【摘要】 细胞色素P450基因CYP9A12的过量表达已被证实与棉铃虫Heliocverpa armigera对拟除虫菊酯的抗性相关。为探明棉铃虫CYP9A12基因的表达调控机理,根据棉铃虫CYP9A12基因cDNA全长的5′-末端核苷酸序列,采用基因组步移方法,获得CYP9 A12的5′-上游区序列(总长为3575bp)。与cDNA序列进行比对,表明在起始密码子上游3bp处有一长为2124bp的内含子。利用NNPP分析软件预测出转录起始位点,与根据CYP9A12全长cDNA序列推测的结果是一致的。TFSEARCH 1.3软件分析转录因子结合位点的结果显示,该序列不仅包含启动子的核心结构序列——TATA-box和CAAT-box,亦包含多个转录因子结合位点,如GATA-1,CdxA,Dfd等。本研究结果为深入研究棉铃虫CYP9A12的表达调控机制及其参与杀虫剂抗性的分子机理奠定了一定基础。更多还原

【Abstract】 Overexpression of cytochrome P450 CYP9A12 gene has been proved to be associated with pyrethroid resistance in the cotton bollworm,Helicoverpa armigera.Based on the 5’-end nucleotide sequence of the full length cDNA of CYP9A12,the 5’-upstream region of CYP9A12 was obtained by genome walking technique to investigate the regulatory mechanism of CYP9A12 gene expression.The 5’-upstream fragment of 3 575 bp was successfully cloned and sequenced,and there is an intron(2 124 bp)located 3 bp upstream of the start codon.The transcription initiation site of CYP9A12 predicted by the NNPP software is consistent with that deduced from the full length cDNA of CYP9A12.TFSEARCH 1.3 software predicted several cis-acting element binding sites in the 5’-upstream region of CYP9A12,including not only the core promoter sequences(TATA-box and CAAT-box),but also several transcriptional elements(GATA-1,CdxA,Dfd,etc.).The current study will provide an important basis for further investigating regulation of CYP9A12 expression and molecular mechanism of CYP9A12 involved in insecticide resistance of H.armigera in future.更多还原