Impacts on Atlantic Killifish from Neurotoxicants: Genes, Behavior, and Population-Relevant Outcomes

Area of Science:

• Environmental toxicology
• Ecotoxicology
• Molecular biology

Background:

• Linking molecular and cellular changes to population-level ecological risks is challenging.
• Atlantic killifish (Fundulus heteroclitus) populations exhibit varying tolerance to contaminants.
• Neurotoxicants like methylmercury and polychlorinated biphenyls (PCBs) pose ecological threats.

Purpose of the Study:

• To link molecular and behavioral data to ecological risk predictions in Atlantic killifish.
• To model the effects of methylmercury and PCB126 on fish cohort growth and survival.
• To assess the ecological relevance of molecular and behavioral responses to toxicants.

Main Methods:

• Used laboratory gene expression and behavioral data from reference (SCOKF) and PCB-contaminated (NBHKF) killifish populations.
• Employed individual-based models to simulate cohort growth and survival from embryonic exposure.
• Quantified gene expression changes and behavioral alterations in response to methylmercury and PCB126.

Main Results:

• Methylmercury exposure altered specific brain gene expression and behaviors in reference killifish, but models showed no growth/survival effects.
• PCB126 exposure reduced physical activity and altered brain gene sets in reference killifish; models predicted decreased growth.
• PCB-tolerant killifish showed altered swimming behaviors with fewer gene set changes; models predicted PCB126 decreased survival in both populations.

Conclusions:

• Molecular and behavioral data can inform quantitative predictions of ecological risk.
• Individual-based models integrating molecular and behavioral endpoints enhance ecological risk assessment.
• This study demonstrates a framework for linking molecular responses to population-level outcomes in environmental toxicology.