Accession Number : AD0771411

Title :   Radiosensitivity of RNA Synthesis Regulation Mechanisms,

Corporate Author : ARMY FOREIGN SCIENCE AND TECHNOLOGY CENTER CHARLOTTESVILLE VA

Personal Author(s) : Tokarskaya,V. I.

Report Date : 16 JUL 1973

Pagination or Media Count : 17

Abstract : It has been shown by the isotope method that intense RNA synthesis takes place in germ in the early stages of seed swelling. The nucleotide composition of these newly-formed RNA fractions was determined, which made it possible to identify them as ribosomal RNA, ribosomal RNA precursor, and messenger RNA. After irradiation of seed with a dose of 20kR, a 40% depression of messenger RNA synthesis, activation of ribosomal RNA synthesis and acceleration of ribosomal RNA precursor conversion into ribosomal RNA were found. The following were shown by the competitive and additive hybridization method: The appearance of new types of RNA (gene activation) at early stages of seed swelling; the appearance of these new types of RNA was not detected after irradiation, which is evidence of repression of gene activation taking place normally at the corresponding stages; RNA synthesis already taking place is suppressed by not more than 15% by radiation; irradiation does not reliably cause repression of active genes. Thus, the regulator mechanisms of RNA synthesis turn out to be more radiosensitive than RNA synthesis already taking place.

Descriptors :   *Ribonucleic acids, *Biosynthesis, *Radiation effects, Ionizing radiation, Molecular biology, Nucleotides, Metabolism, Translations, USSR

Subject Categories : Biochemistry
      Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE