The Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao, 266003, PR China.
The Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao, 266003, PR China.
Chemosphere. 2019 Jun;224:588-596. doi: 10.1016/j.chemosphere.2019.02.157. Epub 2019 Feb 25.
Tetrabromobisphenol A (TBBPA) is ubiquitous and its contents showing an increasing trend in the coastal environment. In order to investigate the effects of TBBPA on marine bivalves, juvenile manila clams Ruditapes phillipinarum were exposed to TBBPA for 28 days. The results showed that shell growth rate of juvenile clams after exposure to 62.5-1000 μg L TBBPA for 28 d were significantly inhibited (p < 0.05). Then in order to link the changes in filtration rate, mRNA expression of insulin-like growth factor homologue (IGF) and tissue thyroid hormone (TH) contents to growth, juvenile clams were exposed to 62.5 and 500 μg L TBBPA for 14 days. The transcriptional levels of neuroendocrine signals (NPF and insulin homologue) associated with filter feeding regulation, and genes of TH synthesis-related enzymes were also examined. The results showed that filtration rates was significantly reduced to 44.1% and 14% of controls after 14 d of exposure. In parallel, exposure to TBBPA significantly increased the expression levels of insulin which may elicit the filter feeding inhibition. TBBPA exposure caused alterations in tissue content of THs and mRNA expression of TH synthesis-related enzymes. However, the data showed increased T content, T/T ratio and mRNA expression of IGF. These data demonstrated that the most important key event of TBBPA could be linked to growth impairment in juveniles was the reduction of filtration rate. These results provide a robust framework towards revealing the underlying mechanism of the growth inhibition caused by TBBPA on bivalves and understanding the adverse outcome pathway across taxonomic phyla.
四溴双酚 A（TBBPA）广泛存在，其含量在沿海环境中呈上升趋势。为了研究 TBBPA 对海洋双壳贝类的影响，将幼龄菲律宾蛤仔 Ruditapes phillipinarum 暴露于 TBBPA 中 28 天。结果表明，暴露于 62.5-1000μg/L TBBPA 28d 后，幼贝的壳生长率显著受到抑制（p<0.05）。为了将滤水率的变化、胰岛素样生长因子同源物（IGF）的 mRNA 表达和组织甲状腺激素（TH）含量的变化与生长联系起来，将幼贝暴露于 62.5 和 500μg/L TBBPA 14 天。还检查了与过滤喂养调节相关的神经内分泌信号（NPF 和胰岛素同源物）和 TH 合成相关酶的基因的转录水平。结果表明，暴露 14d 后，滤水率分别显著降低至对照的 44.1%和 14%。平行地，TBBPA 暴露显著增加了胰岛素的表达水平，这可能引发过滤喂养抑制。TBBPA 暴露导致组织中 TH 含量和 TH 合成相关酶的 mRNA 表达发生变化。然而，数据显示 T 含量增加，T/T 比值和 IGF 的 mRNA 表达增加。这些数据表明，TBBPA 最重要的关键事件可能与幼体滤水率降低有关，这是导致生长受损的关键事件。这些结果为揭示 TBBPA 对双壳贝类生长抑制的潜在机制以及跨分类门理解不良结局途径提供了有力的框架。
