Olfactory responses in a gustatory organ of the malaria vector mosquito Anopheles gambiae
Olfactory responses in a gustatory organ of the malaria vector mosquito Anopheles gambiae
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DOI：
10.1073/pnas.0601107103
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发表时间：
2006-09-05
影响因子：
11.1
通讯作者：
Zwiebel, Laurence J.
中科院分区：
文献类型：
--
作者：
Kwon, Hyung-Wook;Lu, Tan;Zwiebel, Laurence J.
长鼻是昆虫头部的一个重要附属器官，主要被认为在食物摄取过程中处理味觉信息。事实上，在果蝇和其他昆虫中，大多数味觉受体都在长鼻神经元中表达。我们以前的表征AgOR7的表达，一个高度保守的气味受体（OR）的非洲热带疟疾媒介蚊子冈比亚按蚊在唇瓣的喙尖提示在这个蚊子附属器的潜在嗅觉功能。为了验证这一假设，我们使用电生理记录和神经元示踪，并进行了候选OR表达的分子表征，在唇瓣的A。冈比亚。这些研究揭示了一组唇嗅觉反应的一个小范围的人类相关的气味，如异戊酸，丁胺，和几个酮和氧代羧酸。分子分析表明，至少有24个传统的OR基因在整个喙表达。此外，为了更全面地研究该组织内的AgOR表达，我们表征了单个唇嗅感器内的AgOR分布。这项研究提供了令人信服的数据来支持一个假设，即一组神秘的嗅觉神经元，对一小组气味的反应存在于吸血蚊子的口腔部位。这一结果与唇瓣在近距离识别血粉宿主中的重要作用一致，直接影响A.冈比亚传播疟疾和其他疾病。
The proboscis is an important head appendage in insects that has primarily been thought to process gustatory information during food intake. Indeed, in Drosophila and other insects in which they have been identified, most gustatory receptors are expressed in proboscis neurons. Our previous characterization of the expression of AgOR7, a highly conserved odorant receptor (OR) of the Afro-tropical malaria vector mosquito Anopheles gambiae in the labellum at the tip of the proboscis was suggestive of a potential olfactory function in this mosquito appendage. To test this by pothesis, we used electrophysiological recording and neuronal tracing, and carried out a molecular characterization of candidate OR expression in the labellum of A. gambiae. These studies have uncovered a set of labial olfactory responses to a small spectrum of human-related odorants, such as isovaleric acid, butylamine, and several ketones and oxocarboxylic acids. Molecular analyses indicated that at least 24 conventional OR genes are expressed throughout the proboscis. Furthermore, to more fully examine AgOR expression within this tissue, we characterized the AgOR profile within a single labial olfactory sensillum. This study provides compelling data to support the hypothesis that a cryptic set of olfactory neurons that respond to a small set of odorants are present in the mouth parts of hematophagous mosquitoes. This result is consistent with an important role for the labellum in the close-range discrimination of bloodmeal hosts that directly impacts the ability of A. gambiae to transmit malaria and other diseases.