Localization and identification of crystal protein genes in Bacillus thuringiensis strain 4.0718

Abstract:

[Objective] To localize and identify the insecticidal crystal protein genes (cry genes) in high-toxic Bacillus thuringiensis strain 4.0718. [Methods] The genomic DNA of B. thuringiensis strain 4.0718 was isolated by pulse field gel electrophoresis (PFGE), and the PFGE pattern and plasmid pattern were characterized. The cry genes in the strain were analyzed by Southern blot and the cry gene types on the chromosome and plasmid were identified by PCR and restriction fragment length polymorphism patterns of the PCR-amplified fragments (PCR-RFLP). [Results] Southern blots showed that the cry genes in B. thuringiensis strain 4.0718 are present on both chromosome and plasmid. PCR and RFLP patterns showed that the chromosome and plasmid contain four cry genes, cry1Aa, cry1Ac, cry2Aa, and cry2Ab. However, the cry genes on the chromosome may be incomplete, while the cry1Aa and cry1Ac genes localized on the plasmid were found to contain the full coding sequence. [Conclusion] The abundant cry genes were first found on chromosome of B. thur-ingiensis strain 4.0718, and the cry-type genes are the same as the plasmid.苏云金芽胞杆菌；cry基因；定位；脉冲电泳（PFGE）；限制性片段长度多态性分析（RFLP）