Polycyclic aromatic hydrocarbons and dibutyl phthalate disrupt dorsal-ventral axis determination via the Wnt/β-catenin signaling pathway in zebrafish embryos

► Zebrafish embryos exposed to select PAHs and dibutyl phthalate. ► Exposure prior to mid-blastula transition resulted in embryonic axis disruption. ► Axis disruption was mediated through Wnt/β-catenin signaling pathway. ► This may be a unique mechanism of action for these chemicals in vertebrate embryos.