Generational effects and abnormalities in craniofacial chondrogenesis in zebrafish (Danio rerio) embryos upon maternal exposure to estrogen endocrine disrupting chemicals

Bisphenol A (BPA) and diethyl phthalate (DEP) are estrogenic endocrine disrupting chemicals (EEDCs). The present study reconfirmed that the angle of the ceratohyal cartilage (CH) in embryos were larger from maternal BPA and E2, but smaller from DEP compared to the control. However, it is still unknown whether both the BPA and DEP chemicals disrupted the action of E2 and thereby influence the estrogen signaling pathways. Additionally, it remains unclear whether they also disrupted certain related genes in the migratory pathways of neural crest cells (NCCs) in their offspring. The present data showed that nuclear estrogen receptors and membrane estrogen receptors have different disrupted profiles among female zebrafish exposed to BPA (F-BPA), and DEP (F-DEP), and external E2 (F-E2). However, certain related genes in the migratory pathways of NCCs in embryos from F-BPA and F-E2 such as the sox10, chm1, and tgfbr1a mRNA expressions showed a positive relationship compared with CH angles; the gene expressions of sox9a, smad3, and col2a1a and the CH angles of embryos exhibited an opposite relationship upon F-DEP treatments. Thus, we suggested that the genes involved in NCCs migration were potentially induced by the residual maternal DEP contents. Two sets of genes, chm1/tgfb3 and chm1/gper1, exhibited an identical profile in the ovary and its offspring at 2 h of post fertilization upon F-E2 and F-BPA treatments, respectively. We suggested that the maternal mRNA from female to embryos were transferred before the maternal-to-zygotic transition stage.