Abstract
Exposure of bacterial cells to ionizing radiation damages cellular components and causes cell death. We examined the induction of the plasmid-encoded lacZ gene in Escherichia coli JM109 harboring pUC19 after irradiation with gamma rays. The data demonstrated that cells irradiated with 6 or 8 kGy gamma rays lost their ability to grow on nutrient agar plates, but retained the ability to induce lacZ gene expression by IPTG at about 10% the level of the nonirradiated control. Thus, inactivation of cells by irradiation may provide another option for establishing a vehicle of protein and DNA, as nonpropagating protein-producing apparatus, albeit with lower capacity than intact cells. Keywords: Escherichia coli, Gamma rays, Gene expression, lacZ gene