The Anthropocene Epoch poses a critical challenge for organisms: they must cope with new threats at a rapid rate. These threats include toxic chemical compounds released into the environment by human activities. Here, we examine elevated concentrations of heavy metal ions as an example of anthropogenic stressors. We find that the fruit fly Drosophila avoids nine metal ions when present at elevated concentrations that the flies experienced rarely, if ever, until the Anthropocene. We characterize the avoidance of feeding and egg laying on metal ions, and we identify receptors, neurons, and taste organs that contribute to this avoidance. Different subsets of taste receptors, including members of both Ir (Ionotropic receptor) and Gr (Gustatory receptor) families contribute to the avoidance of different metal ions. We find that metal ions activate certain bitter-sensing neurons and inhibit sugar-sensing neurons. Some behavioral responses are mediated largely through neurons of the pharynx. Feeding avoidance remains stable over 10 generations of exposure to copper and zinc ions. Some responses to metal ions are conserved across diverse dipteran species, including the mosquito Aedes albopictus. Our results suggest mechanisms that may be essential to insects as they face challenges from environmental changes in the Anthropocene.

中文翻译：

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迎接人类世的威胁：果蝇对金属离子的味觉回避。

人类世时代对生物体提出了严峻挑战：它们必须快速应对新威胁。这些威胁包括人类活动释放到环境中的有毒化合物。在这里，我们将重金属离子浓度升高作为人为应激源的一个例子。我们发现当果蝇以高浓度存在时，果蝇会避开九种金属离子，而这些金属离子在人类世之前很少（如果有的话）经历过。我们描述了避免在金属离子上进食和产卵的特征，并确定了有助于这种避免的受体、神经元和味觉器官。味觉受体的不同子集，包括 Ir（离子型受体）和 Gr（味觉受体）家族的成员，有助于避免不同的金属离子。我们发现金属离子会激活某些苦味敏感神经元并抑制糖敏感神经元。一些行为反应主要通过咽部神经元介导。在暴露于铜和锌离子的 10 代中，进食回避保持稳定。对金属离子的一些反应在不同的双翅目物种中是保守的，包括蚊子白纹伊蚊。我们的研究结果表明，当昆虫面临人类世环境变化的挑战时，这些机制可能对昆虫至关重要。包括蚊子白纹伊蚊。我们的研究结果表明，当昆虫面临人类世环境变化的挑战时，这些机制可能对昆虫至关重要。包括蚊子白纹伊蚊。我们的研究结果表明，当昆虫面临人类世环境变化的挑战时，这些机制可能对昆虫至关重要。