[The structure of the centromeric region and chromosome behavior in the anaphase after incubating murine cells with the fluorochrome Hoechst 33258].

Mouse chromosome behaviour has been studied in the anaphase, after the cells (culture L) were incubated with fluorochrome Hoechst 33258, provoking the stretching of the chromosome centromeric regions. It was shown that in spite of marked structural changes in the centromere, the cells entered the anaphase and chromosomes preserved their ability to separate towards the spindle poles. At the same time, in the presence of Hoechst 33258, a reliable increase in the anaphase duration could be observed from 4.0 +/- 0.2 min in control to 6.0 +/- 0.5 min after a prolonged incubation of cells with the fluorochrome. Also, the increase in the frequency of chromosomal bridges in anaphase and the appearance of bridges in interphase cells were observed.