Abstract

                                By using the cry24a operon specific primers, DNA fragments of about 4.0 kb were amplified at 55°C annealing temperature without any non-specific amplification from a new Bt strain 47-8 and cloned in pGEM-T(3.0 kb) vector. Double digestion with Sall and Sphl enzymes showed fragments of expected size (3, 4kb) in recombinant clones and one of the positive clones is designated as pTN2A (7.0 kb). Nucleotide sequencing of Bt DNA fragment cloned in pTN2A was carried out with M13F and M13R primers. Totally 983 bases have been sequenced in the insert DNA of pTN2A. Comparison of sequence data obtained from the cloned DNA fragment of Bt strain 47-8 showed 97 to 98 per cent homology to the holotype cry2Aa operon. Hence, cloning of cry24a gene of Bt strain 47-8 is confirmed.

Key words : Bacillus thuringiensis, Cry2Aa, Cry2Aa