Differential neurobehavioral responses to silica nanoparticles and temperature in a wild rhabditid nematode and C. elegans: toward an exposome map of phenotypes

Abstract

Environmental factors shape organismal health through complex interactions known as the exposome. However, the interactions between chemical and non-chemical exposome factors remain largely unclear. Here, a dopaminergic reporter strain of Caenorhabditis elegans and a field isolated rhabditid nematode were used in a behavioral arena to assess natural variation in locomotory behavior in response to silica nanoparticles as a chemical exposome factor, and ambient temperature conditions (15 {degrees}C, 20 {degrees}C, and 25 {degrees}C) as non-chemical factors. Our results reveal that in the C. elegans strain lower temperature (15 {degrees}C) mitigates silica-induced locomotion deficits, while higher temperature (25 {degrees}C) exacerbates neurotoxicity, suggesting a temperature-dependent response. Notably, the wild rhabditid isolate showed distinct behavioral responses compared to the laboratory strain, highlighting the importance of species-specific ecological backgrounds in toxicological studies. This study provides a conceptual basis for integrating environmental factors and natural diversity into exposome research: Phenotype exposome maps, as presented here, broaden the identification of ecotoxicological hazards of nanomaterials across species. Author summaryIncorporating wild rhabditid species with unknown genotypes into neurotoxicology research broadens the traditional model-organism framework by extending beyond C. elegans to encompass a wider range of naturally occurring neuronal and behavioral variation. This phenotype-driven approach enables the detection of both conserved and species-specific responses to neurotoxicants, independent of prior genomic knowledge. Observed differences in locomotor behavior across nematode species may reflect underlying diversity in neural architecture or compensatory mechanisms, offering insights into the functional plasticity of nervous systems. By adopting a comparative perspective grounded in the ecological context, this strategy enhances the environmental relevance of neurotoxicity studies and promotes more inclusive ecological risk assessment through the use of field isolated nematodes in controlled laboratory settings. SynopsisWild nematodes and C. elegans differ in pollutant responses, highlighting the need for broader toxicology models. HighlightsO_LIWe report comparative testing of Caenorhabditis elegans and a wild rhabditid isolate in a behavioral arena. C_LIO_LIC. elegans and the wild isolate were assessed under multiple exposome conditions: silica nanoparticles and ambient temperatures (15-25 {degrees}C). C_LIO_LIField isolated rhabditid nematodes showed distinct behavioral responses to chemical and temperature exposures compared to C. elegans. C_LIO_LIThis study highlights the importance of including wild nematode isolates alongside C. elegans for ecological hazard identification of emerging pollutants like silica nanoparticles. C_LIO_LIWe culture wild nematode isolates under standardized laboratory conditions to probe the limits of C. elegans as a toxicology model and enhance its real-world relevance. C_LI