RESUMEN
@#Abstract: Objective To construct a shuttle vector pHT315-AaCPR100A with two spore-producing-dependent promoters and the target gene AaCPR100A in Escherichia coli-Bacillus thuringiensis. Methods The forward promoter of Cry3A, named Pro-1 (+), was amplified by PCR using pSVP27A plasmid as the template, and the target gene AaCPR100A was amplified using Aedes aegypti RNA reverse conversion cDNA as the template. The plasmid pHT315 was linearized by digestion with Hind Ⅲ and Sal Ⅰ. The forward promoter and the target gene were inserted into the linearized vector pHT315 successively by in-fusion cloning according to the transcription direction. The synthesized plasmid containing the Cry3A reverse promoter sequence was used as the template, and the Pro-1 (-) reverse promoter was amplified by PCR. The intermediate vector containing the forward promoter and the target gene was linearized by EcoR I restriction enzyme, and the reverse promoter was inserted downstream of the target gene by in-fusion cloning in the direction of transcription. Results By agarose gel electrophoresis, the forward promoter, target gene AaCPR100A and reverse promoter bands were clear and of good quality, which could be used for in-fusion cloning experiments. The two spore-producing-dependent promoters and target gene fragments were connected by In-fusion cloning. The recombinant vector pHT315-AaCPR100A was verified by PCR. The forward promoter, target gene fragment and reverse promoter were successfully amplified in the recombinant vector. Nucleotide sequencing verified that the sequencing results of the bidirectional promoter sequence and the target gene sequence were basically consistent with the sequence alignment results, which met the requirements of the construction of vector elements and proved that the recombinant vector was successfully constructed. Conclusions Based on the above results, this study proves that the recombinant shuttle vector with two spore-producing-dependent promoters can be successfully constructed by in-fusion cloning technology, laying the foundation for the construction of engineered Bacillus thuringiensis expressing dsRNA of AaCPR100A.