Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9486356 | Journal of Invertebrate Pathology | 2005 | 8 Pages |
Abstract
Current control of the sheep blowfly (Lucilia cuprina) relies on chemical insecticides, however, with the development of resistance and increasing concerns about human health and environmental residues, alternative strategies to control this economically important pest are required. In this study, we have identified several isolates of Bacillus thuringiensis (Bt), collected from various Australian soil samples, that produce crystals containing 130 and 28Â kDa proteins. These isolates were highly toxic to feeding larvae in both in vitro bioassays and in vivo on sheep. By N-terminal amino acid sequencing, we identified the smaller crystal band (28Â kDa) as a cytological (Cyt) protein. Upon solubilization and proteolytic processing by trypsin, the 130Â kDa crystal protein yielded among others, a truncated 55-60Â kDa toxin moiety which exhibited larvicidal activity against sheep blowfly. The amino-terminal sequence of the trypsin-resistant protein band revealed that this Bt endotoxin was encoded by a new cry gene. The novel cry protein was present in all the strains that were highly toxic in the larval assay. We have also identified from one of the isolates, a novel secretory toxin with larvicidal activity.
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Authors
Joanne M. Gough, David H. Kemp, Raymond J. Akhurst, Roger D. Pearson, Kritaya Kongsuwan,