Nasr Mahmoud, Youssef Mohammed, Alghamdi Abdullah A A, Alghamdi Ali H, Khormi Mohsen A, Aborasain Ali M, Emeish Walaa F A, Elkamel Ahmad A
Department of Fish Diseases, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt.
Department of Animal Physiology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt.
BMC Vet Res. 2025 May 28;21(1):383. doi: 10.1186/s12917-025-04749-1.
Common carp is one of the most economically important freshwater fish species globally. Ammonia exposure, a frequent challenge in aquaculture, can lead to significant economic losses. This study investigated the impact of un-ionized ammonia (UIA) exposure on the expression profiles of three key genes in common carp fry: interleukin-1 beta (IL-1β), corticotropin-releasing hormone (CRH), and leptin a1 (Lep-a1). These genes are crucial indicators of immune response, stress regulation, and appetite control, respectively. Fish were exposed to 0.7 mg/L of UIA, and gene expression was analysed in liver and gill tissues at five time points (12 h, 2-, 4-, 7-, and 14-days of exposure) using quantitative real-time PCR (RT-qPCR).
Results demonstrated that expression levels of all three genes were significantly affected by exposure time and tissue type. IL-1β, CRH, and Lep-a1 were upregulated in both liver and gill tissues, with the liver consistently showing higher expression levels. Notably, significant positive correlations were observed between each pair of the three genes studied, suggesting a coordinated physiological response to ammonia stress. The liver emerged as a key organ in orchestrating the long-term adaptive response, while the gills exhibited a more acute, transient reaction.
This study provides valuable insights into the molecular mechanisms underlying the physiological response of common carp to ammonia toxicity. The findings highlight the complex interplay between immune, stress, and metabolic pathways in coping with ammonia exposure. A deep understanding of these mechanisms could lead to improved management strategies in aquaculture and the development of potential biomarkers for assessing stress responses in fish populations.
鲤鱼是全球经济上最重要的淡水鱼类之一。氨暴露是水产养殖中常见的挑战，会导致重大经济损失。本研究调查了非离子氨（UIA）暴露对鲤鱼幼鱼中三个关键基因表达谱的影响：白细胞介素-1β（IL-1β）、促肾上腺皮质激素释放激素（CRH）和瘦素a1（Lep-a1）。这些基因分别是免疫反应、应激调节和食欲控制的关键指标。将鱼暴露于0.7mg/L的UIA中，并在五个时间点（暴露12小时、2天、4天、7天和14天）使用定量实时PCR（RT-qPCR）分析肝脏和鳃组织中的基因表达。
结果表明，所有三个基因的表达水平均受暴露时间和组织类型的显著影响。IL-1β、CRH和Lep-a1在肝脏和鳃组织中均上调，肝脏中的表达水平始终较高。值得注意的是，在所研究的三个基因中的每对基因之间均观察到显著的正相关，表明对氨应激存在协调的生理反应。肝脏成为协调长期适应性反应的关键器官，而鳃表现出更急性、短暂的反应。
本研究为鲤鱼对氨毒性生理反应的分子机制提供了有价值的见解。研究结果突出了免疫、应激和代谢途径在应对氨暴露时的复杂相互作用。深入了解这些机制可能会带来水产养殖中更好的管理策略，并开发用于评估鱼类种群应激反应的潜在生物标志物。
