Applied Entomology and Zoology (1998) 33, 441-447

Yong Soon Kim, Kohzo Kanda, Kazuki Yamaguchi, Fumio Kato and Akira Murata (1998)
Genetic analysis of the cry1Ab gene in Bacillus thuringiensis strain AF101
Applied Entomology and Zoology 33 (3), 441-447
Abstract: An insecticidal crystal protein (ICP) gene was cloned from Bacillus thuringiensis strain AF101 which has a low toxicity to the silkworm, Bombyx mori. The cloned AF101 ICP gene encoded 1,182 amino acid residues and shared 93% homology with the cry1Ab gene of B. thuringiensis serovar kurstaki HD-1. In the amino-terminal portion of the activated toxin region of AF101 ICP, there were 18 amino acid differences when compared with HD-1 Cry1Ab, but only three amino acid differences in the hypervariable region of the activated toxin. The AF101 ICP gene was also found to contain the Cys-rich region observed in cry1Aa and cry1Ac in its carboxyl-terminal portion of the non-toxin region. In a bioassay of the cloned gene product, toxicity with intact AF101 ICP was nearly 17% less than that of HD-1 Cry1Ab. On the other hand, the activated toxin prepared from ICP by removing the non-toxin region was 9% less than that of HD-1 Cry1Ab. These results suggested that the specific toxicity of AF101 ICP against the silkworm correlated not only with its activated toxin region, but also with the non-toxin region.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Bacillus thuringiensis var. kurstaki (entomopathogen)
Bacillus thuringiensis Cry1A-toxin (entomopathogen)