G protein-coupled estrogen receptor 1 (GPER1) plays a crucial role in the regulation of non-genomic estrogen effect. However, the research about fish GPER1 is still limited. The present study aims to obtain the full-length sequence of gper1 from red common carp (Cyprinus carpio) and characterize its expression pattern, and to further explore its potential role in regulating the environmental estrogen induced immunotoxicity. We first cloned the full-length mRNA and genomic sequences of gper1 in C. carpio by PCR, and obtained a 1908 bp sequence with a 1062 bp open reading frame encoding GPER1 protein with 353 amino acids. Additionally, qRT-PCR showed that gper1 was expressed across different tissues in C. carpio, with the highest expression in the brain, which is similar to that in zebrafish. Moreover, applying a luciferase reporter system, we found that the promotor sequence of gper1 has strong activity, and similar to GPER1 in other animals, carp GPER1 also has seven-transmembrane domains, indicating its potential functions. We confirmed the binding ability of GPER1 with G1 and G15 in primary macrophages of C. carpio by testing the related gene expression levels after 6 h exposure, and similar to G1, bisphenol A (BPA), a typical environmental estrogen, could interact with GPER1 to increase the Ca²⁺ concentration in macrophages treated for 30 min. Furthermore, inhibition of GPER1 with GPER1 antagonist G36 rescued the cellular immunotoxicity caused by BPA, which further suggested that carp GPER1 could mediate the estrogen effect. Our findings contribute to better understanding of the role of carp GPER1.

G蛋白偶联雌激素受体1（GPER1）在非基因组雌激素作用的调节中起关键作用。但是，关于鱼类GPER1的研究仍然有限。本研究旨在从红色鲤鱼（Cyprinus carpio）获得gper1的全长序列并表征其表达模式，并进一步探讨其在调节环境雌激素诱导的免疫毒性中的潜在作用。我们首先通过PCR在鲤鱼中克隆了gper1的全长mRNA和基因组序列，并获得了一个1908 bp的序列和一个1063 bp的开放阅读框，编码了具有353个氨基酸的GPER1蛋白。此外，qRT-PCR显示gper1在不同组织中表达鲤鱼C. carpio，在脑中的表达最高，与斑马鱼中的相似。此外，应用荧光素酶报告系统，我们发现gper1的启动子序列具有很强的活性，与其他动物中的GPER1类似，鲤鱼GPER1也具有七个跨膜结构域，表明其潜在功能。我们通过检测暴露6 h后相关基因的表达水平，证实了鲤鱼初级巨噬细胞中GPER1与G1和G15的结合能力，并且与G1类似，典型的环境雌激素双酚A（BPA）可以与GPER1相互作用。增加Ca ²⁺在巨噬细胞中浓缩30分钟。此外，用GPER1拮抗剂G36抑制GPER1可以挽救BPA引起的细胞免疫毒性，这进一步表明鲤鱼GPER1可以介导雌激素作用。我们的发现有助于更好地了解鲤鱼GPER1的作用。