Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, No. 23 Xinning Road, Xining, 810008, Qinghai, China.
State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, Qinghai, China.
BMC Genomics. 2023 Sep 14;24(1):545. doi: 10.1186/s12864-023-09587-9.
Teleost fish have evolved various adaptations that allow them to tolerate cold water conditions. However, the underlying mechanism of this adaptation is poorly understood in Tibetan Plateau fish. RNA-seq combined with liquid chromatography‒mass spectrometry (LC‒MS/MS) metabolomics was used to investigate the physiological responses of a Tibetan Plateau-specific teleost, Gymnocypris przewalskii, under cold conditions. The 8-month G. przewalskii juvenile fish were exposed to cold (4 ℃, cold acclimation, CA) and warm (17 ℃, normal temperature, NT) temperature water for 15 days. Then, the transcript profiles of eight tissues, including the brain, gill, heart, intestine, hepatopancreas, kidney, muscle, and skin, were evaluated by transcriptome sequencing. The metabolites of the intestine, hepatopancreas, and muscle were identified by LC‒MS/MS. A total of 5,745 differentially expressed genes (DEGs) were obtained in the CA group. The key DEGs were annotated using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The DEGs from the eight tissues were significantly enriched in spliceosome pathways, indicating that activated alternative splicing is a critical biological process that occurs in the tissues to help fish cope with cold stress. Additionally, 82, 97, and 66 differentially expressed metabolites were identified in the intestine, hepatopancreas, and muscle, respectively. Glutathione metabolism was the only overlapping significant pathway between the transcriptome and metabolome analyses in these three tissues, indicating that an activated antioxidative process was triggered during cold stress. In combination with the multitissue transcriptome and metabolome, we established a physiology-gene‒metabolite interaction network related to energy metabolism during cold stress and found that gluconeogenesis and long-chain fatty acid metabolism played critical roles in glucose homeostasis and energy supply.
硬骨鱼类已经进化出各种适应能力，使它们能够耐受冷水条件。然而，青藏高原鱼类对这种适应的潜在机制知之甚少。我们使用 RNA-seq 结合液相色谱-质谱联用 (LC-MS/MS) 代谢组学来研究青藏高原特有的鱼类青海湖裸鲤在低温条件下的生理反应。8 月龄的青海湖裸鲤幼鱼在冷（4℃，冷驯化，CA）和暖（17℃，常温，NT）温度水中暴露 15 天。然后，通过转录组测序评估了 8 种组织（脑、鳃、心脏、肠、肝胰脏、肾脏、肌肉和皮肤）的转录谱。通过 LC-MS/MS 鉴定了肠、肝胰脏和肌肉的代谢物。在 CA 组中获得了 5745 个差异表达基因 (DEG)。使用基因本体论和京都基因与基因组百科全书分析对关键 DEG 进行注释。8 种组织的 DEGs 显著富集在剪接体途径中，表明激活的选择性剪接是组织中发生的关键生物学过程，有助于鱼类应对冷应激。此外，在肠、肝胰脏和肌肉中分别鉴定出 82、97 和 66 个差异表达代谢物。这三个组织中转录组和代谢组分析唯一重叠的显著途径是谷胱甘肽代谢，表明在冷应激期间触发了激活的抗氧化过程。结合多组织转录组和代谢组，我们建立了一个与冷应激期间能量代谢相关的生理-基因-代谢物相互作用网络，发现糖异生和长链脂肪酸代谢在葡萄糖稳态和能量供应中起关键作用。
