The formation of variants with a reversion of properties of transformed cells. VII. Chromosome numbers and re‐reversion in subtetraploid variants

Abstract Variants from polyoma virus transformed cells in which reversion was not associated with a loss of the virus genome have been studied at 3 and 33 weeks after clone isolation. The variants re‐reverted during this in vitro cultivation for properties which were initially suppressed. This re‐reversion was associated with an increase in the total chromosome number from a lower to a higher subtetraploid chromosome number.