Identification Of The Insecticidal Crystal Protein Gene Of The Bacillus Thuringiensis

Polymerase Chain Reaction (PCR) was used to verify the cry3Aa and crylAc genes contained in the engineering strains. The result of SDS桺AGE showed that the engineering strains mainly contained a 68KD protein, the same weight as the expressing product of cry3 gene. There was another protein band weight 13OKD, the same as the expressing product of crylAc.Primers specific to crylC and cry3 respectively were designed and synthesized. 54 Bacillus thuringiensis strains were screened to identify their ICP gene. 28 strains contained crylC gene. According to the result of bioassay, the strains contained crylC gene had high violence to the Spodoptera exigua.The isolated total DNA of YM?3 was fully digested by restriction enzyme BamH I and linked with the PUC19 which was fully digested by Barnfl I too. The linked product was used to transform the receptor E.coli TG?. The transformants were screened on the ampicillin plate by blue white spot screen. The total DNA library of the Bt strain YM?3, which kills the insects of Colepterd, was constructed.