Extent of thyroid signaling disruption in eleuthero embryos of Danio rerio

The amount of synthetic chemicals found in ecosystems, including human environments, is a growing source of concern. Environmental risk assessment by industries relies on proper science-based guidelines build by regulators. Unfortunately, despite being an active field of research, our current understanding of the molecular mechanism and the disrupting potential of chemicals on biological processes, and especially on endocrine systems, is still very limited.We focus on thyroid signaling, a highly conserved and key regulator of development and metabolism throughout life. We characterized the biological impact of four probable or known thyroid signaling disruptors (PTU, TBBPA, PCL and IOP), by using zebrafish embryos in a cosmetic regulation compliant setting. We exposed embryos to individual compounds and thyroid hormones, alone or in combination, at estimated EC10 concentrations based on phenotypic alterations. We next combined functional genomics coupled to system biology to stratify transcriptomic changes and differentiate disruption from other biological responses.