Molecular cloning of the delta-endotoxin gene of Bacillus thuringiensis var. israelensis.

Autor(es): Sekar V; Carlton B C

Resumo: A transformant of Bacillus megaterium, VB131, was isolated which carries a 6.3-kb XbaI segment of the crystal toxin gene of Bacillus thuringiensis var. israelensis (BTI) cloned in a vector plasmid pBC16 to yield pVB131. The chimeric plasmid DNA from VB131 was introduced into a transformable Bacillus subtilis strain by competence transformation. Both the B. megaterium VB131 strain and the B. subtilis strain harboring the chimeric plasmid produced irregular, parasporal, phase-refractile, crystalline inclusions (Cry+) during sporulation. The sporulated cells as well as the isolated crystal inclusions of the pVB131-containing B. megaterium and B. subtilis strains were highly toxic to the larvae of Aedes aegypti. Also, the solubilized crystal protein preparation from VB131[pVB131] showed clear immuno cross-reaction with antiserum to the BTI crystal toxin. 32P-labeled pVB131 plasmid DNA showed specific hybridization with a 112-kb plasmid DNA of Cry+ strains of BTI, and no hybridization with other plasmid or chromosomal DNA of either Cry+ or Cry- variants. These results are in agreement with our previous findings (González and Carlton, 1984) that the 112-kb plasmid of BTI is associated with the production of the crystal toxin.

Palavras-Chave: Recombinant DNA; Aedes aegypti; Transformation, Plasmids; Vector; Crystal toxin; Larvicidal activity

Imprenta: Gene, v. 33, n. 2, p. 151-158, 1985

Identificador do objeto digital: 10.1016/0378-1119(85)90089-7

Descritores: Aedes aegypti - Cell ; Aedes aegypti - DNA ; Aedes aegypti - Genome ; Aedes aegypti - Pathogenesis ; Aedes aegypti - Proteins ; Aedes aegypti - Immunology

Data de publicação: 1985