Dugesia japonica is the best suited of three planarian species for high-throughput toxicology screening

• Published in: Chemosphere (Oxford) Vol. 253; p. 126718
• Main Authors: Ireland, Danielle, Bochenek, Veronica, Chaiken, Daniel, Rabeler, Christina, Onoe, Sumi, Soni, Ameet, Collins, Eva-Maria S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2020
• Subjects: Developmental neurotoxicity; High-throughput screening; Invertebrate; Planarian; Solvents; Invertebrate; High-throughput screening; Solvents; Planarian; Developmental neurotoxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.126718

High-throughput screening (HTS) using new approach methods is revolutionizing toxicology. Asexual freshwater planarians are a promising invertebrate model for neurotoxicity HTS because their diverse behaviors can be used as quantitative readouts of neuronal function. Currently, three planarian species are commonly used in toxicology research: Dugesia japonica, Schmidtea mediterranea, and Girardia tigrina. However, only D. japonica has been demonstrated to be suitable for HTS. Here, we assess the two other species for HTS suitability by direct comparison with D. japonica. Through quantitative assessments of morphology and multiple behaviors, we assayed the effects of 4 common solvents (DMSO, ethanol, methanol, ethyl acetate) and a negative control (sorbitol) on neurodevelopment. Each chemical was screened blind at 5 concentrations at two time points over a twelve-day period. We obtained two main results: First, G. tigrina and S. mediterranea planarians showed significantly reduced movement compared to D. japonica under HTS conditions, due to decreased health over time and lack of movement under red lighting, respectively. This made it difficult to obtain meaningful readouts from these species. Second, we observed species differences in sensitivity to the solvents, suggesting that care must be taken when extrapolating chemical effects across planarian species. Overall, our data show that D. japonica is best suited for behavioral HTS given the limitations of the other species. Standardizing which planarian species is used in neurotoxicity screening will facilitate data comparisons across research groups and accelerate the application of this promising invertebrate system for first-tier chemical HTS, helping streamline toxicology testing. •Comparison of 3 planarian species for neurotoxicity high-throughput screening (HTS).•D. japonica is better suited for HTS than S. mediterranea and G. tigrina.•S. mediterranea moved too little under the red lighting required to assay behaviors.•G. tigrina health/motility decreased with extended storage in multi-well plates.•Differences in solvent toxicity were found among the different species.