Reduced Zebrafish Transcriptome Atlas toward Understanding Environmental Neurotoxicants

Area of Science:

• Environmental Toxicology
• Neuroscience
• Genomics

Background:

• Transcriptomic approaches offer genome-scale insights into molecular mechanisms of toxicant-induced adverse effects.
• Current applications in chemical assessment are limited by high costs and insufficient data mining for mechanistic understanding.

Purpose of the Study:

• To develop and validate a reduced transcriptome atlas (RTA) approach for identifying potential neurodevelopmental toxicants.
• To establish an efficient and cost-effective method for prioritizing chemicals based on neurotoxicity.

Main Methods:

• Integrated transcriptomic datasets from 74 chemicals and 736 gene expression profiles to create 135 exposure signatures.
• Utilized zebrafish neurogenesis and early neuronal development gene panels.
• Employed gene expression index (GEI) analysis with a 300-gene panel for chemical characterization and clustering.

Main Results:

• Identified four distinct sets of neurotoxic chemicals: neuro-active compounds, xenoestrogens, microcystins, and heavy metals.
• Observed distinct yet overlapping enriched biological pathways within chemical sets, indicating shared mechanisms (e.g., VPA and CAR).
• Demonstrated that a 300-gene panel is sufficient for effective chemical clustering and prioritization.

Conclusions:

• The RTA approach provides a cost-effective tool for prioritizing environmental neurotoxicants.
• Offers novel insights into the molecular mechanisms underlying neurodevelopmental toxicity.
• Facilitates early identification of potential adverse outcomes from chemical exposures.