Polyploid series of mammalian cells

Colcemid has been used to produce polyploid sublines sequentially from clonal populations. Matched sets derived in this way include diploid, tetraploid, and octaploid strains of V79 Chinese hamster cells, as well as pig kidney sublines at 2n, 4n, 8n, and 16n levels. In each polyploid series the modal cell volume is proportional to the number of chromosome sets. Logarithmic growth rates are identical for sublines of a related group. Measurements on monolayers of pig kidney cells show that cell shape and dimensional patterns are unaltered by changes in ploidy level. The surface-volume ratio thus declines from 1.0 for diploid cells to 0.5 for 16n cells. No evidence was found to indicate that this shift affects growth rate or population mass. Polyploid cells in matched sets provide models which can be effectively used for the analysis of growth and cytogenetic changes.