encoding protein regions that include consensus domains of representative proteins belonging to different cry groups. a second pcr is performed by using the first-step ... | 2005 | 15691928 |
| disruption of a cadherin gene associated with resistance to cry1ac {delta}-endotoxin of bacillus thuringiensis in helicoverpa armigera. | a laboratory strain (gy) of helicoverpa armigera (hubner) was established from surviving larvae collected from transgenic cotton expressing a bacillus thuringiensis var. kurstaki insecticidal protein (bt cotton) in gaoyang county, hebei province, people's republic of china, in 2001. the gybt strain was derived from the gy strain through 28 generations of selection with activated cry1ac delivered by diet surface contamination. when resistance to cry1ac in the gybt strain increased to 564-fold aft ... | 2005 | 15691952 |
| indian bt gene monoculture, potential time bomb. | 2005 | 15696133 | |
| insect resistance management in gm crops: past, present and future. | transgenic plants expressing insecticidal proteins from the bacterium bacillus thuringiensis (bt) were first commercialized in 1996 amid concern from some scientists, regulators and environmentalists that the widespread use of bt crops would inevitably lead to resistance and the loss of a 'public good,' specifically, the susceptibility of insect pests to bt proteins. eight years later, bt corn and cotton have been grown on a cumulative area >80 million ha worldwide. despite dire predictions to t ... | 2005 | 15637622 |
| glycolipids as receptors for bacillus thuringiensis crystal toxin. | the development of pest resistance threatens the effectiveness of bacillus thuringiensis (bt) toxins used in transgenic and organic farming. here, we demonstrate that (i) the major mechanism for bt toxin resistance in caenorhabditis elegans entails a loss of glycolipid carbohydrates; (ii) bt toxin directly and specifically binds glycolipids; and (iii) this binding is carbohydrate-dependent and relevant for toxin action in vivo. these carbohydrates contain the arthroseries core conserved in insec ... | 2005 | 15705852 |
| plant codon optimized cry genes of bacillus thuringiensis can be expressed as soluble proteins in escherichia coli bl21 codon plus strain as nusa-cry protein fusions. | for optimal expression of delta-endotoxins from bacillus thuringiensis in plants, preferential changes in the codon sequences, and reduction in overall at content in the nucleotide sequence of the genes is important. reports suggest that sequences with such modifications cannot be overexpressed in bacteria. we report here that the modified genes can be overexpressed in a strain of escherichia coli carrying extra trna genes for some of the codons occurring at high frequency in plant genes and les ... | 2005 | 15707873 |
| inheritance of resistance and cross-resistance to deltamethrin in plutella xylostella (lepidoptera: plutellidae) from pakistan. | a field population of plutella xylostella (l) from pakistan was found to be highly resistant to deltamethrin (>500-fold) but had little or no resistance to spinosad, fipronil, indoxacarb, abamectin, bacillus thuringiensis (bt) var kurstaki, bt var aizawai or cry1ac when compared with a susceptible laboratory population, lab-uk. a sub-population was selected for six generations (laboratory g3-g8) with deltamethrin (delta-sel), while a second sub-population was left unselected (unsel). bioassays a ... | 2005 | 15712350 |
| mitochondria permeabilization by a novel polycation peptide btm-p1. | bacillus thuringiensis subsp. medellin is known to produce the cry11bb protein of 94 kda, which is toxic for mosquito larvae due to permeabilization of the plasma membrane of midgut epithelial cells. earlier we found that a 2.8-kda novel peptide btm-p1, which was artificially synthesized taking into account the primary structure of cry11bb endotoxin, is active against several species of bacteria. in this work we show that btm-p1 induces cyclosporin a-insensitive swelling of rat liver mitochondri ... | 2005 | 15713682 |
| parasporin-1, a novel cytotoxic protein to human cells from non-insecticidal parasporal inclusions of bacillus thuringiensis. | pro-parasporin-1 is a parasporal inclusion protein of the non-insecticidal bacillus thuringiensis strain a1190. cytotoxic fragments, named parasporin-1, were generated from pro-parasporin-1 by trypsin digestion. parasporin-1 was purified by a combination of chromatography procedures based on the cytotoxic activity to hela cells. two different fragments of 15-kda and 56-kda were detected in the purified parasporin-1 fraction. these fragments were tightly associated with each other and could not b ... | 2005 | 15713879 |
| long-term evaluation of compliance with refuge requirements for bt cotton. | the success of the refuge strategy for delaying pest resistance to bt crops depends on compliance by farmers. however, the accuracy of previous estimates of compliance has been questioned. we have applied a novel approach based on the use of geographical information system (gis) technology to measure compliance with refuge requirements for bt cotton in six arizona regions from 1998 to 2003. although compliance varied among regions, overall compliance was above 88% in five of six years. with the ... | 2005 | 15714465 |
| validation of a cotton-specific gene, sad1, used as an endogenous reference gene in qualitative and real-time quantitative pcr detection of transgenic cottons. | genetically modified (gm) cotton lines have been approved for commercialization and widely cultivated in many countries, especially in china. as a step towards the development of reliable qualitative and quantitative pcr methods for detecting gm cottons, we report here the validation of the cotton (gossypium hirsutum) endogenous reference control gene, sad1, using conventional and real-time (rt)-pcr methods. both methods were tested on 15 different g. hirsutum cultivars, and identical amplicons ... | 2005 | 15726375 |
| persistence of vectobac wdg and metoprag s-2g against aedes aegypti larvae using a semi-field bioassay in rio de janeiro, brazil. | persistence of bacillus thuringiensis var. israelensis (vectobac wdg) and methoprene (metoprag s-2g) was evaluated against aedes aegypti late third instar larvae of the rockefeller strain in a semi-field bioassay. tests were performed in rio de janeiro, using containers made of plastic, iron, concrete and asbestos, placed in a shaded area. the formulations used were 0.2 g of vectobac-wdg and 1 g of metoprag s-2g per 100 liters of water in house storage containers. vectobac wdg was tested twice, ... | 2005 | 15729468 |
| degradation of cry1ab protein from genetically modified maize in the bovine gastrointestinal tract. | immunoblotting assays using commercial antibodies were established to investigate the unexpected persistence of the immunoactive cry1ab protein in the bovine gastrointestinal tract (git) previously suggested by enzyme-linked immunosorbent assay (elisa). samples of two different feeding experiments in cattle were analyzed with both elisa and immunoblotting methods. whereas results obtained by elisa suggested that the concentration of the cry1ab protein increased during the git passage, the immuno ... | 2005 | 15740023 |
| gil16, a new gram-positive tectiviral phage related to the bacillus thuringiensis gil01 and the bacillus cereus pbclin15 elements. | one of the most notable characteristics of tectiviridae resides in their double-layer coats: the double-stranded dna is located within a flexible lipoprotein vesicle covered by a rigid protein capsid. despite their apparent rarity, tectiviruses have an extremely wide distribution compared to other phage groups. members of this family have been found to infect gram-negative (prd1 and relatives) as well as gram-positive (bam35, gil01, ap50, and phins11) hosts. several reports have shown that tecti ... | 2005 | 15743944 |
| fingerprinting of bacillus thuringiensis type strains and isolates by using bacillus cereus group-specific repetitive extragenic palindromic sequence-based pcr analysis. | a total of 119 bacillus thuringiensis strains (83 type strains and 26 native isolates), as well as five b. cereus group species, were analyzed by repetitive extragenic palindromic sequence-based pcr analysis (rep-pcr) fingerprinting. primers bc-rep-1 and bc-rep-2 were specifically designed according to an extragenic 26-bp repeated sequence found in the six b. cereus group genomes reported. a total of 47 polymorphic bands were detected, and the patterns varied from 5 to 13 bands in number and fro ... | 2005 | 15746337 |
| quantitative molecular assay for fingerprinting microbial communities of wastewater and estrogen-degrading consortia. | a quantitative fingerprinting method, called the real-time terminal restriction fragment length polymorphism (real-time-t-rflp) assay, was developed for simultaneous determination of microbial diversity and abundance within a complex community. the real-time-t-rflp assay was developed by incorporating the quantitative feature of real-time pcr and the fingerprinting feature of t-rflp analysis. the assay was validated by using a model microbial community containing three pure strains, an escherich ... | 2005 | 15746346 |
| improvement of bioinsecticides production through adaptation of bacillus thuringiensis cells to heat treatment and nacl addition. | the present work aimed to increase yields of delta-endotoxin production through adaptation of bacillus thuringiensis cells to heat shock and sodium chloride and to investigate their involvements in bioinsecticides production improvement. | 2005 | 15752327 |
| purification, amino acid sequence and characterization of bacthuricin f4, a new bacteriocin produced by bacillus thuringiensis. | purification and characterization of a new bacteriocin, bacthuricin f4 of bacillus thuringiensis. | 2005 | 15752334 |
| laboratory evaluation of bacillus thuringiensis h-14 against aedes aegypti. | laboratory efficacy and residual activity of a water dispersible granule formulation of bacillus thuringiensis israelensis (bti) at the dosages of 3000, 6000 and 15000 itu/l were conducted in this study. the study was conducted in two different size containers, earthen jar (45 l) and glass jar (3 l) with or without daily replenishment of 6 l and 0.3 l of water in the earthen and glass jars, respectively. results indicate that for both earthen jar and glass jar evaluations, bti at the tested dosa ... | 2005 | 16880748 |
| [study on identification, colonization and reorganization of rice endophytic bacteria]. | endophytic sr-15, sr-25 and sl-37 strains screened from rice hybrid d you 527 in sichuan were analyzed. through penetration and microscopic test, the strains were found be mainly located in the cell gap, vacuole and cytoplasm. puc18 transferring and eric-pcr showed that the recombination strain sr-15 could grow in the plant stably. the strain was identified as bacillus halmapalus based on its chemical components of cell wall, physiological and biochemical characters. it was also shown that the s ... | 2005 | 16416963 |
| field evidence for the exposure of ground beetles to cry1ab from transgenic corn. | non-target organisms associated with the soil might be adversely affected by exposure to the crylab protein from bacillus thuringiensis (bt) in transgenic corn (zea mays l.). to check for such exposure, we used elisa to test for cry1ab in ground beetles collected live from fields with bt corn residues and bt corn (bt/bt), bt corn residues and non-bt crops (bt/non-bt), or non-bt corn residues and non-bt crops (non-bt/non-bt). in fields with bt corn residues (bt/bt and bt/non-bt), cry1ab was prese ... | 2005 | 16402666 |
| membrane proteins modulate the bilayer curvature in the bacterial virus bam35. | biological membranes control the flow of molecules into and out of cells, and they transmit information about the milieu. structural studies of membrane-containing viruses provide one way to study these membranes in situ. cryo-electron microscopy and image reconstruction of bacteriophage bam35 to 7.3 a resolution revealed a membrane bilayer constrained within an icosahedrally symmetric pseudo t = 25 capsid. a total of 60 large transmembrane protein complexes affect the curvature and thickness of ... | 2005 | 16338410 |
| bacillus thuringiensis subsp. israelensis cyt1aa synergizes cry11aa toxin by functioning as a membrane-bound receptor. | bacillus thuringiensis subsp. israelensis produces crystal proteins, cry (4aa, 4ba, 10aa, and 11aa) and cyt (1aa and 2ba) proteins, toxic to mosquito vectors of human diseases. cyt1aa overcomes insect resistance to cry11aa and cry4 toxins and synergizes the toxicity of these toxins. however, the molecular mechanism of synergism remains unsolved. here, we provide evidence that cyt1aa functions as a receptor of cry11aa. sequential-binding analysis of cyt1aa and cry11aa revealed that cyt1aa binding ... | 2005 | 16339907 |
| development of a bacillus thuringiensis-based assay on lygus hesperus. | lygus hesperus knight (hemiptera: miridae) is an economically important insect pest controlled primarily by chemical pesticides. bacillus thuringiensis berliner is a gram-positive bacterium, which upon sporulation produces a parasporal inclusion body, the crystal. the latter, in some strains, exhibits specific insecticidal activities against lepidopteran, coleopteran, or dipteran pests. the aim of the present work was to develop a bacillus thuringiensis-based assay on l. hesperus. several factor ... | 2005 | 16334312 |
| spray-dried bacillus thuringiensis serovar israelensis formulations for control of aedes aegypti larvae. | suspensions containing 0.25 and 1.25 g/liter of bacillus thuringiensis subsp. israelensis (bti) spore-toxin complex were spray-dried by using maltodextrin de-6, corn starch, and nixtamalized corn flour (25 g/liter) as materials to entrap active delta-endotoxin. the inlet air temperature of the drier was kept constant at 141 degrees c and the outlet temperature was maintained at 60 or 70 degrees c. the probit analysis of the concentration-mortality response of third instars of aedes aegypti (l.) ... | 2005 | 16334315 |
| avidin, a potential biopesticide and synergist to bacillus thuringiensis toxins against field crop insects. | a meridic diet was supplemented with avidin at various concentrations to determine its effects on growth and mortality of three lepidopteran insects: helicoverpa zea (boddie), spodoptera exigua (hübner), and anticarsia gemmatalis (hübner). all insects were placed on diet immediately after hatching and observed until death or pupation occurred. at a concentration of 10 ppm, avidin had little or no effect on growth and mortality compared with the control. however at a concentration of 100 ppm almo ... | 2005 | 16334325 |
| western corn rootworm (coleoptera: chrysomelidae) beetle emergence from weedy cry3bbl rootworm-resistant transgenic corn. | three greenhouse experiments were conducted to evaluate western corn rootworm, diabrotica virgifera virgifera leconte, beetle emergence from individual pots containing glyphosate-tolerant transgenic corn, zea mays l., expressing the cry3bbl endotoxin from the soil bacterium bacillus thuringiensis berliner (mon863), nontransgenic glyphosate-tolerant isoline corn, grassy weeds (giant foxtail, setariafaberi r.a.w. herrm; and large crabgrass, digitaria sanguinalis (l.) scop.), and combinations there ... | 2005 | 16334339 |
| field and laboratory studies on water conditions affecting the potency of vectobac (bacillus thuringiensis serotype h-14) against larvae of the blackfly, simulium damnosum. | river water conditions that might influence the efficacy of vectobac, a formulation of the microbial insecticide bacillus thuringiensis h-14 berliner against simulium damnosum sensu lato theobald (diptera: simuliidae) larvae were investigated. a standard formulation was assayed 130 times over 15 months using a mini-gutter system at a field station beside the river pra in ghana. the lethal concentration (lc) values, river temperature, conductivity, turbidity and ph were analysed using univariate ... | 2005 | 16336305 |
| recombinant production of bacterial toxins and their derivatives in the methylotrophic yeast pichia pastoris. | the methylotrophic yeast pichia pastoris is a popular heterologous expression host for the recombinant production of a variety of prokaryotic and eukaryotic proteins. the rapid emergence of p. pastoris as a robust heterologous expression host was facilitated by the ease with which it can be manipulated and propagated, which is comparable to that of escherichia coli and saccharomyces cerevisiae. p. pastoris offers further advantages such as the tightly-regulated alcohol oxidase promoter that is p ... | 2005 | 16336647 |
| efficient growth inhibition of bacillus anthracis by knocking out the ribonucleotide reductase tyrosyl radical. | bacillus anthracis, the causative agent of anthrax, is a worldwide problem because of the need for effective treatment of respiratory infections shortly after exposure. one potential key enzyme of b. anthracis to be targeted by antiproliferative drugs is ribonucleotide reductase. it provides deoxyribonucleotides for dna synthesis needed for spore germination and growth of the pathogen. we have cloned, purified, and characterized the tyrosyl radical-carrying nrdf component of b. anthracis class i ... | 2005 | 16322104 |
| low persistence of bacillus thuringiensis serovar israelensis spores in four mosquito biotopes of a salt marsh in southern france. | we studied the persistence of bacillus thuringiensis serovar israelensis (bti) in a typical breeding site of the mosquito ochlerotatus caspius in a particularly sensitive salt marsh ecosystem following two bti-based larvicidal applications (vectobac 12as, 1.95 l/ha). the treated area was composed of four larval biotopes that differed in terms of the most representative plant species (sarcocornia fruticosa, bolboschoenus maritimus, phragmites australis, and juncus maritimus) and the physical and ... | 2005 | 16328650 |
| spatial variation in bacillus thuringiensis/cereus populations within the phyllosphere of broad-leaved dock (rumex obtusifolius) and surrounding habitats. | the aim of this study was to determine the prevalence and toxin gene diversity of bacillus thuringiensis/b. cereus in the phyllosphere of broad-leaved dock (rumex obtusifolius) at a small spatial scale. b. thuringiensis/cereus populations were isolated from the phyllosphere of dock and neighbouring grass and in neighbouring soil using commercially available selective media which avoided the disadvantageous heat-shock selection procedure. the maximum density of b. thuringiensis/cereus in the dock ... | 2005 | 16332339 |
| distribution of genes encoding putative virulence factors and fragment length polymorphisms in the vrra gene among brazilian isolates of bacillus cereus and bacillus thuringiensis. | one hundred twenty-one strains of the bacillus cereus complex, of which 80 were isolated from a variety of sources in brazil, were screened by pcr for the presence of sequences (bcet, hbla, nhebc, plc, sph, and vip3a) encoding putative virulence factors and for polymorphisms in variable-number tandem repeats (vntr), using a variable region of the vrra open reading frame as the target. amplicons were generated from isolates of b. cereus and bacillus thuringiensis for each of the sequences encodin ... | 2005 | 16332792 |
| flha influences bacillus thuringiensis plcr-regulated gene transcription, protein production, and virulence. | bacillus thuringiensis and bacillus cereus are closely related. b. thuringiensis is well known for its entomopathogenic properties, principally due to the synthesis of plasmid-encoded crystal toxins. b. cereus appears to be an emerging opportunistic human pathogen. b. thuringiensis and b. cereus produce many putative virulence factors which are positively controlled by the pleiotropic transcriptional regulator plcr. the inactivation of plcr decreases but does not abolish virulence, indicating th ... | 2005 | 16332888 |
| rapid ped-2e9 cell-based cytotoxicity analysis and genotyping of bacillus species. | bacillus species causing food-borne disease produce multiple toxins eliciting gastroenteritis. toxin assays with mammalian cell cultures are reliable but may take 24 to 72 h to complete and also lack sensitivity. here, a sensitive and rapid assay was developed using a murine hybridoma ped-2e9 cell model. bacillus culture supernatants containing toxins were added to a ped-2e9 cell line and analyzed for cytotoxicity with an alkaline phosphatase release assay. most bacillus cereus strains produced ... | 2005 | 16333068 |
| bollworm resistance to bt cotton in india. | 2005 | 16333282 | |
| cloning and characterization of a novel gene cry9ec1 encoding lepidopteran-specific parasporal inclusion protein from a bacillus thuringiensis serovar galleriae strain. | a novel delta-endotoxin gene from a lepidopteran-specific bacillus thuringiensis serovar galleriae strain was cloned, and the full sequence of the cry gene was determined. the cloned 6.5-kb dna fragment included the full sequence of the cry gene and three open reading frames located upstream of the cry gene. the gene, designated cry9ec1, encodes a polypeptide of 1154 amino acid residues with a predicted molecular weight of 130 237. the deduced amino acid sequence of the cry9ec1 protein had the h ... | 2005 | 16333339 |
| the molecular structure and catalytic mechanism of a quorum-quenching n-acyl-l-homoserine lactone hydrolase. | in many gram-negative bacteria, including a number of pathogens such as pseudomonas aeruginosa and erwinia carotovora, virulence factor production and biofilm formation are linked to the quorum-sensing systems that use diffusible n-acyl-l-homoserine lactones (ahls) as intercellular messenger molecules. a number of organisms also contain genes coding for lactonases that hydrolyze ahls into inactive products, thereby blocking the quorum-sensing systems. consequently, these enzymes attract intense ... | 2005 | 16314577 |
| evaluating the induced-odour emission of a bt maize and its attractiveness to parasitic wasps. | the current discussion on the safety of transgenic crops includes their effects on beneficial insects, such as parasitoids and predators of pest insects. one important plant trait to consider in this context is the emission of volatiles in response to herbivory. natural enemies use the odours that result from these emissions as cues to locate their herbivorous prey and any significant change in these plant-provided signals may disrupt their search efficiency. there is a need for practical and re ... | 2005 | 16315088 |
| [the role of succinate dehydrogenase in bacterial resistance to the delta endotoxins of bacillus thuringiensis]. | 2005 | 16315992 | |
| overexpression of the pepper transcription factor capf1 in transgenic virginia pine (pinus virginiana mill.) confers multiple stress tolerance and enhances organ growth. | transcription factors play an important role in regulating gene expression in response to stress and pathogen tolerance. we describe here that overexpression of an erf/ap2 pepper transcription factor (capf1) in transgenic virginia pine (pinus virginiana mill.) confers tolerance to heavy metals cadmium, copper, and zinc, to heat, and to pathogens bacillus thuringiensis and staphylococcus epidermidis, as by the survival rate of transgenic plants and the number of decreasing pathogen cells in trans ... | 2005 | 16244910 |
| assessing the transfer of genetically modified dna from feed to animal tissues. | in europe, public and scientific concerns about the environmental and food safety of gm (genetically modified) crops overshadow the potential benefits offered by crop biotechnology to improve food quality. one of the concerns regarding the use of gm food in human and animal nutrition is the effect that newly introduced sequences may have on the organism. in this paper, we assess the potential transfer of diet-derived dna to animal tissues after consumption of gm plants. blood, spleen, liver, kid ... | 2005 | 16245168 |
| gene cloning and expression of cadherin in midgut of helicoverpa armigera and its cry1a binding region. | cadherins belong to one of the families of animal glycoproteins responsible for calcium-dependent cell-cell adhesion. recent literatures showed that the cadherin-like in midgut of several insects served as the receptor of bt toxin cry1a and the variation of cadherin-like is related to insect's resistance to cry1a. the full-length cdna encoding cadherin-like of helicoverpa armigera is cloned by degenerate pcr and race techniques and the gene was designated as btr-harm, which is 5581 bp in full-le ... | 2005 | 16248428 |
| purification and characterization of cry1ac toxin binding proteins from the brush border membrane of helicoverpa armigera midgut. | several cry1ac binding proteins from midgut of helicoverpa armigera were purified using toxin-affinity chromatography. enzyme assays showed that the purified proteins had strong aminopeptidase activity. the n-terminal sequences confidently identified a 124-kda binding protein as an aminopeptidase n (apn), and some similarity suggests that a 162-kda binding protein may also be an apn. two minor binding proteins were not characterized. | 2005 | 16252132 |
| expression of the bacillus thuringiensis mosquitocidal toxin cry11aa in the aquatic bacterium asticcacaulis excentricus. | a mosquitocidal aquatic bacterium has been developed by introducing an operon containing the cry11aa, and p20 genes from bacillus thuringiensis subsp. israelensis (bti) into the gram-negative aquatic bacterium asticcacaulis excentricus. after transformation, the cry11aa gene was successfully expressed in recombinant a. excentricus under the tac promoter, at the level of 0.04 pg/cell. the recombinant bacteria were toxic to aedes aegypti larvae with an lc(50) of 6.83 x 10(5) cells/ml. we believe t ... | 2005 | 16252134 |
| insecticide resistance in culex pipiens from new york. | insecticides are the primary means to control culex pipiens, an enzootic vector of west nile virus, in the usa. to better understand how the evolution of resistance might impact control of this insect, we investigated the levels of resistance in populations collected from 2 metropolitan areas (albany and syracuse, ny) to 4 larvicides (methoprene, phenothrin, bacillus sphaericus [bs], and bacillus thuringiensis israelensis [bti]) and 1 adulticide (phenothrin) registered for mosquito control in ne ... | 2005 | 16252522 |
| [effects of bt toxin cry1ac on biochemical responses of eisenia fetida in an artificial soil]. | bt toxin cry1ac could be introduced into soil by pollen, root exudates, and plant residues. to investigate its toxic effects, the bt toxin was added into an earthworm-cultured artificial soil, and the survival, growth rate, sperm count, protein content, and activities of acetylcholinesterase (ache), catalase (cat), glutathione s-transferase (gst) and cellulase in eisenia fetida were determined. the results suggested that bt toxin cry1ac had little effects on the biomass and physiological charact ... | 2005 | 16262071 |
| comparison of minisatellite polymorphisms in the bacillus cereus complex: a simple assay for large-scale screening and identification of strains most closely related to bacillus anthracis. | polymorphism of five tandem repeats that are monomorphic in bacillus anthracis was investigated in 230 isolates of the b. cereus group and in 5 sequenced b. cereus genomes in search for markers allowing identification of b. cereus and b. thuringiensis strains most closely related to b. anthracis. using this multiple-locus variable number of tandem repeat analysis (mlva), a cluster of 30 strains was selected for further characterization. eventually, six of these were characterized by multilocus s ... | 2005 | 16269689 |
| impact of bt corn on rhizospheric and soil eubacterial communities and on beneficial mycorrhizal symbiosis in experimental microcosms. | a polyphasic approach has been developed to gain knowledge of suitable key indicators for the evaluation of environmental impact of genetically modified bt 11 and bt 176 corn lines on soil ecosystems. we assessed the effects of bt corn (which constitutively expresses the insecticidal toxin from bacillus thuringiensis, encoded by the truncated cry1ab gene) and non-bt corn plants and their residues on rhizospheric and bulk soil eubacterial communities by means of denaturing gradient gel electropho ... | 2005 | 16269702 |
| common, but complex, mode of resistance of plutella xylostella to bacillus thuringiensis toxins cry1ab and cry1ac. | a field collected population of plutella xylostella (serd4) was selected in the laboratory with bacillus thuringiensis endotoxins cry1ac (cry1ac-sel) and cry1ab (cry1ab-sel). both subpopulations showed similar phenotypes: high resistance to the cry1a toxins and little cross-resistance to cry1ca or cry1d. a previous analysis of the cry1ac-sel showed incompletely dominant resistance to cry1ac with more than one factor, at least one of which was sex influenced. in the present study reciprocal mass ... | 2005 | 16269720 |