Department of Functional Biology, Faculty of Medicine, University of Oviedo, Spain.
Anat Rec (Hoboken). 2013 Sep;296(9):1477-88. doi: 10.1002/ar.22747. Epub 2013 Jul 31.
The olfactory system of Drosophila has become an attractive and simple model to investigate olfaction because it follows the same organizational principles of vertebrates, and the results can be directly applied to other insects with economic and sanitary relevance. Here, we review the structural elements of the Drosophila olfactory reception organs at the level of the cells and molecules involved. This article is intended to reflect the structural basis underlying the functional variability of the detection of an olfactory universe composed of thousands of odors. At the genetic level, we further detail the genes and transcription factors (TF) that determine the structural variability. The fly's olfactory receptor organs are the third antennal segments and the maxillary palps, which are covered with sensory hairs called sensilla. These sensilla house the odorant receptor neurons (ORNs) that express one or few odorant receptors in a stereotyped pattern regulated by combinations of TF. Also, perireceptor events, such as odor molecules transport to their receptors, are carried out by odorant binding proteins. In addition, the rapid odorant inactivation to preclude saturation of the system occurs by biotransformation and detoxification enzymes. These additional events take place in the lymph that surrounds the ORNs. We include some data on ionotropic and metabotropic olfactory transduction, although this issue is still under debate in Drosophila.
果蝇的嗅觉系统已成为研究嗅觉的一个有吸引力且简单的模型，因为它遵循与脊椎动物相同的组织原则，并且其结果可以直接应用于其他具有经济和卫生意义的昆虫。在这里，我们回顾了果蝇嗅觉感受器官在涉及的细胞和分子水平上的结构元素。本文旨在反映由数千种气味组成的嗅觉宇宙的检测功能变异性的结构基础。在遗传水平上，我们进一步详细介绍了决定结构变异性的基因和转录因子（TF）。果蝇的嗅觉感受器官是第三触角节和下颚须，它们被称为感觉毛的感觉毛所覆盖。这些感觉毛容纳嗅觉受体神经元（ORNs），这些神经元以受 TF 组合调节的刻板模式表达一种或几种气味受体。此外，前受体事件，例如气味分子向其受体的运输，由气味结合蛋白进行。另外，通过生物转化和解毒酶来快速失活气味以防止系统饱和。这些额外的事件发生在环绕 ORN 的淋巴中。我们包括了一些关于离子型和代谢型嗅觉转导的数据，尽管在果蝇中这个问题仍在争论中。
