该研究通过PCR的方法克隆得到家蚕热激蛋白70基因(Bombyxmorihsp70)5^+侧翼的两个长度分别为538bp和305bp的序列hsp70—538和hsp70—305。生物信息分析结果表明这两段序列在TATA序列的上游存在保守的热激元件HSE(heat shock element)cTnGAAnnTTcnAG。采用双荧光报告基因技术研究表明这两段序列在BmN细胞中都表现出热激活性,转基因家蚕实验证明hsp70—305在家蚕个体中也具有热激活性,可以认为这两个片段具有hsp70热激启动子特性。
We have got two fragments located in the upstream ofBombyx mori hsp70 gene, one was hsp70- 538 (538bp in length), and the other was hsp70-305 (305bp) through the PCR amplification. By comparing analysis, these two fragments possess of the consensus sequence of riSE (heat shock element) associated with the heat shock genes of Drosophila: CTnGAAnnTTCnAG. Applying the technology of dual-luciferase vector, these two fragments can confer heat inducement in BmN cells. And the hsp70-538 fragment can induce more activity than hsp70-305 fragment. We also informed it by transgenic analysis in silkworm. Its activity was increased with the elevated tem- perature. The more exposure to 42℃, the more amount of target gene expression we got. So these two fragments can be considered as heat shock promoters.