[Reproducible chromosomal instability of an established Chinese hamster cell line detectable by flow cytometry]

The karyotypes of individual cells in clones of the established Chinese hamster cell line display a highly heterogeneous pattern. Unlike situation in individual cells, the flow karyotypes of cloned cell populations are very similar. A comparison of these facts suggests that mostly the same certain chromosomal reorganizations, appearing frequently enough, may occur in the cells. As a result, the whole set of possible variants of reorganized chromosomes appear during few cell cycles, regardless of the initial cell karyotype. This hypothesis is supported by our flow cytometry data. The same small peaks corresponding to rarely met (less than 1 per cell) rear ranged chromosomes appear on flow karyotype histograms of parental cell clones and their secondary subclones. Chromosomes with random gamma or UV irradiation-induced reorganizations do not remain in the cell population, unlike certain reorganization of regular nature.