Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal.
Marine Biology Research Group, Biology Department, Faculty of Sciences, Ghent University, Ghent, Belgium.
Curr Protoc. 2021 May;1(5):e131. doi: 10.1002/cpz1.131.
Chemosensation in nematodes is linked to processes that affect their ability to survive, such as the search for food and the avoidance of toxic substances. Since the 1970s, numerous studies have assessed chemotaxis in the nematode species Caenorhabditis elegans, focusing on a multitude of agents, including bacteria (food), ions, salts, hormones, volatile organic compounds, and, to a lesser extent, metal-contaminated medium/food. The few studies evaluating metal exposure have reported a variety of responses (neutral, attraction, avoidance), which generally appear to be contaminant and/or concentration specific. Differences in experimental designs, however, hinder appropriate comparison of the findings and attainment of firm conclusions. Therefore, we herein propose and describe a detailed protocol for the assessment of the effects of metals on taxis-to-food behavior in C. elegans. Distinct approaches are proposed in two innovative stages of testing to (1) screen metals' effects on taxis-to-food behavior and (2) classify the behavioral response as attraction/avoidance/indifference or preference. Use of such a standard protocol will allow for easy comparison across studies and direct interpretation of results. Findings using this model system can contribute to a deeper understanding of the real risks of metal contamination to nematodes and how such contaminants could impact ecosystems in general, given the key environmental roles that these organisms play. © 2021 Wiley Periodicals LLC. Basic Protocol: Assessing the effects of metal contamination on taxis-to-food behavior in Caenorhabditis elegans Support Protocol 1: Synchronization of C. elegans by hand-picking gravid worms Support Protocol 2: Synchronization of C. elegans by using a bleaching solution.
线虫的化学感觉与影响其生存能力的过程有关，例如寻找食物和避免有毒物质。自 20 世纪 70 年代以来，许多研究评估了秀丽隐杆线虫这一种线虫物种的趋化性，重点研究了多种试剂，包括细菌（食物）、离子、盐、激素、挥发性有机化合物，以及在较小程度上，受金属污染的培养基/食物。少数评估金属暴露的研究报告了各种反应（中性、吸引、回避），这些反应通常似乎与污染物和/或浓度有关。然而，由于实验设计的差异，阻碍了对这些发现进行适当比较并得出确定结论。因此，我们在此提出并描述了一种详细的方案，用于评估金属对线虫对食物的趋性行为的影响。在两个创新的测试阶段中提出了不同的方法，（1）筛选金属对线虫对食物的趋性行为的影响，（2）将行为反应分类为吸引/回避/无差异或偏好。使用这种标准方案将允许在研究之间进行轻松比较，并直接解释结果。使用该模型系统的发现可以帮助我们更深入地了解金属污染对线虫的实际风险，以及这些污染物如何影响整个生态系统，因为这些生物在生态系统中扮演着关键的环境角色。
