Transfer of Bacillus thuringiensis Plasmids Coding for δ -endotoxin among Strains of B. thuringiensis and B. cereus

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 79; no. 22; pp. 6951 - 6955
• Main Authors: González, José M., Brown, Barbara J., Carlton, Bruce C.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01.11.1982; National Acad Sciences
• Subjects: Antigens; Antiserum; Bacillus cereus - genetics; Bacillus thuringiensis; Bacillus thuringiensis - genetics; Bacterial Proteins; Bacterial Toxins; Base Sequence; Broths; Cloning, Molecular; Crystals; Endotoxins - genetics; Endotoxins - isolation & purification; Flagella; Gels; Hemolysin Proteins; Immunology; Molecular Weight; Mutation; Plasmids; Species Specificity; Toxins; Bacillus cereus
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.79.22.6951

The recently discovered high-frequency transfer of plasmids between strains of Bacillus thuringiensis was used to study the genetic relationship between plasmids and production of the insecticidal δ -endotoxin crystal. Three strains of B. thuringiensis transmitted the Cry+(crystal-producing) phenotype to Cry-(acrystalliferous) B. thuringiensis recipients. Agarose gel electrophoresis showed that one specific plasmid from each donor strain was always present in Cry+``transcipients.'' The size of the transmissible crystal-coding plasmid varied with the donor strain, being 75 MDal (megadaltons) in size in HD-2, 50 MDal in HD-73, and 44 MDal in HD-263. Immunological analysis showed the Cry+transcipients to be hybrid strains, having flagella of the recipient serotype and crystals of the donor serotype. These results demonstrate that the structural genes for the δ -endotoxin are plasmid borne. Crystal-coding plasmids also transferred into two strains of the related species Bacillus cereus and yielded transcipients that produced crystals of the same antigenicity as the donor strain.