Testing estrogenicity of known and novel (xeno-)estrogens in the MolDarT using developing zebrafish (Danio rerio)

Abstract

The MolDarT is a novel short-term assay for testing mechanism-based molecular effects in developing zebrafish embryos. The objective of this study was to evaluate the inducibility of vitellogenin1 mRNA (Vtg1) by the estrogenically active compounds 17,β-Estradiol (E2), 17α- Ethinylestradiol (EE2), Non-ylphenol (NP), Bisphenol A (BPA), Cyproconazol, and the suspected xeno-estrogen Atrazin in the MolDarT. Freshly fertilized zebrafish eggs were exposed semistatically for 120 h. Using reverse transcription real-time PCR, the relative abundance of Vtg1 was measured. For EE2 a dose-response relationship was established with EC50 = 60.7 ng/L (205 pM). Induction of Vtg1 was significant at concentrations of 84 pM EE2 (25 ng EE2/L) and above, 10 nM E2 (2.7 μg E2/L), 100 nM E2 (27 μg E2/L), 10 μM BPA (2280 μg BPA/ L), and 15 μM BPA (3420 μg BPA/L). At NP concentrations of 0.75 μM(165 μg NP/L) and 1.5 μM(330 μg NP/L) Vtg1 was significantly down-regulated. Both atrazine and cyproconazol showed no effect on relative Vtg1 abundance. With this study we further characterize the MolDarT assay and show its applicability for effect screening Of compounds. © 2007 Wiley Periodicals, Inc.