Molecular Cloning And Expression Of P450Genes From Dastarcus Helophoroides

Insect Cytochrome P450enzymes (Cytochrome P450monooxygenases, P450s), a diverseclass of enzymes found in virtually all insect tissues, fulfill many important tasks, rangingfrom the synthesis and degradation of ecdysteroids and juvenile hormones to the metabolismof foreign toxical chemicals of natural or synthetic origin. Dastarcus helophoroides Fairmaire(Coleoptera: Bothrideridae) is a kind of natural enemy of many longhorned beetles and alsowidely utilized in the national biological control. The adults of this predatory beetle enjoyed arelatively long lifespan which may count to8years under laboratorial conditions. However, todate, no reports regarding to this issue were published. Thus, in this study, P450genes from D.helophoroides were cloned, their mRNA expression and total enzymatic activity of P450s wasalso detected. Our resutls and findings towards the aging mechanism of this predatory beetleare as follows:1. Ninety-six novel P450fragments and three novel P450genes which were1696bp,2031bp and1659bp in length were isolated by PCR-RACE strategy. Their ORFs encoded517aa,514aa and510aa respectively and named CYP6BQ21, CYP6BQ22and CYP6BK18bythe International P450Nomenclature Committee.2. qPCR results demonstrated that both CYP6BQ21and CYP6BQ22were highlyexpressed in adulthood of D. helophoroides. Also, their expression level displayed an upwardtrend with the age grew.3. The total enzymatic activity of P450enzyme also displayed an upward trend with theage grew, which was in conformity with the expression patterns of P450genes.4. The mRNA expression and total enzymatic activity of P450stayed at a relatively highlevel in adults D. helophoroides, indicating that the special resistance and inmmunity of itsphysiological and metabolic system which may be the fundamental basis of a longer lifespan.