Molecular cloning and sequence analysis of cry1A genes from Bacillus thuringiensis.

Specific primers,which were synthesized according to the conservative regions of cry1A gene,were used to amplify genomic DNA from three Bacillus thuringiensis(Bt) strains sreened by polymerase-chain reaction (PCR).Three sequences of cry1A gene with whole length of 3.6kb was obtained,which contained a complete open reading frame.These three full-length coding sequences were 3468,3450 and 2697 bp(GenBank Accession Number GQ385073,GQ385074,GQ385075).Nucleotide sequencing showed that the sequences for these three genes had more than 95 % identical to the known cry1A gene,which encoded 1159,962 and 898 amino acids respectively.Some characters of these three genes that could encode amino acids were analyzed and predicted by the tools of bioinformatics in the following aspects,including the composition of amino acid sequences,hydrophobicity or hydrophilicity,membrane spaning domain and tertiary structure of protein and function.It provided new selection for development of novel Bt products based on its toxins.