Figure 3. Structural and numerical chromosome aberrations. A total of 40 metaphases prepared from two independent cultures were evaluated by G-banding. For a given mitosis, all chromosome aberrations observed therein were listed. (A) Examples of structural (1a, b) and numerical (2) chromosome aberrations listed during scoring. (B) Frequency of all aberrations evaluated as the percentage of cells (mitoses) positive for one or more aberrations plotted over calendar age of the donors. (C) Number of individual aberrations within an altered mitosis plotted over calendar age of the donors. (D) Frequency of structural aberrations plotted over donor age. (E) Frequency of numerical aberrations plotted over donor age. (B-E) Mean values obtained for each donor; SEM < 20% of the values omitted for the sake of clarity; results of linear regression are stated as R2: Pearson's coefficient for goodness of fit, p: probability for slope = 0, dotted lines: 95% confidence limits of linear regression, and N.S.: linear regression of the data revealed no significant age-related change in the parameters.