Embryos of Xenopus laevis (African clawed frog) were exposed to the widespread environmental plasticizers bisphenol AF (BPAF; 0.003-3 μM), bisphenol A (BPA; 1-50 μM), or 17β-estradiol (E2; 10 μM) from just after fertilization through 96 hours of development. The potencies and cellular and morphological effects were compared across chemical treatments and controls. The embryos were staged, counted and imaged, and time-lapse movies collected, on an inverted stereomicroscope and camera. The data show there were both shared and unique effects of BPAF, BPA, and E2, on early cleavage divisions and development of the spinal cord, head, and gut, with BPAF having the greatest potency and toxicity (1000 times more potent than BPA). Specifically, cleavage divisions, within 1-6 hours of exposure had severe irregularities including asymmetrical division, slowed mitosis and cytokinesis, cellular dissociation, and fewer numbers of cells per embryo. By 48 hours of exposure the embryos had curved body axis defects, neural tube defects including curved, incomplete, or two neural tubes, ventral and gut blisters, and overall extreme abnormalities. By 96 hours of exposure estradiol caused tail flexures/bent spines, severe pigmentation reduction, long loosely coiled gut, and a ventral blister in 100% of embryos. BPA caused truncated body axis defects, tail flexures, and head and eye malformations in over 60% of embryos. BPAF, at the lowest doses tested, caused craniofacial defects, shorter tails, ventral blisters, edema and peritoneal effusion in over 75% of the surviving embryos. For a complete description, interpretation of the data and a discussion refer to the article in press Arancio et al., 2018.
Keywords: 17-β estradiol; BPA; BPA alternatives; BPAF; Development; Embryo.