Fig. 2. Induction of oestrogenic biomarkers in pregnant eelpout: 17ß-oestradiol (E₂)-binding activity, vitellogenin (Vtg) in plasma and Vtg mRNA in liver. (A) E₂-binding capacity in hepatic cytosolic extracts. E₂-binding capacity was estimated by single-point assays. (B) Vtg in plasma. (C) Vtg mRNA in liver tissue. Ethidium-bromide-stained agarose gels showing amplified RT-PCR products using Vtg-specific primers (215 bp). As an internal control for the RT-PCR reaction, eelpout ß-actin mRNA was amplified (band at 340 bp) using ß-actin-specific primers. Fish were exposed to isopropanol (C; control), 25 µg l^-1 4-tert-octylphenol (4-tOP) (OP25), 100 µg l^-1 4-tOP (OP100) or 0.5 µg l^-1 E₂ for 17 days. Values are means ± S.E.M. Significant difference from control is indicated by asterisks (^*P<0.05; ^**P<0.01; ^***P<0.001).