Copper (Cu²⁺), which represents a major physiological challenge for crab culture, is ubiquitous in the aquatic culture environment, and gills are the first organs that come into direct contact with the environment. However, the molecular basis of the response of crabs to Cu²⁺ stress remains unclear. Here, we conducted a transcriptome and differential expression analysis on the gills from Chinese mitten crab unexposed and exposed to Cu²⁺ for 24 h. The comparative transcriptome analysis identified 2486 differentially expressed genes (DEGs). GO functional analysis and KEGG pathway analysis revealed some DEGs, which were mostly related to immunity, metabolism, osmotic regulation, Cu²⁺ homeostasis regulation, antioxidant activity, and detoxification process. Some pathways related to humoral and cellular immunity, such as phagosome, peroxisome, lysosome, mTOR signaling pathway, PI3K-Akt signaling pathway, Toll-like receptor signaling pathway, and T cell receptor signaling pathway were enhanced under Cu²⁺ stress. In addition, Cu²⁺ stress altered the expression patterns of key phagocytosis and apoptosis genes (lectin, cathepsin L, Rab7, and HSP70), confirming that Cu²⁺ can induce oxidative stress and eventually even apoptosis. Histological analysis revealed that the copper can induce damage at the cellular level. This comparative transcriptome analysis provides valuable molecular information to aid future study of the immune mechanism of Chinese mitten crab in response to Cu²⁺ stress and provides a foundation for further understanding of the effects of metal toxicity.

铜（Cu ²⁺）代表着螃蟹养殖的主要生理挑战，在水生养殖环境中无处不在，,是最早与环境直接接触的器官。但是，螃蟹对Cu ²⁺胁迫反应的分子基础仍然不清楚。在这里，我们对未暴露并暴露于Cu ²⁺ 24 h的中华绒螯蟹的ill进行了转录组和差异表达分析。比较转录组分析鉴定了2486个差异表达基因（DEG）。GO功能分析和KEGG通路分析显示了一些DEG，主要与免疫力，代谢，渗透调节，Cu ^2+有关。稳态调节，抗氧化活性和排毒过程。在Cu ²⁺胁迫下，吞噬体，过氧化物酶体，溶酶体，mTOR信号通路，PI3K-Akt信号通路，Toll样受体信号通路和T细胞受体信号通路等与体液和细胞免疫有关的通路得以增强。此外，Cu ²⁺胁迫改变了关键吞噬作用和凋亡基因（凝集素，组织蛋白酶L，Rab7和HSP70）的表达模式，证实了Cu ²⁺可以诱导氧化应激，甚至导致细胞凋亡。组织学分析表明，铜可以在细胞水平上引起损伤。这项比较转录组分析提供了有价值的分子信息，有助于将来研究中华绒螯蟹对Cu ²⁺胁迫的免疫机制，并为进一步了解金属毒性的影响提供了基础。