[Effect of cytomegalovirus on cell cycle progression and formation of pathological mitoses in cultured human diploid fibroblasts].

The effect of cytomegalovirus on the cell cycle was studied autoradiographically in an asynchronous culture of human diploid fibroblasts. The analysis of labeled mitosis showed that some cells infected in the S phase ceased to progress through the cell cycle at one of its phases (S, G2, or M); at the same time, at least part of infected cells remained capable of entering mitosis. Beginning from day 2 after infection by cytomegalovirus, the accumulation of pathological mitotic cells blocked at metaphase was observed in the culture. Approximately 50% of these cells contained 3H-thymidine label above chromosomes. This fact suggested the possibility of pathological mitosis in cells that were infected both at the S and other phases of the cell cycle. The detailed morphological analysis of chromosomes at different stages of infection demonstrated that the degree of their morphological changes increases from slight (stronger condensation) to severe pathology (fragmentation). In the aggregate, the results of the study suggested that abnormal chromosome morphology resulted from irreversible cell division arrest under the effect of cytomegalovirus.