Ha Tal Soo, Smith Dean P
Department of Biomedical Science, College of Natural Science, Daegu University, Gyeongsan 38453, Gyeongsangbuk-do, Korea.
Departments of Pharmacology and Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Insects. 2022 Oct 13;13(10):926. doi: 10.3390/insects13100926.
Human and insect olfaction share many general features, but insects differ from mammalian systems in important ways. Mammalian olfactory neurons share the same overlying fluid layer in the nose, and neuronal tuning entirely depends upon receptor specificity. In insects, the olfactory neurons are anatomically segregated into sensilla, and small clusters of olfactory neurons dendrites share extracellular fluid that can be independently regulated in different sensilla. Small extracellular proteins called odorant-binding proteins are differentially secreted into this sensillum lymph fluid where they have been shown to confer sensitivity to specific odorants, and they can also affect the kinetics of the olfactory neuron responses. Insect olfactory receptors are not G-protein-coupled receptors, such as vertebrate olfactory receptors, but are ligand-gated ion channels opened by direct interactions with odorant molecules. Recently, several examples of insect olfactory neurons expressing multiple receptors have been identified, indicating that the mechanisms for neuronal tuning may be broader in insects than mammals. Finally, recent advances in genome editing are finding applications in many species, including agricultural pests and human disease vectors.
人类和昆虫的嗅觉有许多共同的一般特征，但昆虫在重要方面与哺乳动物的嗅觉系统不同。哺乳动物的嗅觉神经元在鼻腔中共享相同的覆盖液层，神经元的调谐完全取决于受体特异性。在昆虫中，嗅觉神经元在解剖学上被分隔成感觉器，一小群嗅觉神经元的树突共享细胞外液，而不同的感觉器中的细胞外液可被独立调节。一种叫做气味结合蛋白的小细胞外蛋白被差异分泌到这种感觉器淋巴液中，在那里它们已被证明能赋予对特定气味的敏感性，并且它们还能影响嗅觉神经元反应的动力学。昆虫的嗅觉受体不是像脊椎动物嗅觉受体那样的G蛋白偶联受体，而是通过与气味分子直接相互作用而打开的配体门控离子通道。最近，已经鉴定出几个表达多种受体的昆虫嗅觉神经元的例子，这表明昆虫中神经元调谐的机制可能比哺乳动物更广泛。最后，基因组编辑的最新进展正在许多物种中得到应用，包括农业害虫和人类疾病传播媒介。
