Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, Korea.
EMBO Rep. 2023 Jun 5;24(6):e56319. doi: 10.15252/embr.202256319. Epub 2023 Apr 28.
Vitamins are essential micronutrients, but the mechanisms of vitamin chemoreception in animals are poorly understood. Here, we provide evidence that vitamin C doubles starvation resistance and induces egg laying in Drosophila melanogaster. Our behavioral analyses of genetically engineered and anatomically ablated flies show that fruit flies sense vitamin C via sweet-sensing gustatory receptor neurons (GRNs) in the labellum. Using a behavioral screen and in vivo electrophysiological analyses of ionotropic receptors (IRs) and sweet-sensing gustatory receptors (GRs), we find that two broadly tuned IRs (i.e., IR25a and IR76b) and five GRs (i.e., GR5a, GR61a, GR64b, GR64c, and GR64e) are essential for vitamin C detection. Thus, vitamin C is directly detected by the fly labellum and requires at least two distinct receptor types. Next, we expand our electrophysiological study to test attractive tastants such as sugars, carboxylic acids, and glycerol. Our analysis elucidates the molecular basis of chemoreception in sweet-sensing GRNs.
维生素是必需的微量营养素，但动物的维生素化学感受机制还知之甚少。在这里，我们提供的证据表明，维生素 C 可以使果蝇的抗饥饿能力提高一倍，并诱导其产卵。我们对经过基因工程改造和解剖切除的果蝇进行的行为分析表明，果蝇通过位于喙部的甜味味觉感受神经元（GRNs）感知维生素 C。我们利用行为筛选和对离子型受体（IRs）和甜味味觉感受受体（GRs）的体内电生理分析，发现两种广谱调谐的 IRs（即 IR25a 和 IR76b）和五种 GRs（即 GR5a、GR61a、GR64b、GR64c 和 GR64e）对于维生素 C 的检测至关重要。因此，维生素 C 可被果蝇的喙部直接检测到，至少需要两种不同的受体类型。接下来，我们扩展了我们的电生理研究，以测试具有吸引力的味觉物质，如糖、羧酸和甘油。我们的分析阐明了甜味感受 GRNs 中化学感受的分子基础。
