Multidimensional in vivo hazard assessment using zebrafish.

Area of Science:

• Environmental toxicology
• Developmental biology
• Computational toxicology

Background:

• Thousands of man-made chemicals lack safety data, necessitating new methods for hazard assessment.
• Existing toxicological methods struggle to prioritize chemicals with limited human health information.
• High-throughput screening and computational tools are crucial for evaluating chemical safety.

Purpose of the Study:

• To develop and validate a high-throughput in vivo screening platform for chemical hazard assessment.
• To evaluate a large set of chemicals using a multidimensional embryonic zebrafish assay.
• To identify chemical predictors and understand biological responses to environmental contaminants.

Main Methods:

• Utilized an experimental design for high-throughput characterization of in vivo effects in embryonic zebrafish.
• Tested 1060 unique U.S. Environmental Protection Agency (EPA) ToxCast phase 1 and 2 compounds.
• Simultaneously measured 18 biological endpoints to serve as a comprehensive hazard sensor.

Main Results:

• 487 out of 1060 tested compounds induced significant adverse biological responses in zebrafish embryos.
• Identified global patterns of variation across tested compounds and evaluated in vitro/in vivo data concordance.
• Highlighted novel biological insights related to notochord development and chemical exposure.

Conclusions:

• The developmental zebrafish assay is a powerful biological sensor for detecting a wide range of chemical hazards.
• This high-throughput approach effectively identifies adverse biological responses missed by less comprehensive testing strategies.
• The findings support the use of zebrafish embryos for prioritizing chemical safety evaluations and understanding toxicological mechanisms.