Japanese medaka embryos were exposed to water accommodated fractions (WAF) and chemically-enhanced WAF of two types of diluted bitumen (dilbit) at concentrations bracketing the EC50s for developmental malformations. Within these treatments, fish were grouped based on the presence or absence of developmental malformations (e.g., blue sac disease (BSD)), and analyzed for novel transcriptomic responses. Microarray analyses identified novel biomarkers and gene networks in dilbit-exposed malformed embryos that were not evident in dilbit-exposed fish without BSD or in controls without dilbit. The top differentially expressed genes (DEGs) included cytochrome P450 transcripts (cyp1) in fish from all dilbit treatments (malformed and non-malformed fish), as well as: fibroblast growth factor (fgf7), AHR repressor (ahrr), and squalene monooxygenase (sqle). In dilbit-exposed fish that did not develop BSD, the only reported individual DEG was eukaryotic translation initiation factor 3 subunit D (eif3d). However, a number of other pathways were enriched, including melatonin effects on circadian clock and the antioxidant response, estrogen and androgen metabolism as well as many receptor signaling pathways. Pathways associated with hedgehog, steroid biosynthesis, and Wnt signaling were significantly altered between low and high concentrations of dilbit exposure. An effect of the dispersant control on swim bladder development was observed at concentrations 10-fold higher than those used to disperse dilbit, and a number of gene targets unique to fish in this comparison were affected. This suggests that the toxic effects of dispersant may involve alternative mechanisms to dilbit, but cause similar phenotypic responses. This study identified novel biomarkers in fish exposed to dilbit, with or without visual malformations, that can be used to assess the risks of dilbit to aquatic ecosystem health.

将日本高加索胚胎暴露于两种类型的稀释沥青（莳萝）的水份（WAF）和化学增强的WAF中，浓度与发育畸形的EC50一致。在这些处理方法中，根据是否存在发育畸形（例如，蓝囊病（BSD））对鱼进行分组，并分析其新的转录组反应。基因芯片分析在暴露于畸形的畸形胚胎中发现了新颖的生物标记物和基因网络，这些基因在没有BSD的暴露于畸形的鱼中或没有对照的对照中不明显。最高的差异表达基因（DEG）包括所有dilbit处理（畸形和非畸形鱼）中鱼的细胞色素P450转录本（cyp1），以及：成纤维细胞生长因子（fgf7），AHR阻遏物（ahrr）和角鲨烯单加氧酶（sqle）。在未发育BSD的暴露于百日咳的鱼类中，唯一报告的个体DEG是真核翻译起始因子3亚基D（eif3d）。但是，丰富了许多其他途径，包括褪黑素对昼夜节律的影响和抗氧化反应，雌激素和雄激素的代谢以及许多受体信号传导途径。在低浓度和高浓度的dilbit暴露之间，与刺猬，类固醇生物合成和Wnt信号传导相关的途径发生了显着改变。观察到分散剂控制对游泳膀胱发育的影响，其浓度要比分散Dilbit所用的浓度高10倍，并且在此比较中鱼的许多基因靶标受到影响。这表明分散剂的毒性作用可能涉及到稀释的其他机制，但会引起类似的表型反应。这项研究确定了暴露于迪尔比特鱼中有无视觉畸形的新型生物标志物，