RNAi-based demonstration of direct link between specific odorant receptors and mosquito oviposition behavior.
RNAi-based demonstration of direct link between specific odorant receptors and mosquito oviposition behavior.
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DOI：
10.1016/j.ibmb.2013.07.008
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发表时间：
2013-10
影响因子：
3.8
通讯作者：
Leal WS
中科院分区：
文献类型：
--
作者：
Zhu F;Xu P;Barbosa RM;Choo YM;Leal WS
西尼罗河病毒的媒介--南方家蚊--有130个气味感受器(ORs)，使年轻的雌性蚊子能找到植物和血液来源，年长的雌性蚊子能找到合适的产卵地点。在我们试图使雌性触角中表达的ORs去孤儿的过程中，我们发现了CquiOR37和CquiOR99，它们狭义地被调节到两种酚类化合物，4-甲基苯酚和4-乙基苯酚。在非洲爪蛙卵母细胞记录系统中，对甲基苯酚和对乙基苯酚对CquiOR37和CquiOR99的EC50分别为6.4和18.2微米和14.4微米和0.74微米(拟合度R2=0.88-0.99)。室内行为分析表明，怀孕的雌性蚊子在添加了这些化合物的水盘中产卵明显多于对照水盘。现场研究证实，4-乙基苯酚的有效剂量范围很广，从0.1微克/L到10微克/L，符合实际应用要求。根据这两个基因构建的双链RNA载体CquiOR37/99-DsRNA在蚕蛹血淋巴中稳定存在3h，在产卵高峰(第9天)，注入CquiOR37/99-DsRNA、β-半乳糖苷RNA或水的幼虫存活率可达40%以上。定量聚合酶链式反应分析显示，在CquiOR37/99-dsRNA处理的蚊子中，CquiOR37和CquiOR99转录水平存在个体差异，但平均水平显著降低。注入水的雌性蚊子和那些接受对照基因处理的蚊子在含有4-乙基苯酚的托盘中产卵显著多于在水盘中产卵，而经CquiOR37/99-dsRNA处理的蚊子产卵正常，但不能区分处理和对照。本研究首次将4-乙基苯酚的特异性受体与产卵增加联系在重要载体Cx上。[医]五倍子属
The Southern house mosquito, Culex quinquefasciatus - a vector of West Nile virus - is equipped with 130 odorant receptors (ORs), which enable young females to locate plants and blood-meal sources and older females to find suitable sites for oviposition. In our attempts to de-orphanize ORs expressed in female antennae, we identified CquiOR37 and CquiOR99, which were narrowly tuned to two phenolic compounds, 4-methylphenol and 4-ethylphenol. When tested in the Xenopus oocyte recording system the observed EC50s for 4-methylphenol and 4-ethylphenol were 6.4 and 18.2 µM for CquiOR37 and 14.4 and 0.74 µM for CquiOR99 (goodness of fit, R2 =0.88–0.99), respectively. Indoor behavioral assays demonstrated that gravid female mosquitoes laid significantly more eggs in water trays spiked with these compounds than in control water trays. Field studies with gravid traps corroborated that 4-ethylphenol is active in a wide range of doses from 0.1 to 10 µg/l, as required for practical applications. A dsRNA construct based on the two genes, CquiOR37/99-dsRNA was stable in pupa hemolymph for up to 3 h. Pupae injected with CquiOR37/99-dsRNA, β-galactosidasedsRNA or water had more than 40% survival rate at the peak of oviposition (day-9). qPCR analysis showed individual variation, but significant mean reduction in CquiOR37 and CquiOR99 transcript levels in CquiOR37/99-dsRNA-treated mosquitoes. Water-injected females and those treated with the control gene laid significantly more eggs in trays containing 4-ethylphenol than in water trays, whereas CquiOR37/99-dsRNA-treated mosquitoes laid normal number of eggs, but could not discriminate treatment from control. This study linked for the first time specific receptors for 4-ethylphenol with increased oviposition in the important vector Cx. quinquefasciatus.