A robust, high-content NAM for repeatable and predictive developmental and reproductive toxicity assessment in C....

Area of Science:

• Toxicology and Ecotoxicology
• Developmental and Reproductive Toxicology (DART)
• New Approach Methodologies (NAMs)

Background:

• Traditional vertebrate models for DART assessment are costly, time-consuming, and resource-intensive.
• Caenorhabditis elegans offers a promising alternative for rapid, cost-effective toxicology.
• Limitations in imaging, endpoints, and robustness have hindered wider adoption of C. elegans for DART.

Purpose of the Study:

• To develop and validate vivoDART, a novel, multiparametric, imaging-based DART assay.
• To overcome limitations of existing C. elegans DART assays through high-resolution imaging and machine learning.
• To establish a sensitive, efficient, and robust platform for chemical prioritization and hazard assessment.

Main Methods:

• Developed vivoDART, a microfluidic-assisted, high-resolution brightfield imaging assay.
• Quantified six developmental and reproductive endpoints, including automated body-dimension analysis and in utero embryo staging.
• Validated the assay using DMSO, methylmercury, and propiconazole across ~400,000 embryos and ~9,200 worms.

Main Results:

• vivoDART demonstrated high repeatability (CVs 1-17%) and statistical power.
• Accurate ECx predictions with narrow confidence intervals across a broad chemical concentration range (1.0-237 µM).
• Late-stage embryo number identified as the most sensitive DART-specific endpoint, preceding general toxicity markers.

Conclusions:

• vivoDART is a sensitive, repeatable, and scalable whole-organism platform for DART assessment.
• The assay effectively distinguishes DART-specific effects from non-specific lethality.
• vivoDART enables rapid, cost-effective chemical prioritization and comparative hazard assessment.