College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
Sci Total Environ. 2021 Apr 1;763:143053. doi: 10.1016/j.scitotenv.2020.143053. Epub 2020 Oct 17.
To further understand the underlying mechanisms involved in the developmental toxicity of crude oil and chemically dispersed crude oil on fish early-life stages (ELS), zebrafish (Danio rerio) embryos were exposed to GM-2 chemical dispersant (DISP), low-energy water-accommodated fractions (LEWAF), and chemically enhanced WAF (CEWAF) of Merey crude oil at sublethal concentrations for 120 h. We employed the General Morphology Score (GMS) and General Teratogenic Score (GTS) systems in conjunction with high-throughput RNA-Seq analysis to evaluate the phenotypic and transcriptomic responses in zebrafish ELS. Results showed that ΣPAHs concentrations in LEWAF and CEWAF solutions were 507.63 ± 80.95 ng·L and 4039.51 ± 241.26 ng·L, respectively. The GMS and GTS values indicated that CEWAF exposure caused more severe developmental delay and higher frequencies of teratogenic effects than LEWAF exposure. Moreover, no significant change in heart rate was observed in LEWAF treatment, while CEWAF exposure caused a significant reduction in heart rate. LEWAF and CEWAF exposure exhibited an overt change in eye area, with a reduction of 4.0% and 25.3% (relative to the control), respectively. Additionally, no obvious impact on phenotypic development was observed in zebrafish embryo-larvae following DISP exposure. Significant changes in gene expression were detected in LEWAF and CEWAF treatments, with a total of 957 and 2062 differentially expressed genes (DEGs), respectively, while DISP exposure altered only 91 DEGs. Functional enrichment analysis revealed that LEWAF and CEWAF exposure caused significant perturbations in the pathways associated with phototransduction, retinol metabolism, metabolism of xenobiotics by cytochrome P450, and immune response-related pathways. Our results provide more valid evidence to corroborate the previous suggestion that ocular impairment is an equal or possibly more sensitive biomarker than cardiotoxicity in fish ELS exposed to oil-derived PAHs. All these findings could gain further mechanistic insights into the effects of crude oil and chemical dispersant on fish ELS.
为了进一步了解原油和化学分散原油对鱼类早期生命阶段（ELS）发育毒性的潜在机制，将斑马鱼（Danio rerio）胚胎暴露于 GM-2 化学分散剂（DISP）、低能量水容纳馏分（LEWAF）和化学增强 WAF（CEWAF）的 Mercy 原油中，浓度为亚致死浓度 120 小时。我们采用一般形态评分（GMS）和一般致畸评分（GTS）系统结合高通量 RNA-Seq 分析，评估斑马鱼 ELS 的表型和转录组反应。结果表明，LEWAF 和 CEWAF 溶液中ΣPAHs 浓度分别为 507.63±80.95ng·L 和 4039.51±241.26ng·L。GMS 和 GTS 值表明，CEWAF 暴露比 LEWAF 暴露引起更严重的发育迟缓，致畸作用频率更高。此外，在 LEWAF 处理中未观察到心率的显著变化，而 CEWAF 暴露导致心率显著降低。LEWAF 和 CEWAF 暴露导致眼区明显变化，分别减少了 4.0%和 25.3%（相对于对照）。此外，在 DISP 暴露后，斑马鱼胚胎幼虫的表型发育没有明显影响。在 LEWAF 和 CEWAF 处理中检测到显著的基因表达变化，分别有 957 和 2062 个差异表达基因（DEGs），而 DISP 暴露仅改变了 91 个 DEGs。功能富集分析表明，LEWAF 和 CEWAF 暴露导致与光转导、视黄醇代谢、细胞色素 P450 代谢外源化合物以及免疫反应相关途径相关的途径发生显著扰动。我们的结果提供了更有效的证据来证实之前的建议，即在石油衍生的 PAHs 暴露于鱼类 ELS 中，眼部损伤是心脏毒性同等或更敏感的生物标志物。所有这些发现都可以进一步深入了解原油和化学分散剂对鱼类 ELS 的影响。
