棉铃虫细胞色素P450 cDNA片段的克隆与序列分析

Cloning and sequence analysis of cDNA fragments of cytochrome P450 from Helicoverpa armigera

以 5龄实验室敏感品系棉铃虫Helicoverpaarmigera的总RNA为模板 ,采用简并性引物 ,利用反转录 -多聚酶链式反应 (RT PCR)扩增出了 2个新的长度分别为 2 3 7bp和 2 40bp的cDNA片段。序列分析表明 ,2 3 7bp的cDNA片段与棉铃虫P45 0CYP4家族有较高的相似性 ,最高达 73 %;而 2 40bp的cDNA片段与CYP6家族有较高的相似性 ,最高达 49%。

Cytochrome P450\|dependent monooxygenase is a very important metabolic system involved in the metabolism of a phenomenal number of endogenous and exogenous compounds.Inorder to reveal the structures and functions of cytochrome P450s in the cotten bollworm, Helicoverpa armigera, we have isolated two cytochrome P450 cDNA fragements(237 bp and 240 bp) from the midgut of the fifth instar larvae of a susceptible strain of this pest using a RT\|PCR strategy with a pair of degenerated primers.The fragment of 237 bp showed high identity of deduced amino acids with that of the known members of CYP4 family cloned from H.armigera, wherase the fragement of 240 bp had high identity of amino acids with that of some members of CYP6 family in insects.