College of Plant Protection, Northwest A & F University, Yangling, Shannxi, 712100, China.
J Chem Ecol. 2012 Mar;38(3):287-94. doi: 10.1007/s10886-012-0085-y. Epub 2012 Mar 9.
Odorant receptors are thought to play critical roles in the perception of chemosensory stimuli by insects. The primary method to address the functions of odorant receptors in insects is to use in vitro binding assays between the receptors and potential chemical stimuli. We injected MmedOrco dsRNA into the abdominal cavity of a braconid wasp, Microplitis mediator, and assayed for expression of this gene 72 h after treatment (RNAi). Quantitative real-time PCR demonstrated that the level of mRNA expression in MmedOrco dsRNA-treated M. mediator was significantly reduced (>90%) when compared with water-treated controls. Furthermore, electroantennogram (EAG) responses of M. mediator to two chemical attractants, nonanal and farnesene, were also reduced significantly (~70%) in RNAi-treated M. mediator when compared to controls. RNAi-treated M. mediator also responded by walking/flying at a lower rate to both chemicals when compared with controls in a Y-tube olfactometer bioassay, which provides direct evidence that MmedOrco plays an important role in perception of nonanal and farnesene in M. mediator.
气味受体被认为在昆虫对化学感觉刺激的感知中起着关键作用。研究昆虫气味受体功能的主要方法是在受体和潜在化学刺激物之间进行体外结合测定。我们将 MmedOrco dsRNA 注入到一种姬蜂，Microplitis mediator 的腹腔中，并在处理后 72 小时（RNAi）检测该基因的表达情况。实时定量 PCR 表明，与水对照组相比，MmedOrco dsRNA 处理的 M. mediator 中的 mRNA 表达水平显著降低（>90%）。此外，与对照组相比，电触角图（EAG）反应显示，两种化学引诱剂壬醛和法呢烯对 RNAi 处理的 M. mediator 的反应也显著降低（~70%）。在 Y 型嗅觉计生物测定中，与对照组相比，RNAi 处理的 M. mediator 对这两种化学物质的行走/飞行反应率也较低，这直接证明了 MmedOrco 在 M. mediator 对壬醛和法呢烯的感知中起着重要作用。
