CIMAR/CIIMAR - Interdisciplinary Centre for Marine and Environmental Research, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; FCUP - Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal; INRAE - National Research Institute for Agriculture, Food and the Environment - Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS20244, 69625 Villeurbanne Cedex, Lyon-Villeurbanne, France.
CIMAR/CIIMAR - Interdisciplinary Centre for Marine and Environmental Research, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; FCUP - Faculty of Sciences of the University of Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.
Sci Total Environ. 2024 Jan 15;908:168061. doi: 10.1016/j.scitotenv.2023.168061. Epub 2023 Nov 4.
The validation of high-throughput toxicity tests with invertebrate species is a key priority to improve hazard assessment of new chemicals and increase the available test guidelines with organisms from a representative set of taxa. This work aimed to contribute to the validation of an embryo test with the freshwater gastropod Lymnaea stagnalis, which has been identified by Organization for Economic Co-operation and Development (OECD) as a potential invertebrate test model, and provide the basis for such an endeavor. Recently, a L. stagnalis reproductive test was standardized by the OECD. However, to encompass the entire life cycle, it is crucial to addresses embryogenic development - a phase highly susceptible to various anthropogenic chemicals, which is covered in the proposed methodology. The approach used in the present study is in line with the OECD guidelines and other published studies, namely the Detailed Review Paper (DRP) on Mollusks life-cycle toxicity testing. Here, the assay quality criteria such as basal mortality and abnormality rates, development, growth and hatching rates, the appropriated testing media, and the optimal assay duration were investigated. Cadmium was chosen as the positive test substance, due to the available data and the verified model sensitivity to this compound, namely in the OECD reproductive test validation process. The obtained data demonstrate that L. stagnalis embryogenesis using the developed methodology is highly sensitive to cadmium. High concentration-response correlation was observed using this reference compound, the EC10 and EC50 for growth are 13.57 and 21.84 μg/L, respectively, after 168 h of exposure. The development EC's 10 and 50 were 15.75 and 38.66 μg/L, respectively, after 240 h. This demonstrates the model sensitivity to this compound when compared with other embryo test models, as well as the model sensitivity during the embryogenesis, if compared with the adult stage. Further, given the determined sensitivity parameters, and incubation times, the test can be performed at 240 h as over 95 % of the control embryos were hatched and no further significant changes in the exposure groups were determined. Overall, the findings of the present study demonstrate that the embryo test with L. stagnalis has potential to high-throughput testing and the model has a high sensitivity to cadmium during this life cycle period. The background data provide by this study will be essential to foster the future standardization of this assay.
利用无脊椎动物物种进行高通量毒性测试的验证是改善新化学物质危害评估和增加具有代表性分类群生物的可用测试指南的关键优先事项。这项工作旨在为淡水腹足纲动物 Lymnaea stagnalis 的胚胎测试验证做出贡献，该测试已被经济合作与发展组织（OECD）确定为潜在的无脊椎动物测试模型，并为这一努力提供了基础。最近，OECD 已经对 L. stagnalis 的生殖测试进行了标准化。然而，为了涵盖整个生命周期，解决胚胎发生发育阶段（这是一个高度易受各种人为化学物质影响的阶段）至关重要，这是拟议方法涵盖的内容。本研究中使用的方法符合 OECD 指南和其他已发表的研究，即关于软体动物生命周期毒性测试的详细审查报告（DRP）。在这里，研究了基本死亡率和异常率、发育、生长和孵化率、适当的测试介质以及最佳测试持续时间等测定质量标准。由于现有数据以及该化合物对这种化合物的验证模型敏感性，选择镉作为阳性测试物质，即在 OECD 生殖测试验证过程中。使用该参考化合物观察到高浓度-反应相关性，暴露 168 小时后，生长的 EC10 和 EC50 分别为 13.57 和 21.84μg/L。暴露 240 小时后，发育 EC10 和 EC50 分别为 15.75 和 38.66μg/L。这表明与其他胚胎测试模型相比，该模型对该化合物的敏感性，以及与成体阶段相比，在胚胎发生期间模型的敏感性。此外，鉴于确定的敏感性参数和孵育时间，可以在 240 小时时进行测试，因为超过 95%的对照胚胎已经孵化，并且在暴露组中没有确定进一步的显著变化。总的来说，本研究的结果表明，L. stagnalis 的胚胎测试具有高通量测试的潜力，并且在该生命周期期间对镉具有高敏感性。本研究提供的背景数据对于促进该测定的未来标准化将是必不可少的。
