STRUCTURAL AND PHYSICOCHEMICAL CHARACTERI STICS OF DNA FROM ANIMAL-TISSUES EXPOSED TO PROLONGED CHRONIC IRRADIATION IN THE CHERNOBYL ZONE

The properties of animal DNAs exposed to prolonged irradiation in the Chernobyl zone, have been studied by the methods of viscometry, therma l denaturation, IR-spectroscopy, and electrophoresis. High content of low-molecular fractions have been observed in the preparations of DNA from liver and spleen, their quantities increasing with age and genera tion of animals. This effect is especially strong in DNA from liver. L ow-molecular fraction of DNA is shown to be enriched with G-C pairs an d to consist of the following four fractions: 1) approximately 500 bas e pairs (B.p.), 2) approximately 1,5 divided-by 2 thousand B.p., 3) ap proximately 4 divided-by 5 thousand B.p. and 4) a mixture of approxima tely 20 thousand B.p. fragments. Further, it has been observed that th e DNA preparations from the tissues of experimental animals contain ab out ten times higher contents of Fe, Zn, Se and other elements as comp ared to the control preparations.