| | Category | ZO | L31 | Exposure to low-dose bisphenol A causes hatching delays in |
| | Medeka fish |
| | Abstract | Bisphenol A (BPA), a widely used monomer of polycarbonate plastics, has |
| | raised concern as it has been found to leach out of the epoxy resin in |
| | canned goods and common plastic containers such as baby bottles, and |
| | water bottles (Whitteelsey, 2003). Bisphenol A is an estrogen mimic that |
| | can act as an endocrine disruptor, which can interfere with hormone- |
| | controlled physiological processes such as homeostasis, growth, |
| | development, and reproduction (Howdeshell et al. 2003). With bisphenol A |
| | leaching into so many common food and beverage containers, several |
| | studies on fish and mice have shown that exposure to low doses of BPA |
| | during embryo development hinder the development of the embryo, and |
| | may cause adverse reproductive affects (Ramakrishnan and Wayne, |
| | 2008). In this study, Japanese Medaka (Oryzias latipes) fish embryos at |
| | both 5 hours post-fertilization and 4 days post-fertilization were exposed |
| | to varying levels of bisphenol A: 0 μg/L, 200 μg/L, and 1,000 |
| | μg/L. The Medaka embryos exposed to BPA at both 5 hours post- |
| | fertilization and 4 days post-fertilization had a delayed hatch rates |
| | compared to the age related controls. Thus, the results showed that |
| | bisphenol A exposure in Medaka embryos decelerated rate of hatch. In |
| | previous studies examining the biological reasons for BPA disrupting the |
| | normal hatching behavior, it has been concluded that BPA disorders the |
| | osmoregulation, the maintenance of an optimal constant osmotic pressure |
| | in the body of a living organism, and thereby affects the normal hatching |
| | behavior and the morphogenesis, the development of structural features |
| | (Zhou et at., 2010). Moreover, as well as affecting the osmoregulation of |
| | the embryos, other studies of the effects of BPA in fish embryonic |
| | development have speculated that the BPA interferes with the normal |
| | function of endogenous hormones, and affects the cell cycle by causing a |
| | delay in the metaphase stage of mitosis by destabilizing microtubules |
| | (Zhou et al., 2010). Altogether, the embryos exposed to 200 μg/L |
| | and 1,000 μg/L of BPA four days after fertilization and the embryos |
| | exposed to 200 μg/L of BPA five hours after fertilization had a |
| | decreased rate of hatch because bisphenol A affected the physiological |
| | equilibrium of the embryos and caused the eggs to lose control of the cell- |
| | cycle regulation (Zhou et al., 2010). |
| | Bibliography | Howdeshell KL, Peterman PH, Judy BM, Taylor JA, Orazio CE, Ruhlen RL, |
| | Saal FS, Welshons WV. 2003. Bisphenol A Is Released from Used |
| | Polycarbonate Cages into Water at Room Temperature. Envirmental Health |
| | Perspectives 9:1180-7. |
| | |
| | Ramakrishnan S, Wayne NL. 2008. Impact of bisphenol A on early |
| | embryonic development and reproductive maturation. Reproductive |
| | Toxicology 2:177-183. |
| | |
| | Whitteelsey FC. 2003. Hazards of Hydration. Sierra 6: 16-18. |
| | |
| | Zhou J, Zhu XS, Cai ZH. 2010. The impacts of bisphenol A (BPA) on |
| | abalone (Haliotis disersicolor supertexta) embryonic development. |
| | Chemosphere 56: 459-510. |