HERPES-SIMPLEX VIRUS THYMIDINE KINASE GREEN FLUORESCENT PROTEIN FUSION GENE - NEW TOOL FOR GENE-TRANSFER STUDIES AND GENE-THERAPY

Green fluorescent protein (GFP) and herpes simplex virus type-1 thymid ine kinase (TK) are commonly used markers in gene transfer studies. Th e latter gene has also proven to be an effective tool in cancer ''suic ide'' gene therapy. To facilitate rapid and reliable selection of cell s expressing TK, we constructed a plasmid expressing a TK-green fluore scent protein fusion gene (TK-GFP). In this fusion gene, the expressio n of each component is coupled to one another, permitting accurate det ermination of the percentage of cells expressing TK by detecting the g reen fluorescence produced by GFP. Transfection of the fusion plasmid to mammalian cells revealed that the construct is fully functional, ma king the cells both fluorescent and sensitive to ganciclovir.