Excessive immune response of pearl oyster after transplantation is the main factor that causes its nucleus rejection and death. In this study, to clarify how the cholinergic system regulates the immune response after transplantation, ACh and mecamylamine hydrochloride (nAChR inhibitor) were used to activate or block the cholinergic system of pearl oysters before transplantation. Transcriptomes of hemocytes were constructed at different times (6, 12, 24, and 48 h) after transplantation. Transcriptome analysis showed that the Kyoto Encyclopedia of Genes and Genomes pathway related to “inositol phosphate metabolism” pathway and Gene Ontology (GO) terms “calcium-ion binding” were significantly enriched in the differential expression genes of the two comparisons, and calmodulin genes were upregulated at 12–24 h after activation of the cholinergic system. Further experiments showed that ACh treatment significantly induced intracellular Ca²⁺ concentration. GO terms related to “antioxidant activity” and “superoxide dismutase activity” were significantly enriched in the two comparisons. The result of enzyme activity showed that the activities of superoxide dismutase and catalase in serum were significantly upregulated after activation of the cholinergic system but downregulated after blockade of this system. Furthermore, the cholinergic system maybe participate in regulating the “DNA replication”, “cell cycle”, “mismatch repair”, and “apoptosis” of the hemocytes after transplantation. These results provide new insights into the molecular mechanism of the cholinergic system in regulating the immunity of pearl oyster transplantation and facilitate the development of immunosuppressive agents to improve the effectiveness of cultured pearls.

珍珠贝移植后过度的免疫反应是导致其细胞核排斥和死亡的主要因素。本研究为阐明胆碱能系统如何调节移植后的免疫反应，在移植前使用乙酰胆碱和盐酸美加明（nAChR抑制剂）激活或阻断珍珠贝的胆碱能系统。在移植后的不同时间（6、12、24 和 48 小时）构建血细胞的转录组。转录组分析表明，与“磷酸肌醇代谢”途径相关的京都基因百科全书和基因组途径和基因本体论（GO）术语“钙离子结合”在两次比较的差异表达基因中均显着富集，和钙调蛋白基因在胆碱能系统激活后 12-24 小时上调。进一步的实验表明，ACh 处理显着诱导细胞内 Ca²⁺浓度。与“抗氧化活性”和“超氧化物歧化酶活性”相关的 GO 术语在两个比较中显着丰富。酶活性结果表明，血清中超氧化物歧化酶和过氧化氢酶的活性在胆碱能系统激活后显着上调，而在胆碱能系统被阻断后则下调。此外，胆碱能系统可能参与调节移植后血细胞的“DNA复制”、“细胞周期”、“错配修复”和“细胞凋亡”。这些结果为胆碱能系统调节珍珠贝移植免疫的分子机制提供了新的见解，并促进了免疫抑制剂的开发，以提高养殖珍珠的有效性。