Research Paper Volume 3, Issue 12 pp 1206—1212

Figure 2. SAC tolerance in the 6 mammalian species analyzed. The tolerance (defined as a lack of stringency) of the SAC is graphed as percent of cells with >4N DNA content for the cell strains used in the analysis. Species are ordered by decreasing adult weight from left to right. DNA content was measured as described in materials and methods. Untreated cultures were cells maintained in serum supplemented growth medium as previously described for replicative lifespan studies [14]. Cultures treated with colcemid were maintained for 72 hours in the presence of the inhibitor and DNA content measures at that time. Error bars are standard deviations from one representative experiment of 3 independent replications. Results at 48 hours following colcemid addition fell midway between the values for untreated and 72 hours colcemid treatment while relative differences between species were consistent with the 72 hour results.