College of Marine Science, South China Agricultural University, Guangzhou, Guangdong, 510642, People's Republic of China.
Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China.
Environ Sci Pollut Res Int. 2020 Jun;27(17):21924-21938. doi: 10.1007/s11356-020-08571-0. Epub 2020 Apr 13.
Widely distributed western mosquitofish (Gambusia affinis) has been used as a new model species for hazard assessment of environmental stressors such as polycyclic aromatic hydrocarbons (PAHs). However, most of the PAH studies using G. affinis rely on targeted biomarker-based analysis, and thus may not adequately address the complexity of the toxic mechanisms of the stressors. In the present study, the whole transcriptional sequencing of G. affinis liver after exposure to a PAH model, benzo[a]pyrene (BaP) (100 μg/L), for 20 days was performed by using the HiSeq XTen sequencers. In total, 58,156,233 and 51,825,467 clean nucleotide reads were obtained in the control and BaP-exposed libraries, respectively, with average N50 lengths of 1419 bp. In addition, after G. affinis was exposed for 20 days, 169 genes were upregulated, and 176 genes were downregulated in liver. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were applied to all the genes to determine the genes' biological functions and processes. The results clearly showed that the differentially expressed genes were mainly related to immune pathways and metabolic correlation pathways. Interestingly, almost all the pathways related with the immunity were upregulated, while the metabolism pathways were downregulated. Lastly, quantitative real-time PCR (qRT-PCR) was performed to measure expressional levels of twelve genes confirmed through the DGE analysis. These results demonstrate that BaP damages immunity and enhances the consumption of all available energy storage to activate mechanisms of the detoxification in G. affinis. Up until now, the present study is the first time that a whole transcriptome sequencing analysis in the liver of G. affinis exposed to BaP has been reported.
广泛分布的西部拟蚊鱼（Gambusia affinis）已被用作评估环境胁迫物（如多环芳烃（PAHs））危害的新模型物种。然而，大多数使用 G. affinis 的 PAH 研究依赖于靶向生物标志物分析，因此可能无法充分解决胁迫物毒性机制的复杂性。在本研究中，使用 HiSeq XTen 测序仪对 G. affinis 肝脏在暴露于多环芳烃模型苯并[a]芘（BaP）（100μg/L）20 天后的全转录组进行测序。在对照和 BaP 暴露文库中分别获得了 58,156,233 和 51,825,467 条清洁核苷酸读数，平均 N50 长度为 1419bp。此外，在 G. affinis 暴露 20 天后，肝脏中有 169 个基因上调，176 个基因下调。应用基因本体论（GO）和京都基因与基因组百科全书（KEGG）通路分析所有基因，以确定基因的生物学功能和过程。结果清楚地表明，差异表达基因主要与免疫途径和代谢相关途径有关。有趣的是，几乎所有与免疫相关的途径都上调，而代谢途径下调。最后，通过 DGE 分析，进行了 12 个基因的定量实时 PCR（qRT-PCR）测量表达水平。这些结果表明，BaP 损害了 G. affinis 的免疫功能，并增强了对所有可用能量储存的消耗，以激活解毒机制。到目前为止，本研究是首次报道 G. affinis 肝脏暴露于 BaP 的全转录组测序分析。
