Maïbèche-Coisne Martine, Merlin Christine, François Marie-Christine, Porcheron Patrick, Jacquin-Joly Emmanuelle
INRA, Unité de Phytopharmacie et Médiateurs Chimiques, Bât. A, route de Saint-Cyr, F-78026 Versailles Cedex, France.
Gene. 2005 Feb 14;346:195-203. doi: 10.1016/j.gene.2004.11.010.
The involvement of cytochrome P450 (CYP) enzymes in olfaction has been demonstrated in vertebrates over the past decade. In insects, these enzymes are well known for their role in biosynthesis of endogenous compounds as well as xenobiotic metabolism, but the presence of olfactory cytochrome P450s was poorly investigated. Using a PCR-based strategy, we have isolated cDNAs of two new microsomal P450s from the antennae of the cabbage armyworm Mamestra brassicae, CYP9A13 and CYP4G20 of two new microsomal P450s, as well as their red-ox partner, the cytochrome P450 reductase (CPR). Their distribution through the body and their cellular localization within the antennae were studied by RT-PCR and in situ hybridization. The three genes are strongly expressed in some sensory units of the antennae, the sensilla trichodea, which are tuned to odorants detection. The putative functions of the corresponding enzymes are discussed in regard to their respective expression patterns and to our knowledge on olfactory P450 metabolism in mammals.
在过去十年中，细胞色素P450（CYP）酶在脊椎动物嗅觉中的作用已得到证实。在昆虫中，这些酶因其在内源化合物生物合成以及异源生物代谢中的作用而广为人知，但嗅觉细胞色素P450的存在却鲜有研究。我们采用基于聚合酶链反应（PCR）的策略，从甘蓝夜蛾（Mamestra brassicae）的触角中分离出了两种新的微粒体P450的互补DNA（cDNA），即CYP9A13和CYP4G20，以及它们的氧化还原伴侣——细胞色素P450还原酶（CPR）。通过逆转录聚合酶链反应（RT-PCR）和原位杂交技术，研究了它们在虫体中的分布以及在触角内的细胞定位。这三个基因在触角的一些感觉单元——即对气味检测进行调谐的毛形感器中强烈表达。我们结合相应酶各自的表达模式以及我们对哺乳动物嗅觉P450代谢的了解，对这些酶的推定功能进行了讨论。
