Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China.
Qingdao Agricultural University, Qingdao 266109, China.
Comp Biochem Physiol Part D Genomics Proteomics. 2023 Sep;47:101098. doi: 10.1016/j.cbd.2023.101098. Epub 2023 May 18.
Hypoxia has become a common problem for aquatic organisms due to the interaction of global climate change and human activity. Black rockfish inhabits rocky reefs in waters of Japan, Korea and China, whereas the limited hypoxia tolerance leads to mass mortality and great economic loss. In this study, high-throughput RNA-seq for transcriptomic analysis was used to investigate the hepatic response in black rockfish under hypoxia (critical oxygen tension, Pcrit; loss of equilibrium, LOE) and reoxygenation (recover normal dissolved oxygen 24 h, R24) to explore the mechanisms underlying hypoxia tolerance and adaptation. A total of 573,040,410 clean reads and 299 differentially expressed genes (DEGs) in total were obtained during hypoxia and reoxygenation. GO annotation and Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the DEGs are mainly enriched in the biochemical metabolic pathways and HIF-1 signaling pathways. Transcriptomic analysis also identified 18 DEGs associated with HIF-1 signaling pathway (hif1α, tf, epo, hmox, gult1, mknk2, ldha, pfkfb3, hkdc, aldoa) and biological process (hif2α, apoeb, bcl6, mr1, errfi1, slc38a4, igfbp1a, ap4m1) as further validated by quantitative real-time PCR. Moreover, hif1α was positively or negatively correlated with glucose (ldha, pfkfb3, hkdc, aldoa) and lipid (apoeb) metabolism-related genes. The mRNA level of hif1α was significantly up-regulated under acute hypoxia stress and obtained the higher values than hif2α. Meanwhile, hif1α recognized the hypoxia response element located in the promoter of ldha and directly bound to the promoter to transactivate ldha expression. These results indicated that black rockfish may mainly utilize glycolysis to maintain homeostasis, and hif1α facilities hypoxia tolerance by modulating ldha expression.
缺氧已成为水生生物的一个常见问题，这是由于全球气候变化和人类活动的相互作用。黑鲈栖息在日本、韩国和中国水域的岩石礁中，但其有限的耐缺氧能力导致大量死亡和巨大的经济损失。在这项研究中，高通量 RNA-seq 用于转录组分析，以研究缺氧（临界氧张力，Pcrit；失衡，LOE）和再氧合（恢复正常溶解氧 24 小时，R24）下黑鲈肝脏的反应，以探索耐缺氧和适应的机制。在缺氧和再氧合期间，共获得了 573,040,410 条清洁读数和总共 299 个差异表达基因（DEGs）。GO 注释和京都基因与基因组百科全书分析表明，DEGs 主要富集在生化代谢途径和 HIF-1 信号通路中。转录组分析还确定了 18 个与 HIF-1 信号通路（hif1α、tf、epo、hmox、gult1、mknk2、ldha、pfkfb3、hkdc、aldoa）和生物学过程（hif2α、apoeb、bcl6、mr1、errfi1、slc38a4、igfbp1a、ap4m1）相关的 DEGs，并通过定量实时 PCR 进一步验证。此外，hif1α 与葡萄糖（ldha、pfkfb3、hkdc、aldoa）和脂质（apoeb）代谢相关基因呈正相关或负相关。在急性缺氧应激下，hif1α 的 mRNA 水平显著上调，并获得高于 hif2α 的更高值。同时，hif1α 识别位于 ldha 启动子中的缺氧反应元件，并直接与启动子结合以转录激活 ldha 表达。这些结果表明，黑鲈可能主要利用糖酵解来维持体内平衡，hif1α 通过调节 ldha 表达来促进耐缺氧能力。
