ABSTRACT
In the present work it is shown that the phenomenon of interphase chromosome centromeric region displacement, previously revealed by the authors, is not realized in Go-lymphocytes with heterozygous BRCAJ/2 gene mutations. The role of these genes in DNA double strand break (DSB) reparation is known. It is concluded that chromosome locus displacement is necessary for DSB repair, at least in the process of homologous recombination. In accordance with the authors' data, some features (pericentromeric cluster disintegration and displacement, the nucleus size increasing) characteristic for S-and G0-lymphocytes are observed in normal Go-lymphocytes treated with 3 and 10 cGy. However, the size of nucleus in Go-lymphocytes is restored through 6 hours after irradiation as opposed to the process in dividing cells. It was proposed that some functions of Go-lymphocytes typical of resting cells after inducing by adaptive doze of radiation are stopped as similarly as after stimulation of cells. It is of interest that the process of the induced chromosome loci displacement is correlated with the decreasing of DNA reparation possibilities under UV -irradiation. The induced apoptosis level also decreases when chromosome loci are displaced. The possible mechanisms of the revealed
phenomenon are discussed. This research supported by RFBR grant (No. 01-0449180).
