FUSION OF GREEN FLUORESCENT PROTEIN WITH THE ZEOCIN(TM)-RESISTANCE MARKER ALLOWS VISUAL SCREENING AND DRUG SELECTION OF TRANSFECTED EUKARYOTIC CELLS

Green fluorescent protein (GFP) and the Zeocin(TM)-resistance gene Sh ble (Zeo(R)) were fused together to generate a bifunctional protein fo r the identification and selection of transfected mammalian cells. Exp ression of this hybrid selectable marker, GFP-Zeo(R), was visually det ected and conferred Zeocin resistance in prokaryotes and eukaryotes. T his selectable marker provides a way to determine transient transfecti on efficiencies in tissue culture cells using fluorescence microscopy. Expression of the GFP-Zeo(R) was also used to identify and select sta ble mammalian cell lines expressing a heterologous gene. Selection was efficient and GFP fluorescence provides an excellent, noninvasive tec hnique to monitor the success of Zeocin selection during the developme nt of the stable cell lines. This hybrid resistance gene combines the functional properties of the Zeocin-resistance marker and GFP and shou ld be useful for combined selection and fluorescence in a variety of o rganisms.