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运用ＲＴＰＣＲ技术从棉铃虫（Ｈｅｌｉｃｏｖｅｒｐａａｒｍｉｇｅｒａ）五龄幼虫中扩增到一个６２７ｂｐ的ＤＮＡ片段。测序表明这一片段为ＣＹＰ６Ｂ２基因的功能保守区。以这一片段为探针对棉铃虫拟除虫菊酯抗性（Ｒ）及敏感（Ｓ）品系的总ＲＮＡ进行点杂交。ＲＮＡ点杂交表明未经氰戊菊酯诱导的情况下Ｒ品系的ＣＹＰ６Ｂ２基因的ｍＲＮＡ水平明显高于Ｓ品系，即为转录水平的调控。而经氰戊菊酯诱导后杂交表明Ｓ品系明显被氰戊菊酯诱导，但Ｒ品系不被诱导。由此推测，棉铃虫Ｒ品系的ＣＹＰ６Ｂ２基因上游调控位点处可能存在突变，从而导致该基因在Ｒ品系与Ｓ品系中于药物诱导时转录水平上的不同。
A 627bp DNA fragment was amplified from the fifth instar larvae of Helicoverpa armigera by RTPCR. Sequencing showed that this fragment was a functionally conserved region of CYP6B2 gene. Using this fragment as a probe, dot blot hybridization was performed on total RNA of the pyrethroid-resistant (R) and susceptible (S) lines of the H. armigera. RNA dot blot showed that the mRNA level of CYP6B2 gene in R strain was significantly higher than that of S strain without fenvalerate induction, that is, the transcription level was regulated. However, cross-fertilization with fenvalerate showed that S strain was significantly induced by fenvalerate but R strain was not induced. Therefore, it is speculated that there may be a mutation in the upstream regulatory site of CYP6B2 gene in the R strain of Helicoverpa armigera, resulting in differences in the transcription level of the gene in the R and S strains at drug induction.