Chan Hiang Hao, Wajidi Mustafa Fadzil Farid, Zairi Jaal
School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
School of Distance Education, Universiti Sains Malaysia, 11800 Penang, Malaysia
J Insect Sci. 2014 Jan 1;14:163. doi: 10.1093/jisesa/ieu025. Print 2014.
Cytochrome P450 monooxygenase (P450) is a superfamily of enzymes that is important in metabolism of endogenous and exogenous compounds. In insects, these enzymes confer resistance to insecticides through its metabolic activities. Members of P450 from family 6 in insects are known to play a role in such function. In this study, we have isolated seven novel family 6 P450 from Aedes albopictus (Skuse) (Diptera: Culicidae), a vector of dengue and chikungunya fever. Induction profile of these seven genes was studied using several insecticides and xenobiotics. It was found that deltamethrin and permethrin did not induce expression of any genes. Another insecticide, temephos, inhibited expression of CYP6P15 for fivefold and twofold for CYP6N29, CYP6Y7, and CYP6Z18. In addition, copper II sulfate induced expression of CYP6M17 and CYP6N28 for up to sixfold. Benzothiazole (BZT), a tire leachate induced the expression of CYP6M17 by fourfold, CYP6N28 by sevenfold, but inhibited the expression of CYP6P15 for threefold and CYP6Y7 for twofold. Meanwhile, piperonyl butoxide (PBO) induced the expression CYP6N28 (twofold), while it inhibited the expression of CYP6P15 (fivefold) and CYP6Y7 (twofold). Remarkably, all seven genes were induced two- to eightfold by acetone in larval stage, but not adult stage. Expression of CYP6N28 was twofold higher, while expression of CYP6P15 was 15-fold lower in adult than larva. The other five P450s were not differentially expressed between the larvae and adult. This finding showed that acetone can be a good inducer of P450 in Ae. albopictus. On the other hand, temephos can act as good suppressor of P450, which may affect its own bioefficacy because it needs to be bioactivated by P450. To the best of our knowledge, this is the first report on acetone-inducible P450 in insects. Further study is needed to characterize the mechanisms involved in acetone induction in P450.
细胞色素P450单加氧酶（P450）是一类酶的超家族，在内源性和外源性化合物的代谢中起重要作用。在昆虫中，这些酶通过其代谢活性赋予对杀虫剂的抗性。已知昆虫6家族的P450成员在这种功能中发挥作用。在本研究中，我们从白纹伊蚊（Skuse）（双翅目：蚊科）中分离出7个新的6家族P450，白纹伊蚊是登革热和基孔肯雅热的传播媒介。使用几种杀虫剂和异生物质研究了这7个基因的诱导谱。发现溴氰菊酯和氯菊酯没有诱导任何基因的表达。另一种杀虫剂双硫磷抑制CYP6P15的表达达5倍，抑制CYP6N29、CYP6Y7和CYP6Z18的表达达2倍。此外，硫酸铜诱导CYP6M17和CYP6N28的表达高达6倍。轮胎渗滤液苯并噻唑（BZT）诱导CYP6M17的表达达4倍，CYP6N28的表达达7倍，但抑制CYP6P15的表达达3倍，抑制CYP6Y7的表达达2倍。同时，胡椒基丁醚（PBO）诱导CYP6N28的表达（2倍），而抑制CYP6P15的表达（5倍）和CYP6Y7的表达（2倍）。值得注意的是，所有7个基因在幼虫期均被丙酮诱导2至8倍，但在成虫期未被诱导。CYP6N28在成虫中的表达比幼虫高2倍，而CYP6P15在成虫中的表达比幼虫低15倍。其他5种P450在幼虫和成虫之间没有差异表达。这一发现表明丙酮可能是白纹伊蚊中P450的良好诱导剂。另一方面，双硫磷可以作为P450的良好抑制剂，这可能会影响其自身的生物活性，因为它需要被P450生物活化。据我们所知，这是关于昆虫中丙酮诱导型P450的首次报道。需要进一步研究来表征P450中丙酮诱导所涉及的机制。
