Behavioural differences and cytogenetic analysis of a transformed cellular population derived from a Vero cell line.

Arising from a Vero cell line, an altered population was spontaneously obtained, which grew in multiple layers. Cytogenetic analyses revealed a higher polyploidy index (19%) than occurred in the initial population (5%). A modal chromosome number of 56 was found for the altered population, while the initial cell culture had only 54 chromosomes. Karyotypic studies showed that the extranumerary chromosomes were homologues of the 8th and the 27th pairs. The altered population probably resulted from a transformation of the initial line, and their transformed phenotypes may have been associated with the cytological differences.