Figure 2.

Differential transcriptional activation of ERα and ERβ1 in yeast. Yeast strains harboring the expression vectors for ERα (red square) or ERβ1 (blue triangle) and the vitellogenin ERE reporter plasmid were incubated with an increasing concentration of E₂ (A), ICI (B), apigenin (C), or genistein (D). After 24 hours of incubation at 30°C, Beta-Glo assays were performed. Luciferase activity (relative light units) was recorded by a luminometer (Victor 2 system). Each point represents an average of triplicates with standard deviations.