• Korean journal of applied entomology
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• v.35 no.1
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• pp.66-73
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• 1996

For the effective control of mosquito larvae, Anopheles sinensis, the expression vector pCYASK5-1 containing cryIVD gene of Bacillus thuringiensis subsp. morrisoni PG-14 was constructed and transformed into the cyanobacterium Synechocystis PCC6803. The transformants were selected on BG-11 medium containing kanamycin. The expression of cryIVD gene in transformant was confirmed by SDS-PAGE and Western blot analysis. The mortality of A. sinensis larvae was scored for 3 days. Furthermore, growth and distribution rate of transformant were examined. The results showed that Synechocystis PCC6803 transformed with cryIVD gene of B. thuringiensis subsp. morrisoni PG-14 was highly toxic to A. sinensis larvae, demonstrating that it will be a potential agent for mosquito control.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.85-90
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• 1996

Bacillus thuringiensis NT0423 produces quite a typical bipyramidal crystals of a common major band of ca. 130 kDa, and has dual specificity against Lepidoptera and Diptera. To enforce the Diptera-toxicity of B. thuringiensis NT0423, cryND gene was transformed 30 B. thuringiensis NT0423. The transfonnant B. thuringiensis PT1227 was obtained from introduction of pCGl0 into B. thuringiensis NT0423 by electroporation. The result showed that cryND and resident crystal protein genes in transformant were stably expressed with its own shape. Furthermore, the toxicity of B. thuringiensis PT1227 against Diptera was highly enforced, suggesting that the enforced toxicity of B. thuringiensis PT1227 was due to synergistic effect of both introduced and resident crystal proteins in transformant.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.173-177
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• 1996

Bacillus thuringiensis subsp. morrisoni PG-14 is a gram-positive soil bacterium producing mosquitocidal parasporal inclusions composed of several crystal proteins. Among these crystal protein genes, cryIVD gene is one of major component which has 72 kDa in size. However, these parasporal inclusions sink quickly from the surface of water where mosquito larval feeding occurred. To develope mosquitocidal cyanobacterium, therefore, we constructed the expression vector, pCYASK 5-1 harboring cryIVD gene. The expression vector, pCYASK5-1 was transformed into the cyanobacterium Syne- chocystis PCC6803 reported as a natural mosquito larval food source and the transformants were selected with kanamycin. Expression of IVD gene in transformant was characterized by SDS-polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis. The mosquitocidal activity of a transformant was determined with Culex tritaeniorhynchus. The results showed that, the transformed cyanobacterium is toxic to mosquito larvae and will be expected as a potential agent that is used for mosquito control.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.176-180
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• 1995

To characterize expression and formation of three type crystal proteins in transformant, Bacillus thruingiensis PT0529 was analysed by transmission electron microscope and SDS-PAGE according to growth. The results showed that the introduced crystal protein genes, rcyIVD and cytA, were well expressed at earlier stage than resident crystal proteins were also expressed with their own morphology. However, resident crystal protein of B. thuringiensis PT0529 was smaller than that of wild type B. thuringiensis NT0423, suggesting that resident crystal protein production was interfered with introduced two type crystal protein genes.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.428-434
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• 1993

Cloning and expression of two different crystal protein genes from transformed Bacillus thuringiensis were investigated. B. thuringiensis NT0423 is toxic to both Lepidopterous and Dipte-rous larvae. The pCG5 vector carrying crystal protein genes (mosquitocidal and hemolytic activity) of B. thurigiensis subsp. morrisoni PG-14 was transformed into B. thurigiensis NT0423. Transformant has expressed two type crystals of bipyramid from NT0423 and ovoid from pCG5 in one cell.