Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China; School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China.
Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China.
Environ Pollut. 2018 Apr;235:730-738. doi: 10.1016/j.envpol.2017.12.087. Epub 2018 Jan 13.
Polybrominated diphenyl ethers have become ubiquitous in the environment and elevated concentrations have often been found in marine organisms. Using the gastropod Crepidula onyx as a study model, this multigenerational study sets out to test the hypotheses that 1) parental dietary exposure to environmentally realistic levels of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) would lead to transgenerational impairments on fitness traits of marine invertebrates, and 2) the organisms might develop adaptation/acclimation after exposure for one or more generations. F generation of C. onyx was fed with the dinoflagellate Isochrysis galbana encapsulated with two concentrations of BDE-47 (1.78 and 16.0 ng million cells, respectively), and half of the F offspring from the higher concentration treatment was returned to control condition (transgenerational group), while the other half received BDE-47 treatment continuously (continuous treatment group). Bioaccumulation and maternal transfer of BDE-47 were evident in all life stages of the F generation and in F eggs, respectively. Exposure to BDE-47 reduced fecundity, delayed sexual maturity, and impeded embryonic development in F to F. In particular, developmental toxicity of F embryos was apparent in the transgenerational group, but not in the continuous treatment group, even when BDE-47 was not detected in the F embryos nor in their mothers and they have never been exposed to the chemical. This study also suggested that the offspring might have developed adaptation/acclimation to the exposure of BDE-47 within two generations of exposure, and that the physiological alterations associated with acclimation/adaptation might have hindered the normal larval development under a stress free condition. These findings highlighted the need for long-term multigenerational studies in the ecological risk assessment of chemicals alike.
多溴联苯醚已在环境中无处不在，海洋生物中经常发现浓度升高。本研究采用腹足纲软体动物石磺作为研究模型，旨在检验以下两个假设：1）亲代暴露于环境中实际浓度的 2,2',4,4'-四溴联苯醚（BDE-47）会导致海洋无脊椎动物的适合度性状产生跨代损伤，2）生物在经历一个或多个世代的暴露后可能会产生适应/驯化。F 代石磺用含有两种浓度 BDE-47（分别为 1.78 和 16.0ng 百万细胞）的甲藻小球藻进行投喂，高浓度处理的 F 代后代中的一半被送回对照条件（跨代组），另一半则继续接受 BDE-47 处理（连续处理组）。F 代的所有生命阶段和 F 代卵中均存在 BDE-47 的生物积累和母体转移。BDE-47 的暴露降低了 F 代的繁殖力，延迟了性成熟，并阻碍了 F 代至 F 代的胚胎发育。特别是，跨代组中 F 代胚胎的发育毒性明显，但连续处理组中没有，即使 F 代胚胎及其母亲体内均未检测到 BDE-47，且它们从未接触过该化学物质。本研究还表明，在暴露于 BDE-47 的两代内，后代可能已经对 BDE-47 的暴露产生了适应/驯化，而与适应/驯化相关的生理变化可能会阻碍在无压力条件下正常的幼虫发育。这些发现强调了在类似化学物质的生态风险评估中需要进行长期的多代研究。
