Adavi Elisha David, Dos Anjos Vitor L, Kotb Summer, Metz Hillery C, Tian David, Zhao Zhilei, Zung Jessica L, Rose Noah H, McBride Carolyn S
Princeton Neuroscience Institute, Princeton University; Princeton, NJ 08544, USA.
Department of Molecular Biology, Princeton University; Princeton, NJ 08544, USA.
bioRxiv. 2024 Aug 22:2024.08.21.608847. doi: 10.1101/2024.08.21.608847.
The olfactory sensory neurons of vinegar flies and mice tend to express a single ligand-specific receptor. While this 'one neuron-one receptor' motif has long been expected to apply broadly across insects, recent evidence suggests it may not extend to mosquitoes. We sequenced and analyzed the transcriptomes of 46,000 neurons from antennae of the dengue mosquito to resolve all olfactory, thermosensory, and hygrosensory neuron subtypes and identify the receptors expressed therein. We find that half of all olfactory subtypes coexpress multiple receptors. However, coexpression occurs almost exclusively among genes from the same family-among odorant receptors (ORs) or among ionotropic receptors (IRs). Coexpression of ORs with IRs is exceedingly rare. Many coexpressed receptors are recent duplicates. In other cases, the recruitment or co-option of single receptors by multiple neuron subtypes has placed these genes together in the same cells with distant paralogs. Close examination of data from reveal rare cases of both phenomena, indicating that the olfactory systems of these two species are not fundamentally different, but instead fall at different locations along a continuum likely to encompass diverse insects.
醋蝇和小鼠的嗅觉感觉神经元往往只表达一种配体特异性受体。长期以来，人们一直期望这种“一个神经元-一个受体”模式能广泛适用于昆虫，但最近的证据表明它可能不适用于蚊子。我们对登革热蚊子触角中的46000个神经元的转录组进行了测序和分析，以解析所有嗅觉、温度感觉和湿度感觉神经元亚型，并确定其中表达的受体。我们发现，所有嗅觉亚型中有一半会共表达多种受体。然而，共表达几乎只发生在同一家族的基因之间——在气味受体（ORs）之间或离子型受体（IRs）之间。ORs与IRs的共表达极其罕见。许多共表达的受体是近期的复制基因。在其他情况下，多个神经元亚型对单个受体的招募或选用，使这些基因与远缘旁系同源基因一同出现在同一细胞中。对数据的仔细检查揭示了这两种现象的罕见情况，表明这两个物种的嗅觉系统并非根本不同，而是处于一个可能涵盖多种昆虫的连续统一体上的不同位置。
