This strain represents a transgenic rat harboring a transgene encoding the enhanced green fluorescent protein (EGFP). EGFP expression is modulated by the CAG promoter ^[1]. The CAG promoter, a synthetic promoter extensively utilized in molecular biology to achieve robust gene expression, constitutes a fusion of the cytomegalovirus (CMV) early enhancer element and the chicken beta-actin promoter. This promoter is renowned for its robust constitutive expression across a diverse array of tissues and cell types ^[2-3].

In this strain, the CAG promoter drives the expression of EGFP throughout the rat body. The EGFP protein can be directly observed under a fluorescent microscope when excited by light. Validation data show that EGFP protein is expressed in the brain, cerebellum, olfactory bulb, heart, thymus, lungs, liver, spleen, stomach, large intestine, small intestine, kidneys, pancreas, uterus, ovaries, adipose tissue, muscle, toes, tail, and ears of SD-CAG-EGFP rats. Therefore, SD-CAG-EGFP rats can be used for research in areas such as the labeling and tracking of rat cells or tissues. In addition, cells isolated from SD-CAG-EGFP rats may be easier to culture than wild-type rat primary cells that have been transfected with EGFP plasmids.