[Dynamic component of maintaining genomic stability in murine bone marrow cells after chronic low-intensity irradiation lasting one year].

For analysis of a dynamic component state of the system of maintenance of genome stability, which represent a condition of its expression (first of all, genes of the control of phases of cell cycle, the DNA repair and redox systems) after a long chronic exposure to a small dose, the activity of replicative, reparative DNA synthesis, DNA damage as well as oxyradical content in the bone marrow cells of mice (critical for radiation effects mammalian system) after 1 year radiation exposure to a dose 63.7 cGy (0.17 cGy/day) were studied. The considerable enhancement of replicative and reparative DNA synthesis activity by 67% (p = 0.0033) and 60% (p = 0.000004) accordingly in relation to the control and some, but statistically not significant (p = 0.149) tendency to increase (by 30%) the content of a superoxide anion-radical were established. Strong and highly significant correlation (r = 0.8681; P = 0.99975) between DNA damage and O2-. content in bone marrow cells of the irradiated mices, which indicate the large DNA damage by oxiradicals, probably, due to the loss of a part of structural proteins and conformation changes in expression sites of a chromatin, were detected. The obtained results interpreted as representing the change of a dynamic component state of a system of maintenance of genome stability, the epigenic transfer of that to descendants of the irradiated cells can be the cause for formation and maintenance of radiation-induced genome instability.