Li Wenyang, Li Ao, Zhang Xianhong, Fei Fan, Gao Xiaoqiang, Fang Yingying, Cao Shuquan, Yang Hongjun, Li Wensheng, Liu Baoliang
State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong 266071, PR China.
Xingguang Marine Ranch Fishery Co., Ltd, Rizhao, 276800 PR China.
Dev Comp Immunol. 2025 Jan;162:105299. doi: 10.1016/j.dci.2024.105299. Epub 2024 Dec 5.
Crowding stress is a significant welfare factor affecting aquatic animals in recirculating aquaculture systems. Little is known regarding the influence of prolonged crowding stress on the immunity of juvenile pearl gentian groupers. However, research exploring the potential mechanisms through which crowding stress affects fish immune function is limited. Therefore, this study aims to investigate the effect of crowding stress on the immune stress of the pearl gentian grouper juvenile (♀Epinephelus fuscoguttatus × ♂ Epinephelus lanceolatus) under prolonged conditions. We focused on the pearl gentian grouper juvenile and selected low- and high-density groups as the experimental breeding densities. Research shows that crowding stress increases the activities of alkaline acid plum and acid phosphatase, reduces the activities of lysozyme and immunoglobulin M content. RNA sequencing and comparative transcriptomic analyses were employed to explore changes in the gene expression of juvenile pearl gentian groupers subjected to crowding stress. Differential gene expression analyses between the low- and high-density groups identified 5777 unigenes that were differentially expressed following crowding stress, with 3216 and 2561 upregulated and downregulated, respectively. In the GO and KEGG enrichment analyses, many of the enriched signaling pathways related to genes were associated with immunity and oxidative stress. In addition, the combined analyses of enzyme activity and transcriptomics indicated that crowding stress suppressed the immune function of juvenile pearl gentian groupers, reducing their immune ability. Overall, these findings offer new insights into the molecular mechanisms underlying crowding stress tolerance in juvenile pearl gentian grouper, suggesting that the NF-κB pathway plays a crucial role in the immune response of the head kidney of the pearl gentian grouper to long-term crowding stress.
养殖密度过大所带来的应激是影响循环水养殖系统中水生动物福利的一个重要因素。关于长期养殖密度过大的应激对珍珠龙胆石斑鱼幼鱼免疫力的影响，目前所知甚少。然而，探索养殖密度过大的应激影响鱼类免疫功能潜在机制的研究有限。因此，本研究旨在调查长期条件下养殖密度过大的应激对珍珠龙胆石斑鱼幼鱼（♀棕点石斑鱼×♂鞍带石斑鱼）免疫应激的影响。我们聚焦于珍珠龙胆石斑鱼幼鱼，并选择低密度和高密度组作为实验养殖密度。研究表明，养殖密度过大的应激会增加碱性磷酸酶和酸性磷酸酶的活性，降低溶菌酶活性和免疫球蛋白M含量。采用RNA测序和比较转录组分析来探究遭受养殖密度过大应激的珍珠龙胆石斑鱼幼鱼基因表达的变化。低密度组和高密度组之间的差异基因表达分析确定了5777个单基因在养殖密度过大的应激后差异表达，其中分别有3216个和2561个上调和下调。在基因本体论（GO）和京都基因与基因组百科全书（KEGG）富集分析中，许多与基因相关的富集信号通路都与免疫和氧化应激有关。此外，酶活性和转录组学的联合分析表明，养殖密度过大的应激抑制了珍珠龙胆石斑鱼幼鱼的免疫功能，降低了它们的免疫能力。总体而言，这些发现为珍珠龙胆石斑鱼幼鱼耐受养殖密度过大应激的分子机制提供了新的见解，表明核因子κB（NF-κB）途径在珍珠龙胆石斑鱼头肾对长期养殖密度过大应激的免疫反应中起关键作用。
