Abstract: Objective To construct a dual-fluorescent rat model specifically labeling vascular endothelial cells using the Cre-Loxp system, in order to study the structure and function of vascular endothelial cells. Method Tek-e ( Cre ) 3 gene knock-in rats, constructed by linking Cre recombinase with a vascular endothelial cell-specific promoter, and Rosa26 knock-in rats expressing the CAG-Loxp-tdTomato3xpolyA-Loxp-EGFP-WPRE-polyA gene were identified and crossed. The offspring rats were genotyped, and their brain and heart tissues were processed into frozen sections for phenotypic observation using a fluorescence microscope. Result Genotyping of the parental rats showed that they were both homozygous. Genotyping of the offspring rats revealed that both genes were expressed in the offspring, which were also homozygous. Under the fluorescence microscope, green fluorescent (EGFP) signals were observed in the vascular regions of the brain and heart tissues of the offspring rats, while other tissues exhibited red fluorescent ( tdTomato) signals, indicating that the Cre-Loxp system successfully expressed the EGFP gene in vascular endothelial cells. Conclusion The dual-fluorescence rat model constructed in this study successfully achieved specific labeling of vascular endothelial cells, providing a powerful tool for studying the structure, function, and related diseases of vascular endothelial cells.

Key words: rat, Cre-Loxp system, fluorescent protein, endothelium

摘要： 目的 旨在利用 Cre-Loxp 系统构建特异性标记血管内皮细胞的双荧光大鼠模型,以便研究血管内皮细胞的 结构和功能。 方法 将使用 Cre 重组酶与血管内皮细胞特异性启动子相连构建的 Tek-e( Cre) 3 基因,定点敲入大 鼠与 Rosa26 定点 CAG-Loxp-tdTomato-3xpolyA-Loxp-EGFP-WPRE-polyA 基因表达大鼠,分别进行鉴定和杂交,对其 产生的子代大鼠进行基因型鉴定,并取子代大鼠的脑和心脏组织制成冰冻切片后,使用荧光显微镜观察其表型特 征。 结果 两种亲代大鼠基因型鉴定结果显示亲代大鼠均为纯合子,对子代大鼠进行基因型鉴定结果显示两种基 因都在子代大鼠中表达且子代大鼠为纯合子。 在荧光显微镜下观察到大鼠脑和心脏组织中血管部位存在着绿色 荧光(EGFP)信号,而其他组织则表现出红色荧光( tdTomato) 信号,指示 Cre-Loxp 系统成功地使 EGFP 基因在血管 内皮细胞中表达。 结论 本研究构建的双荧光大鼠模型成功地实现了对血管内皮细胞的特异标记,该模型的构建 为研究血管内皮细胞的结构、功能和相关疾病提供了有力的工具。

关键词: 大鼠, Cre-Loxp 系统, 荧光蛋白, 血管内皮细胞