Research
| Title： | Dynamic brain responses and systemic regulatory mechanisms in yellow catfish ( Pelteobagrus fulvidraco) exposed to acute hypoxia |
|---|---|
| First author： | Wang, Man; Zhao, Shasha; Wang, Jie; Li, Li; Lin, Ruru; Han, Dong; Zhu, Xiaoming; Zhang, Lei |
| Journal： | AQUACULTURE |
| Years： | 2025 |
| DOI： | 10.1016/j.aquaculture.2025.742177 |
| Abstract： | In intensive aquaculture and live fish transportation, acute hypoxia is common and significantly affects fish health. To assess the impact of acute hypoxia on fish brain tissue, we analyzed the brains of yellow catfish at four time points under acute hypoxic conditions. Acute hypoxia for 96 h induced pathological damage to the brain tissue, structural changes, and increased apoptosis. Additionally, we observed a significant reduction in the immune parameters alkaline phosphatase (ALP), lysozyme (LZM), complement protein (C3), and immunoglobulin M (IgM), highlighting the severe impact on the fish immune system. Using RNA-seq technology, we identified 1247 differentially expressed genes (DEGs) involved in a range of biological processes, such as metabolism, signal transduction, immune processes, endocrine functions, digestion, and neurological functions. Compared with the normoxic group (NG), the hspa5, col1a1, col1a2, and col1a1b genes were remarkably downregulated following hypoxic exposure, whereas egln3, ncam3, kel, slc2a1b, slc4a1a, and were upregulated. The DEG functional enrichment analysis revealed time-specific biological processes in response to acute hypoxia. The significant enrichment of HIF-1 signaling was observed throughout the entire hypoxic response, whereas the glycolysis/gluconeogenesis pathway was notably enriched during the early adaptation stage (<= 24 h). Additionally, ECM-receptor interactions played important roles in hypoxia-related brain function. Notably, pathways associated with the nervous system and neurodegenerative diseases were significantly enriched after 96 h of hypoxic exposure. Trend analysis further revealed dynamic changes in the DEGs, identifying five distinct expression patterns that assisted the fish in coping with acute hypoxic stress. Through visualized KEGG network analysis, we established the relationships between key pathways at different stages of hypoxia and elucidated their interactions with the DEGs. These findings deepen our understanding of changes occurring in brain tissue under acute hypoxia and offer valuable insights into strategies for optimizing aquaculture management and improving fish welfare. |
