College of Food and Bioengineering, Bengbu University, Bengbu, 233030, People's Republic of China.
College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China.
Fish Physiol Biochem. 2023 Jun;49(3):471-486. doi: 10.1007/s10695-023-01201-9. Epub 2023 Apr 28.
The aim of this study was to compare low-temperature tolerances in different strains of large yellow croaker. Dai Qu (DQ), Min-Yue Dong (MY), and Quan Zhou (NZ) strains of large yellow croaker were subjected to cold stress (8.6 °C) for 12 h, 24 h, 48 h, and 96 h. Survival rate, histological observation, and antioxidant and energy metabolism indicators were determined. The results showed that compared with the DQ group and MY group, NZ group aggravated hepatic structure, enhanced ROS, lactate, and anaerobic metabolism (PK gene expression and activity), while inhibited ATP, GSH, antioxidant enzymes (mRNA levels and activities of SOD, GPx, and CAT), and aerobic metabolism enzymes (mRNA levels and activities of F-ATPase, SDH, and MDH), indicating the reduction of cold tolerance in the NZ group was closely correlated with the decrement of antioxidative capacity and energy metabolism efficiency. Nrf2 and AMPK gene expressions were correlated with antioxidant and energy metabolism mRNA levels, respectively, suggesting Nrf2 and AMPK might participate in the modulation of target genes during the cold-stress adaptation. In conclusion, low temperature tolerance of fish depended on the antioxidant defense and energy metabolism efficiency, which contributes to understanding the underlying mechanisms of cold adaptation in large yellow croaker.
本研究旨在比较不同品系大黄鱼在低温下的耐受性。将岱衢（DQ）、闽粤东（MY）和泉州（NZ）三个大黄鱼品系置于冷应激（8.6°C）下 12、24、48 和 96 小时，测定其存活率、组织学观察、抗氧化和能量代谢指标。结果表明，与 DQ 组和 MY 组相比，NZ 组肝组织结构加重，ROS、乳酸和无氧代谢（PK 基因表达和活性）增强，而 ATP、GSH、抗氧化酶（SOD、GPx 和 CAT 的 mRNA 水平和活性）和有氧代谢酶（F-ATPase、SDH 和 MDH 的 mRNA 水平和活性）受到抑制，表明 NZ 组耐低温性的降低与抗氧化能力和能量代谢效率的降低密切相关。Nrf2 和 AMPK 基因的表达分别与抗氧化和能量代谢的 mRNA 水平相关，提示 Nrf2 和 AMPK 可能参与了冷应激适应过程中靶基因的调控。综上所述，鱼类的低温耐受性取决于抗氧化防御和能量代谢效率，这有助于理解大黄鱼冷适应的潜在机制。
