Morphological, Behavioral, and Transcriptomic Profiling Reveals Developmental Toxicity of PCB Metabolites in Zebrafish

We evaluated developmental, neurobehavioral, and molecular effects of parent PCBs, hydroxylated, methoxylated, and sulfated metabolites, and environmentally relevant mixtures using embryonic zebrafish. Morphological abnormalities and photomotor behavior were assessed across early development, followed by targeted cyp1a reporter analysis and transcriptomic profiling for a subset of potent exposures.

Most chemicals induced morphological effects, with hydroxylated and sulfated metabolites producing effects more frequently and at lower benchmark concentrations than parent congeners. Behavioral alterations were more prevalent in embryonic photomotor response than larval photomotor response and generally co-occurred with morphological effects. Environmental mixtures elicited broad phenotypic profiles comparable to highly active individual compounds.