Figure 4.

Gene expression in E₂-treated (low doses) sea bream. Semi-quantitative RT-PCR of estrogen receptors (ERα, ERβa, ERβb) and estrogen-responsive genes, vitellogenin (VgII) and choriogenin (ChgL), in male sea bream liver (see Figure 3 for group abbreviations) 48 h following treatment. Each bar (A) is the mean ± S.E.M. of the relative expression values (target gene/18S) of eight fish. Different letters indicate statistically significant differences between treatments (general linear model using log₁₀ of the relative expression values, P < 0.05). The gel images (B) are representative RT-PCR products for each experimental group.