Hypoxia occurrence is potentiated by eutrophication caused by human activities and it may be the most dramatically increasing environmental factor as a result of the climate change-led increasing temperatures. The crucian carp Carassius auratus is an important aquaculture economical freshwater species and is also a potential model for the study of physiological adaptation. However, the transcriptomics and genomics data available for this species are still scarce. The gills of fish are the major organ of hypoxia and other stresses. In this study, we studied the effect of the exposure to hypoxia (1.0 mg O₂/L for 7 d) and 2 mg/mL Poly I:C on the gene expression of the gills of Carassius auratus using the Illumina sequencing platform. Comparison of the gene expression levels between the experimental and control groups showed differentially expressed genes (DEGs). The DEGs were mainly annotated into glycolysis, oxidative phosphorylation and immune system categories based on the KEGG database. In glycolysis pathway, lactate dehydrogenase, malate dehydrogenase, glyceraldehyde 3-phosphate dehydrogenase, enolase and succinate dehydrogenase were identified. In addition, the DEGs were enriched in the immune-related pathway functions, including pattern recognition receptor (PRR), antigen processing and presentation, B cell and T cell receptor signaling pathways, natural killer (NK) cell mediated cytotoxicity, Fc gamma R-mediated phagocytosis, and the JAK-STAT, p53 and cytokines signaling pathways. This study also produced potential hypoxia biomarkers including FOS, JUN B, lysosomal acid lipase, and HIF-1α. HIF-1 signaling pathway was significantly down-regulated after hypoxia and Poly I: C exposure. Hence, the data generated here may offer a valuable resource information for the further study of the immune response and also provide improved strategies against hypoxia and Poly I:C in teleost fish.

人类活动引起的富营养化加剧了缺氧的发生，并且由于气候变化导致温度升高，它可能是最显着增加的环境因素。鲫鱼Carassius auratus是重要的水产养殖经济淡水品种，也是研究生理适应的潜在模型。然而，可用于该物种的转录组学和基因组学数据仍然稀缺。鱼的鳃是缺氧和其他应激的主要器官。在本研究中，我们研究了暴露于低氧环境（1.0 mg O ₂ /L 7 d）和 2 mg/mL Poly I:C 对鲫鱼鳃基因表达的影响。使用 Illumina 测序平台。实验组和对照组之间基因表达水平的比较显示差异表达基因（DEGs）。基于KEGG数据库，DEGs主要被注释为糖酵解、氧化磷酸化和免疫系统类别。在糖酵解途径中，鉴定出乳酸脱氢酶、苹果酸脱氢酶、甘油醛3-磷酸脱氢酶、烯醇化酶和琥珀酸脱氢酶。此外，DEGs 富含免疫相关通路功能，包括模式识别受体 (PRR)、抗原加工和呈递、B 细胞和 T 细胞受体信号通路、自然杀伤 (NK) 细胞介导的细胞毒性、Fc γ R-介导的吞噬作用，以及 JAK-STAT、p53 和细胞因子信号通路。该研究还产生了潜在的缺氧生物标志物，包括 FOS、JUN B、溶酶体酸性脂肪酶和 HIF-1α。缺氧和Poly I:C暴露后HIF-1信号通路显着下调。因此，此处生成的数据可能为进一步研究免疫反应提供有价值的资源信息，并提供针对硬骨鱼缺氧和 Poly I:C 的改进策略。