Figure 4

BPA effect on otolith development is estrogen receptor-independent. Morphology of the inner ear of zebrafish embryos at 48 hpf following exposure to BPA with or without ER antagonists (ICI 182 780) or agonists (17-β estradiol, E2). Treatment with either 1 μM ICI (A) or 1 μM 17-β estradiol (B) from 5 to 48 hpf does not induce any malformation of the developing semi-circular canals nor otoliths. Moreover, the BPA-induced otolith phenotype is not rescued when embryos are co-treated with BPA 5 μM +ICI 1 μM (A) or BPA 5 μM +βE2 1 μM (B). Interestingly, co-treatment with BPA 5 μM +ICI 1 μM lead to in increased ratio of affected otolith than a treatment with BPA 5 μM alone (A). On the other hand co-treatment with BPA 5 μM +βE2 1 μM gives a similar ratio than a treatment with BPA 5 μM alone (B).