State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200438, China.
Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, 518132, China.
Nat Commun. 2022 Jul 2;13(1):3814. doi: 10.1038/s41467-022-31253-z.
Birds, reptiles and insects have the ability to discriminate humidity levels that influence their survival and geographic distribution. Insects are particularly susceptible to humidity changes due to high surface area to volume ratios, but it remains unclear how humidity sensors transduce humidity signals. Here we identified Or42b-expressing olfactory sensory neurons, which are required for moisture attraction in Drosophila. The sensilla housing Or42b neurons show cuticular deformations upon moist air stimuli, indicating a conversion of humidity into mechanical force. Accordingly, we found Or42b neurons directly respond to humidity changes and rely on the mechanosensitive ion channel TMEM63 to mediate humidity sensing (hygrosensation). Expressing human TMEM63B in Tmem63 mutant flies rescued their defective phenotype in moisture attraction, demonstrating functional conservation. Thus, our results reveal a role of Tmem63 in hygrosensation and support the strategy to detect humidity by transforming it into a mechanical stimulus, which is unique in sensory transduction.
鸟类、爬行动物和昆虫具有辨别影响其生存和地理分布的湿度水平的能力。由于表面积与体积之比高，昆虫对湿度变化特别敏感，但目前尚不清楚湿度传感器如何转换湿度信号。在这里，我们鉴定了在果蝇中表达的 Or42b 嗅觉感觉神经元，该神经元对水分有吸引力。含有 Or42b 神经元的感觉感受器在潮湿空气刺激下显示出表皮变形，表明湿度转化为机械力。因此，我们发现 Or42b 神经元直接响应湿度变化，并依赖机械敏感离子通道 TMEM63 来介导湿度感应（湿度感应）。在 Tmem63 突变体果蝇中表达人类 TMEM63B 可挽救其在水分吸引中的缺陷表型，证明功能保守性。因此，我们的结果揭示了 Tmem63 在湿度感应中的作用，并支持通过将其转化为机械刺激来检测湿度的策略，这在感觉转导中是独特的。
