Zhou Liqing, Jiang Xinyue, Yang Hongsu, Li Jiale, Yang Jinlong, Sun Xiujun, Wu Biao, Liu Zhihong, Li Huawang
Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
Fisheries College, Zhejiang Ocean University, Zhoushan, 316022, China.
Fish Shellfish Immunol. 2025 Oct;165:110570. doi: 10.1016/j.fsi.2025.110570. Epub 2025 Jul 19.
Manila clam (Ruditapes philippinarum) inhabits environments in which dissolved oxygen (DO) concentrations are prone to changes. Hemocytes are important participants in shellfish immune responses and are sensitive to environmental changes. To investigate the effect of DO concentration changes on the ultrastructure of R. philippinarum hemocytes and provide parameters for healthy breeding and management of this species, three DO concentration change modes were designed: normoxia C treatment; normoxia followed by acute hypoxia for 24 h and acute reoxygenation for 4 h, and normoxia followed by chronic hypoxia for 48 h and then chronic reoxygenation for 8 h. Hemocytes were classified as amoebocytes (AMCs), secretory cells (SECs), thrombocytes (THCs), spherical cells (SPCs), and macrophage-like cells (MACs). Granules were present in AMC, SEC, and SPC cytoplasm, and were rarely observed in THCs and MACs. The granule function and number and morphology of various organelles differed among hemocyte types. SPCs lost their spherical structure and their intracellular ultrastructure was severely damaged, leading to apoptosis. AMCs and SECs also suffered ultrastructural damage and apoptosis. AMCs exhibited weak deformability, decreased ability to engulf and remove foreign substances, and decreased secretion ability of SECs. Acute hypoxia damaged the THC ultrastructure and acute reoxygenation triggered coagulation reactions. Chronic hypoxia and reoxygenation severely affected MAC morphology and ultrastructure. Effects of DO concentration changes on the ultrastructure and function of five hemocyte types in Manila clams were clarified, providing a cellular basis for revealing the response of Manila clams to DO concentration changes.
菲律宾蛤仔（Ruditapes philippinarum）栖息于溶解氧（DO）浓度容易发生变化的环境中。血细胞是贝类免疫反应的重要参与者，并且对环境变化敏感。为了研究DO浓度变化对菲律宾蛤仔血细胞超微结构的影响，并为该物种的健康养殖和管理提供参数，设计了三种DO浓度变化模式：常氧C处理；常氧后急性缺氧24小时并急性复氧4小时，以及常氧后慢性缺氧48小时然后慢性复氧8小时。血细胞被分类为变形细胞（AMC）、分泌细胞（SEC）、血栓细胞（THC）、球形细胞（SPC）和类巨噬细胞（MAC）。颗粒存在于AMC、SEC和SPC的细胞质中，而在THC和MAC中很少观察到。不同血细胞类型中颗粒的功能以及各种细胞器的数量和形态各不相同。SPC失去其球形结构，其细胞内超微结构严重受损，导致细胞凋亡。AMC和SEC也遭受超微结构损伤和细胞凋亡。AMC表现出较弱的变形能力、吞噬和清除异物能力下降以及SEC的分泌能力下降。急性缺氧破坏了THC的超微结构，急性复氧引发凝血反应。慢性缺氧和复氧严重影响MAC的形态和超微结构。阐明了DO浓度变化对菲律宾蛤仔五种血细胞类型超微结构和功能的影响，为揭示菲律宾蛤仔对DO浓度变化的反应提供了细胞基础。
