Parental DEHP exposure induces sex-specific reproductive toxicity in zebrafish and behavioral deficits in unexposed offspring

Phthalates (PAEs) have attracted widespread attention as ubiquitous environmental contaminants. Among them, di-(2-ethylhexyl) phthalate (DEHP) is the most prevalent, particularly in the manufacturing of polyvinyl chloride. Although the direct toxic effects of DEHP on exposed individuals are well documented, far less is known about the potential for parentally transferred DEHP to induce adverse outcomes in unexposed offspring. In this study, adult zebrafish were chronically exposed to environmentally relevant concentrations of DEHP (0, 0.3, 3, and 30 μg/L) and subsequently spawned in DEHP-free water. DEHP accumulated in parental gonads and was transferred to unexposed F1 embryos. Compared to controls, offspring from parents exposed to 30 μg/L DEHP showed significantly increased embryo diameter and markedly impaired locomotor activity under light-dark cycles. Integrated multi-omics analysis further revealed that iba57 (mitochondrial function) and a2m3a (neurodevelopment) were consistently dysregulated at both mRNA and protein levels, linking the observed phenotypes to mitochondrial dysfunction and neurodevelopmental disruption. These findings demonstrate that even at environmentally relevant concentrations, parentally transferred DEHP can induce persistent effects in unexposed offspring, suggesting that current ecological risk assessment frameworks may underestimate the long-term risks of DEHP.