SENSITIVITY OF ARTEMIA EGGS TO THE GAMMA-IRRADIATION. I. HATCHABILITY OF ENCYSTED DRY EGGS.

Abstract

In recent years much research has been devoted to investigating conditions which change or appear to change the radiosensitivity of living materials. Such studies are of great importance for understanding the steps between the initial absorption of energy and the manifestation of its effects. The dry eggs of Artenaia are very suitable material for the study of the effect of modifying factor on radiosensitivity, because they can be subjected to so much variation in methods of handling them without altering viability. As the first experiment in a series of papers on sensitivity of Artemia eggs to the γ-irradiation, the delay of hatch and the doseeffect relation in hatchability of irradiated dry eggs, were tested. The eggs were irradiated in the dry state at total doses of 480 kr and 600 kr, and then soaked in 2% NaC1 solution at 27°C. The delay on the development of eggs became greater as the irradiation dose increased. Radiosensitivity based on the hatchability at 72 hour after incubation diminished with dose in a sigmoidal curve. The 50% hatching dose was about 500 kr, and the 100% lethal dose was 900 kr. The low radiosensitivity may be attributed to the low water content and the arrest of metabolism of the eggs.