As rare earth (RE) metals are abundantly present in the soil, in spite of their name, it is conceivable that organisms may encounter and interact with RE ions. In the present study, we demonstrated that the soil nematode Caenorhabditis elegans avoids RE ions, such as yttrium and all examined lanthanide ions, which exhibit toxic effects on nematodes. We also demonstrated that the chemosensory system of this animal mediates avoidance behavior toward RE ions similar to heavy metal (HM) ion avoidance. The C. elegans dyf-11(pe554) mutant is unable to respond to chemosensory cues because it lacks all ciliated endings of the chemosensory neurons required for the detection of environmental chemicals. Cell-specific rescue of the dyf-11 mutant and cell-specific genetic ablation studies revealed that the avoidance behavior toward HM and RE ions was mediated by a partially overlapping but distinct subset of chemosensory neurons (ASH, ADL, ASE, ADF, and ASK). With the help of multiple chemosensory neurons, worms may improve the fidelity of avoidance behavior to evade RE ions. Among the chemosensory neurons in C. elegans, ADF and ASK neurons were involved in RE avoidance, but not in HM avoidance. These results suggested that ADF and ASK neurons in C. elegans have RE-selective mechanisms to mediate the avoidance response.

中文翻译：

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多个化学感应神经元介导了秀丽隐杆线虫对稀土离子的回避行为。

由于稀土 (RE) 金属大量存在于土壤中，尽管它们的名字如此，但可以想象，生物体可能会遇到稀土离子并与之相互作用。在本研究中，我们证明土壤线虫秀丽隐杆线虫避免稀土离子，如钇和所有检测的镧系元素离子，它们对线虫表现出毒性作用。我们还证明，这种动物的化学感应系统介导了对稀土离子的回避行为，类似于重金属（HM）离子回避。秀丽隐杆线虫 dyf-11(pe554) 突变体无法响应化学感应线索，因为它缺少检测环境化学物质所需的化学感应神经元的所有纤毛末端。dyf-11 突变体的细胞特异性拯救和细胞特异性遗传消融研究表明，对 HM 和 RE 离子的回避行为是由部分重叠但不同的化学感应神经元子集介导的（ASH、ADL、ASE、ADF 和 ASK ）。在多个化学感应神经元的帮助下，蠕虫可以提高回避行为的保真度，以逃避 RE 离子。在秀丽隐杆线虫的化学感应神经元中，ADF 和 ASK 神经元参与 RE 回避，但不参与 HM 回避。这些结果表明，秀丽隐杆线虫中的 ADF 和 ASK 神经元具有 RE 选择性机制来介导回避反应。在秀丽隐杆线虫的化学感应神经元中，ADF 和 ASK 神经元参与 RE 回避，但不参与 HM 回避。这些结果表明，秀丽隐杆线虫中的 ADF 和 ASK 神经元具有 RE 选择性机制来介导回避反应。在秀丽隐杆线虫的化学感应神经元中，ADF 和 ASK 神经元参与 RE 回避，但不参与 HM 回避。这些结果表明，秀丽隐杆线虫中的 ADF 和 ASK 神经元具有 RE 选择性机制来介导回避反应。