Chromosome abberations in rat embryo cells transformed after infection with ultraviolet-irradiated herpes simplex virus.

Two rat embryo cell lines (TR1 and TR2) transformed after infection with ultaviolet-inactivated herpes simplex virus type 2 showed modal chromosome numbers in the tetraploid range. In the TR1 cell line a near-diploid cell population replaced during subcultivation the hypotetraploid cells thus explaining the loss of immunofluorescent viral antigens. Both transformed cell lines showed frequent achromatic gaps. In the TR1 cell line such gaps were preferentially located in specific chromosome regions. The occurrence of achromatic gaps is presumably associated with the activity of a viral gene.