fig2

Figure 2. Increase in population diversity and decrease of cell viability both correlate with decrease in cell plating density. (A) Chr7-FISH was carried out in U251 cultures plated at various cell densities and in SA1, a clonal line of U251 established in serum-containing medium. Based on near diploid karyotypes of cells in U251, cells carrying 1, 2 & 4, and 3 & 6 copies of Chr7 were denoted as monosomy-7 cells, STIC and TMC, respectively, as described previously^[13]. Shannon diversity index was calculated based on the percentages of these three cell subpopulations, as described previously^[22]; (B) colony formation rate from one week culture of 50 cells of U251 in 35, 60, and 100 mm dishes in 3, 4, and 10 mL of medium, respectively, in 4-6 replicates