Cloning of partial cry1Ac gene from an indigenous isolate of Bacillus thuringiensis

摘要

The discoveries of novel cry genes of Bacillus thuringiensis (Bt) with higher toxicity are important for the development of new products. The cry1 family genes are more toxic to the lepidopteran insects ------according to the previous reports. In the present study, nine indigenous isolates of Bt were used for screening of cry1 genes by PCR using degenerate primers specific to cry1 family genes. Two of the nine new isolates of Bt showed amplification with cry1 family primers. Partial cry1gene(s) was cloned from one of the cry1 positive isolate of Bt, T133. Nucleotide sequence data generated for partial cry1 gene of T133 showed 98% homology with 1420 bp of the partial cry1Ac1 gene. Deduced amino acid sequence of the partial cry1Ac of Bt strain, T133 showed two per cent variation in comparison to Cry1Ac1 by differing at 5 positions; one deletion at 442th position and five substitutions at the following positions, 296, 367, 440 and 563.