Estrogen Receptor 1 (ESR1; ERα), not ESR2 (ERβ), Modulates Estrogen-Induced Sex Reversal in the American Alligator, a Species With Temperature-Dependent Sex Determination

Human ESR2 transactivation assays were used to assess the estrogenic activity of MC252 oil and COREXIT dispersant. HEK293T cells were triple transfected with ESR2 expression vectors, firefly luciferase reporter vectors containing the estrogen response element and Renilla luciferase control vectors. Cells were then exposed to various concentrations of positive and negative control ligands (17β estradiol and DMSO, respectively) and serial dilutions of COREXIT Water Accommodating Fraction (CWAF) and COREXIT. Exposures were run in triplicate. The ratio of Firefly/Renilla luminescence was used as an indication of ESR2 transactivation. Activation of ESR2 was observed in CWAF mixtures. Oil was also dispersed using a two-component (Lecithin and Tween80, LT) dispersant. Similarly, activation was observed in oil containing treatments only.