Deering R A
Science. 1968 Dec 13;162(3859):1289-90. doi: 10.1126/science.162.3859.1289.
The vegetative cells of the slime mold Dictyostelium discoideum are extremely resistant to cobalt-60 gamma rays. The survival curve has a shoulder at low doses and a 10 percent survival dose of 300 kilorads in air. Dose fractionation experiments indicate that repair of sublethal damage is an important factor in this resistance.