Applied and Environmental Microbiology (1998) 64, 4782-4788
Luke Masson, Martin Erlandson, Marianne Puzstai-Carey, Roland Brousseau, Victor Juárez-Pérez and Roger Frutos (1998)
A holistic approach for determining the entomopathogenic potential of Bacillus thuringiensis strains
Applied and Environmental Microbiology 64 (12), 4782-4788
Abstract: The cry gene content of Bacillus thuringiensis subsp. aizawai HD-133 was analyzed by a combination of high-pressure liquid chromatography (HPLC) and exclusive PCR. A total of six cry genes were detected in genomic DNA purified from HD-133, four from the cry1 family (cry1Aa, cry1Ab, cry1C, and cry1D) as well as a gene each from the cry2 (cry2B) and the cry1I families. To directly determine which genes were expressed and crystallized in the purified parasporal inclusions, solubilized and trypsinized HD-133 crystals were subjected to chromatographic separation by HPLC. Only three proteins, Cry1Ab, Cry1C, and Cry1D, were found, in a 60/37/3 ratio. Dot blot analysis of total mRNA purified from HD-133 showed that both the cry2B and cry1I genes, but not the cry1Aa gene, were transcribed. Cloning and sequencing of the cry1Aa gene revealed an inserted DNA sequence within the cry coding sequence, resulting in a disrupted reading frame. Taken together, our results show that combining crystal protein analysis with a genetic approach is a highly complementary and powerful way to assess the potential of B. thuringiensis isolates for new insecticidal genes and specificities. Furthermore, based on the number of cryptic genes found in HD-133, the total cry gene content of B. thuringiensis strains may be higher than previously thought.
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Database assignments for author(s): Martin A. Erlandson, Luke Masson
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
molecular biology - genes
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Bacillus thuringiensis var. aizawai (entomopathogen) | ||||
| Bacillus thuringiensis Cry1A-toxin (entomopathogen) | ||||
| Bacillus thuringiensis Cry1D-toxin (entomopathogen) | ||||
| Bacillus thuringiensis Cry1C-toxin (entomopathogen) |
