State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Chinese Academy of Sciences Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China.
Elife. 2024 May 30;12:RP91711. doi: 10.7554/eLife.91711.
Almost all herbivorous insects feed on plants and use sucrose as a feeding stimulant, but the molecular basis of their sucrose reception remains unclear. as a notorious crop pest worldwide mainly feeds on reproductive organs of many plant species in the larval stage, and its adult draws nectar. In this study, we determined that the sucrose sensory neurons located in the contact chemosensilla on larval maxillary galea were 100-1000 times more sensitive to sucrose than those on adult antennae, tarsi, and proboscis. Using the expression system, we discovered that Gr10 highly expressed in the larval sensilla was specifically tuned to sucrose, while Gr6 highly expressed in the adult sensilla responded to fucose, sucrose and fructose. Moreover, using CRISPR/Cas9, we revealed that Gr10 was mainly used by larvae to detect lower sucrose, while Gr6 was primarily used by adults to detect higher sucrose and other saccharides, which results in differences in selectivity and sensitivity between larval and adult sugar sensory neurons. Our results demonstrate the sugar receptors in this moth are evolved to adapt toward the larval and adult foods with different types and amounts of sugar, and fill in a gap in sweet taste of animals.
几乎所有的草食性昆虫都以植物为食，并以蔗糖作为进食刺激物，但它们对蔗糖的接受机制仍不清楚。棉铃虫是一种世界性的著名作物害虫，幼虫期主要以多种植物的生殖器官为食，成虫则吸食花蜜。在这项研究中，我们确定位于幼虫下颚须接触化学感受器上的蔗糖感觉神经元对蔗糖的敏感性比成虫触角、跗节和喙上的蔗糖感觉神经元高 100-1000 倍。通过 表达系统，我们发现 Gr10 在幼虫感觉神经元中高度表达，对蔗糖具有特异性反应，而 Gr6 在成虫感觉神经元中高度表达，对岩藻糖、蔗糖和果糖有反应。此外，利用 CRISPR/Cas9，我们揭示了 Gr10 主要被幼虫用来检测较低浓度的蔗糖，而 Gr6 主要被成虫用来检测较高浓度的蔗糖和其他糖类，这导致了幼虫和成虫糖感觉神经元在选择性和敏感性上的差异。我们的研究结果表明，这种飞蛾的糖受体是为了适应幼虫和成虫所食用的具有不同类型和数量的糖而进化的，填补了动物甜味感知领域的一个空白。
