Fig. 2. Centromeres shift to peripheral localization in cellular senescent hMSCs. Cells at passage 3 or 9 were transduced with the CenpA-EGFP (green) and the Lamin A-DsRed (red) lentiviral vectors, and imaging was carried out on cells at passages 6 and 12. (A) Maximum projections of cells at passage 6 or 12 on the x-y and y-z axis. The spatial localization of centromeres was obtained from cells at passage 6 and 12. CDF plots of centromere spatial localization are shown (right). CDF plots show the normalized frequency as a function of a normalized nucleus radius. Statistics show pooled data taken from 12 cells per passage. The Kolmogorov-Smirnov Test (KS Test) P value is indicated and suggests that the underlying distributions differ significantly. (B) Quantification of spatial overlap between CenpA and lamin A. Images of CenpA-EGFP and lamina-DsRed were taken from hMSCs as described in A. Quantitative overlap fluorescence intensities between CenpA and lamina A were spatially analyzed in cross-sections. Maximum projections (x-y axis) of lamin A-DsRed (red) and CenpA-EGFP (green) in a representative cell at passage 6 or passage 12. Fluorescence intensities of both probes are plotted in the y-z or x-z axes (graphs below and to right of confocal images). The spatial overlap between lamin A and CenpA is indicated by arrows. Histograms show the percentage of CenpA overlapping with lamin A, in cells at passage 6 and 12. Results are mean ± s.d. of ten cells.