【摘要】 利用苏云金芽胞杆菌cry1A启动子上游区的不同突变体，观测对BtⅠ-lacZ融合基因表达的影响。结果发现，突变上游弯曲区，导致Btl-lacZ在菌株80-21中的酶活性大幅度下降，均比未突变的上游区降低2～2．5倍。而在菌株HD133-5中却出现相反的结果，即上游弯曲区的突变导致BtⅠ-lacZ的表达比未突变体增高。如果同时突变弯曲区和反向重复区，则BtⅠ-lacZ在菌株80-21中表达增强或下降的幅度大大减少。这表明，在crylA启动子上游区，不同位点在转录调控上的作用不同，这种调控作用也因菌株的差异而改变。更多还原

【Abstract】 Using different mutants of cryⅠA promoter upstream and testing their effects on expression of BtI-lacZ fusion, mutation in the bend region of cryⅠA promoter upstream resulted in the β-gelactosidase activity of BtI-lacZ in strain 8O-21 decreasing by big margin about 2～2.5 fold lower than with wild cry1A promoter upstream was found. But in strain 5, there was a inverted result, which was mutant of upstream bend region resulted in a higher expression of BtⅠ-lacZ than with wild crylA promoter upstream. If mutation in the bend region and inverted region at same time, the increasing or decreasing margin of Btl-lacZ expression in strain 80-21 would be reduced greatly. It suggested that different sites of CrylA promoter upstream might have different functions in the transcriptional regulation of crylA gene. The regulation would vary in various strain of Bacillus thuringiensis.更多还原