Extended screening by PCR for seven cry-group genes from field-collected strains of Bacillus thuringiensis

Eitan Ben-Dov, Arieh Zaritsky, Edith Dahan, ZE'Ve Barak, Rosa Sinai, Robert Manasherob, Allovuddin Khamraev, Eugenia Troitskaya, Anatoly Dubitsky, Natasha Berezina, Yoel Margalith

Research output: Contribution to journalArticlepeer-review

253 Scopus citations


An extended multiplex PCR method was established to rapidly identify and classify Bacillus thuringiensis strains containing cry (crystal protein) genes toxic to species of Lepidoptera, Coleoptera, and Diptera. The technique enriches current strategies and simplifies the initial stages of large-scale screening of cry genes by pinpointing isolates that contain specific genes or unique combinations of interest with potential insecticidal activities, thus facilitating subsequent toxicity assays. Five pairs of universal primers were designed to probe the highly conserved sequences and classify most (34 of about 60) genes known in the following groups: 20 cryl, 3 cry2, 4 cry3, 2 cry4, 2 cry7, and 3 cry8 genes. The DNA of each positive strain was probed with a set of specific primers designed for 20 of these genes and for cry11A. Twenty-two distinct cry-type profiles were identified from 126 field- collected B. thuringiensis strains. Several of them were found to be different from all published profiles. Some of the field-collected strains, but none of the 16 standard strains, were positive for cry2Ac. Three standard and 38 field-collected strains were positive by universal primers but negative by specific primers for all five known genes of cry7 and cry8. These field-collected strains seem to contain a new gene or genes that seem promising for biological control of insects and management of resistance.

Original languageEnglish
Pages (from-to)4883-4890
Number of pages8
JournalApplied and Environmental Microbiology
Issue number12
StatePublished - 1 Jan 1997

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Ecology
  • Applied Microbiology and Biotechnology


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