Specific PCR primers directed to identify cryI and cryIII genes within a Bacillus thuringiensis strain collection.
In this paper we describe a PCR strategy that can be used to rapidly identify Bacillus thuringiensis strains that harbor any of the known cryI or cryIII genes. Four general PCR primers which amplify DNA fragments from the known cryI or cryIII genes were selected from conserved regions. Once a strain was identified as an organism that contains a particular type of cry gene, it could be easily characterized by performing additional PCR with specific cryI and cryIII primers selected from variable regions. The method described in this paper can be used to identify the 10 different cryI genes and the five different cryIII genes. One feature of this screening method is that each cry gene is expected to produce a PCR product having a precise molecular weight. The genes which produce PCR products having different sizes probably represent strains that harbor a potentially novel cry gene. Finally, we present evidence that novel crystal genes can be identified by the method described in this paper.
Instituto de Biotecnología, Universidad Nacional de Colombia, Ciudad Universitaria, Bogota, Colombia.
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Cerón
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Ortíz
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Quintero
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Güereca
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Bravo
D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004731:Endotoxins / Q000235:genetics*; D005798:Genes, Bacterial; D006460:Hemolysin Proteins; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D013045:Species Specificity
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D017931:DNA Primers; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis